Andrew Bourke's Website
As well as conducting research (see here and here), I enjoy pursuing interests in all kinds of natural history, including observing and recording insects (see here and here) and bird watching (see here and here). I also enjoy fossil collecting (see here). So this website is about both my research and these other interests.
SELECTED NATURAL HISTORY HIGHLIGHTS
DIGGER WASP WITH PREY: The small black and white digger wasp Oxybelus uniglumis nests in a sandy 'bee-bank' that we constructed in our garden a few years ago. In the summer (June 2024), I was lucky enough to witness the female wasps returning to their nest with their fly prey. As in the photo, they transport captured flies in a unique manner by carrying the paralysed body behind them impaled on their sting.
SAWFLY LARVAE IN COMMUNAL DISPLAY: These sawfly larvae (Nematus septentrionalis) were eating the leaves of a small Hazel in our garden this summer (June 2024). When disturbed, they mount this striking communal display, raising the rear end of their bodies and twisting them about.
SELECTED RESEARCH PAPER HIGHLIGHTS
COSTS OF REPRODUCTION IN EUSOCIAL INSECT QUEENS: In a paper in BMC Biology, we tested whether queens in annual eusocial insects like the bumble bee Bombus terrestris experience costs of reproduction. We experimentally increased queens’ costs of reproduction by removing their eggs, which caused queens to increase their egg-laying rate. Treatment queens lived significantly shorter lives than control queens whose egg-laying rate was not increased. In addition, treatment and control queens differed in age-related gene expression in both their overall expression profiles and the expression of ageing-related genes. These findings suggest that costs of reproduction are present but latent, i.e. that positive fecundity-longevity associations in queens of B. terrestris and similar species are condition-dependent. They also raised the possibility that a partial remodelling of genetic and endocrine networks underpinning ageing may have occurred in B. terrestris such that, in unmanipulated conditions, age-related gene expression depends more on chronological than relative age.
The paper is: Collins DH, Prince DC, Donelan JL, Chapman T, Bourke AFG (2023) Costs of reproduction are present but latent in eusocial bumblebee queens. BMC Biology 21: 153.
CONFLICT OVER RESOURCE INHERITANCE: In this paper in American Naturalist, we developed a model of queen-worker conflict over nest inheritance and tested it in the bumble bee Bombus terrestris. As the model predicted, we showed that workers harass queens with simulated fecundity loss and that aggressive workers are more likely to become egg-layers. This is consistent with workers monitoring queen fecundity to weigh up the relative benefits of reproducing in the nest after the queen's death versus continuing to keep the queen alive as a source of siblings. These findings provide new support for kin-selected conflict over resource inheritance being a key process in social animals.
The paper is: Almond EJ, Huggins TJ, Crowther LP, Parker JD, Bourke AFG (2019) Queen longevity and fecundity affect conflict with workers over resource inheritance in a social insect. American Naturalist 193: 256-266.