Part 5

For the eastern black racer (_C. c. constrictor_) the following food items have been recorded: 1 robin (_Turdus migratorius_, Storer, 1839:226); 1 copperhead (_Agkistrodon contortrix_, Verrill, 1869:158); 1 weasel (_Mustela_ sp.--presumably the diminutive _M. rixosa_--Atkinson, 1901:148); 3 undetermined mammals, 1 rabbit, 1 undetermined mouse, 7 voles (2 _Microtus_ sp., 4 _M. pennsylvanicus_, 1 _Clethrionomys gapperi_), 1 undetermined bird, 2 robin eggs, 2 garter snakes (_Thamnophis sirtalis_), 1 water snake (_Natrix sipedon_), 1 grass snake (_Opheodrys vernalis_), 1 green frog (_Rana clamitans_), 1 wood frog (_R. sylvatica_), 1 grasshopper (_Melanoplus femur-rubrum_) 2 camel crickets (_Ceuthophilus_ sp.), 5 moths (cecropia, regal, imperial), 4 beetles, 1 currant worm, 1 ichneumonid wasp (_Nematus ribesii_), 1 currant worm (Surface, 1906:170); 1 ribbon snake (_Thamnophis sauritus_, Ditmars, 1907:282); 3 snakes (1 _Liopeltis vernalis_, 1 _Storeria occipitomaculata_, 1 undetermined), 6 white-footed mice (1 _Peromyscus leucopus_, 5 _P. nuttalli_), 1 vole (_Microtus pennsylvanicus_), 16 crickets (9 _Gryllus pennsylvanicus_, 4 _G. assimilis_, 2 _Miogryllus verticalis_, 1 _Nemobius fasciatus_), 2 grasshoppers (_Dissosteira_ sp.), 1 lepidopteran, 3 elaterid beetles (Ortenburger, 1928:200). Richmond and Goin (1938:310) recorded finding the stomach of a black racer crammed with June beetles (_Phyllophaga_). Conant (1938:53) recorded a black racer from Ohio that had a smaller individual of its own species in its stomach. The smaller snake contained a caterpillar. Uhler, Cottam and Clark (1939:34) found food in 16 of 34 black racers from Virginia. Mammals, including a shrew (_Blarina brevicauda_), a mole, a flying squirrel (_Glaucomys volans_), a microtine, and a mouse (_Peromyscus_ sp.) made up 26 per cent, 2 worm snakes (_Carphophis amoenus_), 2 ring-necked snakes (_Diadophis punctatus_), and 1 water snake (_Natrix sipedon_) made up 25.6 per cent, 5 birds including a warbler and a sparrow, made up 17.75 per cent; 2 frogs (_Rana_ sp.) made up 9.38 per cent, 1 fence lizard (_Sceloporus undulatus_) made up 6.25 per cent, and insects, including cicadas (_Tibicen_ sp.) and larval lepidopterans, made up 15.09 per cent. In Indiana, Minton (1944:457) examined 11 food-containing stomachs; there were rodents in six, snakes in five, a tree frog in one, and insects (cicadas, large grasshoppers) in four, and another black racer was found swallowing a small box turtle (_Terrapene carolina_). In Maryland, McCauley (1945:75) examined eight digestive tracts and recorded a shrew (_Blarina brevicauda_) in one, an unidentified mammal in one, 2 small cicadas in one, 2 small chickens in one, a fence lizard (_Sceloporus undulatus_) in one, and frogs and toads (including _Hyla crucifer_) in one; a ninth snake had eaten a half grown rat. In Connecticut, Finneran (1948:124) observed a large black racer eating a 21-inch garter snake (_Thamnophis sirtalis_). Duellman (1951:338) recorded a black racer in Greene County, Ohio, swallowing a large garter snake (_Thamnophis sirtalis_). In Kentucky, Barbour (1950:104) recorded remains of an unidentified snake in one stomach.

