Small Frogs Research Articles

Feeding habits of the frog Pleurodema diplolistris (Anura, Leptodactylidae) in Quaternary sand dunes of the Middle Rio São Francisco, Bahia, Brazil

In this work, we investigate the feeding habits of Pleurodema diplolistris, the most abundant anuran species of the São Francisco sand dunes, during a period of slightly over one year. The fieldwork was undertaken during four excursions to a sand dune in the semiarid Caatinga, Brazil, and the analyses were based on stomach contents. Pleurodema diplolistris were not active during the dry season. The important food categories in diet were Isoptera (winged forms), Coleoptera, and Formicidae. Small and large animals had different food consumption patterns: small frogs showed positive electivity for termites and large frogs, for ants. This pattern was strongly influenced by large male food electivity. High levels of termites consumption occurred during the days of greater capture success. The pattern of high consumption of termites detected here is different from that described in another study on lizards from the same locality and sampled in the same periods. We discuss alternative hypotheses that could explain the observed patterns.

Chondrocranial, hyobranchial and internal oral morphology in larvae of the basal bufonid genus Melanophryniscus (Amphibia: Anura)

Abstract Melanophryniscus is a genus of small toads inhabiting the southern portion of South America. This genus is considered basal within the family Bufonidae. Data on larval chondrocranial morphology do not exist for the genus and larval internal oral anatomy has only been described for a single species. Here, we describe chondrocranial and internal oral morphology in Melanophryniscus montevidensis , M. orejasmirandai and M. sanmartini . Chondrocranial morphology is similar among the species examined. Comparisons with other bufonids and with outgroup taxa suggest that the following chondrocranial characters may represent synapomorphies for the Bufonidae: free (or absent) ceratobranchial IV, a reduced or absent larval crista parotica, the lack of a larval otic process, and late development of thin, poorly chondrified orbital cartilages. The presence of an elongated processus anterior dorsalis of the suprarostral alae and the absence of a chondrified commissura quadratoorbitalis appear to be unique in Melanophryniscus among bufonids. Internal oral anatomy is conserved in Melanophryniscus , and among bufonids in general.

Two Unknown Arboreal Frogs (genus Platypelis) Described from the Rainforests of Northeastern Madagascar (Microhylidae: Cophylinae)

Two new arboreal microhylid frogs are described from the rainforests of northeastern Madagascar. Platypelis tetra is a very small frog, reaching about 20mm SVL, and inhabits phytotelms in screw Pandanus pines. It was found in some low and mid-altitude rainforests, such as Anjanaharibe-Sud, Besariaka, Tsararano, and Masoala Peninsula. This species diverges from the other Platypelis by its small size and colouration, with a series of whitish spots on the back, of which four are more evident. Furthermore, its advertisement call is composed by a long series of discrete notes at about 3.5-4KHz of frequency, and a repetition rate of about 3.0 notes/s. The second species, Platypelis mavomavo, reaches a larger size (about 30mm SVL), and is characterized by a yellowish colouration of the ventral surface, and a dorsal surface with a network of dark spots on a beige-yellow background. It is currently known from Anjanaharibe-Sud and Ambolokopatrika, around the Andapa water-basin, but is expected to have a wider distribution.

Cryptic lineages in a small frog: the post-glacial history of the spring peeper, Pseudacris crucifer (Anura: Hylidae)

The spring peeper ( Pseudacris crucifer) is believed to have been a primary herpetological invader of eastern North America following the most recent period of glacial retreat. We examined the phylogeographic pattern and population structure of P. crucifer to determine whether the distribution of haplotypic variants reflect post-Pleistocene recolonization dynamics. A number of geographically isolated evolutionary lineages were supported by both maximum parsimony and neighbor-joining analyses, and by coalescence approaches applied to mtDNA. South-western Ontario represents a high level of genotypic diversity ( π) due to the presence of two divergent lineages. The geographic distribution of these lineages are interpreted as reflecting post-glacial recolonization dynamics from separate, isolated refugia during the late Pleistocene that have come into secondary contact in SW Ontario. The phylogenetic placement of haplotypes from the range of P. crucifer bartramiana (Florida and South Carolina) does not allow for monophyly of P. crucifer crucifer, and therefore the bartramiana subspecies designation does not reflect a separate evolutionary lineage.

