Historic, archived document Do not assume content reflects current scientific knowledge, policies, or practices. UNITED STATES DEPARTMENT OF AGRICULTURE BULLETIN No. 720 — pe Contribution from the Bureau of Biological Survey HE. W. NELSON, Chief Washington, D. C. PROFESSIONAL PAPER: December 23, 1918 FOOD HABITS OF THE MALLARD DUCKS OF THE UNITED STATES By W. L. MCATEE, Assistant Biologist CONTENTS Introduciion Southern Black Duck 5 Mallard : ‘2 | Items of Vegetable Food Identified . . Black Duek 10 | Items of Animal Food Identified ... WASHINGTON GOVERNMENT PRINTING. OFFICE * my : Cemee | e ;: Oe tale 2 : z . x & Pore a - Ps 5 = 4 : . a ¥ i t a ‘ P “1 Fro Mi Z = Bs ¥ . oe i 3 q PLATE I. Bul. 720, U. S. Dept. of Agriculture. Wo6olla tysory, 218 @ by Lay ‘sopeuroy ‘toddn ‘{sopeur ‘sornsy 10Mory ‘sMOnNg Mov1g GNv auvTIv UNITED STATES DEPARTMENT OF AGRICULTURE Contribution from the Bureau of Biological Survey. E. W. NELSON, Chief. Washington, D. C. PROFESSIONAL PAPER. December 23, 1918 FOOD HABITS OF THE MALLARD DUCKS OF THE UNITED STATES. By W. L. McAtee, Assistant Biologist. CONTENTS. Page. Page. PRtLOGUCHION -s oes anes epee a a aa ee ace f |S Southern' black @uck-2 2... .Sccdeccanasceccce 14 Ic EEUT Ey Bee eae ape Tee 2 SS ee 2 | Items of vegetable food identified. .....__...- 16 iBigek GUCK= - =e eee ee eee ase ee 10 | Items of animal food identified___-_________. 24 a INTRODUCTION. A knowledge of the natural feeding habits of mallard ducks is of value in connection with the propagation of the species in a semi- domesticated condition, as these ducks are used more commonly for this purpose than are any others. It is especially useful also in rela- tion to the improvement of bodies of water and marshes as feeding grounds for wild ducks.* The wild ducks ordinarily occurring within the United States are at present considered to represent 39 species, distributed among 22 genera. They are divided into three groups: The mergansers (Merginz), known also as fish ducks, or sawbills; the river ducks (Anatine), also called shoal-water, puddle, or tipping ducks; and the sea ducks (Fuliguline), also called deep-water, or diving ducks. Although food preferences vary in each of these groups, those of the mallards are fairly representative of their group—the river ducks. The mallard genus, Anas, comprises three species which are among 1 For specific information on this topic see Bull. 205, U. S. Dept. Agr., Eleven Important Wild-Duck Foods, in which are discussed musk grass, duckweeds, frogbit, thalia, water elm, swamp privet, e@igrass, widgeon-grass, watercress, waterweed, and coontail: pp. 25, figs. 23, May 20, 1915; also Bull. 465, Propaga- tion of Wild-Duck Foods, in which are discussed wild rice, wild celery. pondweeds, delta potato, wapato, chufa, wild millet, and banana waterlily; pp. 40, figs 35, Feoruary 23, 1917. Note.—This bulletin presents a technical study of the food habits of three species of mallard ducks: The mallard, the black duck, and the southern black duck. The vegetable food preferences exhibited will serve as a guide to certain wild-duck foods that may be propagated when it is sought to increase the numbers of - these valuable game ducks, either in the wild state or in domestication. 64336°—18—Bull. 720——1 2 BULLETIN 720, U. S. DEPARTMENT OF AGRICULTURE. our most valuable game ducks and includes the most important single species—the common mallard (Anas platyrhyncha). The others are the dusky or black duck (Anas rubripes) and the southern black duck (Anas fulvigula). These river ducks rarely dive so as to disappear entirely beneath the water, but obtain their food in shallows by dipping the head and neck or by submerging all of the body but the tipped-up tail. Vigor- ous paddling with the feet is needed to maintain the latter position in the water. The food usually is obtained within 12 to 16 inches of the surface, and as a result river ducks obtain fewer of the under- ground organs of aquatic plants than the diving ducks. These root systems of the plants include the rootstocks, stolons, tubers, and winter buds, which are stocked richly with nutriment. However, the river ducks wax fat by their own way of living, and although they are distinctly successful foragers, expediency seems to be their rule, as they are more nearly omnivorous than any other ducks. MALLARD. (Anas platyrhyncha.) The mallard (see frontispiece) probably is the most abundant wild duck in the world, and its range covers the entire northern portion of the earth. Wherever it occurs it is popular and is usually the favorite waterfowl. Various races have claimed it for their own, and in consequence it has received such names as English duck and canard francais (French duck). Other common names are wild duck, green- head, gray mallard, and stock duck. The last name refers to the fact that the mallard is the source of most of the breeds of domesti- cated ducks. That it is possible under controlled conditions to pro- duce mallards typically wild both in appearance and behavior has been taken advantage of on duck farms, where birds are reared both for market and sport. The ease with which the mallard can be bred makes it the best species for wild-duck farming. This is an industry which should be developed as extensively as possible, in order to supplement the de- creasing natural supply of game. ‘The mallard is not only susceptible of great increase by game farming, but also may very easily be assisted to increase in the wild state. Its breeding range is so extensive that, at least in the northern half of the United States, where local con- ditions are suitable, strict protection throughout the spring almost certainly will induce it to nest. Its beauty and popularity, hardiness, adaptability, and fecundity fit the mallard as no other duck is fitted to be the game duck of the future. Upon it should be centered a large share of the interest in duck farming and wild-fowl protection. Whatever is learned about FOOD HABITS OF MALLARD DUCKS. 3 increasing the numbers of the mallard and whatever is done to protect and preserve it undoubtedly va prove of benefit to many other piece: of wild ducks. FOOD HABITS. A total of 1,725 gizzards of the mallard, many of them accompa- nied by well-filled gullets, have been examined. Twenty-five were collected in April, August, and September, but not being enough fairly to represent the food in these months were not tabu- lated. One hundred and forty-seven stomachs were examined ! after ascertaining the percentages, which as quoted in the following pages are derived from analyses of the contents of 1,578 stomachs. These were collected in 22 States and in 2 Canadian Provinces. Louisiana is much more heavily represented than any other State, with Arkansas, Wisconsin, Texas, and Florida next in rank in the order named. The over-representation of Louisiana and Arkansas tends to give undue importance to the duck foods common in those States. This is especially noticeable with regard to products of plants of cypress swamps. Some of the stomachs of mallards were interesting on account of the large numbers of individual objects they contained. For in- stance, one collected at Hamburg, La., in February, revealed about 28,160 seeds of a bulrush (Scirpus cubensis), 8,700 of another sedge (Cyperus ferax), 35,840 of primrose willow (Jussixa sp.), and about 2,560 duckweeds (Lemna sp.) as the principal items, a total of more chem 75,200. Another stomach collected at the same locality in December con- tained no fewer than 102,400 seeds of primrose willow (Jussixa lepto- carpa), besides a number of other items in smaller numbers. The seeds in this stomach if sowed one in a place and a foot apart each way would suffice for 24 acres of ground. About one-tenth (9.47 per cent) of the food of the mallard is derived from the animal kingdom and nine-tenths from the vegetable. VEGETABLE Foon. Approximately nine-tenths (90.53 per cent) of the entire con- tents of the 1,578 mallard stomachs examined was derived from the vegetable kingdom. The largest proportion of the food drawn from any single family of plants came from the sedges and amounted to 21.62 per cent of the total. Grasses rank next in importance, supplying 13.39 per cent; then follow smartweeds, 9.83; pondweeds, 8.23; duckweeds, 6.01; coontail, 5.97; wild celery and its allies, 4.26; water elm and hackberries, 4.11; wapato and its allies, 3.54; and acorns 2.34 percent. “Numerous minor items make up the remainder. 