Survival, home ranges and activity patterns of reintroduced giant anteaters (Myrmecophaga tridactyla) in Corrientes, Argentina

DI BLANCO, Y. E.; JIMÉNEZ PÉREZ, I.; DI BITETTI, M. S.

Mendoza

Congreso; The 10th International Mammalogical Congress; 2009

We present preliminary results from the first giant anteater reintroduction in the Neotropics, which is being carried out in the Iberá Natural Reserve, Northeast Argentina. The objective of this study is to evaluate the behavior and survival of captive reared giant anteaters in the wild. Between October 2007 and April 2009 the project released three females and three males fitted with VHF transmitters. We radio-tracked each individual on a 24 h basis during different periods from October 2007 to April 2009. We estimated home ranges with 100% Minimum Convex Polygon (MCP) and 95% fixed Kernel Method. We determined if animals were active and compared their daily activity patterns between seasons. Of the six released individuals, one female lost its radio signal four months after being released and one male died in the wild 2 moths after being released; the other four individuals are still alive with a mean minimum survival time since release of 11.75 ± 7.50 months. MCP home ranges varied from 1.50 to 8.12 km2 (N=5) and from 1.28 to 13.30 km2 with Kernel analysis (N=4). Animals were diurnal during autumn-winter and nocturnal during the spring-summer months (Mardia-Watson-Wheeler test X2= 25.13, d.f.= 2, P< 0.001). Variation in home range size among individuals was high but within the limits of home ranges reported for wild animals. The changes in activity pattern observed between seasons may result from the strong seasonal changes in temperature and the need for thermoregulatory balance, due to the low metabolic rate of this species. More animals are necessary to generalize these patterns, but these reintroduced captive reared animals show behaviors similar to those of wild animals, and have good chances of becoming part of the first reintroduced population of giant anteaters.