Annual variation of breeding patterns of the toad, Melanophryniscus rubriventris (Vellard, 1947)

Abstract

Climate may play a direct role in determining patterns of reproductive activity in anurans. Investigating the responses of males and females attending a breeding site to environmental variation are of particular interest regardless the possible effect of climate change on the decline of populations. I studied annual variation over two years in the breeding population size and breeding phenology of the diurnal toad, Melanophryniscus rubriventris, in a seasonal environment characterized by temporal and spatial uncertainty due to climatic conditions. Breeding activity of this toad was opportunistic throughout a prolonged spring-summer breeding season. Direct influence of rainfall on the onset and extent of breeding activity was detected in both years. Spawning activity showed a clear pattern of two three-day peaks mostly related to heavy rainfall events. Males always significantly outnumbered females at breeding sites. The disparity of rainy season extent between the two breeding seasons studied resulted in different annual patterns of arrival and length of residence of adults. Males and females remained several days longer during the second year than during the first year. Because adults showed highly variable annual patterns of breeding activity studies involving only a few years may yield misleading results concerning the nature and extent of the decline of the species or populations. Future studies on the ecology and conservation of the species should include long-term monitoring.

Direct and Indirect Effects of Climate Change on Amphibian Populations

“…In the same population of R. dalmantina, amount of precipitation in February explained 41% of the variance in number of egg masses deposited [60]. Spawning activity of the diurnal toad (Melanophryniscus rubriventris) is closely associated with heavy rainfall events [61]. The environmental cue associated with timing of reproduction may vary depending on the species' breeding habitat or other life history characteristics.…”

The recognition of Dendropsophus minusculus () (Hylidae, Dendropsophini) as a highly polymorphic, multi-domain distributed species

“…On the other hand, it has also been registered in calling activity throughout the year depositing the clutches in leaves above permanent water bodies (reproductive mode number 24, sensu Haddad and Prado, 2005) in moist forests. Although it is well known that the reproductive season in anuran communities is related to climatic factors (see Vaira, 2005;Zina and Haddad, 2006;Zank et al, 2010), the present study shows that domain characteristics, that are also associated with climatic factors, may not only be correlated to the duration of the reproductive season, but also act as a selective force on the reproductive mode exhibit by the species. This observation reinforces the ecological plasticity of D. minusculus.…”

Temporal niche of acoustic activity in anurans: interspecific and seasonal variation in a neotropical assemblage from south-eastern Brazil

“…However, the species with the lowest variation in niche breadth (A. eugenioi) was significantly affected by all the environmental factors analysed in the multiple regression. Eleutherodactylus parvus and S. hayii were affected by the factors analysed, but for both of them only rainfall at the day of the observation explained an additional part of the variation, suggesting that the effect of immediate rainfall was the most important factor regulating the period of calling activity for these species (e.g., Cree, 1989;Donnelly and Guyer, 1994;Vaira, 2005). These results agree with our field observations in which, soon after it started raining, independently of the hour of the day, males of S. hayii and E. parvus started calling.…”