Action: Protect nests from livestock to reduce trampling
- A before-and-after study from the Chatham Islands, New Zealand found that the population of Chatham Island oystercatcher increased following several interventions including the erection of fencing around individual nests.
- A replicated, controlled study in Sweden found that no southern dunlin nests were trampled when protected by cages; some unprotected nests were destroyed.
As well as altering vegetation (see 'Exclude grazers from semi-natural habitats'), livestock can also reduce the breeding success of ground-nesting birds by trampling nests.
Supporting evidence from individual studies
A study in the Chatham Islands from 1999 to 2005 (Moore 2005) found that the number of Chatham Island oystercatcher Haematopus chathamensis pairs in a 14 km stretch of coastal land increased from 16 to 35 within six years, following several interventions including erecting 10 x 10 m enclosures of 1 m high electric fencing around individual nests to reduce disturbance and trampling by livestock. Other interventions used are discussed in the relevant sections.
A replicated, controlled study between 1999 and 2004 on pastures in southwest Sweden (Pauliny et al. 2008) found that none of 77 southern dunlin Calidris alpina schinzii nests protected with cages were trampled by cattle, whereas 31 of 291 unprotected nests (11%) failed because of grazing livestock. Cages were 20 cm high truncated cones with 7.5 cm gaps between vertical bars and 4 x 4 cm steel mesh covering the top. The effect of cages on predation of nests and adults is discussed in ‘Threat: Invasive alien and other problematic species”.
- Moore P. (2005) Stock fencing and electric fence exclosures to prevent trampling of Chatham Island oystercatcher Haematopus chathamensis eggs, Chatham Island, New Zealand. Conservation Evidence, 2, 76-77
- Pauliny A., Larsson M. & Bloqvist D. (2008) Nest Predation Management: Effects on Reproductive Success in Endangered Shorebirds. Journal of Wildlife Management, 72, 1579-1583