Many authors likewise have recorded food of the southern black racer (_C. c. priapus_). In Georgia, Wright and Bishop (1915:160) recorded finding 2 racerunners (_Cnemidophorus sexlineatus_), a skink (_Lygosoma laterale_), 4 green tree frogs (_Hyla cinerea_) and 1 pine woods tree frog (_H. femoralis_) in stomachs. They also stated that the toad (_Bufo lentiginosus_ [= _terrestris_]) was the most important article of food. Burt and Hoyle (1934:205) wrote that a racer from Rogers County, Oklahoma, had eaten an adult male collared lizard (_Crotaphytus collaris_). In Florida, Carr (1950:80) found one of these black racers eating a leopard frog (_Rana pipiens_). Hamilton and Pollack (1956:523) examined digestive tracts of 62 and found food in 57, comprising the following percentages by volume: _Lygosoma laterale_, 34.2; _Eumeces fasciatus_ and _E. egregius_, 11.3; _Cnemidophorus sexlineatus_, 8.8; _Sceloporus undulatus_, 3.5; undetermined lizard, 3.5; _Opheodrys aestivus_, 6.6; _Diadophis punctatus_, 3.1; _Storeria dekayi_, 1.6; _Coluber constrictor_, 1.8; _Heterodon platyrhinos_, 1.8; _Masticophis flagellum_, 1.8; _Rana_ sp., 5.3; _Hyla cinerea_, 1.8; _Hyla versicolor_, 1.8; _Peromyscus_, 1.8; undetermined rodent, 1.8; lepidopterous larva, 1.7.

In southern Illinois in an intergrading population of racers intermediate between _C. c. priapus_ and _C. c. flaviventris_, Cagle (1942:188) examined several stomachs and found 1 chipmunk (_Tamias striatus_), 2 voles (_Microtus_ sp.), 2 mice (_Peromyscus_ sp.), 2 green snakes (_Opheodrys_ sp.), 1 water snake (_Natrix sipedon_) and grasshoppers. From this same population Klimstra (1959:212) examined 137 digestive tracts of which 115 contained food as follows: 194 locustids, 118 gryllids, 17 undetermined beetles, 13 carabids, 6 scarabaeids, 10 lepidopterans, 9 hemipterans, 1 hymenopteran, 2 homopterans, 1 dipteran, 17 undetermined insects, 73 _Peromyscus_ sp., 19 _Microtus ochrogaster_, 9 _M. pinetorum_, 12 _Sylvilagus floridanus_, 3 _Scalopus aquaticus_, 3 _Rattus norvegicus_, 4 _Mus musculus_, 2 _Tamias striatus_, 2 _Synaptomys cooperi_, 16 _Rana pipiens_, 8 _Acris crepitans_, 2 _Rana clamitans_, 2 _R. palustris_, 1 _R. catesbeiana_, 4 _Hyla crucifer_, 3 _Pseudacris nigrita_, 4 _Lampropeltis calligaster_, 4 _Sceloporus undulatus_, 4 _Chrysemys picta_, 1 _Heterodon platyrhinos_, 1 unidentified reptile, 4 _Sturnella magna_, 1 _Otocoris alpestris_, 4 unidentified birds. Percentages by volume of the various categories in this sample were: insects, 39.1; mammals, 32.9; amphibians, 10.8; reptiles, 8.3; birds, 6.3; miscellaneous, 2.6.

Food of the "buttermilk snake" (_C. c. anthicus_) is known only through Clark's study (1949:249). In an unstated number of examinations he found "mice" in 25, "rats" in five, lizards (_Sceloporus undulatus_ and perhaps others) in eight, frogs (_Rana pipiens_) in seven, and birds in three.

