Diet Of Salamanders Research Articles

Non-native earthworms increase the abundance and diet quality of a common woodland salamander in its northern range.

The online version contains supplementary material available at 10.1007/s10530-023-03168-3.

The Diet of the Cumberland Plateau Salamander (Plethodon kentucki) in an Old Growth Forest of Southeastern Kentucky

Abstract Examining the diet of salamanders is important for understanding their effects on invertebrate communities and the interactions among sympatric salamander species. We examined the diet of the Cumberland Plateau Salamander, Plethodon kentucki (Mittleman), in an old growth forest in southeastern Kentucky. A total of 763 prey items were recovered from 73 salamanders with an average of 10.75 prey items per stomach. The four most important prey groups were Formicidae (ants), Araneae (spiders), Coleoptera (beetles), and Collembola (springtails). Overall, we found a total of 58 different prey types in the stomach contents from 20 invertebrate orders. This study represents one of the few successful uses of nonlethal gastric lavage methods on a large plethodontid salamander and the first description of P. kentucki diet identified to family and genus. Future work should examine diet throughout the year, compare prey species composition to sympatric salamander species, and look at local prey abundances and ...

Diet composition of two larval headwater stream salamanders and spatial distribution of prey

Summary Interspecific overlap in resource use can determine the degree to which different presumed guild members have distinct or similar effects on ecosystem processes or responses to environmental change. Many headwater streams of North America support multiple species of larval salamanders commonly defined as a single guild that can influence macroinvertebrate communities and nutrient dynamics and are sensitive to stream alteration. We explored macroinvertebrate distributions in conjunction with stable isotope and gut content analyses of salamanders to examine similarities in diet between two sympatric larval salamander species (Desmognathus quadramaculatus and Eurycea cirrigera) in four headwater streams. We determined the degree to which larval salamanders used similar prey functional feeding groups (FFGs) and taxa and determined the primary source habitat (pools versus riffles) of prey. Stable isotopes of carbon (δ13C) and nitrogen (δ15N) suggest the two salamander species occupied similar trophic positions and individual‐based stable isotope mixing models indicated similar use of macroinvertebrate predators and filterers by both species. Diet analyses were generally consistent with stable isotope results in identifying prey FFGs that composed the largest biomass of salamander diets. However, despite similarities in diet at the resolution of FFGs, there was little overlap in the specific taxa consumed by the two salamander species: 52 prey taxa were consumed over all samples, with only 16 taxa in common. Further, only five prey taxa were common in dominating diet biomass of both species; there was more overlap in taxa in terms of diet abundance. We assessed patterns in benthic macroinvertebrate biomass and compared the biomass of taxa that were in pools versus riffles to the biomass and abundance of taxa in salamander diets. Total macroinvertebrate biomass was generally higher in pools; however, the majority of salamander prey biomass was from riffle habitats, a trend that was stronger for D. quadramaculatus than for E. cirrigera. There was greater similarity in taxa comprising diet by abundance with the majority of prey items originating from pools. The larval salamander species used similar prey FFGs but differed significantly in specific prey taxa. We hypothesise that species differences in diets were most likely a function of differences in larval size and microhabitat use. Consequently, the treatment of larval salamanders as a guild is probably inadequate for predicting the effect of larval salamander diversity on some stream processes, and species may differ in how they respond to factors affecting prey assemblages.

Selective Foraging on Ants by a Terrestrial Polymorphic Salamander

Abstract Numerous authors have studied the diet of the Eastern Red-backed Salamander (Plethodon cinereus) and have described this species as a generalist predator of invertebrates. In most studies, prey taxa are identified to the family or order level. Additionally, few studies have directly assessed dietary preference by comparing diet to available prey. We chose an important component of the diet of red-backed salamanders (ants) to test whether salamanders altered their diets temporally and to determine if salamanders preyed on a subset of available ant prey. We identified ant species in salamander diets over a 13 mo period. In the fall season we also compared ants in stomach contents to those available in the surrounding leaf litter to determine if territorial residents of P. cinereus selectively forage on different ant species. We found significant temporal differences in ant species incorporated in the diet of P. cinereus that were consistent with our detailed examination of salamander ant preference...