1By E. G. Holt and D. C. Mabbott. + BULLETIN 720, U. S. DEPARTMENT OF AGRICULTURE. SEDGES (21.62 PER CENT). Practically all the sedges contribute to the diet of the mallard. Their fruits, or akenes (the seeds with their immediately investing coats), are of most importance, although the stems, leaves, root- stocks, and tubers also are eaten. Seeds or other parts of bulrushes were found in the greatest number of stomachs. Unidentified bul-. _ rush seeds occurred in 540 gizzards, from 400 to 1,200 in some. The akenes of river bulrush (Scirpus fluviatilis) were identified in 45 stomachs, and those of Scirpus cubensis in 286. No fewer than 28,160 akenes of the latter species were obtained from the crop and gizzard of a single mallard. Akenes of sedges of the genus Fim- bristylis occurred in 279 stomachs, the largest number in any one being 1,000. Eighty-seven hundred seeds of a Cyperus were taken from a single gizzard; tubers of these sedges also were found. Saw grass (Cladium) is rather important among the sedges fed upon by the mallard, and its seeds were identified in 246 stomachs, 1,100 © being the largest number found. GRASSES (13.39 PER CENT). Wild rice (Zizania aquatica) is the most important of the grasses fed upon by the mallard. The value of this plant as a duck food is not exaggerated in popular opinion, and it is unfortunate that the plant is almost as erratic and disappointing in its responses to attempts at propagation as it is valuable as a duck food in the places it chooses to grow. Wild rice was found in 91 of the stomachs examined for this report, and no fewer than 1,200 to 2,400 kernels had been devoured by single birds. The kernels are sometimes taken in sprouting condition, and the leaves of the plant occasionally are eaten. Among the more important of other wild grasses represented in the diet are: Wild millet (Hchinochloa crus-galli), switch and crab grasses ~ (Panicum), rice cut grass (Homalocenchrus), salt-marsh grass (Spar- tina), and white marsh or cut grass (Zizaniopsis). Grain, which is largely produced by plants of the grass family, may best be considered in the present connection. Oats, corn, barley, wheat, buckwheat, and rice were found and together consti- tute 2.99 per cent of the totalfood. Rice only was certainly gleaned by the birds from cultivated fields and all of it was waste. Mallards eagerly feed on rice in the shock when opportunity occurs. Thus in 1917, when various factors delayed harvesting until the arrival of wild ducks from the north, mallards destroyed about $35,000 worth of rice in the vicinity of De Witt and Stuttgart, Ark. Probably all the other grains found in the stomachs of the birds examined were put out as bait for the birds. This is not to say that mal- lards do not feed in grain fields, for they are well known to do so. FOOD HABITS OF MALLARD DUCKS. 5 For instance, Kumlien and Hollister’ state that large numbers of mallards wintering on the prairies of Wisconsin feed chiefly im the cornfields. In Manitoba’ they are said to feed in wheat and barley stubble, rapidly becoming fat. It has been said that mallards at times are destructive to sprouting grain, but this is hardly true. Even if mallards did feed extensively upon sprouting erain, little if any harm would result, as they would only nip off the leaves, not dig up the grain. SMARTWEEDS (9.83 PER CENT). The seeds of smartweeds are produced abundantly in wet situa- tions. Well filled with nutritious material, it is no wonder they are a favorite with wild ducks. The seeds of 13 species of smartweeds have been identified from stomachs of the mallard, besides buck- wheat, Brunnchia, and dock, which belong to the same family. A mallard collected at a locality where buckwheat was used for bait had about 750 of the large akenes in its crop and gizzard. A smart- weed with a prickly four-angled stem and arrow-shaped leaves (Po- lygonum sagittatum) is a favorite with mallards. Its seeds were identified in 107 stomachs, as many as 2,000 being found in one. No fewer than 4,500 seeds of the water pepper (Polygonum hydropiper) were taken from the crop and gizzard of another mallard. PONDWEEDS (8.23 PER CENT). The pondweed family is important to almost all ducks. These submerged plants are abundant and widespread, usually produce a good crop of seeds, and often have fleshy rootstocks and foliage which are wholly edible. Seeds of pondweeds, not further identified, were found in 431 mallard stomachs, up to 560 in number in a single instance. Remains of six species of the genus Potamogeton were found during the analyses. The most important species for the mallard as well as for other ducks is the sago pondweed (Pota- mogeton pectinatus), of which stems, foliage, seeds, rootstocks, and tubers all were eaten. Among other plants of this family, widgeon- grass (Ruppia maritima) was found in 72 gizzards and bushy pond- weed (Naias flexilis) in 67. No fewer than 5,500 seeds of eelgrass (Zostera marina), a salt-water representative of the family, were found in a single mallard’s stomach. DUCKWEEDS (6.01 PER CENT) AND COONTAIL (5.97 PER CENT). Duckweeds (Lemnacex) thickly cover the surface of the water in southern swamps, and coontail (Ceratophyllum demersum) fills the water beneath. Both contribute materially to the subsistence of 1 Bull. Wisconsin Nat. Hist. Soc., III, Nos. 1-3, p. 17, 1903. 2 Proc. U.S. Nat. Mus., XIIT, 1890, p. 476. 6 BULLETIN 720, U. S. DEPARTMENT OF AGRICULTURE. mallards frequenting their home. The former were found in about 300 of the mallard stomachs examined, and there were thousands in some of them. Coontail was found in 669 stomachs. The leaves of the plant as well as the seeds are eaten. The largest number of seeds found in any one gizzard was 150. WILD CELERY AND ITS ALLIES (4.26 PER CENT). Wild celery (Vallisneria spiralis) is well known for its value as a wild-duck food. It is most important to the diving ducks, which are able to feed on the rootstocks and buds, but shoalwater ducks occasionally obtain these parts of the plant.and in the proper season can feed at will on the leaves. Thirty-eight of the mallards exam- ined had fed on wild celery and 135 upon the seeds of a related plant, frogbit (Limnobium spongia). Another plant of the same family, waterweed (Philotria), was found in small quantity im only two stomachs. | WAPATO AND ITS ALLIES (3.54 PER CENT). Wapato belongs to the family of arrowheads, many of which have large and nutritious tubers. The mallard is not particularly adapted to get food requiring such strenuous digging, but nevertheless man- ages to obtain a share of the coveted, tubers where they are abun- dant. From 6 to 8 tubers of the delta potato (Sagittaria platyphylla) were taken at a single meal by some of the birds, as were no fewer than 11 tubers of another species of Sagittaria. Tubers, stems, and seeds of Sagittaria were found in more than a hundred stomachs, and seeds of the related water plantain (Alisma) in three. SEEDS OF TREES AND SHRUBS. Where trees and shrubs bearing nutritious fruits are so situated that their products fall into the water, they sometimes become an important source of wild-duck food. Those most important to the mallard are trees of the elm and oak families. The water elm (Planera aquatica), a common tree of southern swamps, has large nutritious seeds which remain for months in a pertect state of pres- ervation in the water into which they fall. There they are found and eagerly devoured by wild ducks. One hundred and fifty-nine of the mallards examined had fed upon these seeds, no fewer than 200 of them being taken by a single duck. The seeds of hackberry (Celtis), a tree also of the elm family, were found in 46 stomachs; and