Assessing behavioral sex differences to chemical cues of predation risk while provisioning nestlings in a hole-nesting bird

Abstract

Birds can assess nest predation risk and adjust their parental activity accordingly. Risk taking behavior should be related to investment in reproduction as well as to confidence in parenthood that often differ between sexes. In those cases, sexual differences in risk taking behavior may be expected. For example, in blue tits, females invest more time and energy than males in nest-building, egg laying and incubation. Furthermore, confidence in parenthood is supposed to be higher for females, as extrapair paternity is common in this species. Therefore, the reproductive value of nestlings may be higher for females than for males and the former may assume greater risks to ensure nestling growth and maximize their reproductive success. We examined potential sexual differences in the risk assumed by parents in relation to perceived risk of predation inside the nest cavity, where predation risk perception may be higher. We increased perceived predation risk by adding predator chemical cues inside blue tit (Cyanistes caeruleus) nest-boxes, and we tested whether female and male parents differed in the risk assumed when taking care of nestlings. Females and males did not differ in the risk assumed in response to perceived predation risk. However, females reduced time devoted to nest sanitation activities when predator chemical cues were detected inside the nest-box, likely as an anti-predatory strategy to minimize their own risk of predation. Therefore, these results add to the evidence that birds can detect chemical cues of predators inside the nest cavity and suggest that the behavioral response to an increase in risk of predation perceived through olfactory cues is not sex-dependent in blue tit.

Level-dependent effects of predation stress on prey development, lifespan and reproduction in mites

“…Non-consumptive effects-such as predation stresson prey fitness have been demonstrated in previous studies on different prey-predator systems (Abrams and Rowe 1996;Kroon et al 2004;Creel et al 2009;Hawlena and Schmitz 2010;Gurr et al 2017). Most of these studies concern the influences of predation stress on prey development or reproduction in relatively short-term experiments (Warkentin 1995;Walzer and Schausberger 2009;Janssen et al 2014;Jacobsen et al 2016;Rocha et al 2020;Oliveira and Moraes 2021;Saavedra et al 2022), because it is more difficult to conduct long-term experiments with larger animals that have relatively long lifespans while applying predation stress over an extended period of time (Li and Zhang 2019). In addition, it is also not easy to experimentally separate the effects of direct killing from the indirect non-consumptive effects in long-term studies.…”

“…In addition, females had reduced fecundity under predation stress. Sexspecific response to predation stress was observed under a low level of predation stress: females had Abrams and Rowe 1996;Peckarsky et al 2002;Rocha et al 2020;Oliveira and Moraes 2021;Saavedra et al 2022;Majchrzak et al 2022). Long-term effects, such as effects on lifespan, are not often attempted because it is rather time consuming to apply predation stress for the whole lifespan of many animal species, and it is also difficult to separate the effects of direct killing from the indirect non-consumptive effects in many predator-prey systems (Li and Zhang 2019).…”

Predation stress experienced as immature mites extends their lifespan

“…Predation stress has been shown to affect prey life history traits such as development (Peckarsky et al 2002 ; Griffis-Kyle and Ritchie 2007 ; Thaler et al 2012 ; Adler et al 2013 ), and reproductive rates (Dahl and Peckarsky 2003 ; Zanette et al 2011 ; Li and Zhang 2019a ). Previous studies on predation risks focused mainly on the short-term effects on prey, such as development, behavior and reproduction (e.g., Warkentin 1995 ; Abrams and Rowe 1996 ; Oku et al 2003 ; Choh et al 2010 ; Rocha et al 2020 ; Oliveira and Moraes 2021 ; Saavedra et al 2022 ; Majchrzak et al 2022 ). Recent studies on chronic predation stress have shown that predation stress could also reduce female lifespan and fecundity (Pan et al 2018 ; Li and Zhang 2019a ; Wei and Zhang 2022 ).…”