Individual study: Survival of captive-reared Hispaniolan parrots Amazona ventralis released in Parque Nacional del Este, La Altagracia, Dominican Republic
Collazo J.A., White T.H. Jr., Vilella F.J. & Guerrero S.A. (2003) Survival of captive-reared Hispaniolan parrots released in Parque Nacional del Este, Dominican Republic. The Condor, 105, 198-207
This study is summarised as evidence for the intervention(s) shown on the right. The icon shows which synopsis it is relevant to.
Use ‘flying training’ before release
A replicated study in the Dominican Republic in 1997-8 (Collazo et al. 2003) found that 25 captive-reared Hispaniolan parrots Amazona ventralis released in 1998 in a subtropical forest site after intensive pre-release flying ‘training’ had flight muscles in significantly better condition than 24 birds released in 1997 after less intensive training. Intensive training consisted of exercise (making birds fly around their aviary) three or four times a week, as opposed to twice a week, and every day in the final week before release. Survival over the first five weeks was much higher in 1998 than 1997 (no deaths in 1998 vs. five deaths in 1997), but overall first-year survival estimates were similar in both years (29% survival in 1998 vs. 30-35% in 1997). This study is discussed in more detail in ‘Release captive-bred individuals into the wild to restore or augment wild populations’.
Release captive-bred individuals into the wild to restore or augment wild populations of parrots
A replicated study in the Dominican Republic in 1997-8 (Collazo et al. 2003) found that survival rate estimates of captive-reared Hispaniolan parrots Amazona ventralis released in a subtropical forest site were only 30-35% for 24 parrots released in 1997 (with seven birds alive 53 weeks after release, 12 definitely dead and five with unknown fates) and 29% for 25 birds released in 1998 (with ten birds definitely dead). In 1997, five birds died within five days of release, however all birds released in 1998 survived at least ten weeks. Mortality in 1998 may have been affected by Hurricane Georges hitting the release site in September 1998. Birds were held in training cages at the release site for a quarantine period of at least 40 days before release. This study is also discussed in ‘Use ‘flying training’ before release’.