Niemela, P. | bioRxiv Science

bioRxiv2023

Male boldness and female parental care predict reproductive success in a bi-parental cichlid, the rainbow krib (Pelvicachromis pulcher)

O_LIAnimal personality differences, i.e. consistent among-individual behavioural differences within populations, are prevalent across the animal kingdom. However, we are just beginning to understand the adaptive significance of the observed behavioural variation. We are particularly in need of empirical studies testing hypotheses of proposed theoretical frameworks aiming to understand the existence animal personality differences. In this study, we investigated a hypothesis derived from a framework suggesting that sexual selection may generate and maintain personality variation. The authors of this framework propose parental care as a mechanism linking animal personality and reproductive fitness. C_LIO_LIWe repeatedly measured individual boldness in male and female rainbow kribs, Pelvicachromis pulcher, a West African cichlid known for territorial cave breeding and shared parental care. We then formed 54 breeding pairs with varying behavioural contrasts in boldness. For pairs that produced offspring (N = 20), we repeatedly recorded parental care behaviour (parental boldness and brood guarding) of both parents over one month. Reproductive success was measured as the likelihood to reproduce, the number of offspring, and offspring size at the end of breeding. C_LIO_LIIn both sexes, we found consistent among-individual differences in boldness before breeding and in parental care behaviours. Bolder males were less likely to reproduce but, when breeding was successful, produced bigger broods compared to less bold males. Female parental boldness positively correlated with the number of offspring produced. However, individual boldness before breeding did not predict parental care behaviour in either sex and we found no effects of the pairs contrast in prebreeding boldness on parental care coordination or reproductive success. C_LIO_LIThe outcomes of our study may suggest that among-individual variation in male boldness is maintained by males with different behavioural types playing different reproductive strategies of equal average fitness. Future research should delve into understanding the intricate link between male boldness and reproductive success, exploring for instance underlying genetic mechanisms and interactions with environmental conditions. C_LI

animal behavior and cognition↗

bioRxiv2018

Complex responses of global insect pests to climate change

Insect pests strongly affect the productivity and profitability of agriculture and forestry. Despite the well-known sensitivity of insects to abiotic effects such as temperature, their potential responses to ongoing climate change remain unclear. Here we compile and review documented climate change responses of 31 of the globally most impactful phytophagous insect pests, focussing on species for which long-term, high-quality data are available. Most of the selected species show at least one response affecting their severity as pests, including changes in geographic range, population dynamics, life-history traits, and/or trophic interactions. Of the studied pests, 41% only show responses that are linked to increased pest severity, 4% only show responses of decreased severity, whereas importantly 55%, the majority of studied pests, show mixed responses including both increased and decreased severity under ongoing climate change. Variability in impact is further supported by a thermal sensitivity analysis showing little benefit of climate warming in relation to the optimal developmental temperatures for the majority of these pests under both current climate and future projections. Overall the results show that calculating the net effect of climate change on phytophagous insect pest impact is far from straightforward. The documented variation in responses, e.g. between agricultural and forest pests, indicates that efforts to mitigate undesirable climate change effects must target individual species, taking into account the complex ecological and evolutionary mechanisms underlying their responses.

ecology↗