Biology subjects

Reader, S. M.

Publications and source records attributed to Reader, S. M..

4 recordsLinked to original sources

bioRxiv2026

The role of familiarity in grouping decisions of Trinidadian guppies

Social grouping is widely observed in numerous taxa, providing individuals with a variety of benefits including efficient information exchange and predator protection. However, grouping can also carry costs such as increased competition for resources, which means that individuals must often make decisions regarding joining or leaving a group. These decisions to leave or stay might in turn depend on prior experience with potential groupmates. Past work has shown that many fish distinguish between familiar and unfamiliar conspecifics and use these distinctions in their grouping choices. Trinidadian guppies (Poecilia reticulata), well known for their diversity in shoaling preferences, are an excellent system in which to investigate the role of familiarity in grouping decisions. We examined preferences for familiar individuals following both a 15-day and 55-day cohabitation period in two different guppy populations. Utilizing two binary-choice designs, we found no evidence for a familiarity preference in either population, despite observing a high preference to group with conspecifics in both populations. These results suggest that various contextual- and population-level differences may impact familiarity preferences, in turn contributing to the growing body of work on the evolution of social organization and grouping decisions in teleost species and beyond.

animal behavior and cognition↗

bioRxiv2021

Predictors of Taxonomic Inflation and its Role in Primate Conservation

Species are the main unit used to measure biodiversity, but different preferred diagnostic criteria can lead to very different delineations. For instance, named primate species have more than doubled in number since 1982. Such increases have been attributed to a shift away from the biological species concept (BSC) in favour of less inclusive species criteria. Critics of recent changes in primate taxonomy have suggested taxonomic splitting may be biased toward certain clades and have unfavourable consequences for conservation. Here, we explore predictors of taxonomic splitting across primate taxa since the initial shift away from the BSC nearly 40 years ago. We do not find evidence that diversification rate, the rate of lineage formation over evolutionary time, is significantly linked to splitting, contrary to expectations if new species concepts and taxonomic methods identify incipient species. We also do not find evidence that research effort in fields where work has been suggested to motivate splitting is associated with increases in species numbers among genera. To test the suggestion that splitting groups is likely to increase their perceived risk of extinction, we test whether genera that have undergone more splitting have also observed a greater increase in their proportion of threatened species since the initial shift away from traditional taxonomic methods. We find no cohesive signal of taxonomic splitting leading to higher threat probabilities across primate genera. Overall, this analysis sends a positive message: threat statuses of primate species are not being overwhelmingly affected by splitting. Regardless, we echo warnings that it is unwise for conservation to be reliant on taxonomic stability. Species (however defined) are not independent from one another, thus, monitoring and managing them as such may not meet the overarching goal of conserving biodiversity.

zoology↗

bioRxiv2020

The role of behavioural flexibility in primate diversification

Identifying the factors that influence species diversification is fundamental to our understanding of the evolutionary processes underlying extant biodiversity. Behavioural innovation, coupled with the social transmission of new behaviours, has been proposed to increase rates of evolutionary diversification, as novel behaviours expose populations to new selective regimes. Thus, it is believed that behavioural flexibility may play an important role in driving evolutionary diversification across animals. We test this hypothesis within the primates, a taxonomic group with considerable among-lineage variation in both species diversity and behavioural flexibility. We employ a time cut-off in our phylogeny to help account for biases associated with recent taxonomic reclassifications and compare three alternative measures of diversification rate that consider different phylogenetic depths. We find that the presence of behavioural innovation and social learning are positively correlated with diversification rates among primate genera, but not at shallower phylogenetic depths. Given that we find stronger associations when examining older rather than more recent diversification events, we suggest that extinction resistance, as opposed to speciation, may be an important mechanism linking behavioural flexibility and primate diversification. Our results contrast with work linking behavioural flexibility with diversification of birds at various phylogenetic depths. We offer a possible dispersal-mediated explanation for these conflicting patterns, such that the influence behavioural flexibility plays in dictating evolutionary trajectories differs across clades. Our results suggest that behavioural flexibility may act through several different pathways to shape the evolutionary trajectories of lineages.

evolutionary biology↗

bioRxiv2019

Population differences in how wild Trinidadian guppies use social information and socially learn

Animals have access to information produced by the behaviour of other individuals, which they may use (\"social information use\") and learn from (\"social learning\"). The benefits of using such information differ with socio-ecological conditions. Thus, population differences in social information use and social learning should occur. We tested this hypothesis with a comparative study across five wild populations of Trinidadian guppies (Poecilia reticulata) known to differ in their ecology and social behaviour. Using a field experiment, we found population differences in how guppies used and learned from social information, with only fish from one of the three rivers studied showing evidence of social information use and social learning. Within this river, populations differed in how they employed social information: fish from a high-predation regime where guppies exhibit high shoaling propensities chose the same foraging location than conspecifics, while fish from a low-predation regime with reduced shoaling propensities chose and learned the opposite foraging location than conspecifics. We speculate that these differences are due to differences in predation risk and conspecific competition, possibly mediated via changes in grouping tendencies. Our results provide evidence that social information use and social learning can differ across animal populations and are influenced by socio-ecological factors.

animal behavior and cognition↗