altogether seeds of plants of this family com poss 4.11 per cent of the total food of the mallards examined. The next largest item of mallard food produced by trees is acorns. These were found in 37 stomachs and form 2.34 per cent of the whole subsistence. Mallards sometimes resort in flocks to woods where FOOD HABITS OF MALLARD DUCKS. a they can obtain acorns, and occasionally a bird takes so many that it is unable to fly. In connection with acorns it is appropriate to mention hickory nuts, contained in 96 mallard gizzards. These hard nuts might be thought beyond the powers of a duck to digest, but, on the contrary, they are taken care of with ease, being broken by the great pressure exerted by the gizzard as they are on the point of entering that organ. Once wholly within they quickly are ground to fine fragments. Seeds of buttonbush (Cephalanthus occidentalis), a crooked, stiff- branched shrub of swamps, were taken from the gizzards of 428 mallards. Hundreds of them were present in some stomachs. They compose 1.76 per cent of the food. Buttonbush and the — water elm find a congenial home in cypress swamps, and in these swamps tree-borne seeds, or mast, are an 1mportant element of duck food. The cypress itself contributes to this supply in two ways. The rounded cones or balls of the cypress after falling into the water separate into their constituent scales, which are of a size convenient for ducks to swallow. Such scales were found in 113 of the mallard stomachs examined. On the twigs and leaves of cypress grow a number of kinds of galls. These are deformations of the plant caused by the deposition ot gallfly eggs and the subsequent feeding and growth of the larve. Some of those on cypresses are beautiful both in shape and color, simulating flowers. They were eaten by 60 of the ducks examined and together with cypress scales or seeds com- pose 1.33 per cent of the total diet. Among other noteworthy articles of food derived from woody plants are grape seeds, found in 339 stomachs, those of redhaws in 184, poison ivy in 96, hollies in 80, the chmbing bamboo vine, supple jack, or black jack in 60, dogwoods in 51, willow capsules in 32, Styrax in 30, bayberries in 35, swamp privet in 26, and tupelo or Swamp gum in 24. MISCELLANEOUS VEGETABLE FOOD. Additional items of vegetable food that deserve special mention are the waterlilies, waterpennies, and heliotrope. Of the waterlilies, seeds of water shield (Brasenia) were found in 70 stomachs, and of the floating waterlilies (Castalia) in 27. All the waterlilies together constitute a little less than 1 per cent of the food. Seeds of water- penny (Hydrocotyle) were taken from 226 gizzards and make up 1.39 per cent of the subsistence. Seeds of a heliotrope (Heliotropium andicum), a plant introduced from India, are a curious item found in a large number (104) of mallard stomachs. On the average, how- ever, they form but a slight percentage of the food. Other plant foods of interest and.of some importance are alge, including musk grass (Chara); seeds of pickerel weed (Pontederia . g BULLETIN 720, U. S. DEPARTMENT OF AGRICULTURE. cordata); of thalia, a plant related to the cannas; of saltbush, water crowtoots, water milfoil, and mermaid weed; water hemlock; and of Spanish needle, pr bur marigold. Anrwat Foon. The animal food of the mallard duck though extremely varied may be classed in five main groups: Insects, which constitute 2.67 per cent of the total diet; crustaceans, 0.35; mollusks, 5.73; fishes, 0.47; and miscellaneous, 0.25 per cent. INSECTS (2.67 PER CENT). The mallard’s attentions to insects are divided about equally among beetles, bugs, and dragonflies, which together constitute 1.4 per cent of the total diet. All other insects make up 1.27 per cent. As would be expected, the beetles eaten are mostly denizens of the water. They include among others both larve and adults of the crawling water beetles (Haliplide), small spotted beetles, most often seen among alge and other aquatic plants. Twenty different kinds of predacious diving beetles (Dytiscide) also were identified, both adults and larve being taken. The latter, so voracious that they have earned the name water tigers, are very destructive to other water-dwelling creatures and are a pest in fish ponds. Two partly predacious groups, the water scavenger beetles (Hydrophilide) and the whirligig beetles (Gyrinidz) also are preyed upon by the mallard. Among other beetles included in the dietary are ground beetles (Carabidz), which are chiefly useful; and leaf beetles (Chrysome- lide) and weevils, which are injurious. Of the leaf beetles, a group (Donacia) occurring in the mallard’s habitat, and naturally fed upon, live upon waterlilies. The adults rest on lily pads or skip about on the water surface; the larve live in tough cocoons on the lily stems, from which they secure both food and oxygen. One of the weevils identified in the food is the rice water weevil, a pest to cultivated rice. The bugs (Hemiptera) eaten by the mallard are practically all aquatic forms. They include water boatmen (Corixide), hundreds of which have been found in a single stomach; back-swimmers (Notonectide), water scorpions (Nepide), giant water bugs (Belos- tomatide), creeping water bugs (Naucoride), and water striders (Veliide and Gerridz). All these bugs are predacious, but whether they do more good than harm is a question, as many of them prey upon small fishes. Besides the Hemiptera already mentioned, a variety of other bugs occasionally are devoured by the mallard. Dragonflies, or snake-feeders, are active and expert insects on the wing, but in the younger stages they live in the water, where many of them fall a prey to the mallard. No fewer than 100 dragonfly nymphs have been found in one mallard’s gizzard, and from 30 to 40 © | — =a = of ‘ rae! =e. = bP ies cae i A ie De hs ee abies Aes i ete At ds ia cid sty * ‘ twits ods ther FOOD HABITS OF MALLARD DUCKS. 5 in others. Adult dragonflies were found in only one stomach. These insects prey upon mosquitoes, but their nymphs destroy young fish also, so that on the whole they are of no pronounced economic benefit. Most of the other insects eaten by the mallard are more or less aquatic in habits. For instance, the flies (Diptera) eaten are chiefly those having aquatic larve, and it is the larve that are usually obtained. ‘These include craneflies, mosquitoes, gnats, horseflies, soldierflies and flowerflies. Seven adult mosquitoes (Culex restuans) were found in one mallard’s gizzard. Dr. Samuel G. Dixon, Health Commissioner of Pennsylvania, commends the mosquito-destroying capacity of the mallard. He writes: ! After trying the ability of fish to devour larvee and pup of mosquitoes, with varied success, I built two dams near together on the same stream, so that each would have the same environment for the breeding of mosquitoes. Each covered nearly 1,400 square feet. In one twenty mallard ducks, Anas platyrhyncha, were permitted to feed, while the other was entirely protected from waterfowl, but well stocked with goldfish, Carassius auratus, variety americanus. The one in which the ducks fed was for several months entirely free from mosquitoes, while the pond protected from ducks and stocked with fish was swarming with young insects in different cycles of life. To the infested pond ten well-fed mallard ducks, Anas platyrhyncha, were then ad- mitted, and as they entered the pond they were first attracted by the larval bactrachians, tadpoles. They, however, soon recognized the presence of larve and pup of the mosquito and immediately turned their attention to these, ravenously devouring them in preference to any other foodstuff present. At the end of 24 hours no pupze were to be found and in 48 hours only a fewsmall larve survived. The motion of the water, made by the ducks, of course drowned some of the insects—what proportion can not be estimated. For some years I have been using ducks to keep down mosquitoes in swamps that would have been very expensive to drain, but I never fully appreciated the high degree of efficiency of the duck as a destroyer of mosquito life until the foregoing test was made. Maryflies, stoneflies, and caddisflies also are consumed, usually as larve. More than 200 ecaddisfly larve have been obtained from a single stomach. Caterpillars,including an aquatic form which lives in nests made of duckweed, occasionally are disclosed by stomach examination. The other insects eaten include afew ants and other Hymenoptera, Orthoptera and their eggs, and bird lice (Mallophaga). The last- named undoubtedly are obtained from the bird’s own body. That mallards at times feed extensively upon grasshoppers was observed particularly during outbreaks of the Rocky Mountain locust, when from 12 to 49 of these insects were found 1 in various stomachs by Prof. Samuel Aughey.? 