CALIFORNIA FISH-GAME California Fish and Game is a journal devoted to the conservation of wild- life. If its contents are reproduced elsewhere, the authors and the California Department of Fish and Game would appreciate being acknowledged. Subscriptions may be obtained at the rate of $5 per year by placing an order with the California Department of Fish and Game, 1416 Ninth Street, Sacramento, California 95814. Money orders and checks should be mode out to California Department of Fish and Game. Inquiries regarding paid sub- scriptions should be directed to the Editor. Complimentary subscriptions are granted, on a limited basis, to libraries, scientific and educational institutions, conservation agencies, and on exchange. Complimentary subscriptions must be renewed annually by returning the post- card enclosed with each October issue. Please direct correspondence tO: Kenneth A. Hashagen, Jr., Editor California Fish and Game 1416 Ninth Street Sacramento, California 95814 u 0 VOLUME 65 JANUARY 1979 NUMBER 1 Published Quarterly by STATE OF CALIFORNIA THE RESOURCES AGENCY DEPARTMENT OF FISH AND GAME LDA STATE OF CALIFORNIA EDMUND G. BROWN JR., Governor THE RESOURCES AGENCY HUEY D, JOHNSON, Secretary for Resources FISH AND GAME COMMISSION BERGER C. BENSON, President San Mateo SHERMAN CHICKERING, Vice President ABEL GALLETTI, Member San Francisco Rancho Palos Verdes RAYMOND DASMANN, Member ELIZABETH L. VENRICK, Member Santa Cruz Cardiff-by-the-Sea DEPARTMENT OF FISH AND GAME E. C. FULLERTON, Director 1416 9th Street Sacramento 95814 CALIFORNIA FISH AND GAME Editorial Staff KENNETH A. HASHAGEN, JR., Editor-in-Chief Sacramento DARLENE A. OSBORNE, Editor for Inland Fisheries Sacramento RONALD M. JUREK, Editor for Wildlife Sacramento J. R. RAYMOND ALLY. Editor for Marine Resources Long Beacfi DAVID A. HOOPAUGH, Editor for Salmon and Steelhead Sacramento DONALD E. STEVENS, Editor for Striped Bass. Sturgeon, and Sfiad Stockton 3 CONTENTS California Inland Angling Trends for 1971 Through 1974 Krishan La! 4 Movements of Banded Mourning Doves Near Turlock, California Edward Channing 23 Status and Distribution of the California Clapper Rail ( k\]//us longirostris obsoletus) Robert Gill, Jr. 36 Notes Archeological Evidence Concerning the Prehistoric Occurrence of Sea Mammals at Point Bennett, San Miguel Island Phillip L. Walker and Steven Craig 50 Ambicoloration in the Black Abalone, Haliotis cracherodii Leach David W. Behrens 54 Effects of a California-derived Strain of Trichomonas gallinae on Colorado Band-Tailed Pigeons V Robert M. Stabler and Clait E. Braun 56 A Simple, Rapid Method for Marking Individual Sea Urchins Mark Olsson and Ger-iki Newton 58 Food Habits of the Squirrelfish, Adioryx suborbitalis, in the Gulf of California James K. Matthey and William W. Reynolds 62 4 CALIFORNIA FISH AND GAME C.Uil. Fish ,wd dme 65 ( 1) : 4-22 1 979 CALIFORNIA INLAND ANGLING TRENDS FOR 1971 THROUGH 19741 KkbHA\ LAL Inland Fisheries Branch Sacramento, California 95814 This is the eleventh report on California inland sport fish catch estimates based on angler response to postal card questionnaires. Each year from 1971 through 1974, between 0.55-0.59% of the resident license buyers were mailed a questionnaire. Of these, 30-41% responded, providing a systematic sample of 0.17-0.24%. About 2,189,000 anglers, or nearly 11% of all Californians, purchased a sport fishing license in 1974. Estimated annual catch and effort by successful anglers was determined for trout, catfish, panfish, black bass, striped bass, sturgeon, and frogs. License sales, fishing pressure, and the catch estimates for black bass, striped bass, and frogs reached an all time high in 1974. Median catch per angler day was highest for frogs and lowest for sturgeon. INTRODUCTION Periodic angling surveys have been conducted since 1 936 to determine trends in California's inland sport fish catch and effort. This is the eleventh report in the series and covers four annual surveys for the years 1971-74. Previous surveys were described by Curtis (1940), Calhoun (1950, 1951, 1953), Skinner (1955), Ryan (1959), Seeley, Tharratt, and Johnson (1963), McKechnie (1966), Emig (1971), and Pelzman (1973i. The basic format of the postal card questionnaire described by Calhoun (1950) has not been materially altered over the years to insure continuity with past surveys. Rvan ( 1 959 ) grouped closely related species which ^re difficult for many anglers to distinguish, while others added one or more new species or questions. Although these changes helped reduce angler confusion, very little was done to improve data analysis. Emig ( 1971 ) corrected discrepancies in the 1964 survey because subjective interpretation of the terminology had resulted in wrong categorization of angler responses. Therefore, to prevent such errors in the future, I have defined the terminology, and described the logic used to classify angler responses. The sources of sampling error and factors compensating for them were de- scribed by Calhoun (1950). Factors presumably causing exaggerated estimates were discussed bv Seelev, Tharratt, and Johnson (1963). The influence of such factors on the survey is largely unknown; therefore, we cannot regard the estimates as accurate accounts of total annual catch or number of days spent angling. However, if we assume that their effect on each survey is of the same magnitude, then these estimates are useful indicators of trends in sport fishing. California's sport fishing effort maintained an upward trend throughout the 1960's and then leveled off in the early 1970's. However, a record 2.19 million licenses were sold in 1974, and the estimated catch for black bass, striped bass, and frogs reached new highs. METHODS The name and address of every 25th resident sport fish license buyer in the ' Accepted for publication lanuary 1977. INLAND ANGLING TRENDS 5 State was recorded for the years 1971 through 1974. From these, a random sample of the sport fish anglers was drawn annually. The sample size ranged from 0.55 to 0.59% of the total number of licenses sold each year. Each licensee included in the sample was mailed a printed postal card ques- tionnaire (Figure 1). The 1971 questionnaire was similar to that used in two previous surveys for 1969 and 1970. The 1972 and 1973 questionnaires were identical; both were quite similar to the 1971 questionnaire except for adding American shad and frogs and separating striped bass caught in the ocean from fresh water. The 1974 questionnaire was further expanded to include the ques- tions: "Did you go fishing or frogging in 1974<"' and "Did you fish for black bass (freshwater) in 1974?" Certain closely related species which are difficult to distinguish by most an- glers were grouped on the cards to reduce confusion. The "trout" category included steelhead { Salmo gairdneri gairdneri) under 0.45 kg (1 lb) and kokanee salmon (Oncorhynchus nerka); "black bass" included largemouth bass [Mi- cropterus salmoides) , smallmouth bass (M. dolomleui) , redeye bass [M. coosae) , and spotted bass (M. punctulatus); "catfish" included all catfish and bullheads (/cta/urus spfi); "panfish" included sunfish {Lepomis spp) , crappie (Pomoxis spp), and various other "perch-like" fishes. American shad [Alosa sapidiss/ma) , steelhead larger than 0.45 kg (1 lb), striped bass ( Morone saxati- lis) , sturgeon (/^opeme/- spp), and frogs [Rana catesbeiana) are not likely to be confused with any of the listed species. Possible errors in completing the questionnaire were described by McKechnie (1966). In addition, I found that some anglers wrote remarks instead of the information requested, while others, apparently confused by the questionnaire, gave contradictory information. I subjectively reconciled these errors while editing the cards for key punching. Criteria used to classify angler responses into different categories were identi- fied for electronic data processing purposes ( Figure 2 ) . The following definitions explain the terminology used in the survey: 1. QUESTIONNAIRES MAILED: Number based on postal meter count less cards returned undelivered for various reasons. 2. UNUSABLE RETURNS: Cards belonging to any of the following groups: a. Blank or illegible returns; b. Anglers who reported fishing in waters outside California; and c. Licensees who fished only for abalone, clams, or scallops. 3. USABLE RETURNS: Total questionnaires returned less unusable cards. This number includes respondents who did not fish, those who were unsuccessful, and the successful respondents. 4. RESPONDENTS WHO DID NOT FISH: Anglers who did not go fishing during that year. 5. UNSUCCESSFUL RESPONDENTS: Anglers who listed only days fished for one or more species but caught no fish of any kind. However, the same angler, if successful for one species and unsuccessful for other species, was included in the category for successful anglers but was treated as an unsuccessful angler for the species for which he was unsuccessful. 6. RESPONDENTS WHO FISHED FOR TROUT: Anglers who answered yes to the question: "Did you fish for trout in ?" This included both successful and unsuccessful trout anglers. CALIFORNIA FISH AND GAME Will You Help Improve Fishing in California? In order to find out whether our eflForts to provide better fishing are bringing results we need to know what fish are caught each year in California. No one can tell us this as well as the fisherman. We are therefore asking a certain number of California anglers to tell us what they catch. You have been chosen to take part in this test. Will you help? All we ask you to do is: PLEASE WRITE ON THE RETURN CARD your best estimate of the number of each kind of fish you caught last year and the counties where you caught them. Also please give us your best estimates in answer to questions about number of days fished. IF YOU CAUGHT NO FISH OF ANY KIND, PLEASE SAY SO. You do not need to sign the card; this is not a personal checkup. But please do send us the record of your catch, and thus do your bit for better fishing. No postage stamp is necessary. California Depabtment of Fish and Gamk ae4Bi-aoo 10-74 ts.voo ®< PLEASE HELP TO IMPROVE FISHING BY FILLING OUT AND MAILING THIS CARD Did you go fishing or frogging in 1974? No □ Yes D Did you catch any fish or frogs in 1974? No Q Yes D Did you fish for trout in 1974? No D Yes D Did you fish for black bass (fresh water) in 1974? .... No □ Yes □ How many days did you go fishing in 1974? (Please give your best estimate) . Please list below the number of each kind of fish you caught in each county, and the total number of days you df.hed for each kind. KIMB NUH ■ E* OP FISH COUKTT OP CATCH NUH BER OP FISK CouNTT or CATCH NUH •ei OP FitH """ EACH (mo STRIPED BASS (PVOU S»CR*HENro-SAH JOAOUIN ___R|VtR StSTEM, t*l%. AMD OCtAnj STRIPEDBASS (mOM LAKES. RrsERVOIIS. COLORADO RlVtR. AND CAMALfl ,1 STURGEON AMERICAN SHAD ALL TROUT (IHCLUDINC STEELMIAD UMDII 1 POUHO AKD KOKKHlt) STEELHEAD (1 POUND AND OVEX j SALMON i BLACK BASS FROGS 1 CATFISH 1 FRESHWATER PANFISH 1 (■LUfftILL C**rF1C ETC > ' OCEAN FISH j (OTHER Than jTBiPfO ■«•■) 1 '1 FIGURE 1. Postal card questionnaire used in 1974. 7. RESPONDENTS WHO FISHED FOR BLACK BASS: Anglers who an- swered yes to the question: "Died you fish for black bass (freshwater) in 1974^" This question was on the 1974 questionnaire only ancd included both successful and unsuccessful bass anglers. INLAND ANGLING TRENDS 7 8. TOTAL DAYS FISHED: Number of days fished in a year in reply to the question: "How many days did you go fishing in ?" It includes days listed by all successful and unsuccessful anglers and is not to be confused with the number of days fished for individual species. The latter are used in species tables for individual species. 9. SUCCESSFUL RESPONDENTS: Anglers who caught fish of any kind in- cluding ocean fish and also reported total days fished during that year. They may or may not have indicated days fished separately for each species. 10. USABLE RETURNS FOR SPECIES TABLES: As in previous surveys, only those successful anglers who reported both numbers of fish caught and days fished for that species are included in the species table. The number of usable cards on which the results of the four surveys are based ranged from 0.17 to 0.24% of the total sport fishing licenses sold each year. All estimates furnished in the species tables are based primarily on information from successful anglers who listed the number of fish caught and days fished for that species. Thus, those anglers who failed to mention days fished separately for one or more species have been excluded from the estimates, and this has resulted in a partial reduction of the total estimated catch for all species in all surveys. In the four surveys for the years 1971-74, such anglers constituted 12-15% of all license buyers and averaged 15-36% of the total successful anglers for individual species. For the first time in these surveys, I have reported the median annual catch per angler day for each species, based on its median annual catch and median annual days fished. This is considered a more realistic measure of the anglers daily catch than the mean catch per angler day. Also, data on unsuccessful anglers have been presented in this report for the first time. Their percentages have been determined after taking into consideration both categories of success- ful anglers, those who did, and those who did not list days fished. Total angling pressure in California for the period 1935-48 was based on total fishing licenses sold and mean days fished (Calhoun 1950). These estimates are higher because the total licenses sold includes both respondents who did not fish and some unusable returns. Therefore, for computing angling pressure from 1 953 onwards, I used the projected total of all successful and unsuccessful anglers instead of the total licenses sold. RESULTS AND DISCUSSION The results of four annual angling surveys for the years 1971 through 1974 are presented in a form similar to that of previous surveys to preserve continuity. Characteristics of all four surveys show that each year from 6.5 to 8.0% of the license buyers did not fish (Table 1 ). In addition, 10 to 14% of the anglers were unsuccessful. Successful anglers averaged 80% of all license buyers. Projections of angling pressure in California were updated for all surveys covering the period 1953-74 (Table 2). Successful anglers' responses to seven of the eleven species listed on the questionnaire are summarized for each year (Tables 3 through 6). The results for salmon, steelhead, American shad, and ocean fish are not included in this report. Statewide estimates of the number of successful anglers and their catch 8 CALIFORNIA FISH AND CAME CLASSIFICATION OF ANGLER RESPONSES IQUESTIONNAIRES MAILED! QUESTIONNAIRES RETURNED [unusable returns USABLE RETURNS respondents who did not fish RESPONDENTS WHO FISHED FOR TROUT -ITOTAL DAYS FISHED] RESPONDENTS WHO FISHED FOR BASS [UNSUCCESSFUL RESPONDENTS] JSUCCESSFUL RESPONDENTS SUCCESSFUL RESPONDENTS WHO DID NOT LIST DAYS FISHED FOR ANY SPECIES UNSUCCESSFUL ANGLERS FOR EACH SPECIES (NUMBER, DAYS) USABLE RETURNS FOR SPECIES TABLES SUCCESSFUL ANGLERS WHO DID NOT LIST DAYS FISHED (NUMBER, FISH) [ALL TROUTl- 1 CATFISH I I FROGS I- jSALMONl- SUCCESSFUL ANGLERS WHO LISTED DAYS FISHED (NUMBER, FISH, DAYS) -I BLACK bass! PANFISHI ISTRIPED BASS (INLAND)|- I STRIPED BASS (0CE"AN) ^AMERICAN SHADI -ISTEELHEADJ -I sturgeon] -I OCEAN FlSH FIGURE 2. Classification of angler responses. are given in chronological order for each of the seven species (Tables 7 through 13). Total licenses sold, fishing pressure, and catch estimates for these species are graphically presented to indicate trends (Figure 3). The number of unsuccessful anglers for various species are reported for the years 1971-74 (Table 14). Approximately 17-33% of the anglers who fished for anadromous species (sturgeon and striped bass) were unsuccessful compared with 3-8% for freshwater species (trout, black bass, catfish, and panfish). The percentage of unsuccessful anglers was highest for sturgeon and lowest for panfish. INLAND ANGLING TRENDS I g <1j I ■2 I I ^ 6 in in -^ O rsi s^ O O O^ I^ C^ rn en ^ r^ 1 — 'o t-s. sD T3 "O I .