The food of _C. c. stejnegerianus_ is known only from the work of Auffenberg (1949) but his sample was based on 206 racers that had food, among the total of 291 recorded. Unfortunately, he did not present actual numbers of the various prey animals, but divided the food into seven categories and listed these as percentages. He did not indicate whether the percentages represented volumes or numbers of individual occurrences, and evidently there was some error in computation since his combined percentages totalled 111. The categories and their percentages were as follows: grasshoppers, 42.5; crickets, 13.5; miscellaneous insects, .6; earless lizards (_Holbrookia_ sp.), 40.1; scaly lizards (_Sceloporus_ sp.) 2.1; frogs (_Rana_ sp.) 10.0; rodents, 2.2. Auffenberg divided his sample of racers into five size classes, and showed that the smaller snakes fed chiefly on insects whereas vertebrates were increasingly prominent in the food of the larger snakes.

The food of _C. c. mormon_ is known chiefly through the work of Ortenburger (1928:228) who cited instances of a skink (_Eumeces skiltonianus_) and a young garter snake (_Thamnophis sirtalis_) being eaten, and listed the following items from 24 stomachs that he examined: 7 decticids, 8 acridids, 5 oedipines, 1 tryxaline, 6 _Melanoplus_ sp., 3 _M. mexicanus_, 2 _M. devastator_, 1 _M. bivittatus_, 2 _Dissosteira carolina_, 1 _Chortophaga viridis_, 3 _Neduba carinata_, 3 _Trimerotropus_ sp., 7 _Hippiscus_ sp., 2 _Steiroxys_ sp., 3 _Canoula pellucida_, 2 _Stenopelmatus fuscus_, 2 _S. pictus_, 4 _Gryllus assimilis_, 4 _Ceuthophilus_ sp., 1 _Pristoceuthophilus pacificus_, 6 _Gammarotettix bilobatus_ and 2 cicada nymphs. Grinnell, Dixon and Linsdale (1930:149) found that one of these racers had eaten a cricket. Fitch (1936:644) found another in the act of swallowing an adult vole (_Microtus californicus_), and recorded (1935:18) that two alligator lizards (_Gerrhonotus multicarinatus_) were found in the stomach of still another. Woodbury (1931:75) recorded that a racer from Utah had a sagebrush scaly lizard (_Sceloporus graciosus_) in its stomach. Of the specimens examined in the University of California Museum of Vertebrate Zoology, no. 17256 from the Mad River, Trinity County, California, had eaten an alligator lizard (_Gerrhonotus coeruleus_), and no. 10120 from Yolla Bolly Mountain in the same county had eaten a bird (unidentified) and a Jerusalem cricket (_Stenopelmatus_ sp.).

Several authors have published specific information regarding the food of _C. c. flaviventris_. Hurter (1911:171) caught a blue racer in the act of swallowing a copperhead (_Agkistrodon contortrix_). Taylor (1892:331) recorded finding garter snakes in several large racers. Pope and Dickinson (1928:53) recorded instances of blue racers feeding on racerunners (_Cnemidophorus sexlineatus_). Ortenburger (1928:181) examined 22 stomachs and recorded: 1 large garter snake (_Thamnophis sirtalis_), 1 vole (_Microtus pennsylvanicus_), 1 frog (_Rana_ sp.), 31 crickets (_Gryllus assimilis_), 4 decticines, 2 acridids, grasshoppers (1 _Hippiscus_, 2 _Melanoplus_ sp., 1 _M. confusus_, 1 _M. differentialis_, 1 _Dissosteira carolina_, 1 _Sphargemon collare_, 1 _Trimerotropus_ sp., 1 _Orphulella_ sp., 1 _Chloealtis conspersa_, 1 _Chortophaga viridifasciata_, 1 _Omaseus_ sp., 1 _Pedocetes_ sp.), and 2 caterpillars (1 noctuid, 1 sphingid). Gloyd (1928:123) recorded a hatchling glass lizard (_Ophisaurus attenuatus_) in the stomach of a juvenal racer. Force (1930:31) found a racer eating eggs from the nest of a cardinal (_Richmondena cardinalis_) and another racer eating eggs of a red-wing (_Agelaius phoeniceus_). Gloyd (1932:403) recorded an observation of a racer overpowering and swallowing a copperhead. Anderson (1942:210) recorded remains of crickets and grasshoppers in feces. Hudson (1942:55) recorded a racerunner (_Cnemidophorus sexlineatus_) in the stomach of a juvenile and recorded an earless lizard (_Holbrookia maculata_) 3 lizard eggs, and 14 grasshoppers (_Melanoplus differentialis_ and others) in the stomach of another. Marr (1944:484) found a harvest mouse (_Reithrodontomys montanus_) in one. Breckenridge (1944:118) recorded stomach contents including a garter snake (_Thamnophis sirtalis_), a frog (_Rana pipiens_), 3 crickets and 2 moths. Mossimann and Rabb (1952:27) recorded that a racer disgorged several grasshoppers. Fouquette and Lindsay (1955:411) recorded that a blue racer had eaten a harvest mouse (_Reithrodontomys_ sp.). Carpenter (1958:114) recorded that one blue racer had eaten a green snake (_Opheodrys aestivus_) and another had eaten a grasshopper and a camel cricket.

