Breeder aggression does not predict current or future cooperative group formation in a cooperatively breeding bird

Abstract

In cooperatively breeding species, subordinates forgo reproduction to assist breeders in raising offspring. When cooperative breeding is facultative, breeders from the same population may differ in whether they are assisted by non‐breeding helpers. Predation risk is a major source of nest failure and assistance during nest defense is often an overlooked, yet important, way helpers assist breeders. A breeder's aggressive response to a nest predator could have important implications for whether they form cooperatively breeding groups. We investigated the hypothesis that breeder aggression toward a nest predator is related to current and future helper recruitment. We tested the prediction that less aggressive breeders were more likely to form cooperative groups, which could occur if these breeders benefit from helper assistance during nest defense. We also considered the possibility that more aggressive breeders were more likely to form cooperative groups. We assessed the effects of partnerships and tested whether aggression exhibited by breeding partners was correlated. We conducted this work in the facultative, cooperatively breeding brown‐headed nuthatch (Sitta pusilla). We measured breeder aggression in response to a taxidermy model of a nest predator to determine whether breeders’ aggression correlated with their current or future helper recruitment. We found no evidence of a sex difference in aggression among breeders and aggression scores of breeding partners were not significantly correlated. Aggression scores for both breeding males and breeding females were unrelated to whether they formed cooperative groups in the current year. We followed most of the breeding males, though not breeding females, across years and found that breeding males’ aggression scores were unrelated to helper recruitment the following year. Our results suggest that breeders’ responses to nest predators are not related to cooperative group formation in this species and that males and females showed comparable levels of aggression toward a nest predator.

Contribution of hippocampal BDNF/CREB signaling pathway and gut microbiota to emotional behavior impairment induced by chronic unpredictable mild stress during pregnancy in rats offspring

“…The HPA axis and the gut microbiome display bidirectional communication such that alterations in one system may affect the function of the other ( Cryan & O’Mahony, 2011 ; Cryan et al, 2019 ; Cusick, DuVal & Cox, 2021 ). In the study, we investigated the interactive effects of maternal stress and manipulations of the maternal microbiome on offspring growth, gut microbiome composition and diversity, stress response, and emotional behavior.…”

Peer Review #2 of "Contribution of hippocampal BDNF/CREB signaling pathway and gut microbiota to emotional behavior impairment induced by chronic unpredictable mild stress during pregnancy in rats offspring (v0.2)"

“…The HPA axis and the gut microbiome display bidirectional communication such that alterations in one system may affect the function of the other (Cryan and O'Mahony 2011;Cryan, et al 2019;Cusick, et al 2021). In the study, we investigated the interactive Manuscript to be reviewed effects of maternal stress and manipulations of the maternal microbiome on offspring growth, gut microbiome composition and diversity, stress response, and emotional behavior.…”