Diet, Reproduction, and Density of the Leptodactylid Litter Frog Zachaenus parvulus in an Atlantic Rain Forest of Southeastern Brazil

Amphibians and reptiles are important constituents of leaf litter communities in tropical forests (Fauth et al., 1989; Allmon, 1991; Vitt and Caldwell, 1994). Forest floor leaf-litter frogs forage for arthropods (Toft, 1980a,b), and three general guilds can be recognized depending on the proportions of different kinds of prey: ant specialists, non-ant specialists, and generalists (Toft, 1980a). In general, leptodactylid frogs are considered non-ant specialists eating predominantly soft-bodied, mobile arthropods, mainly orthopterans and spiders (Toft, 1980a,b, 1995). Zachaenus parvulus is a small leptodactylid frog, which occurs among the floor litter of the Atlantic rain forest of eastern Brazil (Duellman and Trueb, 1986; Rocha et al., 1998). Information on the species is restricted to data on reproduction (Lutz, 1944) and defense tactics (Sazima, 1978; Rocha et al., 1998), with almost nothing known about other aspects of its biology. In the Atlantic rain-forest leaf-litter anuran community that we studied, Z. parvulus is the second most abundant species (after the brachycephalid Psyllophryne didactyla). Herein, we report an investigation of some aspects of the ecology of Zachaenus parvulus providing information on its diet, reproduction, and density at Ilha Grande, Brazil. The study site was in the Atlantic rain forest at Ilha Grande (23?10'558S; 44?12'499'W), an island in southern Estado do Rio de Janeiro, southeastern Brazil (Fig. 1), at an elevation of approximately 240 m. Rainfall is seasonal, with mean annual rainfall of 2240 mm and monthly averages ranging from 87 mm (July) to 293 mm (January; Bittencourt, 1998). Mean air temperature is 22.5?C, with February being the hottest month (25.7?C) and July the coldest (19.6?C; Bittencourt, 1998). Ilha Grande is covered by Atlantic rain forest with different levels of succession resulting from disturbances caused by human activities through the last centuries (Araujo and Oliveira, 1988). The study area consists of a remnant of undisturbed Atlantic rain forest with trees reaching 30 m, covered by bromeliads and vines, and with a relatively deep leaf-litter layer (80-150 mm). From August 1996 to November 1997 frogs were

PREDATOR EFFECTS ON AN ASSEMBLAGE OF CONSUMERS THROUGH INDUCED CHANGES IN CONSUMER FORAGING BEHAVIOR

This investigation examines how a predator-induced reduction in activity of a prey species (a “nonlethal” predator effect) affects the growth rate of the prey and, indirectly, the growth rate of competitors of the prey. We further determine how the magnitudes of these effects depend on density of the prey species. We develop a foraging model that predicts a predator will reduce the growth of a focal prey species at low prey density but have little effect at high prey density. The model also predicts that presence of the predator will indirectly facilitate growth of a competitor of the focal species, and that this effect will be negligible at low, and maximal at high, focal species density. Thus it is precisely where the effect of the predator on the growth of the focal species is minimum that the indirect effect on the competitor is maximum. We tested these predictions using a system of three species/size classes of anuran larvae and a larval odonate predator (Anax longipes) in cattle watering tanks. By caging the predator we isolated its effect on foraging behavior of the anuran larvae from that of density reduction. We manipulated the density of small green frog larvae (Rana clamitans) while holding density of small bullfrog (R. catesbeiana) and large green frog competitors constant. Small green frogs and bullfrogs reduce their activity in the presence of caged Anax whereas the large green frogs do not. Results were in accord with the model predictions. Caged Anax reduced small green frog and bullfrog growth at low small green frog density but had no effect at high small green frog density. In contrast, caged Anax had a positive effect on large green frog growth, but this effect was negligible at low small green frog density and maximal at high small green frog density. The results also showed that the indirect effects of the predator that arose through reduction in prey foraging activity were comparable in magnitude to those expected through reduction in prey density. These results suggest that the nonlethal effects of a predator on prey and, indirectly, on competitors of their prey, can be large in magnitude and depend strongly on relative species densities.

