Individual study: Impact of a novel design of predator exclosure on nesting success of black terns Chlidonias niger at three wetland sites in southern Maine, USA
Heath S.R. & Servello F.A. (2008) Effects of predation and food provisioning on black tern chick survival. Wilson Journal of Ornithology, 120, 167-175
This study is summarised as evidence for the intervention(s) shown on the right. The icon shows which synopsis it is relevant to.
Use multiple barriers to protect nests
A replicated study from 2001-2002 at three black tern Chlidonias niger colonies in wetlands in Maine, USA (Heath & Servello 2008) found that surrounding nests with both a chick retention fence and a predator exclosure fence but removing the chick retention fence 15 days after hatching in 2002 appeared to reduce predation (three chicks from one nest predated, n = 33 chicks from 14 nests), compared to when the retention fence was left until chicks were 18 days old in 2001 (17 chicks from seven nests predated, n = 36 chicks from 14 nests). The chick retention fence was 30 cm high and 15 cm off the ground, and consisted of a 1 m diameter circular fence with an overhead ‘concealment flap’ of wire covered in landscaping cloth; the predator exclosure fence was 1.4 m high and 4.6 m in diameter. The study did not include control (unprotected) nests, so the overall effectiveness of the fences cannot be judged. This study also discussed nest abandonment; see ‘Can nest protection increase nest abandonment?’
Can nest protection increase nest abandonment?
A replicated trial at three black tern Chlidonias niger colonies in wetlands in Maine, USA (Heath & Servello 2008) found that surrounding nests with both a chick retention fence (a 30 cm high, 1 m diameter circular fence with an overhead ‘concealment flap’ of wire covered in landscaping cloth, 15 cm off the ground) and a predator exclosure fence (1.4 m high, 4.6 m diameter) appeared to cause the abandonment of three nests (of 17) immediately after fences were erected in 2001, however, no nests were abandoned in 2002 (14 nests). This study is also discussed in ‘Use multiple barriers to protect nests’.