AVIS-IBIS

Birds of Indian Subcontinent

Testing assumptions of a supplementary feeding experiment aimed at suburban House Sparrows Passer domesticus

Publication Type:Journal Article
Year of Publication:2013
Authors:Peach, WJ, Mallord, JW, Orsman, CJ, Ockendon, N, Haines, WG
Journal:Bird Study
Volume:60
Issue:3
Date Published:2013
ISBN Number:0006-3657
Keywords:Passer, Passer domesticus, Passeridae
Abstract:Capsule?Empirical support is provided for the design and field methods associated with a replicated supplementary feeding experiment. Aims?We tested assumptions associated with a supplementary feeding experiment in which counts of House Sparrows were used to infer impacts of feeding mealworms and seed on reproductive output and population size. Methods?Supplementary food was provided at 33 House Sparrow colonies spread across suburban London, with 33 unfed colonies serving as controls. We compared the characteristics of fed and unfed colonies and tested whether competition for mealworms increased with colony size. We tested whether counts of young sparrows reflected variation in reproductive output and whether supplementary feeding affected the distribution of young sparrows. Results?Fed and unfed colonies were similar with respect to habitat, cat density, background feeding and initial colony size. Intensity of feeder usage increased with colony size. Counts of fledglings and juveniles were positively correlated with counts of active nests. Supplementary feeding influenced the distribution of juveniles but not that of recent fledglings. Conclusions?Fed and unfed colonies were similar in character. Competition for mealworms was greater at larger colonies and fledgling counts provided a useful measure of variation in reproductive output across colonies.Capsule?Empirical support is provided for the design and field methods associated with a replicated supplementary feeding experiment. Aims?We tested assumptions associated with a supplementary feeding experiment in which counts of House Sparrows were used to infer impacts of feeding mealworms and seed on reproductive output and population size. Methods?Supplementary food was provided at 33 House Sparrow colonies spread across suburban London, with 33 unfed colonies serving as controls. We compared the characteristics of fed and unfed colonies and tested whether competition for mealworms increased with colony size. We tested whether counts of young sparrows reflected variation in reproductive output and whether supplementary feeding affected the distribution of young sparrows. Results?Fed and unfed colonies were similar with respect to habitat, cat density, background feeding and initial colony size. Intensity of feeder usage increased with colony size. Counts of fledglings and juveniles were positively correlated with counts of active nests. Supplementary feeding influenced the distribution of juveniles but not that of recent fledglings. Conclusions?Fed and unfed colonies were similar in character. Competition for mealworms was greater at larger colonies and fledgling counts provided a useful measure of variation in reproductive output across colonies.
URL:http://dx.doi.org/10.1080/00063657.2013.809048
Short Title:Bird Study
Scratchpads developed and conceived by (alphabetical): Ed Baker, Katherine Bouton Alice Heaton Dimitris Koureas, Laurence Livermore, Dave Roberts, Simon Rycroft, Ben Scott, Vince Smith