Landscape and weather determinants of prey availability: implications for the Lesser Kestrel Falco naumanni

Publication Type:Journal Article
Year of Publication:2012
Authors:Catry, I, FRANCO, ALDINAMA, Sutherland, WJ
Journal:Ibis
Volume:154
Issue:1
Date Published:2012
ISBN Number:1474-919X
Keywords:clutch size, Conservation, diet, Falco, Falco naumanni, Falco tinnunculus, Falconidae, habitat management, laying date, mole crickets, prey availability, Tinnunculus
Abstract:Spatial and temporal variation in prey abundance have been shown to impact the time of breeding and breeding success of birds. Understanding the ecological requirements of preferred prey can help develop management measures to improve food supply for target species. For the colonial Lesser Kestrel Falco naumanni, mole crickets Gryllotalpa spp. are one of the most important prey items during the mate-feeding period. Lesser Kestrel colonies with higher mole cricket consumption had earlier egg-laying dates, suggesting that differences between individuals in the time of breeding could be caused by differences in the diet. Moreover, the mean number of mole crickets in pellets was significantly correlated with clutch size (in one of the studied years) and egg volume. Thus, the impact of environmental variables and land use on mole crickets is likely to be relevant to Lesser Kestrel conservation. Weekly consumption of mole crickets was higher following an increase in either precipitation or minimum temperature values. Furthermore, mole cricket consumption was higher in colonies surrounded by higher quality soils and in wetter areas and years. Predicted probability of mole cricket occurrence in surveyed watercourse margins suggested a positive relationship between soil penetrability and mole cricket occurrence. Among variables that might be the target of management, the presence of riparian vegetation positively influenced the occurrence of mole crickets, whilst tillage and sowing of streambeds were revealed as the most important threats. We suggest that the maintenance of native vegetation in the margins of watercourses could improve soil resilience to erosion, increase water retention, soil penetrability and fertility, and provide a food supply and shelter for mole crickets. Overall, the implementation of such recommendations is likely to benefit other farmland species known to consume mole crickets, including several endangered species.
URL:http://dx.doi.org/10.1111/j.1474-919X.2011.01176.x
Short Title:Ibis
Scratchpads developed and conceived by (alphabetical): Ed Baker, Katherine Bouton Alice Heaton Dimitris Koureas, Laurence Livermore, Dave Roberts, Simon Rycroft, Ben Scott, Vince Smith