Effectiveness of population recovery projects based on captive breeding

Published source details Adamski P. & Witkowski Z.J. (2007) Effectiveness of population recovery projects based on captive breeding. Biological Conservation, 140, 1-7.
Share Tweet Email

This study is summarised as evidence for the following.

	Action	Category
	Release captive-bred individuals to the wild Action Link

Release captive-bred individuals to the wild

A before-and-after study in 1991–2003 in a limestone montane grassland reserve in Poland and Slovakia (Adamski & Witkowski, 2007) found that releasing captive-bred Apollo butterflies Parnassius apollo frankenbergeri increased both the population size and the number of occupied sites. Eleven years after the release of captive-bred butterflies began, a population of Apollo butterflies contained ~1,000 individuals, compared to 30 individuals the year before the first release. The number of sub-populations increased from one to more than 12. However, when the number of butterflies in a sub-population was high, the sub-population size in a given year was lower when more captive-bred butterflies had been released the previous year (data presented as model results). In 1991, butterflies from a remnant population were taken into captivity and bred (number captured not specified). From 1992–2001, between 22 and 658 butterflies/year were released across four areas (2,917 butterflies released in total). In 1995, the captive population was supplemented with butterflies from another population to increase genetic diversity. The species’ host plant, stonecrop Sedum maximum, was abundant at the release sites. From 1991–2003, suitable sites were visited twice/week for 1–3 hours during the flight period, and population size was estimated by marking and recapturing all butterflies observed.

(Summarised by: Andrew Bladon)