Predator Effects on an Assemblage of Consumers through Induced Changes in Consumer Foraging Behavior

This investigation examines how a predator-induced reduction in activity of a prey species (a “nonlethal” predator effect) affects the growth rate of the prey and, indirectly, the growth rate of competitors of the prey. We further determine how the magnitudes of these effects depend on density of the prey species. We develop a foraging model that predicts a predator will reduce the growth of a focal prey species at low prey density but have little effect at high prey density. The model also predicts that presence of the predator will indirectly facilitate growth of a competitor of the focal species, and that this effect will be negligible at low, and maximal at high, focal species density. Thus it is precisely where the effect of the predator on the growth of the focal species is minimum that the indirect effect on the competitor is maximum. We tested these predictions using a system of three species/size classes of anuran larvae and a larval odonate predator (Anax longipes) in cattle watering tanks. By caging the predator we isolated its effect on foraging behavior of the anuran larvae from that of density reduction. We manipulated the density of small green frog larvae (Rana clamitans) while holding density of small bullfrog (R. catesbeiana) and large green frog competitors constant. Small green frogs and bullfrogs reduce their activity in the presence of caged Anax whereas the large green frogs do not. Results were in accord with the model predictions. Caged Anax reduced small green frog and bullfrog growth at low small green frog density but had no effect at high small green frog density. In contrast, caged Anax had a positive effect on large green frog growth, but this effect was negligible at low small green frog density and maximal at high small green frog density. The results also showed that the indirect effects of the predator that arose through reduction in prey foraging activity were comparable in magnitude to those expected through reduction in prey density. These results suggest that the nonlethal effects of a predator on prey and, indirectly, on competitors of their prey, can be large in magnitude and depend strongly on relative species densities.

Short Notes

Short Notes On the taxonomic status of Hyla goinorum Bokermann, 1962 (Amphibia, Anura, Hylidae) Ignacio De la Riva Museo Nacional de Ciencias Naturales, CSIC, C/ José Gutiérrez Abascal 2, 28006 Madrid, Spain e-mail: delariva@mncn.csic.es Bokermann (1962) described the small Amazonian hylid frog Hyla goinorum from Tarauacá, State of Acre, Brazil. In the original description, the author considered it somewhat similar to Hyla parkeri Gaige and allied species, but also similar to some dendrobatid frogs. Bertha Lutz (1973) placed H. parkeri and some other species (namely H. lindneri Müller & Hellmich, and H. madeirae Bokermann) in the synonymy of H. fuscomarginata

Matrix habitat and species richness in tropical forest remnants

The abilities of species to use the matrix of modified habitats surrounding forest fragments may affect their vulnerability in fragmented landscapes. We used long-term (up to 19-year) studies of four animal groups in central Amazonia to test whether species' abundances in the matrix were correlated with their relative extinction proneness in forest fragments. The four groups, birds, frogs, small mammals, and ants, had varying overall responses to fragmentation: species richness of small mammals and frogs increased after fragment isolation, whereas that of birds and ants decreased. For all four groups, a high proportion of nominally primary-forest species were detected in matrix habitats, with 8–25% of species in each group found exclusively in the matrix. The three vertebrate groups (birds, small mammals, frogs) exhibited positive and significant correlations between matrix abundance and vulnerability to fragmentation, suggesting that species that avoid the matrix tend to decline or disappear in fragments, while those that tolerate or exploit the matrix often remain stable or increase. These results highlight the importance of the matrix in the dynamics and composition of vertebrate communities in tropical forest remnants, and have important implications for the management of fragmented landscapes.