Even though the sets of data cited above are not entirely comparable, certain trends are evident. The black racers of the eastern states (especially _C. c. constrictor_ of more northern regions) take a high proportion of vertebrates in their prey. Among these vertebrates snakes especially are well represented and the black snake would seem to be of some importance as an ophiphagous predator. The birds and mammals taken include some that are bulky (robin, cottontail, and even a weasel--the most formidable prey eaten). Presumably the rabbits that were eaten were young. In samples from the eastern United States insects made up small to insignificant parts of the food; they were lacking entirely or at least were not mentioned in the samples examined by McCauley and Wright and Bishop. In the blue racer of the central states, insects (mostly grasshoppers and crickets) are much more prominent in the food and vertebrates correspondingly less prominent. The vertebrates eaten are largely lizards, small snakes and mice. _C. c. stejnegerianus_ is much like _flaviventris_ in the trend of its feeding. _C. c. mormon_ is less known than these subspecies in its feeding, but indications are that it takes a higher proportion of orthopteran insects and smaller proportions of mammals and snakes than do any of the other subspecies.

In my own field study a total of 1357 food records were accumulated, one of the largest samples known for any kind of snake. Most of these records were from the small area where my population study was carried on, and studies of other kinds of animals, including those that were the racer's prey, were simultaneously in progress. Because large collections of reference materials were available, it was possible to identify to species many of the prey items found, even though they were incomplete and highly fragmented because most of them were recovered from fecal material.

The prey is, of course, swallowed entire, and the recently swallowed items squeezed from the stomachs provide the best material for the study of food habits. However, relatively few racers had detectable food items in their stomachs; digestion is rapid and often the snake was in a trap for a day or more before it was found. Therefore the greater number of records were obtained from scats. The residue in scats consisted entirely of hard and indigestible parts such as the chitin of insects' exoskeletons and the hair, feathers, scales, teeth and occasional bone fragments of the vertebrate prey. The insects eaten could usually be counted individually by sorting parts, such as heads or hind legs. With mammals, birds and reptiles the hair, feathers, or scales did not permit counting of individuals--each occurrence was assumed to represent one individual but in some instances two or more may have been present. Amphibians, lacking indigestible dermal structures were in most instances not represented at all in the scats, since their tissues were more or less completely dissolved by the digestion of the snakes. Soft-bodied larvae of insects and other invertebrates conceivably could be likewise completely digested, but such occurrences must be rare, as most of the invertebrates known to be eaten have the mouth parts, at least, heavily chitinized.

