Search bioRxiv⌕ Search

Biology subjects

Johns, P.

Publications and source records attributed to Johns, P..

2 recordsLinked to original sources
bioRxiv2022

Aggressive interactions between smooth-coated otters and water monitor lizards in Singapore

Smooth-coated otters (Lutrogale perspicillata) and Malayan water monitor lizards (Varanus salvator) occupy similar habitats and and interact regularly in Singapores waterways. These interactions have a range of potential outcomes and are sometimes lethal. Few formal behavioral studies exist for either species. We analyzed interactions between otters and monitor lizards by gleaning data from publicly available videos from citizen scientists to examine what factors influence aggressive and defensive behaviors, and what influences vigilance in otters. Behavioral sequence analysis revealed no obvious monitor lizard behavior that predicted otter aggression towards monitors. We found that the presence and number of otter pups is positively associated with otter aggression. Otters also tended to be more vigilant in groups with more pups, and more vigilant on land than water. Monitor lizards displayed aggressive and defensive behaviors more frequently than did otters, regardless of whether the otters were aggressive towards lizards. These observations suggests that otters vary their aggression and vigilance levels depending on the context of each interaction.

animal behavior and cognition↗
bioRxiv2021

Multiple reproductive females in family groups of smooth-coated otters

Smooth-coated otters (Lutrogale perspicillata) are inhabitants of the waterways of India and Singapore. Otter families typically consist of a single mating pair with mature, nonbreeding siblings living in family groups, or "romps". We note here the presence of multiple reproductive female otters within some romps, as well as the possible existence of simultaneous litters by different mothers. This phenomenon has not been recorded among L. perspicillata before. Here we address possible influences leading to multiple reproductive females within romps of smooth-coated otters, including inclusive fitness, incomplete suppression of reproduction, and existing in an urban environment. The numerous, recurring observations of multiple reproductive females warrant further investigation; while uncommon, this phenomenon is not as rare as once thought.

animal behavior and cognition↗