— Ln rsi .— O iri 1 — .— rnrsi.— Of'na^r-s O in rn ^ rsi O rn Tj- Tj- rst is^ l\ r^j a^ rsi fs^ 3:= 1 — r<^ r^ ^ ^^- 1^ O rsi — sD rsi in rsT 2 O oc S ^ s E a; o — c i/> t^ lyj a< a, c 3 q2 CC^ o "I a ^ y lA c -o c ro in 'u Q. 3/ O ro •So tr\ t/> 1 1 II -I a; ^ ^r T! ■- l^ 5-^izf r^_0 ^"O O/s^ DC- C L. flu C 0/ 00 c oc c 10 CALIFORNIA FISH AND GAME TABLE 2. Angling Pressure in California 1935-74 Tohil Anglers Total Year license sales who fished Mean days fishing days 1935' 223,098 No data No data 3,120,000 1938 346,661 ' " 4,850,000 1941 453,159 " 14.2 6,440,000 1942 433,431 " 14.3 6,180,000 1943 445,416 " 12.9 5,750,000 1946 766,753 " 13.5 10,350,000 1948 960,027 ' 15.4 14,700,000 1953^ 1,187,367 1,136,442 14 15,910,000 1954 1,240,043 1,240,044^ 15 18,601,000 1956 1,380,787 1,327,049 14 18,579,000 1957 1,433,630 1,371,390 15 20,571,000 1959 1,465,440 1,406,087 16 22,497,000 1960 1,475,691 1,416,506 18 25,497,000 1964 1,585,615 1,523,265" 11 16,756,000 1969 1,935,593 1,846,512 17 31,391,000 1970 2,092,355 1,964,280 ' 18.2 35,750,000 1971 2,064,033 1,918,525 17.3 33,133,000 1972 2,001,675 1,854,552 19.2 35,589,000 1973 2,145,499 2,005,232 18.0 36,134,000 1974 2,189,039 2,014,064 205 41,288,000 ' Estimates for 1935-48 based on total license sales (Calhoun 1950). ^ Estimates for 1953-74 based on anglers who fished, ■'incorrect projection factor (Ryan 1959). "Corrected projection factor (Emig 1971). The general trend of the tour surveys covered in this report showed a 15% increase in fishing pressure since 1970 (Table 2). Estimates of the 1974 catch for black bass, striped bass, and frogs were the highest in the 39-year period cov- ered by the surveys (Table 6). Also, in that year, 2.19 million license buyers and 20.5 mean days fished were highest on record. Trout Trout were the prime target for 45% of California anglers. The estimated annual catch of 12 million trout in 1936 had doubled by 1954 and more than tripled by 1969 (Table 7). Thereafter, it stabilized at about 37 million fish. Whereas these estimates of total annual catch appear exaggerated, nevertheless the number of trout caught in 1971 and 1973 very well exceeds the combined total of all warmwater fishes (black bass, catfish, and panfish). On the other hand, the mean annual catch of trout since 1936 declined drastically from 80 to 40 fish per successful angler. Trout anglers numbered about one million in 1969, 1970, 1973, and 1974, which represents a sevenfold increase over 1936 (Table 7). The number of unsuccessful trout anglers ranged between 6-8% during 1971-74 (Table 14). Catfish The number of catfish anglers has exceeded panfish anglers since 1972, and they are now second in numbers to trout anglers. Successful catfish anglers comprised 1 5-1 8% of all licensees, and their ratio to trout anglers was 1 :3 ( Table 8). The catfish catch exceeded 10 million fish in 1960 and registered an all time INLAND ANGLING TRENDS 11 TRENDS IN CALIFORNIA SPORT FISHING 1943 1951 1953 1954 I95( 1957 1959 i960 l964 YEAR OF SURVEY FIGURE 3. Trends m California sport fishing, 1949-1974. 969 1970 1971 1972 1973 1974 TAI IFf')RNIA FISH AND GAME a; > 3 BO _C "So c < •a i *^ 2 55 V ^ w n> E E lU -J 00 < I I I ■-C: c5 rsj O (^ O^ ao rsi ^ u-i t-Tl g O 1^ o ^ ■ OO <~D ■ P g g o6 o o — ~ CM 1 Ji^ggoco — oggo-'OLriggcd^i— ■ u ^ 1! 5^ rsj O 1"^ O ' — OO o Ln o :3 p o c R °^ TT rsj ^ o c 5 '^ r-s i-vi O Ol ■D 1-/ i^ nj at u £ ^ &. 1/-I 'T3 c C= ^0 "^ TJ "O C _ C rrj 2 -S E - -3 £ t " t T! TZI t >- i-E m 3 "P 5 "O '^ -o ;^ '' c :^ -6 li 2 'u *— ry *^ ^^ ro — *!• LO d; LT) a> -jr '-'^ >_ -3i 0/ oc 'w »TJ fc_ 3 (/) BO "So c < i 5? p< 9< -§ "B <5 o I 0^ CO i/l 04 I/) C o a i/i eo c < C3 ^ ^ CO O O t^ tf) in V W ■ b E E 3 I o ^ t = -S; !:: OC t _ o^ ^ -O -D o a. ■_0 w "C '^^ i_ w '^ ^^ O 3 1^ ,« ^ 3 Oj C ^-— --r C rr^ :-- o 2 0/ Q-. 0/ 0/ 14 CALIFORNIA FISH ANi:) C.AME > 3 (•) DC c < -a i J1 ro 1^ 0^ ^ ^§8 ■ — CO N^ CT\ O O O — oq un CO Q Q en f^ (T^ m -^^ o o o O O u-i O Lr\ o p '5- CO O ^8 CO oq o CT^ O LT) LT) o o o^ ^' .-^ ON a> o o o o o r^ O O LT) r\ -^ o^ :^8 8 OOCOOLOOOrn-— CO r^ •— CO f^j" ID t — r^j ro c c a "<*) DC C < ~5 c 8 o § ro O (T. CD ^j CO o CO ^ § o o o o tn 8 CO on ,_r f~j o o o o o cr> o^ § 88^ rsi -^ o o-l in o o p i-n CO 0^ §i-n rsi . — O O CO tn ^ ^' ^' uS g g Ln og- O 0^ f O TT U 3 i ^ •— (3) (3 , rsi o <-M (^ {—J r^ LH \D Q ,--^ o o O Ln cr^ oj O rM 8_ 8_ f^-i O ro 8 8 fNI rC ■^~ o" CO" tc Ln •^ rN ^s> 0^ O^ oo TO •f o rsj r-s. ■«•' ro rvi E E 3 (/5 ea < I O oi O TO TO CD oc TO CD i_ O) " t TO TO a' ^ ^"2 i C TO "> TO T3 c C TO 5 "3 ^^ TO — X3 U ,_ ^ TO O -^ TO -^ C TO TO "D TO T3 >. p__5- p 2 fc C TO "O t s„ ' =3 (L O TO c TO ■•— oc TO C aJ Q. =.- "J TO -O "a •- - > k 3 l/J BO "5b c < i 00 c < 0 19 E E 3 00 < CT^ CO "^ ""^ t^ f^ ^ 2 2^ "^ GO uS O O O rvT o oo" rsT 0^ e-Nj fN ^ »— CO f^ f^ 3 g ^ _ ^ O " o o o CO' — OOCOO^LTl' — LOCO'^'^ ^^ ''^ rri — ■rr 5 "^ "^ "— "^ rsi o o >^ i-o ;_: 2 CO r-g CT> ^" w— ^— r^ CT^ ("^ ^ :? 2 ^-' u-i rN4 ro O^ ^ ^ O -^ •^- — - sD — -^ o m ^ (^ a^ r\ ^ CO ji; s; tr ^ ^ ^ O oo r-- LnrMLnr\Ocor>PO'«1'rsj '^ O <-; c n-i U-, '~' "— vD Ln CO rsi O^ r^ T ■" ■*. u-t rs| CO u-l •* h^ sD ul •^ CO o^ CO CM r^4 Ln CO~ ^ o -X) Ly-i O — O u-i Ln Ln Ln 5 CO — ^ Ln 0^ vO 1-^ ■^ ,— cr> r~j r^ O 1^ rsi — vO O o — : ? CO m 5 I< rn rvi o Ln Ln Ln O o Ln rn O 1^^ rvi m r^j ^ o rn rsi u 3 1 rs rsi (/) 5 CO rn Ln rsi Ln - ^ 2 — '^ 2-3 2 t -3 -J t t aj :3 aj -:= o; -a c 3 -a g -□ -TJ '^ ^ "T! C ^ C ^ ^ C ^ C -_; "O "^ --- ^ *X "3 .. "D >- TS T3 -a 3 C T! C 3 2 _ ^ -0 o o 0; o "O 0/ ac ^ 13 "O c c ^ Oj o iTi a; a- lb CALIFORNIA FISH Wi:) f ;AME TABLE 7. Trends in California Trout Angling )e,ir Tol.i/c.ilch 1936 12,000,000 1937 11,900,000 1938 12,900,000 1939 12,800,000 1941 15,700,000 1942 ; 10,400,000 1943 15,700,000 1946 17,660,000 1948 18,400,000 1949 16,700,000 1951 18,600,000 1953 22,300,000 1954 28,600,000 1956 26,200,000 1957 30,700,000 1959 27,480,000 1960 28,000,000 1964 32,296,000 1969 38,520,000 1970 37,058,000 1971 37,006,000 1972 36,114,000 1973 37,940,000 1974 37,799,000 SuccesstuI dn^/ers Percentage Annual catch per of .mgling successful angler Number Ik ensees Mean Median 149,000 50 80 50 151,000 48 78 50 160,000 46 79 50 179,000 49 71 37 238,000 53 66 40 234,000 54 70 42 213,000 48 75 37 357,000 47 49 25 415,000 43 44 20 431,000 43 39 - 429,000 42 43 20 530,000 44 42 22 578,000 47 50 22 640,000 46 41 21 718,000 50 43 21 660,000 45 41 21 709,000 48 39 21 788,000 50 41 21 1,006,000 52 38 18 1,087,000 52 34 18 933,000 45 40 21 908,000 45 40 21 967,000 45 39 20 973,000 45 39 21 high of 12 million fish in 1974. While the estimated catch quadrupled and the number of catfish anglers increased tenfold over 1936, the mean annual catch since 1948 has fluctuated between 24-37 fish per successful angler. Only 4-6% of the catfish anglers were unsuccessful during 1971-74 (Table 141. Black Bass The black bass catch estimates have fluctuated between 3 and 6 million fish since 1959 (Table 9). The approximate sixfold increase in its catch since the inception of the surveys is the highest for any species. The number of bass anglers increased sevenfold since 1936, but the percentage they comprise of the total licensees dropped from 11-18% during 1936-46, 11-14% in 1948-57, 14-16% in 1959-70, and 8-9% in 1971-74. The marked decline for the period 1948-57 also coincided with it lowest mean annual catch of 10-16 fish per successful angler. Of the total anglers who fished for bass during 1 971-74, 7-9% were unsuccessful (Table 14). Panfish Panfish were second to trout in number of fish caught annually, but panfish anglers during 1971-74 comprised only about 17% compared to 45% for trout anglers. From 1954 to 1974, both the estimated panfish catch and the number of successful anglers nearly doubled (Table 10). The mean annual catch of 45-58 fish per successful angler during 1971-74 was the highest among all species. Also, for the same period, the percentage of unsuccessful anglers (3- 4%) was lowest (Table 14). INLAND ANGLING TRENDS 17 TABLE 8. Trends in California Catfish Angling Ye.ir Tot,il catch 1936 2,940,000 1937 2,810,000 1938 3,480,000 1939 4,333,000 1941 6,100,000 1942 8,250,000 1943 7,060,000 1946 6,530,000 1948 5,560,000 1949 3,930,000 1951 4,710,000 ]953 7 \i\(\ ruin 1954 7 ' 1956 6,97U,UOU 1957 7,370,000 1959 7,674,000 1960 10,100,000 1964 7,684,000 1969 12,319,000 1970 10,784,000 1971 8,690,000 1972 10,719,000 1973 10,562,000 1974 12,152,000 Successful . anglers Percentage Annual i atch per ol angling successful angler Number licensees Mean Median 38,000 13 78 - 43,000 14 65 - 48,000 14 72 - 75,000 20 58 - 97,000 21 63 - 110,000 25 75 - 101,000 23 70 - 149,000 19 44 - 182,000 19 31 15 161,000 16 24 12 171,000 17 29 12 225,000 19 33 15 220,000 18 37 13 217,000 16 32 10 259,000 18 28 13 232,000 16 32 10 275,000 19 37 15 284,000 18 27 11 422,000 22 29 10 418,000 20 26 10 311,000 15 28 11 348,000 17 31 13 364,000 17 29 11 387,000 18 31 n Striped Bass Except for 4 years, the striped bass estimated catch from 1936 to 1969 re- mained between 1 and 2 million fish annually (Table 11 ). Since 1970, it went above 2 million fish and in 1974 was about 3 million fish, due to additional fishing in the California Aqueduct and its reservoirs. To what extent the increased catch estimates after 1971 were influenced by combining striped bass caught in the ocean and fresh water is not known. The number of successful striped bass anglers has more than tripled since 1936, and they accounted for 8-13% of all licensees during 1 971-74. The mean catch since 1 946 was between 8-1 2 fish per successful angler. About 17% of striped bass anglers were unsuccessful (Table 14). Sturgeon The number of anglers and the total sturgeon catch have fluctuated sharply, probably due to small sample size from the few usable responses (Table 12). It is, therefore, difficult to judge trends. Only 1% of the California anglers fished for sturgeon. Of these about one-third (32-34%) were unsuccessful, which was the highest for all species (Table 14). Frogs Information on frogging was also collected first in the 1972 survey, when the estimated catch was over one million frogs. By 1974, it had doubled (Table 13). The mean annual catch of 24 frogs per successful angler in 1972 jumped to 39 frogs in 1974. Only about 5-7% of the froggers were unsuccessful (Table 14). 2—78185 18 CALIFORNIA FISH AND GAME TABLE 9. Trends in California Black Bass Angling ye,ir Tot^l atch 1936 930,000 1937 849,000 1938 1,190,000 1939 1,340,000 1941 1,530,000 1942 1,340,000 1943 1,570,000 1946 1,700,000 1948 1,890,000 1949 1,160,000 1951 1,280,000 1953 2,300,000 1954 2,300,000 1956 2,550,000 1957 2,440,000 1959 4,493,000 1960 5,150,000 1964 2,992,000 1969 6,067,000 1970 5,327,000 1971 4,097,000 1972 5,160,000 1973 3,983,000 1974 5,692,000 TABLE 10. Ye,jr Totcil c^lch 1954 10,970,000 1956 10,020,000 1957 7,680,000 1959 16,114,000 1960 14,740,000 1964 17,793,000 1969 24,668,000 1970 21,257,000 1971 15,530,000 1972 18,888,000 1973 16,527,000 1974 20,918,000 Successful anglers Percentage Annual catch per of angling successful angler Number licensees Mean Median 34,000 11 17 - 33,000 11 26 - 46,000 13 26 - 67,000 18 20 - 75,000 17 20 - 66,000 15 20 - 79,000 18 20 - 104,000 14 ■ 16 - 128,000 13 15 6 116,000 12 10 5 108,000 11 12 6 161,000 14 14 9 1 54,000 12 15 8 164,000 12 16 9 179,000 12 14 8 218,000 15 20 9 235,000 16 22 9 217,000 14 14 8 306,000 16 20 9 313,000 15 17 8 225,000 n 18 10 214,000 11 24 10 199,000 9 20 8 266,000 12 21 10 n California Panfish Angli ing Successful anglers Percentage Annual catch per of angling successful angler Number licensees Mean Median 205,000 17 53 26 225,000 16 44 18 244,000 17 31 17 281,000 19 56 22 296,000 20 50 22 326,000 21 55 20 463,000 24 53 22 486,000 23 44 20 346,000 17 45 21 325,000 16 58 24 333,000 16 50 17 369,000 17 57 21 Species Rankings For the year 1974, all seven species covered in this report were ranked by several factors. These include the percent of total licensees who fished for each species, percent of successful anglers for each species, ratio of successful anglers to unsuccessful anglers, mean annual catch, mean annual days fished, mean and median catch per angler day (Table 15). The ranking of species on six different criteria puts into perspective their relative importance as measured by angler response. INLAND ANGLING TRENDS 19 TABLE 11. Trends in California Striped Bass Angling Successful anglers Percentage Annual catch per of angling successful angler Year Total catch Number licensees Mean Median 1936 2,110,000 84,000 28 25 1937 2,040,000 82,000 26 25 1938 1,940,000 93,000 27 21 1939 1,880,000 89,000 24 21 12 1941 1,940,000 107,000 23 18 10 1942 1,680,000 88,000 20 19 1943 1,680,000 75,000 17 22 9 1946 1,380,000 113,000 15 12 6 1948 1,650,000 161,000 17 10 5 1949 1,750,000 165,000 17 11 5 1951 1,490,000 144,000 14 10 5 1953 1,590,000 166,000 14 10 6 1954 1,440,000 158,000 13 9 5 1956 1,000,000 127,000 9 8 5 1957 1,890,000 230,000 16 8 5 1959 2,260,000 224,000 15 10 5 1960 2,770,000 231,000 16 12 5 1964 1,838,000 202,000 13 9 4 1969 ■. 1,747,000 214,000 11 8 4 1970 2,380,000 236,000 11 10 5 1971 2,025,000 169,000 8 12 6 1972' 2,590,000 249,000 12 10 6 1973' 2,431,000 258,000 12 9 5 1974' 2,949,000 284,000 13 10 5 ' Figures combined lor striped bass caught in the ocean and iresh water. TABLE 12. Trends in California Sturgeon Angling Successful anglers Percentage Annual catch per of angling successful angler )ear Total catch Number licensees Mean Median 1969 91,000 30,000 2 3 2 1970 67,000 27,000 1 3 1 1971 63,000 18,000 1 4 2 1972 56,000 29,000 1 2 2 1973 67,000 24,000 1 3 2 1974 87,000 27,000 1 3 2 TABLE 13. Trends in California Frogging Successful anglers Percentage Year Total catch 1972 1,191,000 1973 1,524,000 1974 1,948,000 Number 49,000 48,000 50,000 of angling licensees 2 2 2 Annual catch per successful angler Mean Median 19 24 32 39 20 20 20 CALIFORNIA FISH AND CAME TABLE 14. Trends for California Unsuccessful Anglers 1971 1972 1973 1974 Sfiecies Number Percent Number Percent Number Percent Number Percent K Panfish 20,000 4 18,000 4 15,000 3 17,000 3 2. Frogs 3. Cattish 24,000 5 4. Trout 93,000 8 5. Black bass 24,000 8 6. Striped bass 46,000 17 7. Sturgeon 13,000 32 16,000 33 17,000 34 19,000 33 4,000 6 3,000 5 5,000 7 25,000 5 29,000 6 23,000 4 79,000 7 83,000 7 80,000 6 19,000 7 18,000 7 38,000 9 65,000 17 86,000 21 77,000 17 INLAND ANGLING TRENDS 21 X -§ ^-^ 5* ■3 ^^ 2 ^ 1^ a. Sic: CO oq -o <^. Hi O Q. i7i O >- o P ^■ Q- o JO Q. 3 ^ e < M M W W 3 (/I to ,e IS c o a (/I 'c k> o u in 31 [s o ^ 9j t ■:; 3 o » •h »fl fo ^ Q. ^' -TJ L^ CD ro c7) oc o ^ i a I ^"^ ^ c ^ >£) Oj *: c Sj ■-- ?