Abstract
AbstractBrood parasites lay their eggs in the nests of other females, thereby shifting the costs of offspring care onto others. Given that care is costly, potential hosts should evolve mechanisms to avoid brood parasitism. Meanwhile, brood parasites should evolve mechanisms to circumvent host defences. Here we investigate whether hosts or intraspecific brood parasites adjust their egg laying behaviour as a mechanism to reduce or increase the effectiveness of brood parasitism. We use the burying beetle Nicrophorus vespilloides as our study system, in which hosts and brood parasites lay their eggs in the soil around a carcass controlled by the host. To test whether females adjust their egg laying behaviour when breeding as a host or brood parasite, we used an experimental design with three treatments: hosts, where focal females bred alongside a smaller female; brood parasites, where focal females bred alongside a larger female; and controls, where focal females bred alone. We used focal females from a narrowly defined size range to control for potential effects of body size. We found that hosts delayed the start of egg laying, which may allow them to recognise brood parasitic offspring that arrive too early. Meanwhile, brood parasites laid their eggs over an extended period, which may increase the chances that their egg laying overlapped with the host. Our results suggest that adjusting egg laying behaviour is a mechanism used by both hosts and brood parasites that may contribute to the differences in reproductive success shown in prior studies.
Highlights
Brood parasitism is a reproductive strategy found in some egg laying animals, where brood parasitic females avoid the costs of providing care for their offspring by laying their eggs in the nests of other females (Andersson, 1984)
We investigated egg laying behaviour in the context of intraspecific brood parasitism in the burying beetle Nicrophorus vespilloides
We found that females acting as hosts delayed the start of egg laying
Summary
Brood parasitism is a reproductive strategy found in some egg laying animals, where brood parasitic females avoid the costs of providing care for their offspring by laying their eggs in the nests of other females (i.e. hosts) (Andersson, 1984). If hosts adjust their egg laying in the context of intraspecific brood parasitism, we predicted they would delay the beginning of egg laying and reduce laying spread This is because doing so would shorten the window during which brood parasitic offspring could successfully infiltrate the brood, thereby allowing hosts to attain the high levels of reproductive skew reported in prior studies (Eggert & Müller, 2011; Müller et al, 1990a, 2007). We predicted that brood parasites would increase laying spread because this raises the chances that at least some larvae hatch at the right time to avoid infanticide by the host whilst still being able to compete with the host's larvae, thereby providing a mechanism for some brood parasite larvae to infiltrate the host's brood as reported in prior studies (Müller et al, 1990a, 2007)
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
