Nest-sharing behavior of captive Broad-snouted caimans (Caiman latirostris): cooperation or exploitation?

Abstract

Communal egg-laying is not frequently observed in crocodilians that exhibit nest attendance. However, it has been reported for both wild and captive Caiman latirostris. To understand the proximate causes of communal nesting, we aim to describe the nesting behavior of caimans during communal egg-laying in a captive population. Video cameras were placed at nests and the behavior of females was monitored throughout three incubation periods. We documented and analyzed social behavioral data. Nest-sharing behavior consisted of several females congregating and performing nest construction, nest vigilance and nest maintenance. It was observed in all nests previous to egg-laying. After the first laying, one female prevented others from approaching. The second egg-laying female negatively affected the previous clutch. Working together at the same nest would appear to be an exploitative rather than a cooperative activity, and communal nesting could be a competitive interaction, due to limited suitable nesting sites or overcrowding due to captivity.