1 Journ. Amer. Med. Assn., L_XITI, no. 14, p. 1203, Oct. 3, 1914. 2 First Ann. Rept. U. 8. Ent. Comm., oer II, p. 58, 1877. 64336°—18—Bull. 720-2 10 BULLETIN 720, U. 8. DEPARTMENT OF. AGRICULTURE. According to W. Stanley Hanson, of Fort Myers, Fla., mallards are effective enemies of another pest of this group, namely, the mole ericket. He says: My flock of mallards have completely destroyed the mole crickets in my grounds. The ducks feed at night, when the little mole, so destructive in certain parts of Florida, is doing its work. : CRUSTACEANS (0.35 PER CENT). Although a considerable variety of crustaceans are eaten by the mallard they do not form an important element of the diet. Craw- fishes are of most interest among them on account of their destruc- tive habits. They were eaten by 51 of the mallards examined, and from 4 to 6 specimens were found in some stomachs. Other crus- taceans devoured by mallards include water fleas, sand fleas, sowbugs, fresh-water shrimps, and crabs. MOLLUSKS (5.73 PER CENT). Mollusks, the most important element of the animal food of the mallard, comprise three-fifths of this and 5.73 per cent of the total. Fresh-water snails are represented most numerously, no fewer than 50 sometimes being taken at a single meal. Small bivalves also are eaten and as many as 23 were found in a single stomach. OTHER ANIMAL MATTER (0.72 PER CENT). Among miscellaneous animal matter taken by the mallard, fishes, constituting a little less than half of 1 per cent of the total food, are most important. Remains of frogs were found in 19 stomachs. One record of especial interest relates to a duck collected in December, by J. A. Spurrell, at Wall Lake, Iowa. For two days before this was killed it had frequented a small patch of open water in a creek, caused by the water from a drain. The bird had eaten two craw- fishes and two or more frogs, which it must have secured from the muddy bottom to which such animals retreat during the winter. Other animals found in mallard stomachs were nematode worms, including the so-called hairworms; fresh-water bryozoans, marine worms, earthworms, water mites, and spiders. Besides the foregoing items of animal food, the following are stated by various writers to contribute occasionally to the food of the mal- lard: Barnacles, leeches, snakes, mice, salmon eggs, and carrion, including dead salmon and other fishes. BLACK DUCK. (Anas rubripes.) The black duck is a close relative of the mallard. In size and form the two species are practically identical, and in both the female has the same loud resonant quack that distinguishes the mallards Pas J AON TOU FOOD HABITS OF MALLARD DUCKS. _ 11 from all other ducks. The black duck differs radically from the mallard in coloration, however, and also is different from that species in having the sexes colored alike. In temperament, furthermore, the black duck varies considerably from its more abundant relative. It is wilder, seldom lapsing from an attitude of intense wariness; it appears keener in every way, and its senses of sight, hearing, and smell are constantly alert. It is, therefore, a gamier species than the mallard, and for the same reasons is not so susceptible to domestica- tion. It is also distinctly more nocturnal in habit than the mallard. Vernacular names for the species, other than the one commonly used, include dusky duck, black mallard, black stock duck, and qn noir. Breeding from Virginia and Iowa north to Hudson Bay and Lab- rador, the black duck ranges in winter from Nova Scotia south to Florida and Louisiana, and casually to Colorado.t It is not dis- tributed uniformly over this region, however, and the probabilities are that a large majority of the individuals winter in the Atlantic Coast States from New England to the Carolinas. FOOD HABITS. Unevenness in distribution results in the black duck’s feeding more extensively than the mallard in salt marshes and other areas char- acteristic of the coast region. In such places animal food, as mol- lusks and crustaceans, is abundant and contributes more to the sub- sistence of ducks than is the case in inland waters. Accordingly, the black duck consumes almost three times as much animal food as the mallard. The actual percentages, contrasted, are, respectively, 24.09 and 9.47. Due to its habit of frequenting salt water, the black duck also devours far more eelgrass (Zostera marina) than the mallard. The total percentage of vegetable food is 75.91. The number of black duck stomachs examined was 622. In tab- ulating the results 232 stomachs were excluded, as they were either nearly empty or were taken in poorly represented months. The statements as to percentages of food, therefore, are based on the con- tents of 390 stomachs collected in the six months from September to February. This material was obtained in 19 States and in 2 Cana- dian Provinces. The distribution both geographically and through the months 1 is very satisfactory. VEGETABLE Foop. Three-fourths (75.91 per cent) of the food of the black ducks ex- ‘amined consisted of vegetable matter, and fully half of this was derived from such submerged plants as the pondweeds, eelgrass, and ~ 1 Opinion is now almost unanimcus that there are two forms of the black duck, ared-legged bird (Anas rubripes rubripes), occupying the whole northern and interior range of the species; and a dark-legged race (A. 7. tristis), occurring along the Atlantic coast up to the Gulfof St. Lawrence. 12 BULLETIN 720, U. S. DEPARTMENT OF AGRICULTURE. wild celery. The pondweed group alone, including the ordinary pondweeds (Potamogeton), bushy pondweed (Navas), widgeon-grass (Ruppia), horned pondweed (Zannichellia), and eelgrass (Zostera), composed 32.34 per cent of the total diet. Leaves, stems, tubers, winter buds, and seeds of pondweeds are eaten, and 700 seeds were found in a single stomach. No fewer than 4,000 seeds of eelgrass were taken from the gizzard and gullet of one black duck. Wud celery is an important food plant, but as it was not tabulated sepa- rately, its percentage can not be stated. Following the pondweed group in importance are the grasses and sedges, each contributing nearly 11 per cent to the diet of the black mallard. The most important grasses are salt-marsh grass (Spar- tina) and wild rice (Zizania). Some stomachs contained from 1,000 to 1,200 grains of wild rice. Cultivated rice was found in two giz- zards, to the extent of 720 kernels in one. It was gleaned from fields already harvested. A notable part of the total percentage of grasses was made up of corn supplied to the ducks as bait. One bird had taken 227 kernels at a meal. Wheat, also used as a bait, was found in one stomach. The -sedges which supply most food to black ducks are the bul- rushes (Scirpus). Mainly the seeds of these plants are devoured, and 2,000 have been found in one stomach. The tubers, as a rule, are sparingly eaten, but one species (Scirpus pauciflorus), common about the southern end of Hudson Bay, has a tender propagating bud which is eagerly eaten by ducks, and of which the black duck takes its share. Of other sedges, the following total numbers of seeds were taken from single stomachs: Oarex, 320; twig rush (Oladium), 720; and Fimbristylis, 900. The stems, leaves, and rootstocks of sedges also are eaten occasionally. Smartweeds are important to the black duck as fale they