Thomas S. Baskett

Emergence, Breeding, Hibernation, Movements and Transformation of the Bullfrog, Rana catesbeiana, in Missouri

M ANY aspects of the life history of the bullfrog (Rana catesbeiana Shaw) remain little investigated, despite its importance as a game and laboratory animal, and its widespread distribution in North America. The most comprehensive information on the life history of the species is to be found in writings of Wright (1914, 1920) and Wright and Wright (1949, and earlier editions). A general account was presented by Dickerson (1931). Detailed studies of several phases of the life history of the species in Louisiana were made by George (1940). In New York, Raney (1940) and Ingram and Raney (1943) reported movements of the bullfrog; growth rates were investigated by Raney and Ingram (1941) and Ryan (1953). In Missouri, food habits of the bullfrog have been studied in detail by Korschgen and Moyle (in press). These substantial contributions have been augmented by several brief scientific papers, and by popular accounts originating in various states. Nevertheless, the bullfrog has received considerably less attention from researchers than have game fishes, birds, and mammals of similar importance. In Missouri, high rank in the commercial production of bullfrogs was achieved many years ago. In 1908, the commercial harvest of frogs was higher in Missouri than in any other state (U. S. Department of Commerce and Labor, 1911). Bullfrogs undoubtedly contributed a large share of this take. After the early 1900s, the bullfrog resource declined, but the recent expansion of habitat resulting from construction of thousands of farm ponds in this state has set the stage for recovery. Bullfrog populations sufficiently large to afford sustained hunting for sport, at least can be hoped for. This study was undertaken to provide information on the life history and management of the bullfrog in Missouri. The work was begun in February, 1950, and some data were collected as late as April, 1954. During the first 2 years, the work was performed by Moyle, and was confined to farm ponds, most of which were located in Boone County in central Missouri. These ponds ranged from one-fourth acre to 2 acres in area and had maximum depths of from 6 to 15 feet; many of the ponds were of a type approved for construction subsidies and for fish stocking by federal and state agencies. In the second two-year period, the study was made by Willis. The 1952 collections were also made in central Missouri farm ponds, but in 1953, some streams in central Missouri, and ponds in the southwestern portion of the state were included.

Presence and biomagnification of organochlorine chemical residues in oxbow lakes of northeastern Louisiana

Ninety-eight samples of 16 species of animals were collected at Lake Providence, 88 samples of 15 species at Lake Bruin, and 21 samples of 5 species at Lake St. John, Louisiana, between 15 July and 25 September 1980. Residues of 13 organochlorine compounds were identified in these samples. Substantial concentrations of many of these compounds throughout the food webs of all three lakes showed that the lakes act as sumps, accumulating residues from nearby agricultural land. DDT and its metabolites (DDE, TDE, and DDMU), toxaphene, and polychlorobiphenyls (PCBs) were the principal Organochlorine residues detected. With few exceptions, biomagnification of the principal residues was clearly illustrated. Tertiary consumers such as green-backed heron (Butorides striatus), snakes, spotted gar (Lepisosteus oculatus), and largemouth bass (Micropterus salmoides) contained the highest residues. Bluegill (Lepomis macrochims), blacktail shiner (Notopis venustus), yellow-crowned night-heron (Nycticorax violaceus), and other secondary consumers contained lower levels of residues. Primary consumers, crayfish (Orconectes lancifer) and threadfin shad (Dorosoma petenense), contained relatively low residue levels of most of the compounds. Frogs contained lower residue levels than expected based on their position in the food web. It is suggested that residue levels in immature green-backed herons and one or more of the longer-lived predators such as snakes, gars, or largemouth bass could be monitored to evaluate levels of Organochlorine chemical contaminants in aquatic habitats.