Individuality of advertisement calls in the Australian frog Pseudophryne bibroni: Potential for identification of individuals

Pseudophryne bibroni is a small terrestrial frog inhabiting southeast Australia, the males of which call from burrows, both to attract females and maintain territories. This study investigates the capacity for using advertisement calls of P. bibroni to census and monitor frog individuals, through analysis of individually distinct call features. Discriminant analyses revealed that, for 40 individuals, 80% of individual calls were correctly classified, with the analysis of call bouts producing even higher resolution. Given the high level of call individuality in P. bibroni, the potential exists for advertisement calls to be used to identify frog individuals. A system based upon these results is currently being developed, which should provide a practical, field-based method of individual frog identification based on call, allowing the long-term monitoring of frog populations without the necessity for more invasive identification techniques. [I thank David Paton for assistance with supervision, and Nicki Mitchell for assistance with collection of data. This research received financial support from the Department of Environmental Biology Research Fund.]

Effectiveness of pitfall/drift-fence systems for sampling small ground-dwelling lizards and frogs in southeastern Australian forests

The effectiveness of various pitfall trap designs and pitfall/drift fence systems for sampling small ground-dwelling lizards and frogs in the forests of southeastern Australia was examined. Pitfall/drift fence systems employing long drift fences were more effective than short or no-fence systems in terms of the number of individuals and species caught, but were time consuming and caused considerable habitat disturbance. Various pitfall trap designs were compared. Generally, simple open-necked and funnel traps were more effective than traps with shelter and shelter/drift arm traps. It is suggested that in forested habitats, groups of individual open necked pitfall traps or short-fence systems may be just as effective and no more costly in installation time than systems employing long drift fences and more complex bap types.

Localization of prey by the Indian false vampire bat Megaderma lyra

Studies on gleaning bats indicate that they do not mainly rely on echolocation to detect and capture prey from surfaces. In the event of not using echolocation, there may be an error in their passive localization of prey compared to the bats which use echolocation. It is to be tested whether the amount of such error is related with the size of the prey in the passive localization employed by gleaning bats. We conducted experiments on the Indian false vampire bat Megaderma lyra in an outdoor enclosure using small, medium and large-sized frogs as prey. M. lyra captured live and freshly killed frogs only when they jumped or when pulled with a long thread on a sandy floor. Bats were more successful in capturing frogs without error (i.e. landing straight on the frog) under the background of fluorescent light than red light. The number of captures of live frogs without error was also significantly higher compared to the captures of freshly killed frogs under both the lights, except with the large-sized frogs. The number of jumps made by the live frogs decreased with their body lengths increased before M. lyra captured them without error. In a few observations, instead of landing straight on the frogs the bats landed on the floor close to the frogs and then captured them in a short jump (i.e. localization made with an error). The distance between the final position of the frogs and the site at which the bats landed on the floor prior to the capture, is considered as the amount of error committed by bats. While the bats localized and captured the frogs with an error, we found a linear decrease of error with an increase in the body length of the frogs. Bats never responded to the movements of tiny live and dead frogs of 0.8-1.3 cm.

Dynamics of natural infections of Rhabdias cf. hylae (Nematoda) in Bufo marinus (Amphibia) in Australia.

Infrapopulation dynamics of the nematode Rhabdias cf. hylae within naturally-infected Bufo marinus in north Queensland, Australia, were detailed. Over 80% of 580 toads were infected with Rh. cf. hylae with a mean intensity of 16.1. Distribution of Rh. cf. hylae within the toad population was aggregated, with an increase in the variance-to-mean ratio with increasing toad size. Intensity of infection and length of nematode were both correlated with length of toad in the smaller size classes. Length of nematode was not related to intensity of infection at any time. Mean intensity of infection rose significantly in small toads following initial infection after metamorphosis. Over the same period, average length of nematode did not increase implying constant re-infection of the toads. Larger toads were not reinfected to the same extent, and the number of uninfected toads in the larger size class increased which indicated a natural loss of infections. Changes in parameters of Rh. cf. hylae infection within B. marinus were attributed to seasonal rainfall and its subsequent effect on the behaviour of the toad.