are to many other wild fowl. Their seeds make up a twentieth of the food of this bird, and nine different species were identified; from 2,000 to 3,200 were found in individual stomachs, and in one the enormous total of 36,300. Seeds of bur reeds (Sparganium), usually not a conspicuous ele- ment of wild-duck food, were found in 144 stomachs of black ducks, to the number of 200 to 250 in several. They make up 3.37 per cent of the diet. Algz form a larger element of the food of the black duck than of most of its relatives. This is merely because the maritime habits of the bird give it access to seaweeds. Musk grasses (Chara), a fresh-water group, also were among the alge eaten. Other items of vegetable food worthy of mention are the seeds of water shield (Brasenia), waterlilies, and coontail (Ceratophyllum), which together form 1.36 per cent of the food; leaves, roots, and tubers of various wapatos; seeds of pickerel weed, and of grape and FOOD HABITS OF MALLARD DUCKS. ie mermaid weed. Items of especial interest, although of less impor- tance, are huckleberries, of which more than 800 seeds were found in one stomach and 200 in another; seeds of a wake-robin, or trillium, of which one bird had devoured 523; of sea purslane, reaching a total of 800 in the single instance found; and of common ragweed, 900 of which had been consumed at a single meal. Seeds said by Nuttall to be taken by the black duck additional to the vegetable food revealed by these stomach examinations are of a bog plant, Scheuchzeria palustris. ANIMAL Foon. As usual, the animal food consists of a larger number of different items than the vegetable, although individually these are of very much less importance than the plants. In all, they compose 24.09 per cent of the total. A little over half of this, namely, 12.27 per cent, is made up of mollusks or shellfish. Both bivalve and univalve shells are eaten, but many more of the latter, in accordance with their greater abundance. Of the bivalves, the common blue mussel (Mytilus edulis) is most important. It was found in 35 stomachs, and to the number of 30 in a single instance. This shellfish is enormously abundant, and although used to some extent for food and fish bait, can not be said to have a value that renders the birds feeding upon it economically injurious. ) Univalves were taken in all nee, including eggs. No fewer than 650 snails were found in one stomach and of univalves and bivalves together 1,200 were present in a single case. Shells of the genus Litorina are frequently taken, and five species were identified. A common introduced form, L. rudis, was found in 38 gizzards, in one to the number of 150 individuals. Crustacea, including barnacles, sand fleas, water fleas, sowbugs, shrimps, crawfishes, and crabs, are next in importance to Mollusca in the animal food of the black duck. They compose 7.99 per cent of the total diet. Hundreds of the smaller kinds were present in some stomachs, as were also as many as 60 sowbugs and 30 c¢rabs. In asingle instance a specimen of the common edible crab (Callinectes sapidus) was identified. The other items of the animal food that form noteworthy per- centages are insects and fishes. The insects taken are largely aquatic beetles and bugs, but dragonflies, especially in their immature stages, earwigs, crickets, grasshoppers, caddisflies and their larve, two- winged flies, and ants also are taken. The rice water weevil was among the beetles eaten, 20 being found in one stomach. In all, insects amount to 1.89 per cent of the food. Fishes and their eggs were found in 20 stomachs and compose 1.34 per cent of the subsist- 14 BULLETIN 720, U. S. DEPARTMENT OF AGRICULTURE. ence. Aneel and some killifishes (Fundulus), neither of particular food value, were identified, and the fish eggs eaten probably also were those of killifishes. Another item of animal food worthy of mention is marine worms of the genus Nereis. These were found in 17 stomachs, no fewer than 25 in one. These worms prey to some extent upon oysters and other shellfish. Elements of the animal food of the black duck credibly reported by other observers * but not found during the present investigation are: angle-worms, the sand flea Gammarus ornatus, the isopod Idotea marina, and the snail Campeloma decisa. Foop OF THE YOUNG. ~ Having gizzards from representatives of three different broods of black ducks allows brief discussion of the food habits of the young. As is the case with a majority of birds, the percentage of animal food taken by the young is much higher than by the adults. For the three broods examined it ranges from 40 to 79.25 per cent. The constitu- ents of this part of the food are practically the same as those taken by adults with the exception of fish eggs. All of a 6-day-old brood of five black mallards taken on Wallops Island, Va., May 18, 1910, had eaten eggs of fishes, probably of the little lallifishes SO abundant in salt marshes. The ‘tood of a brood from James Bay, Canada, taken July 13, 1914, consisted on the average of 96 per cent caddis larve. The eceuslela food of the young showed no peculiarities, except that possibly more odds and ends, rare items in the dietary, were picked up than would be by an equal number of adults. Such were seeds of marsh mallow (Hibiscus), cleavers (Galium), Hypericum, lamb’s- quarters (Chenopodium), amaranth, Lippia modiflora, and rose. The Wallops Island brood mentioned sine dle on the average 47 per cent of its food of alge. SOUTHERN BLACK DUCK. (Anas fulvigula.) The southern black duck inhabits peninsular Florida and a narrow strip of marsh and swamp land bordering the Gulf of Mexico from Florida to Texas. Usually it is considered to consist of two subspe- cies, the Florida duck (Anas fulvigula fulvigula), and the mottled duck (A. f. maculosa), the latter living in Louisiana and Texas. However, these are treated together here as the southern black duck. This is a smaller and lighter-colored bird than its northern relative and may be recognized by the plain creamy buff throat and foreneck. In the northern black duck these parts are streaked with dusky. 1 This does not include the generalization of Audubon. FOOD HABITS OF MALLARD DUCKS. 15 Besides the vernacular names already mentioned, the following are applied to this species: Summer duck, summer French duck, canard noir d’été, canard des isles, and Mexican mallard. In gen- eral, the habits of this species are much like those of the northern black mallard. 7 FOOD HABITS. The fact that the black duck takes a notably larger proportion of animal food than the common mallard probably is due, as has been | noted, simply to greater availability of this class of food to the black ~ duck, as that species spends more time in coastal marshes, where animal food is more abundant and accessible through a longer season. The southern black duck, living in an area where cold weather is - experienced only occasionally and for only short periods, has abetter opportunity to get animal food than the black duck. It responds to this superior availability, which after all is the guiding principle in the choice of food by birds, by making 40.5 per cent of its diet of ani- mal matter. This exceeds the proportion taken by the black duck by approximately 15 per cent, almost the same (hace nce as between that species and the aula Fifty-one stomachs of the southern black duck have been examined and analyses of 48 of them were used for the percentages. Although this is a rather small representation of the species, the stomachs are distributed fairly well through the six months from November to April and represent all the usual haunts of the species—the Ever- glades and the river marshes of Florida, the coast marshes of Louisi- ana, and the coastal lakes and lagoons of Texas. It is probable, therefore, that they afford a reasonably accurate idea of the feeding _ habits of this species. VEGETABLE Foop. Grasses are the most important element of the vegetable food of the southern black duck, forming almost. half of it. Frequently the rootstocks are dug up and devoured, and some stems