Individual study: Widespread local house-sparrow extinctions - agricultural intensification is blamed for the plummeting populations of these birds
Hole D.G., Whittingham M.J., Bradbury R.B., Anderson G.Q.A., Lee P.L.M., Wilson J.D. & Krebs J.R. (2002) Widespread local house-sparrow extinctions - agricultural intensification is blamed for the plummeting populations of these birds. Nature, 418, 931-932
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Provide supplementary food for birds or mammals
A replicated study of four house sparrow Passer domesticus populations in mixed farmland in Oxfordshire, UK (Hole et al. 2002) found that supplementary feeding in winter increased overwinter survival of a declining population, but not three populations understood to be stable. Monthly overwinter survival rate varied between populations, with that of the declining population lower than the other three populations (0.8 vs 0.9). The apparent survival rate of the declining population over the November-March period increased from 0.39 in 1998-1999 to 0.65 in 1999-2000. There was no effect of supplementary feeding on the other three populations. Three populations were selected at random and the fourth was selected for the availability of historical records, which indicated an 80% decline over the last 30 years. Populations were 6-24 km apart. Supplementary seed food was freely provided to the populations during winter 1999-2000. Nest recording, mark re-sighting and microsatellite-based molecular genetics were used for sampling.