^ .^^ .'o C Ll-I _- Q- o a» TJ c ^ TJ X) O ^ .O 1> -a '=' oc m *^ m -i^ rsi 1^ fO u 3 U ro ty^ B:£ 0:2 u x> J2 J3 IK Q. C o oc rM ro 00 1^ c .— a. a. ro OC O ' c o DC ' Si J3 JS ■5 > 2 To ■o u IE >■ Si ■«3 01 OJ u 01 22 CALIFORNIA FISH AND GAME ACKNOWLEDGMENTS I am thtinktui to Almo ). Cordone for his editing, many helpful comments, and encouragement. To M. Ralph Carpenter goes full credit for programming and data processing. REFERENCES Calhoun, A. I 1950. Cfilitornid dnBlin^ cdlch rctords from posldl c.ird surveys; 1936-1948; with an evaluation of postal card nonresponse. Calif. Fish Game, 36131 : 177-234. 1951. California statewide angling catth estimates for 1949. Calif. Fish Came, 37(1) : 69-7S. 1953. Statewide California angling estimates for 1951, Calif. Fish Game, 39(1). 103-113. Curtis, Brian 1940. Anglers' catch records in California. Amer. Fish Soc. Trans., 69 : 125-131. Emig, )ohn W. 1971. California Inland angling survey for 1969, with corrections for the I9(>4 survey. Calif. Fish Game, 57(2 1 : 99-106 McKechnie, Roheri J 19()6 California inland angling survev for 1964. Calif Fish Game, 52(41: 293-299. Pelzman, Ronald | 1973. California inland angling survey for 1970. Calif. Fish Game, 59(2) : 100-106. Rvan, lames H 1959 California inland angling estimates for 1954, 1956, and 1957. Calif. Fish Came, 45(2) : 93-109. Seelev, Charles VI., Robert C. Tharratt, and Richard L. Johnson. 1963. California inland angling surveys for 1959 and 1960 Calif. Fish Game, 49(3i : 183-190. Skinner, |ohn E. 1955. California statewide angling estimates for 1953. Calif. Fish Game, 41 (1 ) : 19-32. INLAND ANGLING TRENDS 23 Calif. Fish and Came 65(11:23-35 1 979 MOVEMENTS OF BANDED MOURNING DOVES NEAR TURLOCK, CALIFORNIA EDWARD CHANNING 1115 Sierra Drive Turlock, California 95380 The Mourning Dove (Zenaida macroura) is abundant around Turlock at all sea- sons of the year, but the composition of the population varies seasonallv. Present at all times is a resident breeding population that does not migrate or make any sub- stantial movements. There is also a southward flow of transient doves in summer and fall, and a return northward flow in late winter and spring. The seasonal passage of migrants southward and northward through Turlock does not seem to draw any locally fledged doves into migration. Changes in land use in the rural countryside around Turlock are generally adverse to the welfare of doves and there is probably a gradual decline in numbers. However, within the rapidiv expanding urban sprawl fringing the city, the doves are finding optimum habitat and perhaps increased carrying capacity. INTRODUCTION The Turlock area in central California, where this study was conducted, lies between the San Joaquin River and the Sierra Nevada foothills in Stanislaus and Merced counties. The terrain is essentially level and is intensively developed for agriculture. Most of the land is subject to irrigation. Orchards, vineyards, alfalfa, corn, and other grains are primary crops. Limited areas are maintained in pas- ture. Residential developments are spreading out from the central city. My study focused largely on the area 16 km (10 miles) in radius around Turlock. The Western Mourning Dove (Z m. marginella) , is a common breeding bird in the Turlock area. From 1961 to 1968, I banded nestling doves in various locations around Turlock. Additionally, I was permitted to incorporate data on nestlings banded near Turlock by personnel of the Fish and Wildlife Service and other individual banders for the years 1924 to 1971. From 1967 to 1974, doves were trapped in stubble fields where they came to feed during two seasons of the year: (1 ) pre-shooting season, July and August; and (2) post-shooting season, January to April. Shooting season in California includes the month of September, and, since 1965, a late season of about 2 weeks in December. No trapping was conducted during the autumn period. To better understand the southward fall migration of doves through the Tur- lock area I was permitted to cite recoveries from doves banded in the vicinity of Yakima, Washington, bv the Fish and Wildlife Service and collaborators in the years 1964 to 1969. Likewise, Fish and Wildlife Service records of doves banded elsewhere and killed in the Turlock area further elucidate seasonal movements. Additionally, this report includes some observations on dove natural history, food predilections, and effects of land use changes on dove welfare. NESTING Courtship flights are first seen in late January and the first eggs are laid in February. FHowever, it is usually in March that nesting really gets underway. In other California dove nesting studies, McClure (1950) reported nesting to begin Contrihution from Museum of Vertebrate Zoology, Berkeley, Calitornia 94720. Accepted for publication August 1978 24 CALIFORNIA FISH AND GAME in Kern Countv about March 14 and Cowan (1952) gave the same ciatc tor beginning of incubation of the earliest nests in Butte County. The full swing of dove nesting is underway in April. A successful nesting cycle of the Mourning Dove requires approximately 30 to 34 days, distributed as follows: 3 to 6 days of nest construction and egg laying, 14 days for incubation, 11 to 14 days for young to reach fledgling stage. Immedi- ately after completion of one cycle a pair of doves will embark on another. Since the period of nesting extends from March into September, a pair potentially can bring off six broods of two young each (Keeler 1977). In 1962 a pair of doves achieved this potential in a nest situated under the protective eaves of the author's home in Turlock. Two young each were fledged April 17, May 14, June 1 5, July 1 5, August 1 7, and September 1 2, for a total of 1 2 young. Cowan ( 1 952 ) reported a similar feat accomplished by a pair of doves nesting on Cray Lodge State Came Refuge, Butte County. Few pairs, however, achieve this level of production. Cowan found that the average pair reared 6.0 to 6.8 voung per season. Dove nesting in California generally terminates in. early September. McClure (1950) recorded his last nesting near Bakersfield fledging about September 14. Cowan (1952) reported terminal dates between September 7 and 18. Most of the nesting that I observed near Turlock was terminated by early September. However, one determined pair nesting in a hanging flower basket in a patio in central Turlock fledged its final brood on November 24, 1974. Such persistence is rare and probably only occurs in an urban setting. This nest in fact produced 19 successful nestings (38 fledged young) in the period 1972 to 1976. NESTLING BANDING From 1961 to 1963 I banded 200 nestlings in and around the cit\' of Turlock and in an 8-ha (20-acre) almond orchard nearby. Also, the Fish and Wildlife Service supplied records of 756 dove nestlings banded near Turlock. When these additional nestlings are included with my bandings, 1,093 young doves were banded from 1924 to 1971 within 48 km (30 miles) of Turlock (Table 1 ). From 1963 to 1967 I banded 137 nestling doves in a 40-ha (100-acre) vine- yard; records were kept on 123 nests observed (Table 2). Nests were located in May while the vines were being suckered. Most nests were situated in the crown of the grapevines, about 1 m (3 to 4 ft I above the ground. Nests were visited regularly (at least 3 times) ana the young were banded when about 10 days old, or a few days before they would fledge. Nestlings were banded between May 22 and June 26. Although doves renested in the vineyard, I did not attempt to find nests or band young after the end of June because the dense vine growth rendered the nests difficult to locate. The average hatch of eggs in the vineyard nests was 62.0% which is close to the findings of McClure ( 67.1 % ) . Fifty-six bands were reported over a 4-year period following banding, for a 5.1% recovery (Table 3). All were recovered within the Central Valley and most within a short radius of Turlock ( Figure 1 ). Whereas other studies have shown a strong tendency for young doves to drift southward during late summer ( Han- son and Kossock 1963, Lehner 1965), my population would appear to be essen- tially sedentary. Fifty-four of the 56 recoveries occurred in September. One nestling was shot in November, and another was found dead in January. The fact that recoveries occurred locally for several years after banding strongly MOURNING DOVE MOVEMENTS 25 TABLE 1. Mourning Doves Banded in the Turlock Area and Number of Recoveries. All reported recoveries were from hunting \ umber banded Recoveries Percent recovers NEST BANDED Nestlings 1093 56 5.1 TRAP BANDED Summer Immature 831 Adult 126 Total 957 Winter Male 515 Female 502 Total 1017 GRAND TOTALS 3067 231 7.5 TABLE 2. Dove Nesting Record from 40 ha Vineyard 8 km NW of Turlock 83 10.0 17 13.5 100 10,4 46 8.9 29 5.8 75 7.4 )fM 1964 1%5 1%b 1%7 Totdl 35 29 21 17 123 66 58 42 34 242 50 22 27 23 150 75.7 37.9 64.0 67.6 62.0 47 20 23 21 137 1%3 Nests found 21 Eggs laid 42 Eggs hatched 28 Percent hatched 66.6 Fledglings banded 26 TABLE 3. Returns of 1,093 Doves Banded as Nestlings in the Turlock Area, 1924-1971. > e,ir ailer banding Number banded 1st vear 2nd vear 3rd year 4th year Number recovered 56* 42 8 3 3 Percent recovery 5.1 3.8 .7 .3 .3 ■ Recovered within degree block ot banding 48 Recovered from points N of banding site (56 and 257 km) 3 Recovered from points S of banding site (up to 121 km) _5 56 supports the conclusion that birds bre(d in the Turlock area are year-long resi- dents. In any event, not one bird known to have been locally fledged was recovered outside of the Valley. SUMMER TRAP BANDING During the month of June, oat stubble fields are prime dove feeding areas due to the presence of red maids ( Calandrinia caulescens) , a common weed whose tiny black seeds are a principal summer food of doves (Browning 1959). This plant sprouts with the oats during the late fall and matures early in spring. The seeds on the ground become available when the oats are harvested. Twenty to 26 CALIFORNIA FISH AND GAME Figure 1. Recoveries of 56 banded nestlings over a 4-year period following banding. Forty-eight of the recoveries came from mside the 40 km radius circle around Turlock. thirtv trap sites were then cleared of stubble and prebaited with chicken scratch. When dove use was evident, traps were set and checked each morning and evening. Traps were constructed of 2- x 1 -inch gauge welded wire, with entrance funnels located at both ends and a hinged door for removal of doves (Figure 2). The pre-season trapping period extended from Julv 9 to August 30. Sex is indistinguishable in recently fledged doves, but young are easily distin- guished from adults by the presence of juvenile wing coverts. Summer banding seems to be differentially selective for immature birds — those locally produced and those drifting through from northern breeding areas. Birds-of-the-year con- stituted 86.8% of the 957 birds banded in July and August (Table 4). Each pair of breeding doves can be expected to produce 6.0 to 6.8 young per season (Cowan 1952). The age ratio at the end of the breeding year, therefore, could be no more than 75 to ll'^/o young. The real age ratio during July and August MOURNING DOVE MOVEMENTS 27 Figure 2. Dove trap used in this study, shuwing lunnel eniitincei. must be considerably less than that since all young for the season are not yet fledged, and mortality of fledglings must be higher than that for adults as suggest- ed by the lower recovery rate of birds banded as nestlings (Table 1 ). TABLE 4. Records of Summer Banding in Traps Birds banded Returns Percent Total Returns Distant Percent Ve^r Tot^l Adult'' Immature^ immatures return'i < 40 km returns returns 1968 33 12 21 63.6 6 4 2 18.3 1969 137 24 113 82.5 23 20 3 16.8 1970 281 10 34 271 215 96.4 86.3 25 24 16 22 9 2 8.8 1971 249 9.2 1972 103 12 91 88.3 6 4 2 5.8 1973 : 49 12 37 75.5 2 2 0 4.1 1974 105 22 83 80.5 14 14 0 13.3 Total 957 126 831 86.8 100 82 18 10.4 The recoverv percentages for summer-banded immature and adult doves during the first shooting season following banding (direct recovery) are 10 and 1 3.5%, respectively. Eighty-two percent of the 1 00 recoveries were within 40 km (25 miles) of the banding site (Figure 3), all shot in September. Six immatures and one adult were recovered in Mexico during the winter months at distances of 1,900 to 2,900 km (1,200 to 1,800 miles) south of the banding location. Of 18 recoveries at distances in excess of 40 km, 15 were south and 3 were north of the banding site. Greatest longevity was an immature banded in 1969 and recovered in 1974 near Villa Victoria, Michoacan, Mexico. 28 CALIFORNIA FISH AND GAME Figure 3. Recoveries of 100 summer-trapped doves, 82 of which were taken within 40 km (shown by circle) of Turlock. From these recovery data it would appear that some birds are southward bound through the Turlock area in July and August. In point of fact, the initiation of hunting September 1, plus the early fall storms that often occur then, seem to induce substantial shifts in dove populations and the drift is generally south- ward. WINTER TRAP BANDING During the winter months doves feed primarily on corn kernels dropped to the ground during harvest. Although there are many corn fields that appear suitable for dove foraging, the birds often are found concentrated by the thou- sands in a few fields. My winter trapping involved first finding the fields currently in use by doves and then pre-baiting and setting traps in the same manner as during summer. MOURNING DOVE MOVEMENTS 29 In winter the sexes of cloves are discernible but age cannot be distinguished. The sex ratio of 1,017 doves banded during January, February, and early March, was almost equal — 51 5 males to 502 females ( Table 5 ) . However, later in spring, I captured more males (166) than females (134), suggesting that perhaps a greater number of males were migrating into or through the Turlock area at that time. ,> TABLE 5. Records of Winter Banding in Traps Birds Banded Recoveries Year Total Males Females Total returns Recoveries < 40 km Distant recoveries Percent recovery 1%7 1968 71 118 40 64 187 40 65 59 30 30 515 31 54 181 38 63 62 36 37 502 6 10 34 5 8 6 4 2 75 M 3 4 14 1 4 3 2 31 F 2 3 13 1 4 23 M 1 3 5 2 1 2 1 15 F 2 1 2 1 6 8.5 8.5 1969 368 9.2 1970 78 6.4 1971 1972 128 121 6.2 4.9 1973 66 6.1 1974 67 2.9 Total .... 