Authors: Daniel Bennett

Authors: José P. Veiga , Alfredo Salvador , Carmen Blazquez And Patricia Galina

Authors: Indraneil Das And Shyamal Chanda

Authors: Adrian Hailey

Abstract: Condition in the tortoise Testudo hermanni was assessed using the ratio of observed mass (M) to that predicted (M') from the allometric relationship M=aL_b, where L is body length. A condition index (Cl) was based on regressions of log M on log L in July (taken as a standard); these regressions differed significantly between females and males. The Cl log M/M' was slightly left-skewed, but was preferred to the simple ratio M/M' for ease of analysis of interaction effects. Log M/M'ranged from approximately -0.1 to +0. 1 in the wild, equivalent to observed mass of 80-120% of predicted mass. Condition varied seasonally, being low after emergence from hibernation, maximal in spring (April to June), and decreasing in autumn. The detailed pattern of seasonal variation differed significantly between adult females, adult males, and subadults. Regression equations for log M on log L in different months are provided for a seasonally-adjusted condition index (Cl), to assess the relative condition of individuals and annual samples measured in different months.

Keywords: allometry, condition index, season, Testudo, tortoise

Authors: M. Isabel Bellocq, Karin Kloosterman And Sandy M. Smith

Abstract: Diets of adults of amphibian species coexisting in the boreal forest are poorly understood. We quantified and compared the diets of adult amphibians from four jack pine (Pinus banksiana) forests in east-central Canada. Results showed that American toads (Bufo americanus) and northern redback salamanders (Plethodon cinereus) were predominantly ant-eaters; bluespo . tted salamanders (Ambystoma laterale) fed mainly on snails, beetles, and insect larvae; spring peepers (Pseudacris crucifer) took primarily spiders and wasps; and wood frogs (Rana sylvatica) took a variety of alternative prey and had the highest dietary diversity. Diets of these amphibians differed significantly among the species in all study sites. Discriminant analyses showed species separation based on food type, the variable representing the proportion of ants in stomach contents being the major contributor to the discriminant functions in all assemblages.

Keywords: frog, salamander, diet, feeding behaviour

Authors: Miguel Vences , Pedro Galan , Antonio Palanca , David R. Vieites , Sandra Ni Eto And Jorge Rey

Abstract: Habitat use and activity was studied in a common frog (Rana temporaria) population at an altitude of 2200 m in the Circo de Piedrafita, Spain, was studied during July 1998. Adult and juvenile frogs clearly selected moist microhabitats, and avoided dry substrates such as pasture and rocks. Marshes and puddles were the preferred microhabitat of both adults and juveniles; the shore and the water body itself of a larger pond were selected by adults but much less so by juveniles. Regular surveys over seven days indicated that adults showed both diurnal and nocturnal activity, whereas juveniles were more strictly diurnal. The percentage of adults observed at night in the pond was negatively correlated with the minimum air temperature. The rather aquatic habits and diurnal activity patterns appear to differ from low-altitude populations of R. temporaria. They are discussed as adaptations to the lack of humid substrates (forest leaf litter) at high altitudes, and to the extreme and unpredictable climatic conditions (low nocturnal temperatures, and sudden rapid temperature decreases at night) in montane environments.

Keywords: frog, Spain, Pyrenees, alpine environments, activity, microhabitat