RESUMO
Our knowledge about the acoustic behavior of Caviinae species drove us to investigate Kerodon rupestris's (Caviidae: Hydrochoerinae) repertoire. This species is endemic to Caatinga and states as vulnerable in the Brazilian list of endangered species. We recorded sounds uttered by individuals from Santa Luzia, State of Paraíba, Brazil. We promoted interactions among 13 animals during intra and intersexual pairing sessions, under undisturbed interactions in captivity, and in free-living conditions. We found a repertoire of 13 call types, most of them (all except three) shared with Cavia and only five possibly shared also with Hydrochoerus: (1) Close contact and cohesion: tonal and noisy contact calls, tweet, slow-whistle; (2) Social regulation (incitement, subordination or auto-defense): whine, peepy-squeak, yelp; (3) Offensive aggression and status display: roar, snort, and teeth-chattering (4) Warning or intimidation: alarm-whistle, drrr, and drumming; (5) Courtship: purr and slow-whistle. The similarity of Kerodon signals to Hydrochoerinae species, despite the ecological differences, needs to be understood in comparative phylogenetic studies tracing back the origin of the courtship display in Caviidae. Thus, future research should focus on playback studies to test signals' biological function hypothesis.
Assuntos
Roedores , Vocalização Animal , Acústica , Animais , Brasil , Cobaias , FilogeniaRESUMO
OBJECTIVES: Many group-living primate species have evolved the capacity for some individuals to live alone for part of their lives, but this solitary life stage has rarely been the subject of focused research. The mantled howler monkey (Alouatta palliata) is a social primate species with bisexual dispersal that lives in mixed-sex groups with low male-to-female sex ratios. Consequently, males often spend a long period of their lives as solitary individuals. This study compares the tree use, feeding, and long-distance vocalization behavior of solitary and group-living mantled howler monkey males living within a fragmented rainforest in Costa Rica, La Suerte Biological Research Station. Based on differences in competitive ability between solitary and group-living males, we predicted that lone males would be found in significantly smaller feeding and resting trees, consume more low-quality foods, and produce shorter howling bouts made at lower rates than group-living males. MATERIALS AND METHODS: We collected data on tree use and feeding during 30-min focal samples on male focal animals, recording data at 2-min intervals. We measured the trees in which the monkeys fed and rested for two or more intervals, and recorded the plant parts consumed. We recorded howling behavior using all-occurrences sampling. RESULTS: Lone males used significantly smaller feeding and resting trees, consumed more low-quality foods, and howled at lower rates but had longer howling bouts triggered by anthropogenic noise more than group-living males. DISCUSSION: Our results demonstrate that lone males differ in their behavioral ecology compared to group-living males, thus improving understanding of the solitary male life stage in primates.
Assuntos
Alouatta/fisiologia , Comportamento Social , Vocalização Animal/fisiologia , Animais , Antropologia Física , Costa Rica , Comportamento Alimentar/fisiologia , Masculino , Floresta ÚmidaRESUMO
OBJECTIVES: When closely related species overlap geographically, selection may favor species-specific mate recognition traits to avoid hybridization costs. Conversely, the need to recognize potential same-sex rivals may select for lower specificity, creating the possibility that selection in one domain constrains evolution in the other. Despite a wealth of data on mate recognition, studies addressing rival recognition between hybridizing species are limited to a few bird species. Using naïve populations, we examine the extent to which failed rival recognition might have affected hybridization patterns when two species of howler monkeys (Alouatta pigra and A. palliata) first met after diverging in allopatry. METHODS: We simulated first contact between naïve subjects using playback experiments in allopatric populations of the two purebred species. Using linear mixed models, we compared their look, move, and vocal responses to conspecific and heterospecific loud calls. RESULTS: Although not different in overall response strength to playbacks, the two species differed in reaction to heterospecific callers. Male A. pigra ignored calls from male A. palliata, but the reverse was not true. DISCUSSION: Despite striking differences in vocalizations, A. palliata respond equally to calls from both species whereas A. pigra respond only to conspecifics. This apparent failure of A. pigra males to recognize interspecific rivals might have biased hybridization (F1 hybrids = male A. palliata x female A. pigra), a pattern previously hypothesized based on genetic analysis of hybrids. Given that A. pigra males could be losing reproductive opportunities to heterospecific males, our findings add to growing evidence of potential costs for overly specific species recognition.