Honeybee colonies could be collapsing because younger bees are flying out to forage, raising their risk of death.

Many bee colonies are failing, probably because of parasites, pathogens and pesticides. Bees react to such stressors by foraging at a younger age, so to learn how this might cause rapid population declines, Andrew Barron at Macquarie University in Sydney and his colleagues radio-tagged bees in experimental colonies to monitor their flight behaviour. The insects that began foraging earlier in life completed fewer successful trips and had a lower survival rate than those that foraged at the normal age.

Mathematical models showed that the resulting decrease in food for the colony and the increased forager mortality over time led to rapid colony collapse. The authors suggest that supplemental feeding of colonies could help to stave off bee declines.

Proc. Natl Acad. Sci. USA http://dx.doi.org/10.1073/pnas.1422089112 (2015)