Common Raven (Corvus corax) Max A. Henschell
Ketchikan, AK 5/20/2009 © Doug Leffler
(Click to view a comparison of Atlas I to II)
Jet black with a shaggy throat, highly varied extensive forest cover. Migration has been recorded at Whitefish Point and Brockway hoarse utterances and an affinity for carrion, the Mountain, though it is most evident only in the Common Raven is often associated with war spring (Binford 2006). The destination of these and death and thus, has earned a less than migrating birds is unclear. endearing place in the avian community. But its ability to problem-solve, count, and even play Historically, the Common Raven was found should earn the Common Raven the title of throughout southern Michigan, into Ohio, Most Intelligent Bird in Michigan. Not the black Indiana and Illinois. Forest clearing and bird you often see in towns of the Upper widespread shooting of Common Ravens led to Peninsula, that position is typically reserved for their extirpation in the three states directly south the smaller American Crow, the wedge-tailed of Michigan, as well as the withdrawal of the Common Raven patrols the treetops of unbroken species into the UP (McPeek and Adams 1994). forests, rolling in the wind and soaring with the eagles. With a Holarctic range, the Common During MBBA II, Common Ravens were found Raven, largest of all songbirds, is a familiar in just over 42% of townships in the state. sight throughout the northern hemisphere. However, due to habitat requirements, it was not
evenly distributed throughout the state. The Distribution species was found in more than 80% of the The Common Raven is found throughout North townships in the UP, just over 50% of the America, but is absent in the Great Plains, the blocks in the NLP and in less than 1% of the southeast states and westwards into east Texas. blocks in the SLP. All three regions of the state It can be found in a variety of remote habitats witnessed increases in Common Raven records including deserts, mountains, and tundra as well between the first and second atlas. The NLP as boreal and deciduous forests (Boarman and recorded the largest change in occurrence, up Heinrich 1999). In the Great Lakes, it prefers 25% from MBBA I; the SLP had no records extensive tracts of the latter two habitats for during MBBA I. The MBBA II map shows an breeding. This species is a year-round resident, overall southward extension of Common is far more common in the UP than in the NLP, Raven’s breeding range. and is rarely found in the SLP, which lacks
© 2011 Kalamazoo Nature Center Common Raven (Corvus corax) Max A. Henschell
Common Ravens occurred most frequently in data show that the number of Common Ravens the northern third of Wisconsin (Matteson 2006) reported per route in 2007 was five times greater and Ontario north of the Precambrian shield than at the beginning of MBBA I (Sauer et al. (Peck 2007). A comparison of the Atlas maps 2008). This increase in the state is paralleled by from Wisconsin, Michigan and Ontario shows a regional increases in Common Ravens. The trend that breeding records are rare south of a expansion in range is also evident when line along the southern boundaries of Manistee, comparing MBBA I and MBBA II occurrence Wexford, Missaukee, Roscommon, Ogemaw maps. Eight counties in the NLP had confirmed and Iosco Counties, extended into Wisconsin breeding reports of Common Raven that did not and Ontario. have confirmations in the first Atlas.
Breeding Biology Conservation The breeding season for Common Ravens in In the early twentieth century, forest clearing for Michigan begins in February or March, with the agricultural lands and cities throughout New construction of a stick nest of up to four feet in England and the Great Lakes areas removed diameter. These are typically located high in a vast expanses of Common Raven breeding tree, up to 50 ft off the ground, quite often in habitat. Ravens were also persecuted by coniferous trees (McPeek and Adams 1994). poisoning, trapping and shooting during this Nests have also been found on cliff faces. One time period. This change in the landscape was nest found during MBBA II in Marquette accompanied by increased American Crow County was located in the Little Garlic River populations, a species closely associated with Canyon. The habitat was mixed conifer-upland, anthropogenic change (Boarman and Heinrich dominated by hemlock. The nest was above the 1999). Common Ravens were pushed north; river on a ledge of a granitic cliff face. The nest they disappeared from the LP during this time. was similar in size, three to four ft, and height By the middle of the century, reforestation off the ground, 40-50 ft, of those found in trees efforts had reestablished habitat for Common (S. Haas, pers. comm.). Nests are typically lined Ravens. The first successful nest in the LP in with soft material such as hair, shredded bark or decades was in 1976 (Boarman and Heinrich moss (Boarman and Heinrich 1999). 1999).
Three to seven eggs are laid less than a week Though protected by the Migratory Bird Treaty after the completion of nest construction. The Act, their similarity to American Crow probably eggs are incubated for 20-25 days, after which results in the accidental shooting of a few the young emerge blind and sparsely covered Common Ravens annually during lawful crow with down. The parents care for the young for harvest activities and under "Depredation order about six weeks, after which the young fledge for blackbirds, cowbirds, grackles, crows and and leave the family area within one week magpies" (50 CFR 21.43 [2008]) which allows (Boarman and Heinrich 1999). for the shooting of American Crows and other blackbirds causing conflicts to humans, crops or Abundance and Population Trends creating health hazards. If this is occurring, this (Click to view trends from the BBS) does not appear to be affecting the population of The Michigan population of Common Raven is Common Ravens, as BBS records are on the estimated at 12,000 birds (PIF 2007), though rise. It appears that the reforestation of the NLP estimates of Common Raven populations are and the Common Raven’s increased tolerance difficult due to their irregular and unpredictable for humans are allowing this species to distribution (Boarman and Heinrich 1999). BBS recolonize areas from which it was extirpated.
© 2011 Kalamazoo Nature Center Common Raven (Corvus corax) Max A. Henschell
Literature Cited results and analysis 1966-2007. Version 5.15.2008. USGS Patuxent Wildlife Brewer, R., G.A. McPeek, and R.J. Adams Jr. Research Center. Laurel, MD. (eds.). 1991. The Atlas of Breeding Birds of Michigan. Michigan State University Press. Suggested Citation East Lansing, MI. Binford, L.C. 2006. Birds of the Keweenaw Henschell, M.A. 2011. Common Raven (Corvus Peninsula, Michigan. MP 195. University of corax). In Chartier, A.T., J.J. Baldy, and Michigan Muzeum of Zoology. Ann Arbor, J.M. Brenneman (eds.). 2010-2011. The MI. Second Michigan Breeding Bird Atlas. Boarman, W.I., and B. Heinrich. 1999. Kalamazoo Nature Center. Kalamazoo, MI. Common Raven (Corvus corax). In The Accessed online at:
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