Description of the Tadpoles of Hyla giesleri and Hyla microps from Southeastern Brazil

-The previously unknown tadpole of H. giesleri is described and illustrated based on two populations from Southeastern Brazil, one from Rio de Janeiro State and the other from Espirito Santo State. The tadpole of H. microps is redescribed and illustrated from Rio de Janeiro State and compared with that of H. giesleri. The mean length of tadpoles of H. giesleri in stage 33 varies from 17.9 (Rio de Janeiro State) to 22.5 mm (Espirito Santo State). The mean length in H. microps is 16.9 mm. Tadpoles of H. giesleri have the terminal portion of tail orange (red in H. microps). These species can also be distinguished by other details of their color patterns. Remarkable differences of size and color were found between the two studied populations of H. giesleri. The Hyla parviceps group was defined by Duellman and Crump (1974) and modified slightly by Duellman and Trueb (1989). Wild (1992), following the conventional grouping, provided detailed larval characters for this group. The small hylid frogs of the Hyla parviceps group occur mainly in the Amazon Basin and northern South America (Duellman and Crump, 1974). The only exceptions are Hyla microps Peters, 1872 and H. giesleri Mertens, 1950, which occur in southeastern and southern Brazil. These species were originally described from Rio de Janeiro State. Weygoldt and Peixoto (1987) described H. ruschii from Espirito Santo State, suggesting that it could also be a member of the Hyla parviceps group. Hyla microps and H. giesleri were long considered as synonymous due to the great morphological similarity of their adults (Cochran, 1955; Bokermann, 1966; Lutz, 1973; Duellman and Crump, 1974). Heyer (1980) revalidated H. giesleri based on differences found in the mating call and color pattern of subocular region. Bokermann (1963) briefly described the tadpole of H. microps from material collected in Sao Paulo State. Heyer et al. (1990) also described the tadpole of H. microps from Sao Paulo State. Herein, we describe and compare the tadpoles of H. giesleri and H. microps. The description of the former species was based on two distinct populations. MATERIAL AND METHODS All specimens examined in this study belong to the Collection of Departamento de Zoologia, Instituto de Biologia, Universidade Federal do Rio de Janeiro (ZUFRJ). We collected adults and tadpoles of H. giesleri (ZUFRJ 2324, 928) from two populations (Fig. 1), one in Rio de Janeiro State (Municipio de Mage, 22?39'S; 43002'W) and the other in Espirito Santo State (Municipio de Linhares, 19?23'S; 40?04'W). The tadpoles from Rio de Janeiro were obtained from eggs collected in March 1984 and raised in captivity. Those tadpoles from Espirito Santo State were collected in January 1980. The tadpoles of H. microps (ZUFRJ 4145, 4390, 4391) were collected from a single population in Rio de Janeiro State (Municipio de Teresopolis, 22?24'S; 42?57'W) (Fig. 1). The tadpoles ZUFRJ 4145 were obtained from eggs (ZUFRJ 4011) collected in September 1989, the others were collected in February and March 1991. Tadpoles were anesthetized in 0.1% chloretone and stored in 5% formalin. Adults were anesthetized in 0.25% chloretone, preserved in 10% formalin, and stored in 70% alcohol. Some couples collected in amplexus were kept alive to obtain eggs. Tadpoles that emerged from these eggs were reared until the stages desired for study. Tadpoles collected in the field were identified by means of comparisons with those obtained from eggs or reared until metamorphosis and then compared with determined adults. Tadpoles were reared in captivity in aquariums (measurements: 60 x 30 x 30 cm) with slightly acid water and a dense layer of leaves on the bottom. About 20 tadpoles were maintained per aquarium. Fish food was provided regularly. The water temperature was not controlled. Tadpoles in stage 33 (Gosner, 1960) were used in the descriptions and measurements. Measurements were taken according to the methods of Altig (1970) and Duellman (1970), except for interorbital distance, which was taken between This content downloaded from 157.55.39.149 on Sat, 09 Jul 2016 04:57:02 UTC All use subject to http://about.jstor.org/terms

