Table 2. Breeding bird groups and their vulnerability to window collisions.

Comparison between building collision vulnerability for bird groups and species within respective groups that were documented or not documented as carcasses during the breeding seasons 2009–2012, northwestern Illinois, USA. Vulnerability estimates based on Loss et al. (2014). “Risk values indicate the factor by which a species has a greater chance (for positive residuals) or a smaller chance (for negative residuals) of mortality compared with a species with average risk” (Table 5, Loss et al., 2014).

Bird group vulnerability	Residual	Risk	Species found as carcasses	Species not found as carcasses
Hummingbirds and swifts	1.52	33.2	Ruby-throated Hummingbird	Chimney Swift
Kingfishers	0.56	3.6	Belted Kingfisher	–
Waxwings	0.55	3.6	–	Cedar Waxwing
Warblers	0.54	3.4	Ovenbirda	–
Nuthatches, tits, and creeper	0.50	3.1	Black-capped Chickadee, White-breasted Nuthatcha	–
Cuckoos	0.46	2.9	Yellow-billed Cuckoo	–
Mimic Thrushes	0.41	2.6	Gray Catbird	–
Cardinaline Finches	0.36	2.3	Indigo Bunting, Northern Cardinal	–
Thrushes	0.25	1.8	American Robin	–
Cardueline Finches	0.23	1.7	House Finch	American Goldfinch
Woodpeckers	0.15	1.4	Downy Woodpecker, Northern Flickera	Red-bellied Woodpecker
Doves and pigeons	0.08	1.2	–	Mourning Dove, Rock Pigeon
Sparrows	0.08	1.2	–	Chipping Sparrow
House Sparrow	−0.15	1.4	House Sparrowa	–
Wrens	−0.20	1.6	–	House Wren, Carolina Wren
Flycatchers	−0.41	2.6	Eastern Wood-Pewee	Eastern Phoebe
Vireos	−0.55	3.6	Red-eyed Vireo	–
Starling	−0.56	3.6	–	European Starling
Blackbirds, meadowlarks, and orioles	−0.64	4.4	Baltimore Oriole	Common Grackle, Brown-headed Cowbird
Gnatcatchers	−1.68	48.1	–	Blue-gray Gnatcatcher

Notes.

^aCarcass found in either 2011 or 2012 when estimating daily mortality, but not during the summers of 2009 and 2010 when community composition was assessed.