Geographic distribution, habitat use and vocalizations of the leaf-litter frog Ischnocnema henselii (Anura: Brachycephalidae) in the subtropical Atlantic Forest

Abstract

Data on geographic distribution and ecology are essential when defining the conservation status of a species. Herein, we present new information about the geographic distribution, habitat and advertisement call of Ischnocnema henselii, an endemic species of the southern Atlantic Forest. We conducted this study in forest fragments in the state of Santa Catarina, Southern Brazil, from January 2008 to November 2012. We recorded I. henselii in eight fragments over 100 ha in size, both inside and outside conservation units. We often observed less than 20 males in calling activity. The calling activity was daytime and nighttime, and more intense in the rain. We observed individuals perched on vegetation, on leaves or branches, on the leaf litter or under tree trunks. Duration of advertisement calls ranged from 14.71 ± 1.68 s (n = 11 calls) and interval between notes was 0.22 ± 0.13 s (n = 99 notes). We observed that the advertisement calls had a feature that we call "alternating modulation" in the amplitude of the notes. We suggest that further bioacoustic studies should analyze the relevance of this alternating modulation, to understand its role in communication. Although I. henselii is a habitat specialist, it is currently considered a common species, classified as Least Concern by Brazilian and IUCN lists. In the region studied, characterized by small and isolated remnants of the Atlantic Forest, I. henselii is not an abundant species and its spatial distribution is always associated with wet forest fragments. The increasing degradation of forest remnants in this region causes microclimatic and structural changes that may compromise the permanence of strictly forest and moisture-dependent species for reproduction, such as I. henselii. Resumo. Distribuição geográfica, uso do habitat e vocalizações da rãzinha-de-folhiço Ischnocnema henselii(Anura: Brachycephalidae) na Mata Atlântica subtropical. Informações sobre distribuição geográfica e ecologia são essenciais para a definição do estado de conservação de uma espécie. Aqui, nós apresentamos novas informações sobre a distribuição geográfica, habitat e canto de anúncio de I. henselii, um anfíbio endêmico do Sul da Mata Atlântica. Nós conduzimos o estudo em fragmentos florestais no estado de Santa Catarina, sul

Signatures of functional bacteriome structure in a tropical direct-developing amphibian species

“…Haddadus binotatus and I. henselii generally share the same forested habitats and activity patterns. However, we observed I. henselii vocalizing on the ground as well as within bromeliads and on leaves, branches, and trunks up to 1.5 m above the ground, consistent with the few previous natural history observations for the species [ 80 ]. In contrast, we never observed H. binotatus in bromeliads or vocalizing at heights greater than 20 cm from the ground, although they have occasionally been observed up to 80 cm above the ground [ 92 ].…”

“…Both I. henselii and H. binotatus were observed in forested areas near and away from streams. During dryer months, I. henselii may be observed very close to streams and occasionally submerged in water [ 80 ], whereas H. binotatus has been observed in holes and under debris during dryer periods in other studies, possibly because they are larger-bodied and more tolerant of dry conditions [ 81 ]. These divergent strategies for overcoming hydric stress may lead to different encounter rates with environmental Bd reservoirs (streams) and environmental bacterial reservoirs.…”

Anurans of a remnant of Mixed Rainforest in southern Brazil

“…(Kwet Di-Bernardo 1999, Kwet & Faivovich 2001, where they are typically found in rocky streams at the edge or in the interior of dense forests (Santos et al 2009). Rhinella henseli, in turn, inhabits the forest and, during the breeding season, it is found in small streams, temporary pools (Kwet et al 2010, Haddad et al 2013, Lucas et al 2018. Species found in both the forest and the edge (Table 1) are typically less demanding of habitat, allowing them to exploit different environments.…”