Southern Two-Lined Salamander Diets in Urban and Forested Streams in Western Georgia

Abstract Streams are heavily affected by watershed urbanization as increased stormwater runoff changes their physical and chemical composition. Benthic macroinvertebrate species richness has been consistently shown to decline with urbanization. Conversely, biomass of macroinvertebrates can increase with urban development. We examined the effect of such shifts in macroinvertebrate assemblages on the diet of larval Eurycea cirrigera (Southern Two-lined Salamanders). Salamanders have been documented to decrease in diversity in urban habitats; however, Southern Two-lined Salamander larvae which persist in urban streams (at lower densities) tend to grow larger than larvae in forested streams. Diet may play a role in these diversity and growth trends. We examined prey consumed by larval salamanders during spring, summer, and winter seasons across urban and forested watersheds. Prey diversity in salamander digestive tracts peaked during summer. We found Chironomidae (Diptera) larvae to be the most common prey it...

Forest structure and stream salamander diets: Implications for terrestrial-aquatic connectivity

Forest structure and stream salamander diets: Implications for terrestrial-aquatic connectivity

Feeding Ecology of Stream-Dwelling Pacific Giant Salamander Larvae (Dicamptodon tenebrosus)

Pacific giant salamander larvae in a northern California stream were found to consume a wide variety and size range of prey in a one-year diet study. Aquatic insects made the greatest contribution to salamander diets, both numerically and by volume, with ephemeroptera nymphs being the most frequently consumed prey type. Although terrestrial invertebrates that fell into the stream constituted a small proportion of the diet numerically, they comprised a large proportion of diet volume throughout the year. Stomach contents mass and the proportion of intact prey in the stomach contents did not vary with time of day. In contrast, larval salamanders exhibited a strong diel activity pattern, being inactive and under cover during the day and active on the streambed surface at night. As larval salamanders grew, they included larger prey in their diet but continued to consume large numbers of very small prey. Small salamanders were able to consume a large proportion of the size range of most common prey, whereas only large salamanders were capable of consuming rare, large prey (e.g., large odonates, megalopterans, fish, and small salamanders). There was considerable dietary overlap among three co-occurring salamander size classes suggesting that food resources were not strongly partitioned among them. Relative abundances of prey in the diet were not correlated with their relative abundances in the environment, indicating that larval salamanders feed preferentially on certain prey taxa while avoiding, not encountering, or being unable to capture others. Electivity values were consistently positive for ephemeropterans and large, mobile invertebrate predators but were consistently negative for small, cryptic invertebrates and case-building caddisflies. In addition, mean sizes of three common mayflies were consistently larger in salamander stomach contents than in the benthos, indicating that predation on benthic invertebrates by larval Dicamptodon tenebrosus is size selective.

New function for the granular skin glands of the eastern long‐toed salamander, Ambystoma macrodactylum columbianum

AbstractWhile it has been accepted for over 50 years that salamanders use their tails for fat storage, no caudal adipose tissue was detected in the eastern long‐toed salamander, Ambystoma macrodactylum columbianum. We provide evidence to show that a proteinaceous material, sequestered in the epidermally derived caudal granular skin glands, is the storage product. An increase in the size of these glands, at the expense of fat deposits in the tail, is interpreted as a solution to a conflict between two of the tail's major functions: nutrient storage and predator deterrence. Loss of caudal lipid allows for larger granular glands. With more secretory product available for defense, the possibility of the salamander's surviving an encounter with a predator is apparently enhanced. Storing protein is energetically beneficial because salamander diets are primarily protein, and its has been demonstrated by previous investigators that converting protein to fat for storage is metabolically inefficient.

Energy Flow and Nutrient Cycling in Salamander Populations in the Hubbard Brook Experimental Forest, New Hampshire

Energy flow through salamander populations in the Hubbard Brook Ecosystem is about 11,000 kcal/ha yr (=46,000 kJ/ha yr). This is approx. = 0.02% of the net primary productivity, and is approx. = 20% of the energy flow through bird and mammal populations. Salamanders are efficient (60%) at converting ingested energy into new tissue and produce more new tissue annually than do bird populations. Salamanders are insignificant agents as sinks for nutrients or as agents for nutrient cycling in the ecosystem. Sodium is the possible exception, as an amount equivalent to >8% of the Na in annual litter fall passes through salamander populations; all other nutrients (Ca, Mg, K, P, N, S, and Zn) are that of most of their invertebrate prey. There is some evidence that invertebrates rich in Ca content, such as snails and mites, are necessary components of the diet of salamanders. Salamander tissue is higher in protein content than that of birds and mammals and represents a source of high-quality energy for potential predators. Salamanders have restricted home ranges and are not significant agents in the movement of nutrients into or out of the system.