Changes in breeding bird richness and abundance in Montreal parks over a period of 15 years

We compared the breeding bird population and vegetation structure of 201 ra ndomly selected 1 ha plots in 49 urban parks in Montreal, 15 years apart (i n 1979-1981 and 1994). The constancy of 17 bird species increased significa ntly, while that of four others decreased. Increased large-tree cover and a reduction in shrub cover do not explain more than a small proportion of th is variation in species constancy. We contend that the installation of bird feeder stations in and around parks goes a long way toward explaining thes e changes, although the recent arrival in Quebec of the House Finch (Carpod acus mexicanus) and the Northern Cardinal (Cardinalis cardinalis) has defin itely played a major role in the changes of the bird assemblage. (C) 1999 E lsevier Science B.V. All rights reserved.