Age Estimation, Growth Rates, and Population Structure in Missouri Bullfrogs

vocal sac; ovary packed with heavily pigmented eggs each approximately 1.5 mm in diameter. Skin of head not co-ossified with skull, roof of skull not exostosed. Dimensions.-Head and body 57.0 mm; head length 20.5 mm; head width 19.8 mm; femur 32.3 mm; tibia 32.2 mm; heel-to-toe 40.0 mm; hand 17.0 mm. Color in alcohol.-A dingy white with tiny melanophores scattered over all dorsal surfaces but restricted to a narrow band on top of the thigh. Notes.-When we examined this specimen in Paramaribo just a few weeks after it was preserved it still retained some of the dark green dorsal pigmentation it had in life but by the time it was shipped to us from Pittsburgh nearly a year later the green coloration had completely faded and all that remained of pigment or pattern was minute, scattered melanophores on the dorsum and dorsal surfaces of the limbs. These have the effect of making the specimen a dirty white rather than clear milky white. The type was taken at night from a large aroid plant beside a house in the Arawak village of Powakka. A diligent search by five of us in the same area a few weeks later failed to turn up any more specimens. Mr. Walter Polder of Paramaribo, who is well acquainted with the local fauna, told us that he caught an individual of what he believes is the same species in the suburbs of Paramaribo but that it escaped before he was ready to preserve it. The type-specimen is filled with mature, pigmented eggs and apparently was ready for amplexus. The species is named in honor of our friend, Murray de la Fuente, who collected the type.

Metals in riparian wildlife of the lead mining district of southeastern Missouri

Five species of riparian vertebrates (425 individuals) primarily representing upper trophic levels were collected from the Big River and Black River drainages in two lead mining districts of southeastern Missouri, 1981–82. Big River is subject to metal pollution via erosion and seepage from large tailings piles from inactive lead mines. Black River drains part of a currently mined area. Bullfrogs (Rana catesbeiana), muskrats (Ondatra zibethicus), and green-backed herons (Butorides striatus) collected downstream from the source of metal contamination to Big River had significantly (ANOVA, P<0.05) higher lead and cadmium levels than specimens collected at either an uncontaminated upstream site or on Black River. Northern water snakes (Nerodia sipedon) had elevated lead levels below the tailings source, but did not seem to accumulate cadmium. Levels of lead, cadmium, or zinc in northern rough-winged swallows (Stelgidopteryx serripennis) were not related to collecting locality. Carcasses of ten bank swallows (Riparia riparia) collected from a colony nesting in a tailings pile along the Big River had lead concentrations of 2.0–39 ppm wet weight. Differences between zinc concentrations in vertebrates collected from contaminated and uncontaminated sites were less apparent than differences in lead and cadmium. There was little relationship between metal concentrations in the animals studied and their trophic levels. Bullfrogs are the most promising species examined for monitoring environmental levels of lead, cadmium, and zinc. Downstream from the source of tailings, bullfrogs had markedly higher levels of these metals in most of their tissues. The species is also widely distributed in North America, easily caught, and relatively sedentary.

Mobility of Missouri deer and their harassment by dogs

There is little information on the mobility of the white-tailed deer (Odocoileus virginianus) in the middle United States; data are equally limited on the mobility of whitetails on land that is primarily agricultural or where there is yearlong harassment by dogs. The present study was made under all those conditions. It was based principally upon repeated observations of individually marked deer rather than upon kill records of tagged animals, which have often been the principal source of movement data for deer. The study was carried out on the University of Missouris Ashland Wildlife Research Refuge in Boone County and on adjacent private farmland. Most of the 2,240-acre refuge is forested with secondgrowth oak and hickory. Few stands of mature timber are found, but mast-producing trees are abundant. Large, bottomland corn fields are nearby, and small, ridge-top openings are planted to crops or are in various stages of old-field succession. The deer population in this locality probably did not exceed 20 per square mile during the study. Snow was never deep, and the deer did not yard. The period of intensive study was September 1952 to May 1956, but some data were gathered as early as March 1951, and as late as November 1957. Deer were captured in modified Stephenson-type traps baited with ear corn and stock salt. Although trapping was carried on intermittently throughout the year, most of it was done during the winter and spring. The animals were marked individually in various ways. All except those recognized by distinctive antler shapes or other natural markings were tagged with plastic discs that were attached to the ears with button-type stock tags. Several ear-tagged deer were also marked with small bells attached to dog collars or with wide, colored collars, as described by Progulske (1957). Searches for marked deer were made by varied methods: on foot, from a tower, blind, automobile, small airplane, and by trailing in the snow; a few records were obtained from hunting recoveries. Although there is probably some bias in favor of the more sedentary deer, deliberate attempts were made to avoid this by varying methods, routes, and times, and by frequent searches for marked deer several miles from any trap. One hundred ninety-four records of movement were obtained for 31 deer identified by the markings described above. These included 17 recognizable adult bucks, 11 adult does, and 3 fawns. Nine other deer were tagged but not seen again. An adult doe, tagged in November 1954, was shot in November 1957; this 36-month span was the longest for any of the marked deer. The greatest number of records for any one animal was 30; this number was obtained both for a doe shot 19 months after being tagged, and for a buck last seen 6 months after being marked.