1017 7.4 Of 75 recoveries of winter-banded birds, 54 were taken in subsequent hunting seasons within 40 km (25 miles) of the site of banding, and 21 were taken at more distant points ( Figure 4) . Whereas summer banding recoveries were most- ly from points to the south of Turlock, winter taken birds were more varied in their movements— north (6), east (4), south (10), and west ( 1 ). Yet all but two of these recoveries came from the Central Valley or Sierra foothills. Three doves banded in February or March were shot near Turlock the following December. Three others were recaptured in my traps— one the following September, two a year later in March. One female was shot at Brewster, Washington, 32 months after banding, and a male was recovered near Ukiah in Mendocino County. Although the sexes were banded in almost equal numbers, band recoveries were higher in males, particularly at distant points (35 oo to 15 oo) and in years subsequent to the year of banding ( 22 oo to 1 0 oo ) . I presume that males wander farther than females and that thev live longer. DOVES BANDED ELSEWHERE The movements of doves in and about Turlock are further elucidated by recoveries of birds banded elsewhere (Figure 5). Twelve winter-banded birds came from points in Arizona, New Mexico, and Texas, suggesting a spring migration to California or points beyond for breeding. Thus far, there have been no recoveries in those areas of doves banded here. Eighteen summer-banded birds came from sites largely to the north and east of Turlock. One recovery of particular interest was a nestling banded in eastern Michigan and recovered here 15 months later. Presumably this bird would have been of the eastern race of Mourning Dove (Z m. carolinensis) and a true vagrant rather than a migrant. But most of the summer banded doves shot near Turlock in September presuma- bly were following normal movements from their breeding areas to wintering JO ( w \\'()R\\\ (ISO \\n (;avif Turlock WINTER Figure 4. Recoveries by circle) of Turlock ot 75 winter-trapped doves, 54 of which were taken within 40 km (shown MOURNING DOVE MOVEMENTS 31 grounds. As the map clearly shows, there is no well defined pattern to these fall movements, the incoming migrants originating from widely scattered localities in the western states. Evidence of the strong southward drift of doves originating in populations north of Turlock is shown by recoveries of birds banded in summer ( pre-season ) in the vicinity of Yakima, Washington, in 1964, 1968, and 1969 (Figure 6). Of the 87 recoveries outside of the block in which the banding occurred (lat 46°N, long 120°W), all were generally to the south — 3 in Oregon; 37 in California; 14 in the Rocky Mountain states (Nevada 4, Utah 3, Arizona 4, Colorado 2, New Mexico 1); and 33 in Mexico, mostly in the central highlands west of Mexico City. One adventuresome traveler went as far south as El Salvador. Figure 5. Banding locations of 30 doves subsequently siiot near Turlock. Twelve winter-banded birds (triangles) came trom banding stations southeast of Turlock. Eighteen summer- banded birds (circles) came from all points of the compass but mostly from northerly stations. 32 CALIFORNIA FISH AND GAME Figure 6. Points of recovery of 87 doves banded in summer near Yakima, Washington, and recov- ered outside of the banding locality. A strong southward drift is indicated. CONCLUSIONS REGARDING DOVE MOVEMENTS Considering all the data available to me, I conclude that the population of doves nesting in the Turlock area is basically resident and does not migrate. Of 56 locally bred birds banded and subsequently recovered over a 4-year period, not one had left the Central Valley and only 8 had wandered far in the Valley itself. Among birds trapped and banded in summer, there seems to be a mixture of locally produced juveniles that will not migrate and drifting juveniles from breed- ing sites to the north and east that are in transit southward. A number of these MOURNING DOVE MOVEMENTS 33 migrants end up in distant areas, as far south as central Mexico. Relatively few adults are captured in summer and I presume that the ones captured are local breeders. The winter situation is more complex. However, mv personal interpretation is as follows: the winter trapped doves include many local residents, but with a substantial mixture of birds that have come here to winter from their breeding sites in the Pacific and Rocky Mountain states, and some transient migrants that have spent the mid-winter months in Texas, New Mexico, Arizona, and probably Mexico, and are on their way back to more northerly nesting areas in March. Some of these transients will return southward through Turlock and be repre- sented in the September hunting bag. The seasonal intermixture of resident and migratory doves is somewhat com- parable to the White-crowned Sparrows {Zonotrichia leucophrys) of the Pacific seaboard, first described by Blanchard (1941 ). A resident population of spar- rows (Z /. nuttdlli) lives year-round along the California coast from Eureka to Santa Barbara. Each autumn an invading population of migrants (Z /. pugetensis) sweeps down the coast from the breeding grounds in coastal Ore- gon, Washington, and Vancouver and mixes with the resident sparrows. But in spring the migrants depart, leaving the local birds to pursue their own breeding cycle. The two populations of sparrows are virtually identical morphologically, but there is a recognizable difference in the song. The two populations of doves are indistinguishable by any criteria known to me, except that one is resident and the other is migratory. CHANGING LAND USE AFFECTING DOVES IN THE TURLOCK AREA During the Cold Rush, Stanislaus County was largely devoted to livestock grazing, but in the 1860's increasing areas were plowed for dry grain farming. In 1868 the County produced nearly 2,500,000 bushels of wheat which made it the grain center of California. In 1871 Miller and Lux began to build the San Joaquin Canal in the southwestern part of Stanislaus County, and, with the establishment of the Turlock Irrigation District in 1 887, irrigation became the new trend. Grain farming was pushed into the less productive foothills, and the rich bottomlands, once famous for wheat, were converted to orchards, vineyards, dairies, and row crops. The amount of irrigated land increased from 1,522 ha (3,757 acres) in 1901 to 69,107 ha (170,635 acres) in 1974. With irrigation has come much more intensive farming, with decreasing habitat for most wildlife, including doves. Oat stubble, which provides prime summer feeding sites, has decreased drastically; in 1976 I drove hundreds of miles around Turlock without finding a field suitable for dove trapping. Sprinkler irrigation itself is menacing to nesting doves; I found 12 out of 17 nests in an almond orchard broken up by spraying. The rural landscape around Turlock, as a home for mourning doves, is graduallv deteriorating. Evidence of recent trends in dove numbers is inconclusive. Data obtained from the mourning dove call count made by the Department of Fish and Game each vear since 1966 showed an apparent decrease in numbers of cooing males from 1966 to 1975, but a sharp increase in the years 1976 to 1978 along three counting routes in the general vicinity of Turlock (Table 6). Deteriorating habitat is not reflected in this measure of abundance. However, the Department annual- 34 CALIFORNIA FISH AND CAME Iv conducts a mail survey of hunters, and th(^ r(^turns from Stanislaus County suggest a falling success ratio among dove hunters. The reported bag/hunter/ year was 21-23 in the early 1960's and in recent years has been 12-16. Keeler (1977:284) cites parallel evidence for a gradual decline in dove populations throughout the United States. Although the Mourning Dove is a remarkably adaptive game bird it cannot be expected to maintain population levels indefi- nitely in the face of progressive adverse habitat change. TABLE 6. Summary of Mourning Dove Call-count Taken Near Turlock, 1966-78. California Department of Fish and Game Data. Sumber of duves heard per 20-stop route Year 1966. 1967. 1968. 1969. 1970. 1971. 1972. 1973. 1974. 1975. 1976. 1977. 1978. tanislaus- Merced Merced Fresno Mean 20 4 11 11.7 20 6 5 10.3 32 8 14 18.0 7 7 10 8.0 11 10 7 9.3 13 1 11 8.3 11 2 8 7.0 12 4 1 5.7 19 7 1 9.0 10 10 6 8.7 23 5 16 14.7 19 13 2 11.3 25 10 5 13.3 On the other hand, I see abundant evidence that the urban and suburban dove habitat within the city limits of Turlock itself is improving and enlarging. Residen- tial buildings and their associated plantings offer many favorable nesting sites. Vacant lots, garden plots, small fields, and home bird feeders supply abundant and reliable supplies of food. City doves do not appear to move about the countryside, hence are little exposed to hunting. The Mourning Dove in Stanis- laus County is increasingly colonizing urban habitats as it loses ground in rural habitats. ACKNOWLEDGMENTS I am deeply grateful to Dr. A. Starker Leopold of the University of California for his encouragement, suggestions, and aid in writing this report. My thanks also are extended to Gene Christman, who prepared the figures; Nobu Asami, who typed the manuscript; Henry Reeves and George Jonkel of the Bureau of Sport Fisheries and Wildlife, who made available band return records and scientific reports otherwise unavailable to me; Harold Harper and staff of the California Department of Fish and Game for supplying data on various dove studies; and, last but not least, to my wife. Midge, for her patience and assistance. REFERENCES Blanchard, B. D. 1941. The White-crowned Sparrows (Zonotrichia leucophrys) of the Pacific seaboard: envi- ronment and annual cycle. Univ. Calif. Publ. Zool. 46 (1): 1-178. Browning, B. M. 1959. An ecological study of the food habits of the Mourning Dove. Calif. Fish Came 45 (4): 313-331. MOURNING DOVE MOVEMENTS 35 Cowan, ). B. 1 952. Life history and produttivity of a population of Western Mourning Doves in California. Calif Fish Came 38(4): 505-521. Hanson, H. C, and C W. Kossack 1963 The Mourning Dove in Illinois III. Conserv Tech Bull 2. 133 pp. Keeler, |. E 1977 Mourning Dove Pages 275-298 inC. C. Sanderson, ed Management of migratory shore and upland game birds in North America. Int. Assoc. Fish Wildl Agencies, Wash., DC. Lehner, N. 1965. Some observations on the ecology of the Mourning Dove in New York. N.Y. Fish Came | 12(2); 147-169. McClure, H. E. 1950. An eleven year summarv of Mourning Dove observations in the west Trans \ \vn Wildl Conf. 15: 335-346. 36 CALIFORNIA FISH AND CAME ////: Fi'.h and Came 65(1): 36-^9 1 979 STATUS AND DISTRIBUTION OF THE CALIFORNIA CLAPPER RAIL [Rail us longirostris obsoletus) ROBERT CILL, )R. U. S. Fish and Wildlife Service Anchorage, Alaska California Clapper Rail population and distributional data were derived from 120 censuses conducted over 5,000 ha (12,350 acres) of greater San Francisco Bay area tidal marshes from February 1971 to December 1975. Breeding populations are re- stricted to San Francisco Bay. Humboldt, Morro, and Tomales bays, and perhaps Elkhorn Slough, no longer support breeding Clapper Rails. Within San Francisco Bay, major populations exist in San Mateo, Santa Clara, Alameda, and Marin counties and in Napa Marsh. Breeding and nonbreeding season population densities did not differ significantly within the major population centers of the range. The Clapper Rail population was estimated to be 4,200-6,000 birds during this study. South San Francisco Bay and Napa Marsh supported 55 and 38%, respectively, of the population. INTRODUCTION The California Clapper Rail i Rallus longirostris obsoletus) was an endemic railici of most estuarine marshes of central coastal and northern coastal California (A.O.U. 1957). Accelerated loss of habitat after 1900 resulted in significant reductions in both its range and numbers and in its being declared "Endangered" by both the Secretary of the Interior (U.S. Fish and Wildlife Service 1973) and the California Fish and Game Commission (California Department of Fish and Game 1976). This subspecies has been the subject of numerous studies throughout its range. The resulting literature was recently summarized (Wilbur and Tomlinson 1976). Much of the literature addresses aspects of breeding biologv. There are few data regarding the population dynamics of obsoletus, and since 1944 there have been no comprehensive reports on its distribution. Since 1944, approximately 2,832 ha (7,000 acres) of California Clapper Rail habitat have been eliminated through diking, filling, or conversion to salt evapo- ration ponds, representing a 20% loss in rail habitat. In light of the continuing elimination or alteration of California's estuarine marshes and the continuing threat of major environmental catastrophes, such as oil spills, it becomes critical that current data on endangered species be available to guide protection efforts. Throughout its range, the California Clapper Rail is restricted to tidal salt marsh that is interspersed with drainage channels inhabited by an abundant inverte- brate fauna, including Modiolus demissus, Macoma balthica, Hemigrapsus ore- gonesis, and Pachygrapsus crassipes. Principal vegetative dominants of San Francisco Bay marshes inhabited by R. I. obsoletus \nc\u6Q cord grass iSpartina foliosa), pickleweed ( Salicornia spp ) , salt grass ( Disticlis spicata) , and gumplant I Crinc/elia spp). Bulrushes i Scirpus spp) , silverweed i Potentilla pacifica) , and Baltic rush i Juncus balticus) are dominant in Napa Marsh, upper Petaluma River, and along Sonoma Creek. The marshes of Elkhorn Slough, Bolinas Lagoon, and Tomales Bay are predominantly Salicornia. This study, conducted from February 1971 to December 1975 and augmented by more recent data, reports on the historic and current distribution and abun- dance of the California Clapper Rail. Habitat utilization, limiting factors, and potential range expansions are also discussed. CALIFORNIA CLAPPER RAIL STATUS 37 STUDY AREA The study was conducted on approximately 5,000 ha (12,350 acres) of the greater San Francisco Bay area tidal marshes, including Elkhorn Slough, Bolinas Lagoon, Tomales Bay, and Suisun Marsh (Figure 1 ). These tidal marshes have a varied flora (Hinde 1954; Pestrong 1965, 1972; Gerdes 1974; Madrone Associ- ates 1977). METHODS Historic distribution and abundance data were collected from published and unpublished literature, including sight records and newspaper accounts. The following collections were searched for specimens and egg sets: MVZ — Museum of Vertebrate Zoology, Berkeley; CAS — California Academy of Sciences, San Francisco; SJSU — San Jose State University, San jose; LANHM — Los Angeles Natural History Museum; SU — Stanford LJniversity; SDNHM — San Diego Natu- ral History Museum; and Western Foundation of Vertebrate Zoology, Los Ange- les. Current distribution, abundance, and habitat requirement data were collected from (1) published and unpublished sight records, (2) surveys by Gould (1973), and (3) 120 censuses conducted in known or suspected rail habitat during the breeding (1 March-31 August) and nonbreeding (1 September-28 February) seasons from 1971 through 1975 (Table 1). These censuses were conducted both jointly and independently by personnel of the California Depart- ment of Fish and Game and of the U.S. Fish and Wildlife Service and by volunteers from local Bay Area Audubon Society chapters, universities, and colleges. TABLE 1. Census Effort, February 1971-December 1975. No. of censuses Area of coverage County Breeding season Nonbreeding season (fta) (%) ' Monterey 3 2 78 32.1 Santa Cruz 1 1 12 48.0 San Mateo 5 