Admittedly the factors discussed above would cause some bias in the percentage composition of the food determined from scats, but I believe that the amount of error introduced was slight, because, judging from the records of items from stomachs, amphibians are not eaten frequently, and even mammals are not eaten frequently enough so that there is much chance of a snake taking two or more individuals at the same meal, unless it is robbing a nest containing a litter of young.

[Illustration: Fig. 13. Diagram showing percentage frequency of occurrence of various categories of prey in a sample of 1008 food items identified from scats and stomachs of blue racers from the Reservation and Rockefeller Tract. Insects, especially, orthopterans, made up the great majority of prey items taken.]

The largest sample, based on 1008 food items, was obtained from 479 scats collected from the Reservation and Rockefeller Tract over the period 1949 through 1961. Items recorded were: 183 gryllid crickets (144 _Gryllus assimilis_, 36 _Gryllus_ sp., 3 unspecified); 353 locustid grasshoppers (41 unspecified, 73 _Arphia simplex_, 67 _Melanoplus femur-rubrum_, 66 _M. bivittatus_, 39 _M. differentialis_, 17 _Melanoplus_ sp., 15 _Dissosteira carolina_, 8 _Chortophaga viridifasciata_, 6 _Syrbula admirabilis_, 6 _Sphargemon equale_, 2 _Melanoplus scudderi_, 2 _Schistocerca obscura_, 1 _S. americana_); 94 camel crickets (_Ceuthophilus_ sp.), 93 katydids (36 _Neoconocephalus robustus_, 15 _Orchelimum vulgare_, 15 _O. nigripes_, 6 _Conocephalus_ sp., 4 _Orchelimum_ sp., 2 _Amblycorypha inasteca_, 1 _Neoconocephalus_ sp., 1 _Daihinia brevipes_); 7 cicadas (5 _Tibicen_ sp., 1 _T. pruinosa_, 1 _T. lyrica_); 45 unidentified insects; 17 beetles (including 1 _Phyllophaga_, 1 _Calosoma scrutator_, and 2 other carabids); 2 noctuid moths (_Mocis latipes_) and 1 caterpillar; 2 homopterans, 1 bee, 1 ant, 1 spider; 69 voles (59 _Microtus ochrogaster_, 9 _Microtus_ sp., 1 _M. pinetorum_); 31 white-footed mice (15 _Peromyscus leucopus_, 14 _Peromyscus_ sp., 1 _P. maniculatus_); 36 miscellaneous small mammals (6 _Cryptotis parva_, 4 _Sigmodon hispidus_, 4 _Reithrodontomys megalotis_, 3 _Blarina brevicauda_, 2 each of _Scalopus aquaticus_, _Sylvilagus floridanus_, and 1 unspecified shrew); 50 snakes (16 _Coluber constrictor_, 15 _Diadophis punctatus_, 14 _Thamnophis sirtalis_, 4 _Elaphe obsoleta_, 1 _Natrix sipedon_); 7 lizards (5 _Eumeces fasciatus_, 1 _E._ _obsoletus_, 1 _Cnemidophorus sexlineatus_); 3 unspecified "reptiles"; 5 birds (none identified to genus); 3 bird eggs, 1 narrow-mouthed toad (_Gastrophryne olivacea_).

[Illustration: Fig. 14. Diagram showing estimated percentage by weight of various categories of prey in a sample of 1351 items, including all those represented in Fig. 13 and others from various parts of Kansas. Since the vertebrate items are on the average much bulkier than the insects eaten, vertebrates comprise most of the food, even though insects are eaten in much larger numbers.]

[Illustration: Fig. 15. Diagram showing estimated percentages by weight of various categories of prey in a sample of 69 food items squeezed out of stomachs of the blue racers captured at Harvey County Park. Most of the items were vertebrates, and lizards (_Cnemidophorus_) were especially prominent in the food at this locality. Samples of prey from scats (included in Figs. 13 and 14) and from stomachs show somewhat different trends, and neither is entirely representative of the actual feeding. Also, local differences in food sources are important.]

