Uticaj variranja sredinskih parametara na strukturu populacije obične krastače (Bufo bufo)
Influence of environmental parameters on the common toad (Bufo bufo) population structure
Abstract:
One population of common toads was monitored on the breeding grounds for five consecutive years (2011–2015). Individuals were counted, measured and samples of hind leg toe phalange were taken for age assessment by sкeletochronology. The main goal was to analyse the effects of some weather parameters on reproductive phenology of this population. Change of effective and census population size, sex ratio, age structure and body mass condition index (BMCI), as well as relations among female fecundity, age, and body size, were also analysed in adult part of this population over time. Female fecundity was calculated regarding body mass, derived by comparison with earlier study. The trend was found toward increase of average daily air temperature in period before start of the breeding season, but it didn’t have impact on change in temporal dynamics of the breeding season. Positive correlation was found between winters with more precipitation and reproductive population size. Effective population size and age structure significantly varied along years, but independently from variation of weather parameters. Weak negative correlation was found between warmer winters and BMCI. BMCI also varied significantly along years. Females were larger than males. Index of sexual dimorphism in body size varied along years. Assortative mating was not confirmed. Males recorded in amplexus were bigger than solitary males, but generally didn’t differ in BMCI. Heavier females also had higher projected fecundity, and it didn’t change with age. Significant fluctuations of structure and dynamics were recorded in this population, but more years of monitoring are required to check possible impact of variation of weather parameters.
Keywords:
Bufo bufo; Weather parameters; Reproductive phenology; Adult population size; Sex ratio; Age structure; Sexual size dimorphism; Assortative mating; Body mass condition index; Female fecunditySource:
Faculty of Biology; University of Belgrade, 2021, 1-128Funding / projects:
- Evolution in Heterogeneous Environments: Adaptation Mechanisms, Biomonitoring and Conservation of Biodiversity (RS-MESTD-Basic Research (BR or ON)-173025)