Individual study: Soft release improves survival of captive-bred Attwater prairie chicken Tympanuchus cupido attwater after release, but recruitment remains very low
Lockwood M.A., Clifton P., Morrow M.E., Rendel C.J. & Silvy N.J. (2005) Survival, Movements, and Reproduction of Released Captive-Reared Attwater's Prairie-Chicken. The Journal of Wildlife Management, 69, 1251-1258
This study is summarised as evidence for the intervention(s) shown on the right. The icon shows which synopsis it is relevant to.
Use holding pens at release sites
A replicated study reviewing a reintroduction programme in two prairie sites in Texas, USA, in 1996-7 (Lockwood et al. 2005) found that six month survival rates of released, captive-bred and hand-reared Attwater’s prairie chickens Tympanuchus cupido attwater (an endangered subspecies of the greater prairie chicken) were higher for birds that spent 14 days in an ‘acclimatisation pen’ (47% of 97 birds alive after six months) compared to birds that spent only three days in the pens (19% of 31 birds alive). Further analysis revealed that this difference was due to increased survival in the first two weeks after release. This study is discussed further in ‘Release captive-bred individuals’.
Release captive-bred individuals into the wild to restore or augment wild populations of gamebirds
A review of a reintroduction programme in two prairie sites in Texas, USA, in 1996-7 (Lockwood et al. 2005) found that two-week survival rates of 119 released, captive-bred and hand-reared Attwater’s prairie chickens Tympanuchus cupido attwateri (an endangered subspecies of the greater prairie chicken) were 51-82%. The date of release (July-October), release habitat (prairie or soybean ‘food plot’) or type of radio-transmitter used to track birds did not affect six-month survival rates, whereas time spent in cages prior to release did (discussed in ‘Use holding pens at release sites’). Movements and range-sizes were similar for released and wild birds but there was no known recruitment into the population from released birds. Mortality was mainly from predation, whilst known nesting failures appeared to be due to invasive red fire ants Solenopsis invicta.