Evaluating cultivation near duck blinds to reduce lead poisoning hazard.

After 10 years of hunting on a state waterfowl area in Missouri, lead shot in 215 soil samples taken 5.1 cm deep in front of 2 fixed blinds were more than 4 times as numerous in uncultivated as in cultivated soils. In 220 soil samples taken 9 years later in front of 5 blinds, percentage of shot content of 5 cm soil strata sampled to a depth of 25 cm differed significantly in samples from recently cultivated areas vs. samples from less recently and less frequently cultivated check areas. The top 5 cm stratum contained 66.5 percent of the shot in check areas but only 45.0 percent in recently cultivated areas. Where water control and soil conditions permit, cultivation near hunting blinds can lessen the availability of residual lead shot to waterfowl by burying it more deeply in the soil.

REPRODUCTION AND DEVELOPMENT IN CONFINED SWAMP RABBITS1

Swamp rabbits (Sylvilagus aquaticus) in a 2-acre enclosure and in smaller pens (23 X 48 ft) were studied throughout the 1965 breeding season and portions of the 1964 and 1966 seasons. The captive population at the start of the 1965 breeding season consisted of 8 males and 13 females; in 1966 there were 6 males and 17 females. Earliest littering occurred about March 18 in 1965 and about February 11 in 1966. Most final litters were born from late June to mid-July, but three were born in August and one in September. Females in pens had first litters later than females in the enclosure. In 1965, yearlings had first litters about as early as older rabbits; in 1966, under more crowded condi- tions, they littered later than older rabbits. Postpartum estrus was the rule, and synchrony in breeding was common. Gestation periods ranged from 35-39 days. Litter size increased from first to second litters, then decreased in later litters. Females surviving throughout the breeding season had 2-5 litters. Eyes of young opened at about 1 week, and young left the nest at about 2 weeks. They continued to nurse for a period after emerging from the nest. Young born late in the breeding season initially grew faster Abstract: Swamp rabbits (Sylvilagus aquaticus) in a 2-acre enclosure and in smaller pens (23 X 48 ft) were studied throughout the 1965 breeding season and portions of the 1964 and 1966 seasons. The captive population at the start of the 1965 breeding season consisted of 8 males and 13 females; in 1966 there were 6 males and 17 females. Earliest littering occurred about March 18 in 1965 and about February 11 in 1966. Most final litters were born from late June to mid-July, but three were born in August and one in September. Females in pens had first litters later than females in the enclosure. In 1965, yearlings had first litters about as early as older rabbits; in 1966, under more crowded condi- tions, they littered later than older rabbits. Postpartum estrus was the rule, and synchrony in breeding was common. Gestation periods ranged from 35-39 days. Litter size increased from first to second litters, then decreased in later litters. Females surviving throughout the breeding season had 2-5 litters. Eyes of young opened at about 1 week, and young left the nest at about 2 weeks. They continued to nurse for a period after emerging from the nest. Young born late in the breeding season initially grew faster than other young. No evidence of juvenile breeding was found.

Cholinesterase inhibition of birds inhabiting wheat fields treated with methyl parathion and toxaphene

Red-winged blackbirds (Agelaius phoeniceus) and dickcissels (Spiza americana) inhabiting wheat fields treated with 0.67 kg AI/ha methyl parathion and 1.35 kg AI/ha toxaphene showed brain cholinesterase (ChE) inhibition compared with birds inhabiting untreated fields. Maximum inhibition occurred about five days after insecticide application. ChE activities again approached “normal” 10 days after treatment. ChE inhibition for dickcissels and red-winged blackbirds differed significantly (p<0.05); maximum inhibition for the former species was 74%, and for the latter, 40%. These differences could not be explained by the diets of the two species, as they were similar.