Over the same period that the sample of scats was collected, a much smaller food sample of 73 prey items was collected by squeezing recently eaten food from the racers' stomachs, or by finding the snakes actually swallowing their prey. These items from stomachs are listed separately because they include relatively more vertebrates than do the items from scats. A grasshopper or cricket eaten by a large racer might have passed undetected, while a relatively large item such as a vole or lizard would have produced a conspicuous bulge in the snake that ate it, and would have excited the curiosity of the investigator. A second difference is that the items from stomachs included several frogs, whereas amphibians were absent from the much larger sample from scats. A third difference is that the many insects found in stomachs were all orthopterans with the exceptions of three noctuid moths and the larva of a moth. Miscellaneous insects, such as beetles, bees and ants recorded from scats were not found in stomachs. Amphibians eaten are digested so completely that no recognizable parts of them are to be found in scats, but remains of the insects previously eaten by amphibians are to be seen in racers' scats. If not recognized as secondary items, such remains might lead to erroneous conclusions regarding the racer's food.

The items from stomachs were as follows: 21 grasshoppers (5 oedipines, 4 tryxalines, 5 _Melanoplus bivittatus_, 3 _M. differentialis_, 1 _M. femur-rubrum_ and one each of _Chortophaga viridifasciata_, _Dissosteira carolina_, and _Sphargemon equale_); 8 crickets (_Gryllus_ sp.), 3 katydids, 3 camel crickets (_Ceuthophilus_ sp.), 3 noctuid moths, 1 larva of a moth; 10 voles (_Microtus ochrogaster_), 6 white-footed mice (5 _Peromyscus leucopus_ and 1 _P. maniculatus_), 4 harvest mice (_Reithrodontomys megalotis_); 1 shrew (_Cryptotis parva_); 4 snakes (3 _Thamnophis sirtalis_, 1 _Storeria dekayi_); 4 lizards (2 _Eumeces obsoletus_, 1 _Cnemidophorus sexlineatus_, 1 _Ophisaurus attenuatus_); 4 frogs (_Rana pipiens_), 1 tree-frog (_Hyla versicolor_).

Records from the Harvey County, Kansas study area include a series of 69 food items from 55 stomachs (of living snakes) and 210 food items from 113 scats. There is a relatively high proportion of vertebrates, including some frogs, in the stomachs, and with no frogs but more miscellaneous insect material in the scats. But, for the sake of brevity, the two categories of items are combined in the following list: 55 grasshoppers (12 unspecified, 1 "locustid," 31 "oedipines," 7 "tryxalines," 5 "locustines," 2 _Melanoplus bivittatus_ and one each of _M. femur-rubrum_, _M. scudderi_, _M. differentialis_, and _Arphia simplex_); 48 crickets (31 _Gryllus assimilis_, 17 unspecified); 14 katydids (11 _Daihinia brevipes_, one each of rhadiphorine, conocephaline and _Neoconocephalus_ sp.); 9 noctuid moths and 1 moth larva; 26 miscellaneous insects (including 13 "beetles," 1 elaterid, 1 curculionid, 1 lygaeid bug, 1 ant, 1 wasp); 1 spider, 7 mice (5 _Peromyscus maniculatus_, 2 unspecified), 4 unidentified mammals, 1 vole (_Microtus ochrogaster_), 1 shrew (_Cryptotis parva_), 84 lizards (77 _Cnemidophorus sexlineatus_, 6 _Sceloporus undulatus_, 1 unspecified), 6 snakes (4 "natricines," 1 _Thamnophis_ sp., 1 _Pituophis melanoleucus_), 1 "reptile," 1 "bird," 9 frogs (4 unspecified, 1 _Rana catesbeiana_, 4 _Rana pipiens_, 1 _Rana_ sp., 1 _Pseudacris triseriata_).