Alimentación de las ranas pardas, <i>Rana gr. temporaria</i>, en el circo de Piedrafita, (Pirineos, España)

Feeding of high Pyrenean mountain brown frogs were studied in the pre-wintering period. The main prey is beetles (44'97o), two-winged flies (12'9%) and bees, wasps, ants, etc (11'4%). For the whole of the frogs, the most frequent prey size is the small (smaller than 10 mm). Big frogs tend to consume bigger prey in not ,o. many quantity, while small frogs consume more quantity of preys but smaller in size. From prey way of life, frogs eat mainly terrestrial and aerial preys, although capture of aquatic prey was observed (11'5%) and these preys were eaten inside the water.

Work and power output in the hindlimb muscles of Cuban tree frogs Osteopilus septentrionalis during jumping.

It has been suggested that small frogs use a catapult mechanism to amplify muscle power production during the takeoff phase of jumping. This conclusion was based on an apparent discrepancy between the power available from the hindlimb muscles and that required during takeoff. The present study provides integrated data on muscle contractile properties, morphology and jumping performance that support this conclusion. We show here that the predicted power output during takeoff in Cuban tree frogs Osteopilus septentrionalis exceeds that available from the muscles by at least sevenfold. We consider the sartorius muscle as representative of the bulk of the hindlimb muscles of these animals, because this muscle has properties typical of other hindlimb muscles of small frogs. At 25 degrees C, this muscle has a maximum shortening velocity (Vmax) of 8.77 +/- 0.62 L0 s-1 (where L0 is the muscle length yielding maximum isometric force), a maximum isometric force (P0) of 24.1 +/- 2.3 N cm-2 and a maximum isotonic power output of 230 +/- 9.2 W kg-1 of muscle (mean +/- S.E.M.). In contrast, the power required to accelerate the animal in the longest jumps measured (approximately 1.4 m) is more than 800 W kg-1 of total hindlimb muscle. The peak instantaneous power is expected to be twice this value. These estimates are probably conservative because the muscles that probably power jumping make up only 85% of the total hindlimb muscle mass. The total mechanical work required of the muscles is high (up to 60 J kg-1), but is within the work capacities predicted for vertebrate skeletal muscle. Clearly, a substantial portion of this work must be performed and stored prior to takeoff to account for the high power output during jumping. Interestingly, muscle work output during jumping is temperature-dependent, with greater work being produced at higher temperatures. The thermal dependence of work does not follow from simple muscle properties and instead must reflect the interaction between these properties and the other components of the skeletomuscular system during the propulsive phase of the jump.

TRAIT-MEDIATED INDIRECT INTERACTIONS IN A SIMPLE AQUATIC FOOD WEB

This investigation examines the role of trait-mediated indirect interactions in a simple aquatic food web. We conducted the experiments in cattle watering tanks in order to establish whether competitive and predator-prey interactions between two species are affected by other species in the system; i.e., are pairwise interaction strengths affected by the background species assemblage? We examined the survival and growth response of small bullfrog (Rana catesbeiana) and small green frog (Rana clamitans) tadpoles in the presence and absence of a competitor (large bullfrogs), the lethal presence of the larval odonate predator Tramea lacerata,and the nonlethal (caged) presence of the larval odonate predators Anax junius and Anax longipes. We demonstrate that large bullfrog competitors and caged Anax affect traits (foraging activity level) of small bullfrog and small green frog tadpoles and that these changes in traits, in turn, affect interactions of the small tadpole species with each other and with the other species. In particular, the following four trait- mediated indirect interactions were evident: (1) Presence of large bullfrog competitors increased the predation rate of Trameaon small green frogs and small bullfrogs. (2) Presence of nonlethal Anax reduced the predation rate of Tramea on small green frogs. (3) Presence of nonlethal Anax increased the competitive advantage of bullfrogs over green frogs. (4) Presence of nonlethal Anax facilitated midge invasion of the experimental units. The pro- posed mechanisms (changes in small tadpole activity) involved in these trait-mediated indirect interactions were supported by observational data on tadpole activity and resource levels in the experimental units, and in laboratory experiments examining tadpole activity responses to predators. The occurrence of strong trait-mediated indirect interactions in this simple food web underscores the potential importance of such interactions in animal com- munities.