and leaves are eaten. Of the grass seeds consumed, cultivated rice is most impor- tant. Most of that found in the stomachs was waste, being taken in winter, and as it included red rice, some good was done by eating it. However, as the southern black duck spends the summer in the country where much rice is grown, it has the opportunity of feeding upon the crop in the younger and more appetizing stages. It is said to do this sometimes to a destructive extent. However, the game value of the duck makes it undesirable to take aggressive measures against it on behalf of the rice crop. A toll large enough, if not too large, is taken of the birds during the hunting season. Next to grasses the seeds of smartweeds are preferred. They form © almost a tenth (9.54 per cent) of the total diet. No fewer than 800 16 BULLETIN 720, U. S. DEPARTMENT OF AGRICULTURE. seeds of prickly smartweed (Polygonum sagittatum) were taken from a single stomach. The seeds and tubers of sedges compose the next largest item, namely, 6.34 per cent. Seeds of waterlilies and coontail make up 3.11 per cent and seeds, stems, and foliage of pondweeds and widgeon-grass, 1.6 per cent. Other items of vegetable food worth mentioning are bayberries and seeds of buttonbush. ANIMAL Foop. As is true of both of its close relatives, the southern black duck consumes more mollusks than any other kind of animal food. These shellfish compose five-eighths of the animal diet and nearly 27 per cent of the whole food. Snails as large as one inch in diameter were among those eaten. Insects, making up less than a third as much of the food, are next in importance. Dragonfly nymphs, rarely adults, water bugs, caddis larve, a variety of beetles, and flies, including horsefly larve, are the principal items taken. Crustacea, chiefly crawfishes, contribute 2.77 per cent of the food, and fishes, no doubt small worthless kinds, 2.57 per cent. TaBLE I.—Items of vegetable food identified in stomachs of mallard ducks and the number in which found. Southern : Common] Black Kind of food. black mallard. duck, ducks otal numperiof stomachs examined 8.2.2.2 8e-0 o nee eee eee 1, 725 622 51 SUBKINGDOM EUTHALLOPHYTA. ROA oUKG Vevat a0 (6 REY Kets heen RE ea ate WR ae EE ne ARs OO SS noase 21 OL sata ee CRATCISD = (GHAUS Ke STS) ete sea ee ede ca cre eee A Payee 29 2. | ose See Fucus sp. (seaweed).........- fee Desk Sines RE RR te Nie ay nee, = ee Ry is ee ee he See SUBKINGDOM BRYOPHYTA. HiIccrellasp. oat pe livieEWwOLb) ==. aes eee ee eee eee eee (4 eee Se SA eee woe IMIOSS a Eke os SS css hee ees Sse acta ore ge ec es ne eet ee 1 Fl SRR Sees nostic 8 SUBKINGDOM PTERIDOPHYTA. Marsileacez. Marsilea vestita (pepperwort)......-..-.---- Ste ee a noted Sapo ee 3 3/2. 22st ee Marsiled Sp..(pePPeCLWOrk)). ooo se ep tere eee eee 7 ol is EE S| RR coo Se Equisetacez. i GUAsetum’Sp.|(MOrsetail) S25 eee = te ee ree eee 1 ees ees sero SUBKINGDOM SPERMATOPHYTA. Pinacee. Pinusiceaaleblollymine) ta. 2:. sees eee eee ee eee 7A a a eA al ee ea eS IPINVUSisps (pine), “Meedles ve. ...c3osc- sae es ee eee eee eee ae | eee 2 bi Sos eee PAcearsp-1(Spruce),;needles,..22 422 Sole seek See ee eee ene ane 1 OY ioe sea! PROLOG IMI SiiChim (bald Gy PreSS)/. 550 eee eee eee 113 i a ee Paroduum disiichun (bald cypress), galls o. .s se scemem eee eee | 60. cae SS eee Sparganiacez. | SPULGMIUULINACILAnOCladiLimn, (DUE TECU) = ce. a heme eee =e eee 6 BY eee SPAUngGAanvuLmicunyconrpum (pDULTeed)\. .-.- 422 22s eee eee eee ee | 25 2 SDATGONUENE SP (DUET OOO) Ke are arci-in cielo alele cree ere epee enines eee eRe eee 1 FOOD HABITS OF MALLARD DUCKS. 17 TABLE I Enos of vegetable food identified in stomachs of mallard ducks and the number in which found—Continued. Kind of food. RofalnumMbenousloMmachsiexantmnedeee n= keen ee oe Sa. ee oe ees SuBKINGDOM SPERMATOPHYTA—Continued. Potamotegonacee. Potamogeton lucens (shining pondweed).......-.:--.------------------ Potamogeton prelongus (white-stemmed pondweed)...-.-....-----.--- Potamogeton foliosus (leafy pondweed) Potamogeton friesii (Fries pondweed) Potamogeton pusillus (small pondweed)........-------------------2--: Potamogeion pectinatus (sago pondweed) Potamogeton perfoliatus (redhead grass) .......-------------!-+-1------ Potamogeton sp. (unidentified pondweed) RALp DUP Maritim Qvaadseon-Prass) =a: 222 4-2-2 se se de EA Zannichellia palustris (horned pondweed) Zostera marina (eelgrass) Naiadaceee. Naias fiezilis (bushy pondweed) Juncaginacee. Triglochin maritima (arrow-grass) Alismacee. IE CHULOEOTALSISD A (UBM Ca Ge ree osteo aoe ok ne, Se ee ieee Ree Alisma plantago-aquatica (water plantain) AIST OS Da WabeIe at CAIM)) ie = ae ee ed Ba fa a ee ee Sagittaria platyphyilla (delta potato) Sagittaria latifolia (wapato) CGULATITCT ES) (BOOSC-ETASS) mats ao eee erie Se ee eee eae eee Sagittaria graminea? (grass-leaved wapato) Sagitiaria sp. (arrowhead) Damasonium californicum Hydrocharitacez. Philotria canadensis (waterweed) Vallisneria spiralis (wild celery) Limnobdium spongia (frogbit) Graminez. Baa LEMP Li COMORASSES HEE wee a a) ia hee Se Se ce ee ae Zeaz mays (Indian corn) SERU MAE SOLE 555 So Cae a ere eS eam Ie SRN ak hah Paspalum distichum ! POSTOINID SOS og SURSE SOR AS GeO Ie SOO eae eee Echinochloa crus-galli (wild millet) EAI CU MESD ASAE NET ASS) eis ec a Sas oes oie 2 oes Ne te ee ee Panicum dichotomifiorum (switch grass) Cheztochloa lutescens (yellow foxtail) Chziochloa sp. (foxtail grass) CEN ENTAESTS Ma OTITETASS) Pisses a aoa os Soca Se i ae i as _Zizantopsis miliacea (cut grass) ae Zazaniemprerica (wild TiGe) 2s vos 8 5.28 eben edewecdeecunensece nce Homalocenchrus oryzoides (rice cut grass)...........-----..------------ Homalocenchrus lenticularis (catch-fly grass) Homatocenchruswirginicus Galserice).2..0:..------- 62-202 soe sans ons Homalocenchrus sp. (unidentified cut grass). Common mallard. ecesesec--- 13 | ol 2 Paspalum boscianum and chon punctata also have been identified from a common mallard’s stomach by L. H. Dewey. 64336°—18—Bull. 720-3 18 in which found—Continued. | Kind of food. Common Total numberiofstomachs examined 222 2). s22cee 5-2 sas8 ees sce see eee eee 1,725 SUBKINGDOM SPERMATOPHYTA—Continued. Graminese—Continued. Oryzarsativa(cultivatediice) 2 sao eee eee eee ee See eee ee 60 Avenarsativa(Gultivated oats) nates tase eee ee ees 3 Danthoniasp.(OaviSrass) eee a. see eee vk ge abe ia a an gene 1 SPONLUTOISD 4 (SAUGTNATS ST AGS)) We erste oye eee 20 Hepiochtowslonbunda(deather orass) ees eases eee eee eee eee 1 LH RAGTOSTIS|S Ds LOW E\ETEASS) toe eee eee eter ae ara eee a 5 IMONONENOCNLOGIIELOT ALIS eae ein Seale Se Sa eet eee ae ee 7 Disieniiss picataSalGierass) eee eee eee eee eee eae Cb iste Cychenel: tha 4 Panicularia nervata (meadow grass)..........-------------ee22-2--2--- 12 ‘Poa sp xCneadow: Srass) eek 28... bosses eaees§ 2k See ee a MESHICCIOTachypbylia ({CSCUC STASS))ooec2 ee eee Ce eo ee EB TOIMALS|SD oi (OE O TINE! STASS)) oe vey ote ee eset apt eet a il HOT ACU TUS CELUI (DATICY) setae eee ee i eee eee Eee eee 7 OTe ny ILL) (wala ipariey,) sence ere ee eee ee 1 IPRILICUMIVCESTLOU TIL GWANEAL) Beene nen ar eee ee eee ene ene eee il Cyperacee. Agni exbimediSed oO). aires Re Cae cee ec Uy phate inp ee Ne ne eR ae 114 Gupenusesculentisn(Chuta) sae oe ee peer ee aaa eee Pie) Tia Ne Ga 1 CU DETUSIETAL (ChUTA) oS pects es eRe eee ee eT ee pa ora a 10 CYPETHUSSDS (CHUA SE Soe e Ree ee eas Arteta a eB ey Sohne ie OS 48 Scirpus paludosus (prairie bulrush)...--. Des op Sie Eee Lae ene eee ea 9 SCUPUSHLUUIOLIIS iver OULTUSH) sssase See seen eee eee eee eee rene rene 45 NeIpuscwvensis (Dulrush) seer ok. eee ee eee ee ee Ree eee 286 SCILPUSIAMENIC ANUS (GHEEC-SQUALC) Lanes eee eee ee eee eee ee eee | 22 SCUPUS PAUCiLOnUs (Cliab-TuSh)s.c--eeee eee oe ee Hee ee eee eee eee eee ks ORs SCipUssSp-(UuMmiGentin#ed ulus) es sa eases eee eee Caer 540 Hleocharisisp.(Spike-Tush))430.c02<- ote ce ted de eee eee neem enone 37 VMOTISYUS SDs (GCAO) cee senceher Ok aoe eee eee Lee eee ee 279 Psilocarya nitens (bald rush) so. 2222222. ----- 222 SEU ak nl Seu nat teat 3 PSHOCATY ASD | (Wal GUSH) esse aces cok SER eee eee 10 Cladium effuswm (Saw grass)...