Nashville Warbler (Oreothlypis Ruficapilla) Julie A

Nashville Warbler (Oreothlypis ruficapilla) Julie A. Craves

Port Huron State Game Area, St. Clair Co., MI June, 2009 © Willie McHale

(Click to view a comparison of Atlas I to II)

Nashville Warblers are common migrants said it was common “in the north.” A similar pattern held in both MBBA I and MBBA II, throughout the state as they journey between with breeding concentrated in the UP and their wintering areas in the Neotropics and eastern NLP; Atlas records were slightly scarcer northern breeding sites. There are two widely in the western NLP in both periods. This separate breeding populations: one in the distribution likely corresponds with the favored northwestern U.S. and parts of adjacent Canada, nesting habitat of the eastern population, which and the other in north central to eastern Canada, includes tamarack swamps and spruce-cedar New England, the upper Great Lakes, and the bogs, and occasionally jack pine or second Appalachians to West Virginia (Williams 1996). growth aspen stands (Williams 1996).

Participants in MBBA I found nesting Nashville It has been commonly believed that the eastern Warblers most often in mesic and wet conifer population winters mainly in northeastern forests and mesic mixed forests. Mexico to Guatemala, while the western population winters in California and western In the SLP, the actual summer status of Mexico (Curson et al. 1994, Williams 1996). Nashville Warblers is a bit unclear. In MBBA I, However, recent molecular studies found the southernmost confirmed nesting was in eastern breeding individuals throughout the Midland Co. There were no confirmations and entire wintering range; the analysis included only five townships with records at the level of feather samples taken in southeastern Michigan probable in the SLP. There were a modest at the Rouge River Bird Observatory in number of possible records in both Atlas periods Dearborn (Lovette et al. 2004, Smith et al. in the SLP, some of which should be viewed 2005). with caution. Nashville Warblers have quite

protracted migration periods, with spring Distribution migrants in the southernmost counties into June, Barrows (1912) reported the Nashville Warbler and presumed southbound migrants appearing in as a frequent summer resident throughout the late July or early August (Kelley 1978, Craves NLP and most of the UP, preferring tamarack 2007). swamps, especially near edges and openings. That being said, in MBBA II there was an Wood (1951) noted it as a summer resident increase in the number of townships recording south to Montcalm County, while Payne (1983) probable or confirmed nesting activity in the

SLP; confirmations were in Huron, Gratiot, and especially in the UP. Overall, this species was Barry Counties. Ohio, as well, seems to be noted as probable or confirmed in a higher seeing more evidence of nesting Nashville percentage of townships in MBBA II than in Warblers. MBBA I; this increase was nearly 27% for the UP. Breeding can be hard to confirm, as Although the first Ohio Breeding Bird Atlas Nashville Warblers build well-concealed nests recorded only one unmated male (Peterjohn and on the ground, often under a fern or shrub Rice 1991), the first three years of their second (McLaren 2007). Still, they were confirmed in a Atlas effort has recorded one probable and two higher proportion of blocks in which they were possible records (OBBA 2009). found in MBBA II – 21% versus 15% in MBBA I. In contrast, Ontario reported a similar distribution between their two Atlases, with this Conservation Needs species being mostly absent in the An important component of nesting habitat for southwesternmost part of the province Nashville Warblers is a well-developed (McLaren 2007). Wisconsin had only one quad, herbaceous layer, so light penetration to the assigned a level of probable, in the southern two forest floor is essential (Roth 1977, Williams tiers of the state (Howe 2006). They have not 1996). Therefore, these birds often utilize edges been recorded breeding in Indiana (Castrale et and openings, including along roads and edges al. 1998, BBA Explorer 2009). Nor were any created by timber harvesting. This adaptability found during the Illinois Atlas (Kleen et al. may help to support continued good numbers of 2004) although they were apparently regular Nashville Warblers in northern Michigan for the summer residents in northeastern Illinois and near future. southern Wisconsin in the late 1800s (Cory 1909, Pitelka 1940). Longer term, climate change may be a concern. Price (2000) listed Nashville Warbler as a Breeding Biology species that may be potentially extirpated from Nashville Warblers construct well-hidden cup Michigan by the year 2100. Using several nests on or near the ground, where they can be different climate change models, Matthews et al. difficult to find (McLaren 2007). This species (2007) predicted a decrease in habitat suitability raises a single brood, of typically four to five for Nashville Warblers in the state along with a young, each season, and is an uncommon corresponding decrease in abundance, especially cowbird host (Williams 1996). A couple of in the NLP. interesting reports of cowbird-parasitized nests from Michigan and Ontario described young Nashville Warblers sitting on the backs of cowbird nest-mates in order to be fed by their parents, or a female warbler sitting on the back of a cowbird nestling to reach and feed her own young (Roth 1977, Williams 1996).