7 3% 48.9 Santa Clara 3 8 206 29.9 Alameda 7 18 1,056 87.0 Contra Costa 4 8 202 25.0 Solano 6 5 889 45.3 (Napa Marsh) (4) (3) (420) (84.0) (other) (2) (2) (469) (32.1) Napa 6 1 465 46.0 Sonoma 8 11 1,161 60.0 (Napa Marsh) (4) (5) (600) (85.7) (other) (4) (6) (561) (45.3) Marin 5 _n _2[3 43.0 Totals 48 72 4,778 * Percent of existing marsh habitat censused, by county Selection of rail census techniques was dictated by vegetative components of marshes throughout the study area, seasonal variations in tide height, and behav- ioral differences of o^5o/e^6/5 between breeding and nonbreeding seasons. Mar- shes in south San Francisco Bay, Marin County, and Monterey County were most effectively censused during the breeding season by a rope drag method (Gill 1972) and by broadcasting taped Clapper Rail calls. During the non- 38 CALIFORNIA FISH AND CAME breeding period, however, visual censusing during cJaylight flood tides was most effective. Since flood tides occur only at night during the breeding season, this technique was not used during this period. Flood tides were considered to be tides greater than +6.5 feet MLLW (mean lower-low water) at Fort Point, San Francisco. During flood tides, rails are usually forced to the highest exposed areas of the marsh and become more visible and are easily censused. This is especially true of marshes in south San Francisco Bay which have vegetation of a rather uniform height; these marshes often become completely inundated by flood tides. Napa Marsh, comprising portions of Napa, Sonoma, and Solano counties, marshes along the Petaluma River, and marshes in west Contra Costa County were effectively censused by eliciting rail calls from taped calls. Taped calls were broadcasted during low or moderately high tides during both breeding and nonbreeding seasons. The height and density of vegetation remaining exposed during flood tides precluded visual censusing by the flood tide method. Data on habitat use by obsoletus were derived from ( 1 ) extensive censusing of marsh areas and then projecting these data to other similar and often contigu- ous habitats, and (2) extensive spot checking of marsh areas not censused to note the presence or absence of rails. Population densities were projected from average mean densities of breeding and wintering populations censused under similar tide conditions and by similar techniques. RESULTS ' : Historic Distribution Estuarine marshes of San Francisco Bay have historically supported the largest populations of California Clapper Rails. Tidal marsh once covered an estimated 81,000 ha (200,300 acres) along San Francisco Bay (Nichols and Wright 1971 ) (Figure 1 ). The marshes along the entire south arm of the Bay in San Mateo, Santa Clara, and Alameda counties were favored by obsoletus (Grinnell 1915, Grinnell and Miller 1944, Sibley 1952). Elsewhere in the San Francisco Bay area and along the central California coast, the California Clapper Rail was more restricted in its distribution and probably absent from Napa Marsh until the mid-1930's. Contra Costa County Grinnell (1915) made no reference to o/?5o/e/^5 occurring in Contra Costa County; however, sightings and specimens from San Pablo were reported by 1919 (Grinnell and Wythe 1927, MVZ 31308). Two specimens (SjSU 3883, 3884) taken in April 1920 near Richmond indicate a possible breeding popula- tion at that time. Breeding was also known as late as 1956 near Pt. Isabel (Williams 1957); however, Farrar felt that no California Clapper Rails could be found in Contra Costa County as of 1962 (Cutler and Pugh 1962). Solano and Napa County The eastern limit of R. I. obsoletus has been reported as Southampton Bay, Solano County (Grinnell and Miller 1944). Other sightings from this area are few, but there are breeding records (Williams 1957, Cogswell 1958), including an egg set from 1948 (E. Stoner, Western Bird Banding \ssoc., pers. commun.). FHistoric records were not found from other parts of Solano County, including Suisun Marsh and portions of the Napa Marsh. TAIIFORNIA CLAPPER RAIL STATUS \ 39 Petaluma Humboldt^ Bav Morro Bav \ Historic DisiRimrrioN of Tidal Mivrsh Figure 1. Study area and historic distribution of tidal marsh, ca. 1850 (from Nichols and Wright 1971 ). The former breeding distribution of the California Clapper Rail included all marsh areas except Napa Marsh. 40 CALIFORNIA FISH AND GAME Sightings or records of California Clapper R.uls from Napa County are similarly scarce. A single specimen (SU 10863) is recorded trom the "Napa River Valley" in 1939. Marin and Sonoma Counties The occurrence of the California Clapper Rail on the San Francisco Bay marshes of Marin and Sonoma counties has apparently fluctuated over the years. Crinncll (1915: 46) felt that obsoletus "occurred formerly, 25 or more years ago . . ." in these areas. Crinnell and Wythe (1927) listed a single record from Manzanita, Marin County, in 1920 and described o65o/e/^^/5 as occurring "casual- ly" near Petaluma, Sonoma County. By the early 1930's, Jencks (1930) and Bryant (1931) listed several records from Manzanita, including a breeding record in 1930. Breeding is known to have occurred near Greenbrae, Marin County in 1931 (MVZ 7961, egg set). California Clapper Rails were also known from several coastal marshes in western Marin County. Sight records and specimens exist from Point Reyes Station, Hamlet, and other parts of Tomales Bay ( Storer 1915; Brooks 1 940; MVZ 2491 5, 1 00396; CAS 2234, 1955). Storer (1915) reported a 1 91 4 specimen ( MVZ 24915) as the first record of obsoletus from the ocean side of Marin County. San Francisco County No records of California Clapper Rails were found from San Francisco County other than instances of vagrancy, e.g., the Farallon Islands (Bryant 1888). A population most likely occurred in San Francisco County prior to the late 1880's, by which time almost all marshlands had been reclaimed. San Mateo and Santa Cruz Counties The early status of obsoletus or\ coastal marshes of San Mateo and Santa Cruz counties is also unclear as few records were found; none indicated a breeding status. Prehistoric evidence of R. I. obso/etus irom Santa Cruz County has been found from midden remains north of Santa Cruz (SJSU SCr-7; Matthiesen, San Jose State Univ. pers. commun.). More recently, the species is known from Pescadero Marsh (Orr 1942) and from marshes near Santa Cruz (MVZ 90458, 90459, 90460). These three specimens, all winter records, were taken between 1938-1940 and could have been part of a small resident population or winter dispersals from other areas, such as Elkhorn Slough. Monterey County Although Crinnell (1915) questioned the presence of obsoletus in the Monte- rey Bay area, Silliman (1915) reported it as regularly, but sparsely, inhabiting salt marshes of Elkhorn and Tembladero sloughs and other marsh tributaries of Monterey Bay. By 1918 Crinnell described obsoletus 3iS occurring in small num- bers near Elkhorn Slough (Crinnell et al. 1918). Prior to 1908 it is unlikely that o^5o/e^iy5 existed in what is now Elkhorn Slough since the area was a freshwater lagoon and a tributary of the Salinas River. Two years after the 1906 earthquake, the area was cut off from the Salinas River and only then became an estuary capable of supporting obsoletus (Browning 1972). Elsewhere in Monterev County, California Clapper Rails were known from Pacific Grove (Kimball 1922), but even then were considered as vagrants. Other Areas Outside of the greater San Francisco Bay area the California Clapper Rail has been reported from FHumboldt Bay, FHumboldt County. Breeding populations CALIFORNIA CLAPPER RAIL STATUS 41 existed in 1932 on Indian Island, Humboldt Bay, and at the mouth of the Mad River, Humboldt County, but no confirmed breeding records have been report- ed since (Yocom and Harris 1975). South of Monterey Bay, obsoletus has been reported breeding only at Morro Bay, San Luis Obispo County (Brooks 1940). Specimens taken in mid-February 1939 (MVZ 100404, 100405) indicate a possible breeding population at that time. The subspecific identity of these Clapper Rails is still disputed, but it is generally considered to be obsoletus (Brooks 1940, Wilbur and Tomlinson 1976). Early sighting records of California Clapper Rails in the State of Washington were (luestioned by Dawson and Bowles (1909). Current Distribution The California Clapper Rail occupies approximately 60% (5,650 ha or 13,950 acres) of the estuarine marsh within its current range (Table 2). The present breeding distribution of the California Clapper Rail is now apparently confined to the greater San Francisco Bay area (Figure 2i. Apparently this rail no longer breeds in Humboldt County or Morro Bay. Several reports of this species from both areas in recent years indicate that obsoletus may still occur there, most likely as vagrants (Yocom and Harris 1975, Wilbur and Tomlinson 1976). Very recently, a Clapper Rail was heard calling trom a marsh in Morro Bay in April 1977 (Tim Manolis, pers. commun.). TABLE 2. Available Tidal Marsh and Amount Utilized by the California Clapper Rail in Its Present Range. Amount of tidal marsh Available Utilized County (ha) 1%7 Iha) 1%? r%7 Monterey 243 2.6 206 84.7 3.6 Santa Cruz 25 0.3 0 San Mateo 809 8.6 750 92.7 13.3 Santa Clara 688 7.3 421 61.2 7.5 Alameda 1,214 12.9 995 81.9 17.6 Contra Costa 809 8.6 252 31.2 4.5 Solano 1,963 20.8 458 23.3 8.1 (Napa Marsh) (5001 (5.0) 1458) (91.61 (8.1) (other) (1,463) (16.0) (0) Napa 1,012 10.7 816 80.6 14.4 Sonoma 1,936 20.5 1,435 74.1 25.4 (Napa Marsh) (700) (7.4) (615) (87.8) (10.8) (Petaluma River) (1,236) (13.1) (820) 166.3) (14.5) Mann 728 7.7 319 43.8 5.6 Totals 9,427 100.0% 5,652 100.0% Percent of available habil.it throughout the subspecies range ' Percent of available habitat utilized in each county ■* Percent of habitat utilized throughout the range Monterey County Until recently, California Clapper Rails were considered to be resident in Elkhorn Slough, occurring from approximately 300 m (1,000 ft) west of State Highway 1 to Kirby Park. From 1966 to 1969 several were observed north of Kirby Park, including adults with young (D. Pine, biologist, Calif. Dept. Fish and Game, pers. commun.). Varoujean (1973) did not find any north of this area in 1972, and at that time he estimated a minimum population of 14 birds for Elkhorn Slough. However, no Clapper Rails were found in the slough in special ■ ^'IRMA, f'Z'-' ^\n CAMF SUISUN »Mg Redwood Creek, Westpoint, Corkscrew Smith, Steinberger. : sloughs, plus marshes south o' : ng provide most or i habitat. Small marshes near stable populations. E\entuali'v. ine areas of Bair Island now being re^iw- ^^ i,,,,. Santa Clara Countv Major populations are fou'^d wrthtn r*^ the Palo Nature Interpretive Center n Sloueh - larger fringing marshes of C : Aiviso sloughs. ~ 'om the mouth of Alviso Slough ea^; ..or.age. rireeding is not known east of DrawbriOK- luv^c^cf. uunr^ i Jv, several winter sightings have come from this area. Alameda Count\ Populations of Clapper Rails occur along all fring _ -^ to the Dumbarton Bridge, including Mowrv Slough, Newa^- marsh along Plummer Creek. Also, thev occur fro j mile) north of the Dumbarton Bridge to the mouth o: .j.-ig Old Alameda Creek upstream approximately 2 km ' ^ c - ..^sent from the recently created Alameda Flood Control C but can be expected to inhabit this area once suitable habitat develops. North of Mt. Eden Creek, populations are limited and confined to Arrowhead Marsh in San Leandro Bav Alameda South Shore, and marshes adjacent to the San Francisco-Oakland Ba . Bridge. Contra Costa Countx Remnant breeding populations occur in salt marshes along Wildcat and San Pablo creeks. Small, scattered populations occur between San Pablo Creek and Point Pinole and most likely still occur in the remnant marshes east of Point Isabel. The\ are not know n to breed elsew here in the county. I consider sightings from vNest Pittsburg i March 1964* and Frank's Tract i September 1963) t Lvnn Farrar, pers. commun. ) to be dispersing young, possiblv from Southampton Bav. but more likely from Napa Marsh. 44 CALIFORNIA FISH AND CAME Solano County Resident populations occur along portions of Dutchman, South, and China sloughs within Solano County. They also occur from the mouth of White Slough and fringing marshes from approximately 1 km (0.6 mile) south of the Vallejo Bridge north to Slaughterhouse Point. Obsoletus\s apparently absent from Mare Island and the broad Salicornia marsh fronting San Pablo Bay. There have been no breeding records of Clapper Rails from Southampton Bay since 1 958; howev- er, the species was heard calling from this area on two occasions in late March 1977 (T. Manolis and F. Beyer, Napa-Sonoma Audubon Soc, pers. commun.). The Clapper Rail is absent from Suisun Marsh and eastern Solano County. Napa County They are resident and breed along Devil, South, China, Napa, Mud, Fagan, and Steamboat sloughs. They also occur within the marshes of Fly Bay, Coon, and Edgerly islands, and along the marshes of the Napa River from the Napa-Solano county line north to Bull Island. Sonoma County Clapper Rails breed within the marshes of Napa, hludeman. Steamboat, and Second and Third Napa sloughs. They also occur m low numbers along Sonoma Creek to Wingo, along the Petaluma River to Schultz Creek, and on Lower Tubbs Island fCould 1973). Apparently they are now absent from upper Tolay Creek. Marin County On the San Pablo Bay shores of Marin County the Clapper Rail is common and breeds from the mouth of Novato Creek south to the mouth of Callinas and Miller creeks and upstream along these drainages for approximately 0.5 km. (0.3 mile). They occur in small numbers along Novato Creek upstream to 2 km (1.2 miles) north of State Highway 37. Small numbers are also found from the mouth of Corte Madera Creek upstream to State Highway 101, and from the mouth of San Rafael Creek upstream approximately 1 km (0.6 mile). Apparently the Clapper Rail is absent from Richardson Bay, the last sighting from this area being in 1967 (R. Stallcup, pers. commun.). At that time the population was confined to marshes near Mill and Tamalpais valleys and was estimated to be fewer than six birds. There have been two sightings of obsoletusirom coastal Marin County (Bolinas Lagoon) since 1970 (P. Hendersen, biologist. Point Reyes Bird Observ- atory, pers. commun.; Gould 1973). Historic and Current Abundance Quantifiable data on the historic abundance of the California Clapper Rail are meager. The earliest published accounts of rail abundance refer only to numbers taken from local areas for commercial or sport use and do not relate to popula- tion densities or numbers supported by a given area. It can, however, be inferred from some of these early accounts that thousands of California Clapper Rails inhabited the south arm of San Francisco Bay alone. A newspaper account from the San Mateo Leader oi October 23, 1 897, referred to at least 5,000 "rails" killed during a 1-week period that year. Similar reports between 1890-1910 of individ- ual hunters killing 30 to 50 rails a day are not uncommon (Redwood City TImes-Cazette and San Mateo Leader }mO-'\^]0) . The majority of these were undoubtedly Clapper Rails as concern over the killing of such numbers of "rails" during this period led to immediate enactment of laws regulating Clapper Rail hunting. CALIFORNIA CLAPPER RAIL STATUS 45 Population studies of Clapper Rails in south San Francisco Bay by Applegarth (1938) and Zucca (1954) provide the only comparable data on population densities during the breeding and nonbreeding seasons. Applegarth reported breeding densities of 1.59, 4.35, and 1.69 rails/ha for three 4-ha ( 10-acre) study plots in 1937. Zucca, censusing during flood tides, found densities in winter of 2.37 and 2.92 rails/ha for a 26-ha (63-acre) study area in 1950 and 1951. I found mean densities in utilized habitat over the five major population centers in San Francisco Bay to range from 0.3 to 1 .6 rails/ha during the breeding season, and from 0.1 to 1.1 rails/ha during the nonbreeding season (Figure 3). A test for the comparison of means of samples of unequal variance revealed no significant difference (all p>0.05) between breeding and nonbreeding season densities over a given area. The population projection for each area, therefore, is based on the average of the mean densities for the breeding and nonbreeding seasons (Table 3). 