SURVIVAL RATES OF TROPICAL AND TEMPERATE PASSERINES - A TRINIDADIAN PERSPECTIVE

Mark-recapture data collected using mist nets over a 10-yr period in T rinidad were used to estimate adult survival rates for 17 species of f orest passerines. Trinidadian survival rates (mean 65%, range 45%-85%) were significantly higher than published estimates for European (mean survival 52%, range 32%-71%) and North American (mean survival 53%, r ange 29%-63%) passerines of similar body size (equivalent to 45% highe r mean life expectancy in Trinidad). These findings were confirmed aft er controlling for phylogeny using a method of independent contrasts. Transient and/or young birds were an important feature of the Trinidad data, and studies that fail to allow for the presence of such birds r isk underestimating adult survival. This study lends support to the hy pothesis that avian survival rates are higher in the humid tropics, al though the magnitude of the difference may be smaller than previously suggested.