-.-.---------- 20-22-22 2 e eee eee 45 239 Cladiim moanscordes (iwAg Tush)cer eee ee eee eee ee eee een eee 7 Rhynchospora corniculata (pollywog)...........-.2+-+-+-2-2-2------+--- 24 hynckosporasp. (beaked Tush))..0.¢-¢252.- 2 asereneae eee eee eee enees | 5 DiChTOMERTS Dee ese! = EE cee oe MEE SE eR ae ee eee | 6 Stlenza qeticulors Grat rush). ceswece tose ee eee Pitas mack NAVARA CORAL WO (CER RIOSIN)) So oe acoso asusseecm ote ddasee Jeo wae see Th Re es DCLENG|SPe CUUG USI) hare ear eye ee eee RAT Ss ws | 13 Carex decomposital(panicledisedge)ialeeces- ences ane ee cee ae eee ae 77 Corevlupuling (hopisedge) iscsi ssn. s 2-2 eee cee ee eee eee eee eee | 1 Carcolupiulijonniis| (HOP SCAEC) asses sas ees ae ene eee eee eee ene eee | 7 Canexguganted (HOpSedge) ieee. -cseoeee oo aeee eee ee eee eee eee 12 Ganerspe (Sedge). tee. oo hao Sek odd Eee Soe ee ee a 28 Araceze. Peltandra virginica (hog wampee)............-.--..--- PRES SA ae LE ea Se I Lemnacez. Henna minor (smalliduckweed)...<-.2.-222-- oe eure eee eee ee eee 10 ETI LHISCHICO(StantiGuUCkwiPd) onic: Ee Ae tae et eet eee eee 1 Lennaspy (inidentined:iduckweeds)s..-6---eeeee sere eee ener .| 247 BULLETIN 720, U. S. DEPARTMENT OF AGRICULTURE. Black duck. 622 TasLe 1.—Items of vegetable food identified in stomachs of mallard ducks and the number Southern black duck. eee e ce eee FOOD HABITS OF MALLARD DUCKS. __ 19 TABLE I.—Items of vegetable food identified in stomachs of mallard ducks and the number in which found—Continued. ; Common Black Ee Kind of food. mallard. | duck. pee Totalinwumiber ofstomachsexaminmed see. eye thee seen eee se 1,725 | 622 51 SUBKINGDOM SPERMATOPHYTA—Continued. Lemnacee—Continued. Spirodela polyrhiza (greater duckweed).. Seacoast RPT iG Sa?) 2 fon. at sve em OY WMolfia columbiang (water meal) 222-2. = 222 sae snetes 222 eee a EER eek CR Bee Be Wolfizispa@watermeal) ro tere kere che eee wad DR es 66 1S | Boea Ee Eriocaulacez. PFOCOUMOTUSD 3. (PIPCWOEL) sce aes Bee ee eee Ree Lee eRe LL eer Pa) Sa, [Se See Xyridacee. | EX@TISISp= | CVellGw-ey.ed!) Grass) seer nee an eee Re eee RE ee 16) 52% Sen eae Commelinacez. | | Commelingsps (dayilowen eeeee- ease ae eee eee eee eee eateee Se 1 Oe ae Pontederiacee. iRantedericordard (pickerel weed)e= eee s2 cen ae es ee ce ee Se ck 31 | 11 2 Liliacez. Wimidentiti cde rete asses sane a ese eR eh oe eee he ea). Da ees haetase tea as Convallariacez. Vagnend spe (dalse}Solomonss seal) <4 eee ee eee eee nese ae ella Ae he Tse eee Trilliacez. ETUUNY Spee cia ae eee ee ee cia eee ENE Severe ct. cehn | ess skee 1 al baa a Smilacee. ; SMIATISD a (SLECN Dram) anatase sees ea ene cee eee Loe ea eee Pee ee 6 2 2 Marantacee. A OLECA TUT ICOLC ee ae aes eae e als ate ha bs oe 5's ANY ON Rey ate pce Resta Juglandacez. 3 CUR EGUAiGG: (DILLE mA PECAT)h isseee shave tne a ai aoe see e xe Oe vil Rai 2 (Re toauts : EHCOTID Spx CHICKOLY))- © =: acepsiainieias oc wie ieiciseeaicieis = Amygdalacez. Prunus virginiana (chokecherry).........--<-----+-----cee-eeeeeceeees STALNUUSISD =i( CHOLLY, ine cites ne as aisrocoie wis Sete Sei sie see wisie ee eisie Sisie eases ae Ceesalpinaceze. Gassiassps (SONNA) Bae eet recess Soe erst eee ceminet ce emia seers Fabacez. eT OLUL TUS Ps (CLOW ET) Banat ieee sols Soin ia Siete cain, ol oreve seietntaiminiietw is eereveP= Soe Medicago denticulata (bur clover).......----------------+-+-----++---+-- SIECSPCCEZSD = (OUSINCIOVED) eisrmien ime sloe = = at, 2) cls seis seis eee espedezMStniatai (apa CLOVER) je seccciaise ai-esie -ieies aeie eee Tee SELODAOSLYLES SP GWA DCAM oop steams > sia Sista Nala aigy a sisin a1 ate wi claimeinyeie estos PISUTUSAtLUUNY (CUItIVAtEG DCA) = mallard. 622 te tet ee eee 24 BULLETIN 720, U. S. DEPARTMENT OF AGRICULTURE. TaBLe II.—IJiems of animal food identified in stomachs of maliard ducks and the number in which found. : Common Kind of food. mallard. Total mumber of stomachs examined 22 52 3-2 <2. = onsen eee e eee eee eee << i> SUBKINGDOM C@ELENTERATA. Alcyouaria (Sea tans)! .2 2.252282 552525252 ote eae ae cote ne cenece ates Le ee Hydrozoa (Hy droid). 220502 e sees saa aee ee ene oe eae 1 SUBKINGDOM NEMATHELMINTHES. Gordiidse Chairworm) = 22sec seen coe eee oe Seen 1 SUBKINGDOM MOLLUSCOIDA. | Phylactolaemata (fresh-water Diy 0208) = =. 2.25 saooce se eecenee see ese een ee 12 SUBKINGDOM ECHINODERMATA. Echinoidea (sea urchin) Ppa a cee ee ee a ee a ed ee ea re eae Fe Ee St Wan dentitied nin eli 2 25 oat eo ea ite ee a a ee ere 1 ‘iumbricomorpna (earth worth) esos ee ee ee ee 1 NETeISiSP2CNAHING WOM) 2 2 cae soe eee Se Sans ee Se ee ee meee 2 SUBKINGDOM ARTHROPODA. CLass Crustacea (CRUSTACEANS). Order CIRRIPEDIA (Barnacles). Balanus Gniphitrite- 4-06 ono 5 fone a os aan ee eee ee ee ee Chithamalis(F0qthts 422 Fae 5 a a ee ee ee ee Wnidentified =. 52 - 2S. so he nc Ske Se oS ene eee re ee ee ee ees | See Gammarid@ (sand-fleas). TANUMATUS CN NULATUS So eS a re ee GOMAMATUS LOCUSTDS 3 2 Se Oe Ee ee re 1 Podoceride. AC phithoe TUuOTeCale 2} Ss _ osha ee ee ee eee bee ae Grubia compta.........- siya aalctas Sak Mee Dee Sn ee SS Photide. MICTOREIHODUS OTYNOURL DUS =... 3-5 5a 2 eee eee | ee Res Orchestiide. | LECTION Es 5) a ra ERT Re Af ee eS 2 peBTVLEHG CONTIG on a ooo on sone wane os bao e Se Ong Eee ee ae eee EY CLEL MICK ETL DOCK ETE ico hn. w 50 on woot ao eee ee eee 1 Or chestia Qritius opine) seen wae cnn es oe eee oe e ae eee ee ee TOUITUS TREQGIODNIRGUBUS 25 =. cons oo cen coca cen seman eee Pen ene eee Black Southern duck, 622 black duck, 51 tet et ee eee sete recess settee em eee set ew ere es sete tecece er PP oS eee FOOD HABITS OF MALLARD DUCKS. 29 TasLeE II.—IJtems of animal food identified in stomachs of mallard ducks and the number im which found—Continued. : Common Kind of food. iallard: Tots] numberof stomachs examined. ..5:.-:....---.-2--s0-ccececeeeccceee 1,725 CLASS Crustacea (CRUSTACEANS)—Continued. Order ISOPODA. Wen dentine meeps are ees tes cise ae ate meat te owes ee oneeeee Al Oniscidz (Sowbugs). . OPRERS TT UTG? su SACS SEG SABC CEs Soe Ae eee eee Lewanae Bae LOBEL VEERUE (OG | G85 Soi ea ee © He ele ee Sena etme Leahey | 2 Asellide. PAISELUUSISD Mane eee eae ee een ae eee eens sta e eae bs sb aeeeioeS Ans Pee PMO NCOSCLULSIS DP mgt rete tte ete eee ein one a a sale ca cine ses Se 2 Idotheide. | [YAU WINER 3 o305 nag nebs2 2552 ss0es 25 acoso son es eS aoc uses sua asesenes Iseabcdoace LRT D SUDAN (PATONG Te Saas -sasae Soa oe Ie oe seeS ea SSeS SIE Se SES eeEeS | Snseeees AOL CO TOCIE NICU ree ae oe oe ee ons [sa cmereara Idotea phosphorea.......--.....---------- 1 cE paeseacs oe, gp Sse a sas ene dee Order DECAPODA (Shrimps, Lobsters, Crabs, etc.). Suborder MacruraA (Shrimps, Lobsters, etc.). (QE GIELEGG) 2 2 oo doo sagsaasasocosSoseesonascasscsgo5 saSSe Ss soS Seen enaesee 1 Crangonide (sand shrimps). CHD SEDATE DIDIS Ds sas Sonn o5 as de Sp SOC S COO DOUCO TB OO GSC N5ANS5I 60545 boasuacEeS Palemonide (fresh-water shrimps). : ROULCIONCLESICL ILD CS eee yA eee swim Se Sica a sceeeeie Saco See 4 CLL INONELESL DULG UTES hot ee ee oe aio eee Oe Se eine ew crise sek 1 HOLL ITMOTICLESIS Dt eae See TS eso lniee Sse se ctor oen/e Sie diel Sides 1 _ Astacidee (crawfishes). COMDUTUSTONGUSLALUSED mere e eee Sass se oaee ese ete se oeeeeces 1 COMTATUS CLOT Meee eee see ee oe Se ee owe nce ce scence eee cree 1 COMDETUSY CULE Te ee aaa Eoin eae cleo ocak Sas He Sena Schiele 1 COMDOTUS Dirt Smo eee eee mee ee oan wee ee oe eee sooo eecece os 4 Winidentificd basse ss aso e seco occ e SSSR T EE ORGS ESR eee 44 Suborder BRACHYURA (Crabs). (Uitte iieih ehh on § ae SEEGERS SS ESS On SSO Sea ae et ee eran 9 Pilumnidz (mud crabs). | NCO DIL ILO DELCO MESULY Lema ee toes eee a(om ciclo aes oeiciniaeie cinta iseininien sisewiseiecieis Hexapanopeus angustifrons....-.-.------2+-+-02-0eeeeseece ec eeeeeeeees Eee Portunide (green crabs). | COR GEOLUZS CICHONS. 