3.0 2.0 1.0 33 w f Breeding Nonbreeding SE - Mean Rangi 4 ■EB- So. S. f. BU NiPl MlRSH MtRIN COUNir ( S. f. BU ) CONTRA COSTl Co. PETiLUMit RIVER Figure 3. Breeding and nonbreeding season densities of the California Clapper Rail over major population centers throughout San Francisco Bay, 1971-1975. Number of censuses is shown above each area. DISCUSSION The present range of the California Clapper Rail has become extremely frag- mented as a result of habitat elimination and alteration. South San Francisco 46 CALIFORNIA HShl AND GAME Bav continues to be the major population center, while only isolated populations remain along the Contra Costa County shoreline. The San Pablo Bay marshes in Marin Countv support a small but stable population. The population in Elkhorn Slough apparently has declined since 1972 and may no longer exist. Napa Marsh now supports a much larger population than in past years. This is interesting, considering that prior to 1940 only two references could be found to Clapper Rails occurring in Napa Marsh and that as late as 1952 major portions (1,800 ha) of the marsh had been converted to salt evaporation ponds, thereby elimi- nating a major rail population, if, in fact, one existed. When considering the extent of Clapper Rail studies and specimen collections elsewhere in San Fran- cisco Bay prior to 1940, it seems unlikely that a population of the present size went unnoticed for so long. I consider the Napa Marsh population to be a relatively recent range extension, probably resulting from a change from a mostly freshwater marsh to a more brackish one due to substantial decreases in freshwater inflow to the marsh. TABLE 3. Average Yearly Population of California Clapper Rails over Major Population Centers of the Range, 1971-1975. Utilized Densih Population Area habitat (ha I i birds/ha l projection Range^ Elkhorn Slough, Monterey County 206 14 14 (minimum)' So. San Francisco Bav 2,166 1.31 2,837 2,415-3,249 VV. Contra Costa Countv 252 0.14 35 20-50 Napa Marsh 1,889 1.04 1,964 1,605-2,304 Petaluma River 820 0.17 139 86-184 Mann Countv 'San Francisco Bav) 319 0.48 153 102-204 Totals 5,652 5,142 4.242-6,005 ' Range is ± one S.E. about the mean. ' From VaroLiiean (1972i. No range given Within its former range, obso/etus can be expected to inhabit most areas being restored to tidal marsh. Extensions into areas not historically inhabited by ob- so/etus w'\\\ probably be limited to Suisun Marsh, marshes along the north shore of Contra Costa County, and possibly other portions of the Sacramento-San Joaquin Delta. It is conceivable that with the future planned reductions in out- flow from the Delta river system, there will be a corresponding change in benthic fauna and marsh flora as the salinity gradient increases and moves east (Skinner 1972). This change toward a more saline marsh would probably provide all the requirements necessary to support populations of obso/etus. Since the mid-1960's the overall population of California Clapper Rails has remained relatively stable. However, during this study I noticed that portions of the population, especially in south San Francisco Bay, exhibited fluctuations similar to those reported for /?. /. creptans along the east coast of the United States, where intraspecific competition for nesting territory is thought to be a major factor governing population levels (Ferringo 1966, Widjeskog 1974). There, the principal cause of territorial conflict and subsequent population fluc- tuations is successive years of high rail production because of a lack of normally disruptive high tides during the nesting period. Ferringo (1966) also felt that a period of drought, superimposed on the above conditions, resulted in increased nest loss and chick and adult mortality. While high tides might be a factor in limiting populations of obso/etus (Zucca CALIFORNIA CLAPPER RAIL STATUS 47 1954), I feel a more important factor contributing to population fluctuations is a change in biomass, production, and relative composition of Spartina and Salicornia, the preferred nesting habitats of obsoletus throughout most of its range. This occurs as a result of changes in soil and water salinities which, in turn, are determined by weather and seasons ( Cameron 1 972. Mahall and Park 1 976a, 1976^;. Mahall and Park (1976b), during a study of plant zonation in salt marshes in San Pablo Bay in 1972-1973, found Spartina to be much less tolerant than growth of Spartina. They noted, following the extremely dry winter of 1971- 1972, a reduction in both biomass and net productivity of Spartina the following spring, and after the extremely wet 1972-1973 winter they observed a faster growth of Spartina in spring. Assuming that Spartina and Salicornia were similarly affected in marshes in adjacent south San Francisco Bay, there would have been a decrease in Spartina biomass in 1972 and, thus, an overall reduction in the amount of nesting habitat available that season. This would have increased intraspecific competition for nesting territories in adjacent Salicornia and less used nesting cover such as Grindelia. This may have accounted for the approximately 40% reduction in rail numbers in 1972 compared with the higher numbers found during the 1971 season when Spartina was heavily used as nesting cover (Gill 1973, 1977). These fluctuations in Spartina biomass and productivitv might also account for the variations in preferred nesting habitat reported by other investigators during studies of obsoletus in similar marsh areas, (and, in two instances, the same marsh area) in south San Francisco Bay (DeCroot 1927, Applegarth 1938, Zucca 1954, Gill 1973). ACKNOWLEDGMENTS I am grateful to the Leslie Salt Company for permitting access to much of their lands. Walt Stieglitz, Dick Nugent, Liz Cummings, and Cathy Osugi, formerly with the San Francisco Bay National Wildlife Refuge, and Dick Kroger and Frank Michny of the U. S. Fish and Wildlife Service, Sacramento, are thanked for their participation. I especially thank the more than 60 volunteers from local Bay Area Audubon Society chapters, without whose help this study would not have been possible. Of equal help in conducting much of the field work were the following employees of the California Department of Fish and Game: Bruce Elliott, Gordon Gould, Jim Michaels, Cal Hampy, Glen Rollins, Don Pine, Ron jurek, Alan Craig, and especially, Gil Thomson. Rich Stallcup provided valuable sight records from Audubon Field Notes and American Birds. The Museum of Vertebrate Zoology was helpful in providing access to their specimens, as were the California Acade- my of Sciences and San Jose State University. Sandy Wilbur was kind enough to share specimen information obtained from the San Diego Natural FHistory Museum, Los Angeles Natural History Museum, and the Western Foundation of Vertebrate Zoology. Dick Mewaldt, Ron Jurek, Bruce Browning, Alan Craig, and Colleen Handel made useful comments on earlier drafts of the manuscript. REFERENCES American Ornithologists' Union 1957. Check-list of North American birds, 5th ed. Port City Press, Inc., Bal- timore t>91 pp Applegarth, ).H. 1938. The ecology of the California Clapper Rail on the south arm of San Francisco Bay. Master's Thesis, Stanford Univ. 153 pp. 48 CALIFORNIA FISH AND CAME •\rbih R jr., efi 1971 71sl Christmas bird (ount Am. Birds 25:119-524. 1972,?. 72nd Christmas bird count. Am Birds 26:135-550. . 19726 Middle Pacific Coast Region. Am. Birds 26:819-922. Brooks, A. 1940. The Clapper Rail ot Morro Bay. Condor 42:126-127. Browning, B. M. 1972. The natural resources of Elkhorn Slough; their present and future use. Calif. Dep. Fish and Came, Coastal Wetlands Series No. 4. 105 pp. Brvani, D A 1931 August field notes. Cull 13 <9):3-4. Bryant, VV E 1888. Proceedings of California Academy of Sciences. Series 2, 1888:42. California Department of Fish and Came. 1976. At the crossroads, a report on California's endangered and rare fish and wildlife. Sacramento, 99 pp. Cameron, G. N. 1972. Analysis of insect trophic diversity in two salt marsh communities. Ecology 33:58-73. Cogswell, H. L. 1958. Middle Pacific Coast Region. Audubon Field Notes 12:383. Cutler, B D., and E A. Pugh. 1962. Middle Pacific Coast Region. Audubon Field Notes 16:70. Dawson, VV. L , and ). H Bowles. 1909. The birds of Washington. Occidental Publ. Co., Seattle. 997 pp. DeCroot, D. S. 1927. The California Clapper Rail: its nesting habits, enemies and habitat. Condor 29(61:259- 270. Ferringo, F. 1966. They go up and down: population dynamics of the Clapper Rail. N. j. Outdoors, 16(8):2-9. Gerdes, G. 1974. The natural resources of Morro Bay. Calif. Dep. Fish and Came, Coastal Wetlands Series No. 8. 103 pp. Gill, R., jr. 1972. South San Francisco Bay breeding bird survey, 1971 Calif. Dep. Fish and Game, Wild!. Manage. Branch Admin Rept. 72-6. 68 pp 1973. The breeding birds of the south San Francisco Bay estuary. MA. Thesis, San jose State University. 145 pp. 1977. Breeding avifauna of the south San Francisco Bay estuary. West. Birds 8:1-12. Gould, C. 1973. California Clapper Rail survey — 1973. Calif. Dep. Fish and Came, Spec. Wildl. Invest., Federal Aid in Wildl. Restoration, Project W-54-R-5, lob 11-10. 6 pp. Grinnell, ). 1915. A distributional list of the birds of California. Pacific Coast Avifauna No. 11. 217 pp. Grinnell, ]., H. C. Bryant, and T I Storer. 1918. The game birds of California. Univ. of Calif. Press, Berkeley. 624 pp. Grinnell, )., and A H Miller. 1944 The distribution of the birds of California. Pacific Coast Avifauna No. 27. 608 pp Grinnell, )., and M. W. Wythe. 1927. Directory of the bird-life of the San Francisco Bay region. Pacific Coast Avifauna No. 18. 160 pp. Hinde, H. P 1954. The vertical distribution of salt marsh phanerograms in relation to tide levels. Ecol. Monogr. 24:209-225. lencks, F. M. 1930. August field notes. Gull 12l9»:3-4. Kimball, H. H. 1922. Bird records from California, Arizona and Guadalupe Island Condor 24:96-97. Madrone Associates. 1977. The natural resources of Napa Marsh. Calif. Dep Fish and Game, Coastal Wetlands Series No. 19. 97 pp Mahall, B. E., and R. B. Park. 1976d. The ecotone between Sparlina ioliosa Trin. and Salicornia virginica L. in salt marshes of northern San Francisco Bay. I. Biomass and production. ). Ecol. 64:421-433 19766. The ecotone between Spariina folio',a Trin. and Salicomia virginica L. in salt marshes of northern San Francisco Bay. II. Soil water and salinity. |. Ecol. 64:811-819. Nichols, D. R , and N. A. Wright. 1971. Preliminary map of historic margins of marshlands, San Francisco Bay, California. San Francisco Bay Region Environment and Resource Planning Study. Basic Data Contribution 9. U.S. Geologic Survey, Menio Park, Calif. Orr, R. T 1942 A study of the birds of the Big Basin Region of California. Am. Midi. Nat. 27:273-337. Pestrong, R. 1965. The development of drainage patterns on tidal marshes. Stanford Univ. Pub. in Earth Sci , Vol. 10, No. 2. 87 pp. 1972. San Francisco Bay tidelands. Calif. Geology 25:27^*0. Sibley, C. G. 1952. The birds of the south San Francisco Bay region. Dep. Biol. Sci., San lose State Univ. 44 pp Silliman, O. P. 1915. Range of California Clapper Rail. Condor 17:201. Skinner, |. 1972. Ecological studies of the Sacramento-San Joaquin estuary. Calif. Dep. Fish and Game, Delta Fish and Wildl. Protection Study, Rep. No. 8. 94 pp. Storer, T. I. 1915. Additional records of the California Clapper Rail and Red Phalarope in California. Condor 17:98. U.S. Fish and Wildlife Service, 1973. United States list of endangered fauna. Office of Endangered Species and lniprn,itlonal Activities. 22 pp. CALIFORNIA CLAPPER RAIL STATUS 49 Varoujean, D. H. 1973. A study of the California Clapper Rail in Elkhorn Slough, 1972. Calif. Dep. Fish and Game, Spec. Wild!. Invest. Project W-54-R-4., Final Rep., |ob 11 10 pp VVidjeskog, L. 1974. Clapper Rail study. New jersey Dep. Envir. Proj., Div Fish and Shell Fish Prog Rep. W-53-R-7. 13 pp. Wilbur, S. R., and R. E. Tomlinson. 1976. The literature of the western Clapper Rails. U.S. Fish and Wildlife Service. Spec. Sci Rep., Wildl. No. 194. Williams, L. 1957. Middle Pacific Coast Region Audubon field notes 11:427. Yocom, C. F., and S. W. Harris. 1975. Status, habitats, and distribution of birds of Northwest California. Humboldt State Univ. Areata, Calif. 68 pp. Zucca, I I 1954. z^, study of the California Clapper Rail. Wasmann J. Biol. 12:135-153. 