Trapping of 134Cs+ in frog skin epithelium as a function of short circuit current

In the sodium/potassium pump of the isolated frog skin epithelium, 134CS+ can to a certain degree replace potassium. If 134CS+ in almost a carrier-free amount is added to the solution bathing the inside of the frog skin in an Ussing chamber, there will be an uptake of 134 CS+ into the epithelium cells which is proportional to the short circuit current. Transepithelial flux of 134CS+ in leaky epithelia, for instance small intestine and frog skin glands, indicates a paracellular pathway. The consequences of these findings for the recycling-theory are discussed.

Predation by grass snakes (Natrix natrix) at a site in southern England

The prey and feeding frequency in free‐living grass snakes was studied during 1993 and 1994 at a site in southern England. Individual snakes and common toads were recognized using PIT tags and a small number of adult snakes were radio‐tracked over long periods to determine predation rates.Grass snakes fed, almost exclusively, on common toads (adult, juvenile, and tadpoles). A positive correlation was found between prey size and snake size. Large snakes did not appear to prey upon small toads, although clearly capable of doing so.Male and female snakes ate large meals (toads) approximately every 20 days between May and September, with females fasting for a period of about 45 days during gestation and egg‐laying. After allowing for differences in the number and size of toads predated by male and female snakes, the mean amount of food consumed per day was estimated to be 2.3% and 1.6% of body weight.

The uptake and effects of lead in small mammals and frogs at a trap and skeet range.

This study was performed to evaluate the bioavailability and effects of lead in wildlife at a trap and skeet range. The total lead concentration in a composite soil sample (pellets removed) was 75,000 micrograms/g dry weight. Elevated tissue lead concentrations and depressed ALAD activities in small mammals and frogs indicate that some of the lead deposited at the site is bioavailable. Mean tissue lead concentrations (micrograms/g dry wt.) in white-footed mice (Peromyscus leucopus) at the range liver = 4.98, kidney = 34.9, femur = 245) were elevated (P < 0.01) 5- to 64-fold relative to concentrations in mice from a control area. Tissue lead concentrations in the only shorttail shrew (Blarina brevicauda) captured at the range (liver = 34.1, kidney = 1506, femur = 437) were elevated 35- to 1038-fold. Femur lead concentrations in green frogs (Rana clamitans) at the range (1,728 micrograms/g) were elevated nearly 1000-fold, and the lead concentration in a pooled kidney sample (96.2 micrograms/g) was elevated 67-fold. There was significant depression of blood ALAD activity in mice (P = 0.0384) and depression of blood and liver ALAD activity in frogs (P < 0.001). Hematological and histopathological lesions associated with lead toxicosis were observed in some animals. Hemoglobin concentrations were reduced 6.7% in mice (P = 0.0249), but hematocrit was not significantly affected in mice or frogs. Intranuclear inclusions were present in the renal proximal tubular epithelium of two of the mice and the shrew that were captured at the range, and necrosis of the tubular epithelium was also evident in one of the mice. Kidney:body weight ratios were similar in range and control mice. Soil ingestion may be a significant route of lead uptake in small mammals at the range. However, the tendency of lead to concentrate in the bones rather than in more digestible soft tissues may minimize food chain uptake of lead by predators, especially raptors that regurgitate undigestible material.