Red-eyed Vireo (Vireo olivaceus) Mike Bishop
Magee Marsh Wildlife Area, Ottawa Co., OH. 5/27/2007 © Darlene Friedman (Click to view a comparison of Atlas I to II)
It would border on the impossible to spend any and New York, their second atlases showed an increase in detections of red-eyeds over their time during the summer in or near a forest of first atlases (James 2007, McGowan 2008). In just about any size and not hear the persistent Michigan this vireo’s distribution is more than and somewhat monotonous “cher-wit, cheerio, likely little changed from the period prior to cheer-oh….” of the Red-eyed Vireo. More settlement with the exception of the densely often heard than seen, this treetop forager sings populated Detroit metropolitan area. All of continuously throughout the morning and well Michigan, both the UP and LP, are within the into the afternoon when most other birds are heart of its eastern range. Consequently, within silent. Furthermore, it sings late into the Michigan, the Red-eyed Vireo is found in any summer, still being heard towards the end of area where there are forested lands. Densities August when many of the other long distance increase with an increase in larger contiguous migrants have already begun their journey forest tracts. Furthermore, mature forests south. The Red-eyed Vireo’s breeding range support a greater abundance of Red-eyed Vireo extends from Newfoundland to the eastern compared to younger forests. Yukon and south to northern Washington and the Dakotas and southeast through the eastern About 90% of all townships in the state Great Plains to the Gulf states (Cimprich et al. exhibited at least possible breeding status, with 2000). The winter range of the North American probable designations being in the majority. populations of Red-eyed Vireo is in northern The distribution of Red-eyed Vireos is South America east of the Andes. This includes remarkably uniform across the state. Clearly, Colombia, Venezuela, Guyana, Suriname, the availability of forests, whether large or Ecuador, Peru, and western Brazil (Cimprich et small, mature or young, provide Michigan al. 2000). populations of this species with acceptable
breeding habitat, though the quality of that Distribution habitat can vary considerably. Considered to be one of the most common forest songbirds in eastern North America (Cimprich Breeding confirmation by township was 14.8% et al. 2000), Red-eyed Vireos can be found of the townships surveyed. While this may anywhere within their range where there are seem low, the preponderance (68.3%) of reasonably sized forest tracts. In both Ontario
© 2011 Kalamazoo Nature Center Red-eyed Vireo (Vireo olivaceus) Mike Bishop probable breeding status designations supports Abundance and Population Trends the successful breeding of this species BBS trend data for Red-eyed Vireos in throughout the state. The UP boasted the Michigan have demonstrated a significant highest documentations with 75% of all gradual increase of approximately 3.7% from townships exhibiting probable breeding status 1983 to 2008 (Sauer et al. 2008). This is almost and approximately 21% exhibiting confirmed twice the increase observed for red-eyeds for breeding status. This is undoubtedly due to the USFWS Region 3, which includes the Upper extensive mature forested habitat present in the Midwest and western Great Lakes. Between the UP. time of data collection for the first atlas and that of the second, Michigan’s Red-eyed Vireo Interestingly, these changes translated to only population index nearly doubled, from an very subtle and sometimes contradictory average of 13.5 birds per BBS route to 28.3 differences in breeding confirmations between birds per route. the first and second Michigan atlases. Of the townships surveyed in the UP there was in Conservation Needs increase in reported breeding confirmations Like many other forest breeding birds, Red-eyed from 8.5% to 18.5%. However, the NLP and Vireos are an area sensitive species. Therefore, SLP saw decreases from 13.1% to 10.9%, and fragmentation of breeding habitat could become 16.1% to 11.3% respectively. For all three a threat to population stability (Cimprich et al. regions the increase in probable breeding 2000). Fragmentation also results in increased detections increased from 46.4% to 62.3%. It is pressure from nest predators and nest parasites. safe to say that total detections were high during Furthermore, impacts on the quality of the both atlas periods reflecting the success of the wintering grounds could affect vireo numbers as species in the state. well. Finally, collisions with buildings, cell towers, and wind turbines, all of which are Breeding Biology increasing in number, will continue to pose a Red-eyed Vireos arrive in Michigan by early to threat to Red-eyed Vireos (Graber et al. 1985, mid-May in the LP and by late May in the UP. Stevenson and Anderson 1994). The small, neatly woven cup nest of the Red- eyed Vireo is usually placed at a height of 1.5 to 3 m in the fork of a branch in a small understory tree. Foraging occurs at all levels of the forest ensuring their need for well developed vegetation layers. One brood is raised per season and by mid-July young have fledged and are being cared for by parents away from the nest (Southern 1958). As with most songbirds, Red-eyed Vireos have to contend with nest parasitism by Brown-headed Cowbirds. A 1980 study documented a parasitism rate of 69.3% between 1922 and 1978 (Southern and Southern 1980). After breeding adults begin their southward migration by the end of August with the young departing soon afterwards.
© 2011 Kalamazoo Nature Center Red-eyed Vireo (Vireo olivaceus) Mike Bishop
Literature Cited Suggested Citation Cimprich, D.A., F.R. Moore, M.P. Guilfoyle. Bishop, M. 2011. Red-eyed Vireo (Vireo 2000. Red-eyed Vireo (Vireo olivaceus). olivaceus) in A.T. Chartier, J.J. Baldy, and Account 527 in A. Poole and F. Gill, editors. J.M. Brenneman, editors. The Second The Birds of North America. The Birds of Michigan Breeding Bird Atlas. Kalamazoo North America, Inc., Philadelphia, Nature Center. Kalamazoo, Michigan, USA. Pennsylvania, USA. Accessed online at: Graber, J.W., R.R. Graber, and E.L. Kirk. 1985.
© 2011 Kalamazoo Nature Center