50 CALIFORNIA FISH AND GAMt NOTES ARCHAEOLOGICAL EVIDENCE CONCERNING THE PREHISTORIC OCCURRENCE OF SEA MAMMALS AT POINT BENNETT, SAN MIGUEL ISLAND Beyond their importance in assesssing the nature of human subsistence activi- ties, archaeological remains also can provide information concerning the biology of animal species utilized by prehistoric human populations. Faunal remains from archaeological sites on San Miguel Island are of particular importance in this respect since they are the only source of information currently available concerning the recent history of the exceptionally diverse assemblage of sea mammals which presently inhabit the island. The objective of this report is to provide data concerning the structure of the San Miguel sea mammal commu- nity prior to the decimation caused by the commercial fur trade of the 18th and 19th centuries. Data relating to the prehistoric abundance of seals, sea lions, and sea otters was obtained through an analysis of faunal remains recovered from archaeologi- cal excavations conducted by Charles Rozaire of the Natural History Museum of Los Angeles County (LACM) on San Miguel Island at the site SMI-525 (Ro- zaire 1965). This archaeological site is located directly above the present sea mammal rookery on the west end of San Miguel Island at Point Bennett. Two 5-ft^ pits were excavated in this stratified shell midden to a maximum depth of approximately 12 ft. Although no radio-carbon dates are available from the site, relative dating of artifacts recovered indicates that part of the deposit represents an occupation dating from at least 1000 years before the present. Although the duration of occupation is unknown, use of the portion of the site excavated by Rozaire apparently terminated before the historic period since no post-contact (16th century) artifacts were recovered. Osteological remains from SMI-525 were identified using comparative materi- al from LACM; the California Academy of Sciences; the University of California at Berkeley; the Santa Barbara Museum of Natural History; the United States Geological Survey, Menio Park; and the Department of Anthropology, Univer- sity of California at Santa Barbara. The minimum number of individuals from each stratum were computed by tabulating the most frequently occurring unique skeletal element for each species (Table 1 ). Whenever possible, individuals included in the count of minimum number of individuals were classified as adult or sub-adult (Table 2). Adults were distinguished from sub-adults using a variety of criteria which included extent of dental attrition, annular rings on the teeth, epiphyseal fusion, and long bone dimensions. Since there is selective retardation in the fusion of long bone epiphyses in sea mammals (Versaggi, pers. commun.), this criterion was used with considerable caution in the identification of adults. In general, if both proximal and distal epiphyses were securely attached to the diaphysis the indi- vidual was considered to be adult. Since faunal remains from SMI-525 are a product of human subsistence activ- ity, they cannot be considered an unbiased sample of the sea mammal popula- tions living prehistorically in the vicinity of San Miguel Island. NOTES 51 5 . — r^ rvi r^i ^ rsi < — rsi "O c 19 01 3 SO c IS c 0 -S 5 P I :3 I 0 rsi — o a. m I i ^- c ri ^ E 1 .^ '^ 'T V §^ S^ n E F-o fV c , ■i:; ?^ P "N -s '^. '-^ '^ ^■5 ■^ 0^ DC ~S: "^ ^ ■^ if c '2 ^*-^ ■- c ■^ ■^ " f c o^ .^^ 0; ^ "^ 0- H ^ ^ .3 ■§ x c t £ i it ca 1/) " ^ ::;> ^ _2 c ^ ^ ~5 T U o 5 o"^ !? "^ « ^ ^ < ^ ■^ -c^ i ^J '•^. ^ i ■i. C -L ■^ \i .2 1 3<^ N ~?5 ^ '^ w U) o .i^ ; ^ I r , — r*^. ■ — '-^jrv-i.-^. — rsjrsjrsj'"^' — •^' — ■ — ^— GO rsifVirs|fN»^ ' — '— * — ^— ^ — ^- I CO Tro^'^op'^OOf^oo'gro^P'^ooTO'^^oo ^^ w— r— % — w~ r~- r— w— ^ NOTES 53 Human selectivity in respect to species taken, age of selected animals, and cultural biases in processing prey species all influence the composition of ac- cumulations of faunal material in archaelogical sites. Biases in the composition of faunal assemblages, however, are not unique to archaeological proveniences. The skewing effects of predation, differential deposition, and variable preserva- tion also influence the distribution of animal remains from paleontological deposits which are not the product of human activity (Shotwell 1955). Despite uncertainties concerning sampling biases, faunal remains can yield useful infor- mation relating to the past distribution of animal species exploited by humans. Although all of the pinniped species currently utilizing San Miguel Island are represented in the site material, the relative frequency of certain species differs significantly from what would be predicted from their present abundance on the island. The remains of the Guadalupe fur seal, Arctocephalus townsendi, were more abundant than any other species recovered. This abundance is in sharp contrast to the present marginal status of the species on San Miguel Island which is a result of commercial sealing activities that reduced the species to a relict population centered around Guadalupe Island, Baja, California. DeLong (1975) reports that one female and several adult and sub-adult males have periodically appeared on Point Bennett since 1968. During 1973 and 1974, a single adult male secured a territory at Point Bennett, displacing California sea lions, Zaiophus californianus. The relative frequency of Arctocephalus remains at SM 1-525 is consistent with data from other archaeological proveniences in the Santa Bar- bara Channel area which indicates that Arctocepha/us was more abundant than any other pinniped species prior to European contact (Lyon 1937). The remains of California sea lions were more frequent in the site material than those of any other sea mammal except the Guadalupe fur seal. At present California sea lions are by far the most abundant pinniped on San Miguel Island. Although recent estimates place the islands total Zaiophus population at between 1 5,000 and 20,000 animals ( DeLong 1 975 ) , this abundance is a recent development which has resulted from an exponential increase in the size of the California sea lion populations in the Channel Islands since the 1930's (Bar- tholemew 1967). In contrast to California sea lions, the size of the Stellar sea lion, Eumetoplas jubata, population, which peaked at around 2000 individuals in the late 1930's on San Miguel Island, has been steadily decreasing during the past 30 years (Bartholomew 1967). At present the Eumetoplas population on San Miguel Island is composed of fewer than 100 animals (Bartholomew 1967; DeLong 1975). The relative frequencies of Zaiophus and Eumetoplas remains in the various levels of the SMI-525 excavations indicate that Eumetoplas'm the vicinity of San Miguel Island probably had a marginal status throughout a considerable portion of the Island's prehistoric occupation ( Table 1 ) . We feel that the relative frequencies of E. jubata ar\d Z. callfornlanus'm the deposit accurately reflect their past abundance for the following reasons: (i) At present, the terrestrial breeding periods of the two species nearly co-occur on the Point Bennett rookery; (ii) There is no ethnohistoric or archaeological evidence that Zaiophus vjas prefer- entially l^unted; and (iii) Steller sea lions are encountered infrequently in other prehistoric archaeological deposits from the Channel Islands (Lyon 1937). The remains of harbor seals, Phoco v/tullna; uorthem elephant seals, Mlroun- ga angustirostris; and northern fur seals, Callorhlnus ursinus, were infrequent in 54 CALIFORNIA FISH AND GAME the faunal remains trom SMI-525. The paucity of harbor seal remains is not unexpected since these animals often bear their young in the surf zone and have no extensive period of terrestrial breeding activity which would make them accessible to prehistoric hunters. Hunting difficulty probably does not account for the infrequetil occurrence of C. ursinus and M. angustirostris remains in the deposit. Both of these species experience extended periods of terrestrial breeding activity during which they are extremely susceptible to human predation. The fact that these animals are easily hunted is documented abundantly by the success of 1 8th and 1 9th century sealers (Scammon 1874). The remains of sea otters, Enhydra lutris, are nearly as abundant as those of California sea lions in the SMI-525 material. Early Spanish accounts indicate that prestige value was attached to sea otter pelts by the aboriginal inhabitants of the Channel Islands area (King 1971; Woodhouse, Cowen, and Wilcoxon 1976). This cultural factor may have resulted in relatively high levels of prehistoric sea otter exploitation. Because of this potential cultural bias, it is unlikely that the relative frequency of otter remains recovered accurately reflects the prehistoric abundance of the species. REFERENCES Bartholomew, George. 1967. Seal dnd sea lion populations of the California islands, \-i. 229-244. In Ralph N. Philbrick ed. Proc. of the symposium on the biology of the California islands. Santa Barbara Botanic Garden (Pub.), Santa Barbara, California. 363 p. DeLong, Robert. 197.5. San Miguel Island management plan. U.S. Mar. Mam. Comm., Unpub. Rep. King, Chester, 1971. Chumash inter-village economic exchange. The Indian Historian, 4 (1): 31-43. Lyon, C. M. 1937. Pinnipeds and a sea otter from the Point Mugu shell mound of California. Univ. Calif. Los Angeles, Publ. Biol. Sci., 1(8): 133-168. Rozaire, Charles 1965. Archaeological investigations on San Miguel Island U.S., Nat Park Serv , Unpub. Rep. Scammon, Charles. 1874. The marine mammals of the northwestern coast of North America lohn Carmany and Co., San Francisco, Calif 319 p Shotwell, |. Arnold. 1955. An approach to the paleoecology of mammals. Ecology, 36: 327-337. Woodhouse, Charles, Robert Cowen, and Larry Wilcoxon. 1976. A summary of knowledge of the sea otter Enhydra lutri<<, L., m California and an appraisal of the completeness of biological understanding of the species. Nat. Tech. Infor. Serv. Rep. P.B. 270-374. 71 p. Phillip L. Walker and Steven Craig, Department of Anthropology, University of California, Santa Barbara, California. Accepted for publication January 1977. AMBICOLORATION IN THE BLACK ABALONE, HALIOTIS CRACHERODII LEACH A review of the recent abalone literature suggests that the black abalone, hialiotis cracherodii Leach, 1817, is distinctive, showing variation to a lesser degree than other members of the family ( Cox 1 960, 1 962; Owens 1 961 ; Owens, McLean, and Meyer 1971; Talmadge 1955, 1977). There have been no reports of ambicoloration or morphological "odd-balls" in this species. Owens et al. (1971 ), who recognize 12 hybrids of southern California hialiotis, report that /-/. cracherodii is the only eastern Pacific member of this family not known to hybridize. , On October 1 5, 1975, a live hi. cracherodii, best dr<;cribed as albino or at least colorless, was collected intertidally by R. W. Richardson near Double Rock, San Luis Obispo County, California. The specimen (Figure 1 ), measuring 92 x 69 x NOTES 55 25 mm (shell dimensions) and weighing 132 g, varies from the species descrip- tion only in mantle coloration. FIGURE 1. Ventral view of ambicolored black abalone, showing a portion of foot, mantle, and epipodium. Photograph bv the author. In contrast with the normally smooth black body of H. cracherodii, the epipodium and mantle of this specimen were whitish to cream yellow. The eyes also lacked color. The only color on the external surface of the body was the dark appearance of the creases on the foot caused by accumulation of debris. Examination of the mantle cavity and viscera revealed normal coloration, and the specimen was found to be a female. The animal has been kept alive in aquaria at Pacific Gas and Electric Company's Diablo Canyon Biology Labora- tory. REFERENCES Cox, Keith W. 1960 Review of the abalone in California. Calif. Fish Came, 46(4): 381^06. 1962. California abalones, Family Haliotidae. Calif. Dept. Fish and Came, Fish Bull., (118): 1-133. Owen, Rodericks. 1961. Hybndization in western American haliotids. Amer. Malac. Union, Rep. for 1961, Bull., 28: 34 (abstract). Owens, Buzz, James H. McLean, and Richard j. Meyer. 1971. Hybridization in the Eastern Pacific abalones i~ H.iliotis) . Nat. Hist. Mus. Los Angeles Co., Bull., 9: 1-37. Talmadge, Robert Raymond. 1955. Variation factors in the Haliotis. Min. Conch. Club So. California., 148: 4-6. '977 Notes on a California hybrid Haliotis (Gastropoda: Haliotidae). Veliger, 20(1 ): 37-38. David W. Behrens, Pacific Cas and Electric Company, Biology Laboratory, P.O. Box 117, Avila Beach, CA 93424. Accepted tor publication January 1977. 56 CALIFORNIA FISH AND CAME EFFECTS OF A CALIFORNIA-DERIVED STRAIN OF TRICHOMONAS GALUNAE ON COLORADO BAND-TAILED PIGEONS Band-tailed pigeons ( Columba fasciata) are important and highly sought game birds in states of the Pacific Coast region (Jeffrey 1977). Two major populations exist north of Mexico, with the Interior race (C f. fasciata) occur- ring primarily in the states of Arizona, Colorado, New Mexico, and Utah, with the more abundant Coastal race (C /' monilis) occurring primarily west of the Sierra and Cascade crests in California, Oregon, Washington, and into south- western British Columbia (Braun, Brown, and Zapatka 1975). Outbreaks of trichomoniasis in band-tailed pigeons, caused by the protozoan flagellate Trichomonas galllnae, are poorly documented, with no naturally oc- curring deaths reported for the Interior race. Stabler and Herman ( 1951 ) docu- mented trichomoniasis in band-tailed pigeons from Monterey and Inyo counties in California in the late 1940's. Merton Rosen (Calif. Dept. of Fish and Game, pers. commun.) also verified the presence of trichomoniasis in band-tailed pigeons obtained from various localities in California over a period of years. Because of the apparently significant numbers of band-tailed pigeons found moribund or dead with suspected trichomoniasis within 160 km (100 miles) north and south of Pebble Beach, California, in 1974 and 1975 (personal com- munication from G. Gerdes, R. Gutierrez, M. Rosen, and the late F. John Ward), attempts were made to obtain specimens of pigeons with living T. gallinae to confirm the virulence of the particular strain. Through the efforts of F. John Ward we received a moribund band-tailed pigeon from Pebble Beach, California. Earlier papers (Stabler 1950, 1951; Stabler and Matteson 1950) reported on the incidence of T. gallinae in band-tailed pigeons in Colorado, while Sileo and Fitzhugh (1969) reported on the incidence of this parasite in bandtails from Arizona. More recently we ( Stabler and Braun 1 975 ) experimented with virulent strains of T. gallinae in captive band-tailed pigeons trapped in Colorado. METHODS Free-living wild band-tailed pigeons of the Interior race were trapped near Colorado Springs, Colorado. Trichomonads used were of the suspected virulent strain of T. gallinae isolated from the band-tailed pigeon from Pebble Beach, California. Inoculations were made directly from domestic pigeon carriers of this strain or from dead bandtails killed by it. Two Tnchomonas-negal'we bandtails were infected with a non\'irulent strain of T. gallinae from a domestic pigeon {Columba livia). Inoculations involved pipetting 5,000-1 0,000 flagellates into the recipients' mouths. Emtryl (Stabler and Kitzmiller 1967) was used to eliminate the trichomonads from a naturally infected bandtail. RESULTS AND DISCUSSION Trichomonas-negatwe band-tailed pigeons. Twelve bandtails (eight adults and four immatures) were inoculated from domestic pigeon reservoirs of the virulent trichomonad. The adults died on day 19 (av.) post-inoculation, the immatures on day 15 (av.). Four bandtails (two adult and two immatures) were inoculated from bandtails kilted by the virulent strain. The adults died on days 16 and 24, the immatures on days 4 and 16. NOTES 57 Tr^homon3S-pos'\t'\\/e band-tailed pigeons. Two adult bandtails infected with avirulent T. gcillinae of domestic pigeon origin were inoculated, the first with virulent flagellates from the reservoir pigeons, the second with trichomonads from a dead bandtail. The former died on day 10, the latter on day 11. Five bandtails with natural T. gallinde infections were variously inoculated with the virulent strain. Two adults given parasites from a dead bandtail died on days 11 and 13. One immature bandtail given virulent trichomonads from a domestic pigeon reservoir died on day 13. One positive adult, also inoculated from a domestic pigeon reservoir, was alive and well when sacrificed 34 days later. A naturally infected bandtail was cleared of its infection with Emtryl. Had this bird's parasites produced a premunitive state it should have shown some immu- nity. Given trichomonads from a dead bandtail, it died on day 8. It apf)ears that no matter whether the recipient bandtail was an adult or an immature, whether il was free of T. gallinae or was already infected, whether the virulent organism was derived from a domestic pigeon carrier or from the l)()dy of a dead bandtail, the Colorado race of the band-tailed pigeon is highly susceptible to a strain of T. gdllinae isolated from a moribund bandtail of the Coastal race from Pebble Beach, California. Obviously, the strain of T. gallinae present in some band-tailed pigeons in the Pebble Beach area of California in 1974-75 was virulent and could have caused the dead and moribund pigeons found throughout that area in that time interval. Because of the frequent reports of pigeons dead or dying in the Monterey region from suspected trichomoniasis over a long period (Stabler and Herman 1951; C. Gerdes, M. Rosen, and F. J. Ward, personal communications), and the importance of this region for migrat- ing and wintering band-tailed pigeons of the Coastal race, it would appear to be desirable to study further the role of T. gallinae as a mortality factor of this species. ACKNOWLEDGMENTS This study was supported in part by Colorado Federal Aid in Wildlife Restora- tion Project W-88-R. We acknowledge the encouragement and assistance in this project of the late F. John Ward of Pebble Beach, California. Without his persist- ance and willingness to cooperate this study would not have been possible. Merton Rosen and Gene Gerdes of the California Fish and Game Department provided useful information as did Ralph J. Gutierrez of the University of Califor- nia, Berkeley. Nancy J. Kitzmiller, Colorado College, and Howard D. Funk, Colorado Division of Wildlife, critically reviewed the manuscript in its early stages. The assistance of all these individuals is appreciated. REFERENCES Brdun, C. E.. D. E Brown, ). D. Pederson, and T. P. Zapatka. 