Habitat suitability index models for the wood frog (Rana sylvatica) and boreal chorus frog (Pseudacris triseriata maculata) in the foothills parkland natural sub-region and Bow River sub-basin, Alberta

Habitat suitability index models for the wood frog (Rana sylvatica) and boreal chorus frog (Pseudacris triseriata maculata) in the foothills parkland natural sub-region and Bow River sub-basin, Alberta

Habitat suitability index models for the wood frog (Rana sylvatica) and boreal chorus frog (Pseudacris triseriata maculata) in the foothills parkland natural sub-region and Bow River sub-basin, Alberta

Habitat suitability index models for the wood frog (Rana sylvatica) and boreal chorus frog (Pseudacris triseriata maculata) in the foothills parkland natural sub-region and Bow River sub-basin, Alberta

Influence of prey diet quality on predator-induced traits in wood frog tadpoles (Lithobates sylvaticus)

Diet quality and predation are two critical factors in determining the growth and development of organisms. Various anurans are susceptible to phenotypic changes influenced by these factors. Yet, few studies examined prey diet quality as potential influence over predator-induced traits. Using wood frog tadpoles (Lithobates sylvaticus) as a model species, we investigated the effects of three diet compositions (plant-based, animal-based, omnivorous) crossed with presence or absence of chemical cues from predatory dragonfly larvae (Aeshnidae). After 35 days, we recorded 11 morphological measurements, Gosner stage, and intestinal length of tadpoles to assess phenotypic changes under the six different experimental conditions. Our results showed the additive effects of both diet quality and predator chemical cue without detection of interactions between the two. Tadpoles receiving the omnivorous diet grew and developed faster with wider denticle rows than those receiving the plant or animal diets. The growth and development of tadpoles receiving only the animal diet were significantly hindered. These results emphasize the importance of diet quality in the growth and development of larval wood frogs. Chemical cues from predators significantly reduced tadpole body size but, in contrast to previous findings, did not affect tail size. Our experimental procedure of providing water containing predator and injured conspecific chemical cues on a weekly basis likely provided relatively weak predation risk perceived by tadpoles compared to previous studies using caged predators. The predator environment in our experiment, however, represents one ecologically relevant scenario in which predation risk is not urgent.

Distribution and Conservation Status of the Hyrcanian Wood Frog (Rana pseudodalmatina) in Azerbaijan

In Azerbaijan, the Hyrcanian wood frog (Rana pseudodalmatina) usually inhabits forests in the Talysh Mountains and the Lenkoran Lowland from –28 to 2265 m above sea level. Drier regions to the north and west of the Talysh Mountains limit the species distribution. The species can locally penetrate to a no forested zone in the northern and western foothills of the Talysh Mountains and the Zuvand Desert. In order to study the distribution and estimate ecological preferences of the species, we applied MaxEnt using 98 localities from Azerbaijan, Iran, and Turkmenistan. The range of the species covers mainly pre-Caspian slopes of the Talysh and Alborz ridges. Of the parameters included in the model, the precipitation of driest month and the habitat homogeneity (index related to vegetation types) were variables with highest percentage contributions. Based on our data, in Azerbaijan R. pseudodalmatina is very common species in most places and in some localities is the most numerous amphibian species. The frog does not avoid human-transformed biotopes. The main factors influenced on a local declining of R. pseudodalmatina are the introduction of fishes (including invasive) and the common raccoon, destruction and contamination of suitable breeding water bodies. The most suitable method of conservation of the frog is construction of new ponds for their reproduction and wintering.