Research published today in Proceedings of the Royal Society B has found that black-tailed prairie doThe prairie dogs live in groups which must be constantly vigilant to detect predators. Living in groups is advantageous for such prey animals as it means individuals can devote more time to foraging for food whilst their neighbours are on the lookout for predators.
However, sharing the responsibilities for keeping watch means prairie dogs need to collect up-to-date information about how alert other members of the group are. The study published today, led by Professor James Hare from the University of Manitoba, suggests that the jumping display of the prairie dog, the ‘jump-yip’ which is accompanied by a ‘wee-oo’ sound, is used to see if other members of the social group are paying attention.
The jump-yip is a contagious behaviour which spreads though the community like ‘the wave’ around a sports stadium as neighbouring prairie dogs respond by copying the display from each other. Scientists have speculated in the past that its purpose could be to mark territory, give an ‘all clear’ signal or promote social bonding. The scientists behind this study hypothesised that the jump-yip is used to probe how alert other individuals in the group are. This could help determine the risk of a prairie dog reducing their own vigilance to forage for food.
The team studied how the responsiveness of the colony to the jump-yip affected how vigilant the instigating prairie dog was for 1 minute after the display. Vigilant prairie dogs take on an upright posture, so when the prairie dogs had their heads above the horizontal plane they were observed to be alert and when below they were treated as foraging. To assess how responsive the group were the researchers measured the total time that the wave lasted, the number of individuals who responded to the initial jump-yip, and the time it took them to respond.
The team’s results showed that though the time taken to receive a response had no significant effect on the behaviour of the instigator, the longer the wave lasted and the greater the number of prairie dogs who responded to the display the less vigilant the instigating prairie dog was afterwards. The team found that instigators of the jump-yip wave increased the proportion of time they spent foraging, decreasing the proportion of time they were vigilant, as the responsiveness of other prairie dogs increased.
The findings shed some light on the purpose of the jump-yip display and suggest that the prairie dogs could be using it to gather social information about the rest of the group so they can judge the risk of reducing their own vigilance in order to forage. The team says that ‘it is not surprising that these highly social animals have evolved coordinated social behaviour and commensurate cognitive abilities promoting their success in the face of intense predation pressure’.gs use a jumping display to test how alert their neighbours are.