2m BOSS BSS ESS OS SEH Se er Re bear eet CaLLiNPCles SA pidusi(edi Die Crab) ase << «<5 = one wie anne c seein Sates |e eee Nee Ocypodide (fiddler crabs). ASIAN ON AAT MIMOES) Pere oe ios cio sae clone ccm ciscls cccecs iawn ccieee eet ce ce 1 Chilopodar(ceBtipedes) 22 sas ee as sk ae we Secor seew en aciecscismecsccct 7 Cass Insecta (INSECTS). Superorder AMPHIBIOTICA (Damselflies and Dragonflies). Unidentified odonate nymphs and adults (few of latter).......- DeLee ees 144 | Order ZYGOPTERA (Damselflies). CHU ST ray (ease oS ee aR ne 6 OVO 2D. ORE ak SA te Se A ee ere 1 | Bla ok Southern duck. Be duck. 622 51 15 12 26 BULLETIN 720, U. S. DEPARTMENT OF AGRICULTURE. TaBLe I1.—Items of animal food identified in stomachs of mallard ducks and the number in which found—Continued. : Common} Black |’ outhern Kind of food. | black mallard. | duck. | duck. |. Total number of stomachs examined..........-.. eh Bt ae ae eae. oy 725 622 51 Cuass Insecta (INSEcTS)—Continued. Order ANISOPTERA (Dragonflies). Unidentified: nymphs and adults <2. jocee 20 cen cene seecaee ane aa sae aoee 21 ign4h| Gite nowt ZEschnide. GOmpPhin ass he sasiatalarsars = visti S aic steraye rato re i ttere eee arte Sea emer aera 2 | 2. “Sep seal Sees = PE SRN OCOUPOTNICG 5s cise Nas Ae iaeisracie eeloe wee os ae ise IS Se eee 1 |......-.-+ p----+---- FE SRNOGISD 228 x ayro mo oe Bae eS eerie aw Seo sence SER eRe ee eae oor PS). Paes epg eset AOL UTUUS SN ata we ora cio ers elle ae sie aie SG SS Sas Se eae a en CS ae 3 itl ackescss. DI ROMOG OME DNAUS:SP sorce= meee eta SNES aS eo SS ee ee 13) --22 eke so aeanaee Libellulide. IMOCEOMIGULLTIOCN STS ae eee Pee ee eC ealelsteaieans cere eee J ATAU GUO TIUA DIU em coe Re ooh Gk ee 22 See Sse co Seb eer ee ceSsc oc = soues 4) | pasties eene see REET OG ONCUTIONS is ciara See ea at ata ae ashe amare at eee ee ee Dsfeackqea sec eee = Gee Umi dentifiede ao: Sashes end Jon Soe es oan see oe eee FE eee ee lazaeseseos Order AGNATHA (Mayfles). ; Unidentiiiedimayiites;and any miplse sass ae see ee ee eae eee eee 6 [el ee Order DERMAPTERA (Earwigs). AIMASOLBDIS MOLUETM OL oaiz wa aiccnie/stlewte ws Serna REISS LIER oer ROC REL ESE Ree eee i EA eT eae Order ORTHOPTERA (Grasshoppers, etc.). : lUmidentinedtOrthoperarandiegessaee sone cee ea esas eee eee neee eee eee eee - 20 1 OR eas Tettigide. (NOMOECLELE SP amet soso w ns iia Snins Bate Raa w ae Gee SEES AEC eee jG eee ee as fpebeneeeee RELETTIOT NU OLUS eterna rate ete hei ce en DIE EE eee eee Ls. |. s areopgoetaahee =e Umidentitied < 2Rste sackiadtaeciacrs hice nae rears Sener ery aloe neal water eerste 16 Datiauatiie ss Acridiide. te Melanoplus bivitiatus--.-----.----€2---------------------2-+---------- Ti. | ce cea Vian eee IMClaNG DUS SPsa85 eae ees eee Seeman Ee ode cope eae nena ces: 1-22 eee pe ue gate SOUSIGGAREL CUG EYL see 3 a noosa eb eons Sebo cocsec cee. = speecesscoeceaks: felceae eee haces ore eat err brie cies euhso das Be ee Sk cen ree ee nee en ear 6.) ees eeneles yecelie Locustidz (green grasshoppers).........-- scvciesrohapavanetarsyaict arareiawraverererctleters mer tele 5 '|da nomen eee MoEES Gryllide (crickets). INEMOOULSSP= Bo oe2 asia m Son Sat ro SORT IESE SESE ECEEE 3 WIS es Order PALEOPTERA (Roaches). ’ Windentitied noaches andes ese meet ee eee Di leccseihe Soho eee Order MALLOPHAGA (Bird Lice). LOiebie Kes OV AUG :%G Ee eee Cena i A Ee Beton amor taee pubesosekes | hal SE iene 3B fed aids so Order HETEROPTERA (True Bugs) Banidentiied= vs... 0. <2 ss bawteaet alee ee ee SOE ee 27 OM Fa es on ah Corixide (water boatmen). COTIGUACOAOMINGIS ai. cee eee ee eee | IS ines Sepcemcses| artes See aim COTIT OMRON ISIU = xo on 2 vse cn Soo ea odie cs ote secon sees Ee eee Irls2 Seen Sate eae eee lUmrden tified ss 25 3 Anisota sp. (pup of oak caterpillars). (2222222. 5-22 10 ---------- INOCLOIG=S (CULM OFMS ec etc a Se oa re ee ee eee er Ener 2| 1 Pyralids Soe es ee ee ee a Rare Se ae ee ee ee aes 3 | 5S aaa ined as ee eS Sts oe ee ee es olen eet ee eee | 3 Wnidentii#ied TROLS sees ane Ss ses oe ee ence ee 2) eet Wnidentiried\ Cocoon far 25— 2 Sse a ee ee ree ae 20 |---------- Unidentified chrysalids...........-.-- d sorted Sa AEA an tes Nae te § oa a ee 9 |---------- . nidentsmed carerpilars - osteo see a ee ee ee eee 2 3 | Order COLEOPTERA (Beetles). | | dgridenined beetles 20 2 Cove a ean ee ee ee Bae ee: CicindenGredive;r i DeeTles) 2 eee. ere ee en ee ee | i ie ee ee ee | Carabide (ground beetles). Anomoglossus pusillus.......-.-------- Te lembns cn be ee ae eee DS ote ey BS PMUMIRA FAQUEES soci Sac ee neo e chee ese e sous nse oes | § lsseeadascc Scaphidiidee (shining fungus beetles). | SAD LOOT, TOL TMU AUD 3 ae SaaSo cae Doe bans ado Ben OE eas OneGbSRScona il |bosésos@ec ' Erotylide (banded fungus beetles). | WSCHUYRUSIG MOCKUP UILCLOLUSH tral - a nei Bee = aiciaia ae oe as w\eisinie sie = se nee © 1 |-----.---- YIU ATE G ESO fo oso AA a oe er eee eee 1 Histeride (shining carrion beetles). | FETT WS BASS a Oe DE ee HONS soccer FETE GaSe 8 ee a I re Ia eee Southern black duck. 51 a BULLETIN 720, U. S. DEPARTMENT OF AGRICULTURE. TasBLe II.—Items of animal food identified in stomachs of mallard ducks and the number in which found—Continued. Kind of food. Total numberorstomachs examined <2. ss22) se eee ee ee ee : CLASS INSECTA (INSEcTS)—Continued. Order COLEOPTERA (Beetles)—Continued. Parnide. Heteroceride (mud beetles) . ; ETCECT OCCTULS OT LIE TREUS 9 aso en ae eee IETCLCTOCET US COLLOT IS ee No at ee Re ree ee Ne eR ee ee HET CCET OCCTAES ET ESTERS Se Se ee ee aE te ee Elateride (click beetles). WT ASTCTAUS CLEANS roe as eras ee eet Se ee oe ee | DD FASECTIUS SP) cress ren ae eee a ae ee ce Se ne ee eres Wm Gerntiied =. | Aas e ss aoecdan Sonate ne eee Mee eas Rese ae ea eee Lucanide (stag beetles). IP GSSCLUS COTMULUS SERA La oe a ee eae BEES SELAES. SP) set ofan cre = aaa ae Paw ater tamer Setar Coe Sea er eens Scarabeide (leaf chafers). TAU TTUES COOMELUS Re ano Smee ae rctars a See ee ne ee ee See AE ents SEF IQOLUR 522 Uke Soe ee cee oe He UAT S Fes Sa Sect Sac 6 sabe Sq cece Seesoe Ss co cds cS oesae sees ec edesacs | PA DROGUSIS Dita a aaete See aes ae Oe eR Te OC Tee CE TEER OTE SP ee te See oo he ane ae ae a CHOICES ET LCTEU DUG US a eral a le aa Cleotus globosus....------- Foaatic a sostecussetesasdives toes dasmeue eee Onthophagus hecate-n 5-228. osc ac se nw se on ee ORONLAGUS DETTSYLPONICUS xo ae waits enn ree a ne ee Onthophagus Sp. -..------+----- NEE ROSE BREA een cee Boe ek iahocee PRONLUSCOTTAL ED saan aoe Sea aaa ee ote ee eee PRYLODIAGE SP Be ona a cen ro tae ee ee LJTNG GTS 5 See oe ee neo ceea ce soceee ae cece see sence cee t occ seceeaeecce Chrysomelide (leaf beetles). OCROLO TONER UTE Oe ee eee ee eee BD OTUL ETERS ee Seca eee oa IB UTR ry Woe nc odasnocce ones So sneeoseeses ct de coed aes soccensececessesc IMAYOCHTOUS | BCRECOLLIS) = eae oo cal pn se a ett ree area CHiGiONUCHIS CONCINNGS\ ar eh oe a ee eee ee Gidionychis scalaris:< &..<..2225 22 Sec aocten a ee een le ee eee Systenaihudsonias 32s. 5.2 Be Oe ae oe Foe ee eee Papophorus canNEWuUs 6 soso ae oo eae aoe Seo as a eae eee eee Wnidentified: 5-2... 2.22822 Sak ee ee ee eee Tenebrionide. TAM ECUS UTUNTICUS. ~~ Sosa neo cosn Sees eee ce eee IBIGDSUNUSISD sas s2n. coerce sees doles e eee eee eee eee ee ODQETATAES TOU US ee an oo ae ae Tribolium ferruginewm .........-..--20-2eeeeceeeeeeeneceneeees Bese see Wnidentinied 2 as.2 52. 2. dash sehen 5) Sem one ee cee ae eee Anthicide (flower beetles). AULT CALS SPP 2 ae ean as amine oo nn a on oe RTE ARS RTELET ERE PIOUS 9 Seniesa = ema = Soe Sete tees Southern Binge | “ck : duck. 622 51 ete wee tee FOOD HABITS OF MALLARD DUCKS. 31 Taste II.—Items of animal food identified in stomachs of mallard ducks and the number in which found—Continued. CLASS Insecta (INSEcCTS)—Continued. Southern : - Common} Black Kind oi food. SSeS eS black duck. | etal RUBIDCEOLSLOHTIACHS EXAMINE #5020! eo Se oS od ee ee PS 1,725 | 622 | 51 | | Suborder RHYNCHOPHORA (Weevils). | Denidioms¥fied Ls cece SE ee ee | 18 {|e Otiorhynchide. | | PMAUGOGUSIS Pana re naa eae ees ass Saeco ees eeee se dy oso cone eee SESE I MITIE I ILRTEMEL TER Me es tee Pe 2 ae oa ee oan sheen nase |se- esos se ioe Curculionide (snout beetles). Pbsriclens taki celine estes i ae ee Se a Na eee ence |e eopre ecie a CAO TENET CUES TIES Ae ace win tel