Parental Behavior in Swamp Rabbits

Parental behavior of confined swamp rabbits ( Sylvilagus aquaticus ) was studied in a 2-acre enclosure and in four adjacent pens (23 by 48 feet). Observations were made from July 1964 to April 1966, on a breeding population numbering from 14 to 23 rabbits. Most of 47 active nests examined were built against or under fences, bases of trees, boards, lean-to shelters, and similar structures. Some nests were built a few days prior to parturition, but others apparently were built on the night of parturition. Females often built dummy nests, and about half as many dummy as active nests were found. Females littering on about the same date sometimes built nests close together. One closely-observed female lined her nest with fur immediately before, and nursed her young immediately after, parturition. Young were occasionally scattered at birth. Dawn and dusk appeared to be the favored times for nursing the young. Nursing periods were commonly 10 to 20 minutes long. When young were in the nest, the nursing female sat in front of the nest and rolled her body forward over the entrance; when the young were older, and out of the nest, she simply crouched on all four legs. By manipulation, milk could often be expressed from teats, but this was not a reliable indicator of nursing status or recency of parturition. Distress cries of young sometimes attracted the mother. Females made no effort to move their young to safety when high water flooded the nests. Strange young placed in nests were readily adopted. In spite of frequent human disturbance, only one nestling litter was abandoned. Males showed no parental interest.

Effects of Radio-Tagging on Breeding Behavior of Mourning Doves

Cooing rates of captive unmated male mourning doves (Zenaida macroura) decreased markedly during a 2-day adjustment period following radio-tagging. In 4 of 7 experimental trials, cooing rates returned to previous levels by the 3rd day. In the other 3 trials cooing rates remained low, but dominance problems related to penning may have been a factor. In 4 of 6 experimental trials, captive radio-tagged males successfully paired with introduced females and began nesting. In the wild, 2 of 5 unmated radiotagged males successfully paired. Cooing rates of free-flying unmated radio-tagged males were comparable to those of back-tagged males in previous studies (8.7 vs. 8.2-8.9 coos/3 min). Based on 12 experimental trials and observations of 24 free-flying radio-tagged doves (both sexes), radio-tagging did not adversely affect previously established pair bonds. J. WILDL. MANAGE. 45(2):428-434 Radiotelemetry has been used extensively in avian research, but few thorough evaluations of effects of radio packages on behavior have been made. Inferences usually are drawn from field observations, although some have been based on controlled experiments; reported effects varied greatly with the species studied. Major studies include Ramakkas (1972) findings that radio-tagging resulted in reduced courtship and atypical breeding behavior in male woodcock (Philohela minor). In controlled experiments, captive red grouse (Lagopus 1. scoticus) consumed less food and were less active following radio-tagging (Boag 1972); however, breeding performance was not affected if radio packages were attached late in incubation (Lance and Watson 1977). Female willow grouse (L. 1. lagopus) adapted to the radio package and incubated and hatched their eggs normally (Erikstad 1979). In an experimental study, Greenwood and Sargeant (1973) observed that radio-tagged mallard (Anas platyrhynchos) and bluewinged teal (A. discors) preened more than controls and exhibited a partial aversion to swimming. However, Gilmer et al. (1974) believed that social and breeding behaviors of instrumented mallards and wood ducks (Aix sponsa) were not adversely affected by radio packages. This study evaluated the effects of radio-tagging on the breeding behavior of mourning doves based upon controlled experiments with penned birds and observations of free-flying radio-tagged doves. We thank M. A. Parker and L. L. Wollard for technical aid; S. S. Clark, E. K. Fritzell, and F. B. Samson for editorial suggestions; and K. C. Sadler for advice and administrative support. METHODS AND MATERIALS Pen studies were conducted from May to August 1976-78. Three experiments 1Contribution from the Missouri Cooperative Wildlife Research Unit (U.S. Fish and Wildlife Service, Wildlife Management Institute, Missouri Department of Conservation, and University of Missouri, cooperating). Research was funded by the Accelerated Research Program for Migratory Shore and Upland Game Birds, Contract USDI 14-160008-2091, administered by the Missouri Department of Conservation through agreement with the University of Missouri. Work was supported in part by Missouri Agricultural Experiment Station Projects 182 and 184; this is Journal Series paper 8441. 428 J. Wildl. Manage. 45(2):1981 This content downloaded from 207.46.13.112 on Mon, 03 Oct 2016 05:08:23 UTC All use subject to http://about.jstor.org/terms RADIO-TAGGING BREEDING MOURNING DOVES* Sayre et al. 429 were designed to evaluate behavioral effects associated with radio-tagging during different stages of pairing or nesting.