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Providing evidence to improve practice

Individual study: Does the removal of avian brood parasite eggs increase host productivity? A case study with brown-headed cowbirds Molothrus ater and song sparrows Melospiza melodia near Ithaca, New York, USA

Published source details

Hauber M.E. (2009) Does the removal of avian brood parasite eggs increase host productivity? A case study with brown-headed cowbirds Molothrus ater and song sparrows Melospiza melodia near Ithaca, New York, USA. Conservation Evidence, 6, 83-88


This study is summarised as evidence for the intervention(s) shown on the right. The icon shows which synopsis it is relevant to.

Remove brood parasite eggs from target species’ nests Bird Conservation

A replicated, controlled study from 1997-1999 in grassy fields in New York State, USA (Hauber 2009) found that song sparrow Melospiza melodia nests paratised by brown-headed cowbirds Molothrus ater had lower productivity when cowbird eggs were removed, compared to paratised nests when cowbird eggs were not removed (median of 0% of eggs from nests with eggs removed produced nestlings vs. 75% of eggs from nests where cowbird eggs were not removed). There were no differences in the number of song sparrow nestlings surviving to five days old between paratised nests, non-paratised nests and paratised nests with cowbird eggs removed.