_Kinds of Prey_

Throughout the range of the racer small mammals make up an important portion of the food, and the bulk of those eaten are voles (_Microtus_ sp.) and white-footed mice (_Peromyscus_ sp.). The voles being diurnal, and having habitat preferences similar to those of the racer, are especially subject to attack, but only large adult racers are capable of swallowing a full grown vole. Probably most of the voles eaten are immature. Of the white-footed mice, _P. maniculatus_ especially prefers a grassland habitat, and is usually found in situations frequented by the racer. Being mainly nocturnal and crepuscular, it is usually in hiding at times when the racer is prowling, but may be flushed from its nest in a shallow burrow or beneath a sheltering object, and overtaken by the snake. Other mammals that are important in the food are harvest mice and other mice, shrews, and young cottontails. The latter are small enough to be eaten by racers only in the early stages of their life in the nest before weaning. Rats (_Rattus_, _Sigmodon_), moles, sciurids, and weasels are less frequent prey, ordinarily too large to be eaten by racers and taken chiefly as defenseless juveniles.

Predation on birds is relatively uncommon, and in most instances it involves the eggs or nestlings, or fledglings still slow and clumsy and incapable of sustained flight, or, occasionally, injured adults. Nests that are vulnerable are chiefly those of ground nesting species, or of kinds that nest near the ground in grass or thickets. Many of the birds recorded have not been identified to species, but those identified have included a variety of small passerines and also domestic chicks.

Lizards figure prominently in most of the food samples, but only a few species, those that live on or near the ground in grassy places, have been recorded. Most of the records pertain to scaly lizards (_Sceloporus undulatus_ and _S. graciosus_), earless lizards (mainly or entirely _Holbrookia maculata_), racerunners (_Cnemidophorus sexlineatus_) and skinks (_Lygosoma laterale_ and _Eumeces_ sp.).

Snakes are important in the racer's food in most parts of the range, but the large racers of the Northeast are those most inclined to ophiphagous habits. The common garter snake (_Thamnophis sirtalis_) is the species most commonly eaten. Probably this is a matter of availability rather than preference, since the garter snake is one of the commonest and most widely distributed of North American snakes, occurring throughout most of the racer's range. The green snakes (_Opheodrys_) also are represented frequently. The other snakes eaten are mostly medium-sized to small colubrids, of a variety of kinds. However, there are three records (from Connecticut, Missouri and Kansas) of the racer preying on the venomous copperhead. There are many records of the racer preying on smaller individuals of its own species. In my own records racer remains appeared 18 times, equalling in frequency those of the common garter snake and exceeding all other kinds. In four of these instances the scale remains were relatively few and the scales were relatively large, suggesting as an alternative to actual predation that a racer may have eaten part of its own sloughed skin, or that patches of shed skin may have adhered to the scat after its deposition in the trap. However, in the remaining 14 instances the remains of racer found in scats clearly indicated cannibalism, since the scales found were small and numerous and often were associated with bone. Cannibalism seems to occur frequently enough to be a significant factor in the reduction of the first year young. Liner (1949:230) described two instances of cannibalism in a litter of blue racers hatched in captivity. In one instance two young had seized the same lizard, and one having swallowed the lizard, continued to engulf the other snake, although it was of a size approximately equal to that of the first snake. Nevertheless, swallowing was completed, with the snake eaten pressed in a series of curves. A second instance of cannibalism occurred when one young racer attempting to catch a lizard struck another racer by mistake, then retained its hold and commenced swallowing. A similar instance was observed in a brood that I kept in 1962 after hatching had occurred in the laboratory.

Hatchling turtles of two kinds (_Chrysemys picta_, _Terrapene carolina_) have been reported in the racer's food. Probably other kinds are eaten also. However, the awkward shape and almost inflexible shell of the prey on the one hand, and the slender form of the racer, with limited distensibility of the gullet on the other, would limit this type of predation to occasional instances involving an unusually large racer and a small turtle.