Moa were many by Dr NJ Gemmell, Dr K. Schwartz and Dr C. Robertson
Until a few hundred years ago, New Zealand hosted several species of giant flightless birds (similar to emu), collectively known as the moa. Their demise following the arrival of humans to New Zealand has been widely documented, but a long standing controversy is whether moa were already in decline prior to human settlement. Using new genetic analyses on an extinct species for the first time we have been able to shed light on this mystery. We estimate that, as little as 1,000 years ago, the standing population of moa was c. 312 million. This estimate is much larger than the accepted population estimate (c. 159,000) for moa at the arrival of humans and suggests that moa numbers had already declined prior to human settlement, perhaps as a result of habitat loss through volcanism or disease. If our new estimates of moa numbers are correct then we need to think again about the factors that might have influenced these populations prior to the arrival of humans, perhaps gaining greater insight into modern conservation problems from the lessons of the past.
Contact: Dr Neil Gemmell, School of Biological Sciences, University of Canterbury, PB 4800, CHRISTCHURCH 8008, New Zealand
The social implications of winner and loser effects by Dr LA Dugatkin and Dr M Druen
More and more evidence from the animal world suggests that "winning begets winning" and "losing begets losing." Prior work on such winner and loser effects has focused on pairwise interactions, and not the extent to which winner and loser effects impact hierarchy formation. We examined the impact of winner and loser effects on hierarchy formation in the green swordtail, Xiphophorus helleri. Our results demonstrate that randomly chosen winners in pairwise contests were more likely to emerge as top-ranked individuals in a hierarchy, while randomly chosen losers were more likely to emerg
Contact: Tim Watson