Abundance and Population Trends (Click to view trends from the BBS) BBS trends indicate a slightly positive, non- significant trend in Michigan for the period spanning the two Atlas periods. MBBA II data suggest Nashville Warblers may be increasing,

Literature Cited . Accessed 13 Feb 2009. Barrows, W.B. 1912. Michigan Bird Life. McLaren, P.L. 2007. Nashville Warbler. In Special Bulletin. Michigan Agricultural Cadman, M.D., D.A. Sutherland, G.G. Beck, College. Lansing, MI. D. Lepage, and A.R. Couturier (eds.). 2007. Breeding Bird Atlas Explorer [BBA Explorer]. Atlas of the Breeding Birds of Ontario, 2009. U.S. Geological Survey, Patuxent 2001-2005. Bird Studies Canada, Wildlife Research Center and National Environment Canada, Ontario Field Biological Information Infrastructure. Ornithologists, Ontario Ministry of Natural Indiana Breeding Bird Atlas 2005-2010. Resources, and Ontario Nature. Toronto, . Accessed 18 Feb 2009. Cornell Lab of Ornithology. Cory, C.B. 1909. The Birds of Illinois and . Accessed 6 Feb 2009. Publication No. 131, Chicago, USA. Peterjohn, B.G., and D.L. Rice. 1991. The Craves, J.A. 2007. The Birds of Dearborn, An Ohio Breeding Bird Atlas. Ohio Department Annotated Checklist. Rouge River Bird of Natural Resources. Columbus, OH. Observatory, Dearborn, Michigan, USA and Pitelka, F.A. 1940. Nashville Warbler breeding Lulu Press, Inc., Morrisville, North in northeastern Illinois. Wilson Bulletin Carolina, USA. 57:115-116. Curson, J., D. Quinn, and D. Beadle. 1994. Price, J. 2000. Modeling the potential impacts of Warblers of the Americas. Houghton Mifflin climate change on the summer distribution Co., Boston and New York, USA. of Michigan’s nongame birds. Michigan Howe, R.W. 2006. Nashville Warbler. In Birds and Natural History 7: 3-13. Cutright, N.J., B.R. Harriman, and R.W. Roth, J.L. 1977. Breeding biology of the Howe (eds.). 2006. Atlas of the Breeding Nashville Warbler in northern Michigan. Birds of Wisconsin. Wisconsin Society for Jack-Pine Warbler 55:129-141. Ornithology. Waukesha, Wisconsin, USA Smith, T.B., S.M. Clegg, M. Kimura, K.C. Kleen V.M., L. Cordle, and R.A. Montgomery. Ruegg, B. Mila, and I.J. Lovette. 2005. 2004. The Illinois Breeding Bird Atlas. Molecular genetic approaches to linking Illinois Natural History Survey, Special breeding and overwintering areas in five Publication No. 26. University of Illinois, Neotropical migrant passerines. In Urbana-Champaign, Illinois. USA. Greenberg, R., and P. P. Marra (eds.). 2005. Lovette, I.J., S.M. Clegg, and T.B. Smith. 2004. Birds of Two Worlds: The Ecology and Limited utility of mtDNA markers for Evolution of Migration. John Hopkins determining connectivity among breeding University Press, Baltimore, Maryland, and overwintering locations in three USA. Neotropical migrant birds. Conservation Williams, J.M. 1996. Nashville Warbler Biology 18:156-166. (Vermivora ruficapilla). In The Birds of Matthews, S.N., L. R. Iverson, A.M. Prasad, A. North America, No. 205. Poole, A. and F. M., and M.P. Peters. 2007. A Climate Gill, editors. The Birds of North America, Change Atlas for 147 Bird Species of the Inc., Philadelphia, Pennsylvania, USA. Eastern United States (database). Northern Research Station, USDA Forest Service, Delaware, Ohio.

Suggested Citation

Craves, J.A. 2010. Nashville Warbler (Oreothlypis ruficapilla). In Chartier, A.T., J.J. Baldy, and J.M. Brenneman (eds.). 2010. The Second Michigan Breeding Bird Atlas. Kalamazoo Nature Center. Kalamazoo, MI. Accessed online at: .