Quick Dips

Familiarity Breeds Success?

Results of several studies suggest that, when shifting birds to new areas for conservation purposes, use of familiar individuals may aid successful establishment of the new colony. However, recent work on New Zealand whiteheads, robins and saddlebacks indicates that familiarity does not necessarily produce beneficial effects on survival, pair bonding or reproduction of the translocated birds.

"Birds were effective at establishing new relationships and pair bonds with previously unfamiliar birds, and most existing breeding pairs and and groups broke up after translocation," the researchers concluded in a recent paper.

The study has important implications for bird management. While it is potentially beneficial to use familiar birds as the basis for a founder group in a new location, there are also genetic reasons for selecting animals from different localities. A group of birds taken from one location may be susceptible to inbreeding depression as a result of sharing a common genetic background.

"We felt it was important to assess the effect of familiarity in translocations because it might prove a valuable tool in improving translocation success. We also feared that there might be an increasing tendency to avoid taking birds from close to one another, for genetic reasons, and that this might jeopardize the success of many translocations," noted Doug Armstrong, an ecologist from Massey University, in conjunction with fellow researchers from the Department of Conservation, MAF and Auckland University.

The researchers were interested to find that familiarity at the original site appeared irrelevant following translocation. One possible factor involved in this may be the actual stress of moving. Stress reduces aggressiveness in birds, so it may reduce potential for antagonism between unfamiliar individuals. Stress also promotes rapid dispersal, so that familiar birds -- both mates and neighbours -- end up settling in different places in the new location.