1975. Results of the Four Corners Cooperative Band-tailed Pigeon Investigation. U.S. Fish and Wildl. Serv. Resource Publ. 126. 20p. lellrev, R. G 1977. Band-tailed pigeon (Columb^i f.isciats) . p 208-245. In C C. Sanderson ed. Management of migratorv shore and upland game birds in North America. Intl. Assoc. Fish and Wildl. Agencies, Washing- ton, DC. 358p. Sileo, L. Jr., and E. L. Fitzhugh. 1969. Incidence of trichomoniasis in the band-tailed pigeons of southern Arizona. Bull Wildl. Dis. Assoc, 5(3): 146. Stabler R M. 1950. r/-/r/?omo/?.w _^a///>7,^e In columbid birds in Colorado. ). Colo. -Wyo. Acad. Sci., 4(2 ): 83. 58 CALIFORNIA FISH AND CAME __^_. 1951. A survey of Colorado band-tailed pigeons, nnourning doves, and wild common pigeons for Trichomonas gdllinae. ]. Parasil., 37(51: 471-472 Stabler, R. M., and C. E. Braun. 1975. Effect of virulent Trichomoncis g.illincU'on the band-tailed pigeon. |. Wild! Dis., 11(4); 482-483. Stabler, R. M , and C. M. Herman 1951. Upper digestive tract trichomoniasis in mourning doves and other birds. Trans. N. Am. Wildl. Conf., 16: 145-162. Stabler, R. M., and N. ). Kitzmiller 1967 Emlryl in the treatment of trichomoniasis in pigeons and hawks. ). N. Am. Falconer's Assn., 6(1 ): 47-49 Stabler, R. M., and C. P. Vlatteson. 1950 Incidence of Tnchomon,!', g,i//in,ie in Colorado mourning doves and band-tailed pigeons. |. Parasit., 36(61: 25-26. Robert M. Stabler, Colorado College, Colorado Springs, Colorado, 80903 and Clait E. Braun, Colorado Division of Wildlife, Fort Collins, Colorado 80522. Accepted for publication July 1977. A SIMPLE, RAPID METHOD FOR MARKING INDIVIDUAL SEA URCHINS INTRODUCTION The importance of the sea urchin, Strongylocentrotus spp, in the ecology of the southern California kelp bed community (Jones, Leighton, and North 1966; Paine and Vadas 1969) has prompted the development of tagging techniques for long-term population studies. Various spine tags have been used for short peri- ods (Sinclair 1959; Vacquier 1964), but tag life is limited to a few weeks. Further, the manipulative difficulty of in situ tagging techniques (Lees 1968) led to a search for a more rapid and efficient procedure. The method described herein proved to be fast, easy, inexpensive, and did not require that sea urchins be removed from their rocky substratum. The core of the method is a textile marker tag made of nylon. Thorson ( 1967) reported the use of such tags to mark fish, and his report should be consulted for a description of the tags and applicator. The technique presented here utilizes similar equipment to bore a hole in the test and to anchor the tag by fixing it in place with a silicone rubber seat. The tag bears a vinyl disc marked with an identification number (Figure 1). MATERIALS AND METHODS Three-inch nylon tags, common in the textile industry, were used. The un- modified tags were one-piece, consisting of a tab and a "T" bar joined by a long, thin shaft (Figure 1 ). A "Swiftacher" ^ tagging gun (applicator), "Swiftachment fasteners" (tags), and tagging needles were purchased from Dennison Eastman Corporation. The index finger grip on the handle of the tagging gun was removed to minimize spine contact during the tagging procedure. Tags were prepared in groups of no more than 10 to facilitate handling and to prevent tangling while tagging. A lead fishing sinker, size "BB," was crimped tightly midway on the shaft of each tag. A small conical seat made of RTV 108 (General Electric silicone sealant) was formed beneath each sinker and dusted with powdered calcium carbonate to facilitate tag handling while curing. Tags were numbered with round plastic identification discs, 2.5 cm (1 inch) in diameter, constructed of 0.05-cm (0.02-inch) white "matte vinyl." Identifying ' Use of trade names does not constitute endorsement NOTES 59 numbers were drawn on both sides of the disc with a black permanent marker (Sanford's "Sharpie," No. 3000). Then, a thin coat of clear RTV 108 was smeared on the disc to limit algal growth and marker fade. The tab was folded and inserted through a 4-mm (0.16-inch) off-center hole in the disc, stringing the disc on the tag shaft. FIGURE 1. Sea urchin tag in position in the test. The components of the tag are (A) tab; (B) identification disc; (C) shaft; (D) lead sinker; (E) RTV silicone seat; (F) "T" bar; (C) sea urchin's test. The sinker is in position 1 before tagging, and as shown, in position 2 after tagging. The tag is attached to the urchin by placing the tagging needle against the urchin and, while applying light pressure, rotating the gun back and forth through an angle of about 90° with a drilling motion until the test is perforated (Figure 2). Internal scar tissue formed most readily around the "T" bar when the sea urchin was tagged at the ambulacral-interambulacral plate interface. With care, needles last through 50 taggings. Pressure must be maintained against the urchin w hile the tag is being inserted or the gun will be forced away from the hole. The actuating level on the tagging gun should be kept depressed while the gun is withdrawn. The tag is then pulled tight, away from the urchin, while needle-nose pliers are used to slide the sinker and the silicone rubber seat down the shaft against the urchin, thereby sealing the hole and pinning the tag in place. Minimal spine damage may occur during tagging. An effort was made to place the tag as far from the oral-aboral axis of the urchin as was possible without moving the urchin. 60 CALIFORNIA FISH AND GAME FIGURE 2. Tagging Strongvlocentrotus franciscanwi in situ. The tagging needle has penetrated the sea urchins test and depression of the actuating level will insert the tag. Note the tagged sea urchin in left foreground. Photo by Fred Fischer. RESULTS AND DISCUSSION We tagged 150 giant red sea urchins, Strongvlocentrotus franciscanus, in January 1976, off La Jolla, California (Figure 3). We employed a tagging rate of one sea urchin every 2 min and at a tag cost of less than five cents per urchin. Reobservation data were collected on 40 sea urchins. All data points in the graph were derived from actual observations within the test area; hence some sea urchins were not accounted for owing to movement from the test area or unrecovered fatalities. Test recalcification in the area of the tag was not observed in any of the sea urchins tagged by this method. However, one sea urchin, tagged without an identification disc, was removed months after tagging with no apparent ill ef- fects. Many urchins showed signs of test decalcification or thinning in the vicinity NOTES 61 of the "T" bar. One urchin lost its tag in this manner after 9 months and appeared to be recovering when collected for study. O 5 100- d 90- Q_ o 80h ^ 70 i 60 S2 50 cr. o 40- ^30- co 20- W 10- ^ 0 o Reobserved • Cumulative Mortality 12 3 4 5 6 MONTHS FIGURE 3. Percentage survival and mortality of 40 sea urchins tagged January 1976. Higher recovery figures may be obtained if fish predation on tagged sea urchins can be reduced. Several tags have been found lying free of any sea urchin's test with tooth marks on the identification discs and with bent "T" bars. We attribute these losses to sheephead, Pimelometopon pulchrum, biting and pulling the tags from the sea urchin's test. Plastic fluorescent pink streamers were attached to some tags to aid in relocation, but we observed that these were soon shredded and lost to garibaldi, Hypsypops rubicunda. To eliminate this fish- inflicted mortality, shorter tags with green identification discs are being evaluat- ed. The short tag shaft should keep the identification discs lower among the spines and protect it from sheephead and other curious fishes. ACKNOWLEDGMENTS We gratefully acknowledge Bert Kobavashi for his valuable advice, instruc- tion, and generous time offered during the course of this study. Also, we are grateful to the numerous University of California, San Diego, scuba divers who donated much of the phvsical effort underwater necessary for the completion of our project. This project was supported by a University of California Presi- dent's Fellowship. 62 CALIFORNIA FISH AND CAME REFERENCES lones, L. C, D. L. Leighlon, and W. ). North 1960 Ecological relalionshifis belween giant kelp and sea urchins in southern California, p 141 1 S3, In E. G. Young and | L. McLachlan Eds, Int. Seaweed Symiiosium, Sth, Proc, Pergamon Press, London. Lees, D. C. 1968. Tagging subtidal echinoderms Underwater naturalist, 5(31: 16-19. Paine, R T., and R. L. Vadas. 1969. The effects of grazing by sea urchins, SlrongylocentrolW' spp., on benthic algal populations. Limnol. and Oceanogr., 14(5): 710-719. Sinclair, A. N. 1959. Observations on the behavior of sea urchins Aust. Must. Mag., 13(1): 3-8. Thorson, K. N, 1967, A new high-speed tagging device, Calif, Fish Came, 53(4): 289-292. V'acquier, V. 1964. Kelp habitat improvement project. Calif. Inst. Tech., Ann. Rep , 1964-1965: 55-57. Mark Olsson and Gerald Newton, University of California, San Diego, La folia, CA 92093. Accepted for publication July 1977. FOOD HABITS OF SQUIRRELFISH, ADIORYX SUBORBITALIS, IN THE GULF OF CALIFORNIA The squirreltish, Adioryx suborbitalis ( Berycitormes: Holocentridae), which ranges from the central Gulf of California to Ecuador and the Galapagos Islands (Thomson and McKibbin 1976), is reported to be a nocturnal feeder that forages mainly on small crustaceans (EHobson 1968; Thomson and McKibbin 1976). In an effort to characterize more fully the food habits of this species, we speared 12 specimens in the Gulf of California along the coast of Baja California Sur, between Loreto and Cabo Pulmo, during July and August 1976. The fish ranged from 160 to 245 mm (6.3 to 9.7 inches) total length (tl). We did not measure food volumes, but counted only the numbers of recognizable, individual prey items in the stomachs. All fish were taken shortly after sunrise (0600 to 0800 hr), when their stomachs were full and digestion had not yet rendered the contents unrecognizable. We found these fish congregated in groups of 10 to 40 in crevices under rocks during early daylight hours. Crabs, primarily brachyurans, were the dominant food type in all but the smallest (160 mm tl) individual which had eaten four small sergeant majors, Abudefduf troschelii, and two shrimps (Table 1 ) . Other food items were amphi- pods, shrimps, gastropod molluscs, isopods, and fish. Two stomachs contained fish bones and one contained a 6-mm long bivalve mollusc shell and one sea urchin spine which could have been picked up with the crabs. Altogether, crustaceans comprised 93.7% of the total stomach contents, confirming Hob- son's (1968) general observation. Although these fish sometimes were observed to make forays from their rock lairs during daylight hours, but seldom in direct sunlight, no feeding was observed during the day, thus confirming their nocturnal foraging behavior. The presence of fish and gastropods in some stomachs, as possibly the bivalve mollusc and sea urchin sprine, indicates an opportunistic component in food selection of squirrelfish. The temporal pattern of nocturnal feeding and diurnal occupation of rock crevices is diametrically opposed to the habits of the diurnal substrate-feeding angelfishes Pomacanthus zonipectus an^ Holacanthus passer (Reynolds 1977; Reynolds and Reynolds 1977) which are sumpatric with A. suborbitalis. Competition among these species is an example of temporal resource partitioning. Competition is for space rather than for food because angelfishes feed largely on sponges. NOTES 63 U 3 (J c 0^ 3 O E o :5 "5 I E o •a c 3 o E it •a o o Q. >^ C »0 E 3 Z OD i -31 I 5 -§ ^ It I I 1 si ^ -c -c ^ HI > > o o .— O r^ — I r^ O^ »— »— rv| 1 — I r^ CO rsiOOOO -^OLnoOvDrMiCTNLn OOOCOO OOOOOOOICO — \D t^ CO o^ r^rocor^LTiO^^I^^ :::::■!::::: : S :::::•:::::: : "O :::::::::::: • c :::::::::::: : 3 :::::::::::: : ^ :::::•:::::: : j; ;:::::::.... tn : : : : : ::::::; j£ en: ""•■■•■ rn . orMr\or~-oQi-nLni^LntJ^ tso Ol^oOCra^OO — rvirornT 0-? , — , — t— 1 — 1 — rNirMrs4rsrsi(^rsl \— Z- 64 CALIFORNIA FISH AND GAME ACKNOWLEDGMENTS We thank Nicholas P. Yensen, Richard Schmidt, ancJ [Ronald A. Thomson for encouragement and helpful assistance. REFERENCES Hobson, E S. 1968. Preddlory behavior of '.nmc ^hnrc fishe<. In the Cult of Callfornid. Bur. Sport Fish. Wildlife Res., Rep. (No. 73): 1-92. Reynolds, W. VV. 1977 Substrate feeders and facultative cleaners: cleaning behaviour in some Gulf of California marine animals. Anim. Behav., 25: 1063. Revnolds, VV. W , and L. |. Revnolds. 1977. Observations on food habits of the angelfishes Pom.u.wlhus zonipiKtus and Hol.Ucinthw, passer \n the Gulf of California Calif. Fish Game, 63(2): 124-125. Thomson, D. A., and N. McKibbm. 1976. Gulf of California fishwatcher's guide. Golden Puffer Press, Tucson. 75 p. James K. Matthey and William W. Reynolds, Department of Biology, The Penn- sylvania State University, P.O. Box 1830, Wilkes-Barre, Pennsvlvania 18708. Accepted for publication November 1977. Pbotnolcctroiiic conipmilinn by ("\l.l|.OR\l\ (IHK > Oh ST\TK PHI\TI\(; 7818.T — 800 8-7H 4,.5(K) LD.^ INSTRUCTIONS TO AUTHORS EDITORIAL POLICY The editorial staff will consider for publiention orifrinal articles and notes dealing with the conservation of the fauna and flora of California and its adjacent ocean waters. 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