Providing evidence to improve practice

Action: Control invasive ants on islands Bird Conservation

Key messages

A replicated, randomised and controlled, before-and-after paired sites study in the USA found temporarily increased fledging success, but no decrease in injuries inflicted by Solenopsis geminata on wedge-tailed shearwaters Puffinus pacificus following ant control. However, there was no change in fledging success or injury rate on an island dominated by the big-headed ant Pheidole megacephala following its eradication, either on the experimental or control island.

 

Supporting evidence from individual studies

1 

A replicated, randomised and controlled, before-and-after paired sites study over three breeding seasons in 2002-2004 on two pairs of offshore islets (< 5 ha) in Hawaii, USA (Plentovich et al. 2009), found that wedge-tailed shearwaters Puffinus pacificus from an island previously dominated by the invasive tropical fire ant Solenopsis geminata showed temporarily increased fledging success, but no decrease in injuries inflicted by S. geminata following ant control (27-38% of chicks injured in all seasons), whilst fledging rates remained constant and injuries increased on an untreated island (8% injured in 2002, 80-100% in 2003-4). There was no change in fledging success or injury rate on an island dominated by the big-headed ant Pheidole megacephala following its eradication, either on the experimental or control island, but very few chicks were injured by ants. Severely injured chicks (20% of tissue on their feet lost) weighed significantly less than uninjured chicks and did not fledge. Between 15 and 43 chicks were monitored on each islet each year. Following a year of baseline data collection, ant populations were controlled with granular protein-based ant bait in February 2003 on one randomly selected islet of each pair.

 

Referenced papers

Please cite as:

Williams, D.R., Child, M.F., Dicks, L.V., Ockendon, N., Pople, R.G., Showler, D.A., Walsh, J.C., zu Ermgassen, E.K.H.J. & Sutherland, W.J. (2017) Bird Conservation. Pages 95-244 in: W.J. Sutherland, L.V. Dicks, N. Ockendon & R.K. Smith (eds) What Works in Conservation 2017. Open Book Publishers, Cambridge, UK.