One of the joys of Maine is seeing or hearing a Common Raven.\u00a0 These massive birds belong to the perching birds or passerines, the largest order of the birds.\u00a0 All passerines have three toes pointing forward and one pointing backward, adapted to hold on to a branch or other support for perching.\u00a0 We normally think of perching birds as small creatures like chickadees, goldfinches and sparrows.\u00a0 With a wingspan of more than four feet and a weight of three pounds, the Common Raven is the biggest perching bird in the world.<\/p>\n
The Common Raven is widely distributed in the Northern Hemisphere, ranging from north of the Arctic Circle to the mountains of Central America.\u00a0 The black plumage and large size of these birds make them conspicuous birds, particularly in winter.\u00a0 The raven figures prominently in the folklore and mythology of many northern peoples.\u00a0\u00a0 Many early peoples associated the raven with death.\u00a0 This association is perpetuated in Edgar Allen Poe’s well-known poem, “The Raven”.<\/p>\n
Although the Common Raven is larger than a Red-tailed Hawk, ravens lack the strong bill and long, sharp talons to kill their own prey.\u00a0 As a result, ravens depend on carrion for most of their food.\u00a0 In the winter, when a dead animal is likely to be frozen, ravens have difficulty in opening the corpse to feed.\u00a0 They must depend on coyotes and other scavengers to tear through the skin of a frozen animal.<\/p>\n
The behavior of Common Ravens is winter has been the focus of a decades-long study by Dr. Bernd Heinrich of the University of Vermont.\u00a0 Heinrich has a camp near Mount Blue where this research project is based.<\/p>\n
The project began one October many years ago when Heinrich observed a small group of ravens which had just located the carcass of a moose.\u00a0 This moose represented many meals for the ravens, enough to keep them well-fed for many months.\u00a0 Oddly, the ravens were quite loud, giving penetrating calls which resulted in other ravens coming to the carcass.\u00a0 Why would the ravens that found the moose want to share their feast?\u00a0 Why should ravens be unselfish?\u00a0 Wouldn’t it be better to be quiet and keep the moose meat for themselves?<\/p>\n
Heinrich describes his research in the book “Ravens in Winter”.\u00a0 The book reads like a biological detective story as Heinrich seeks to understand why ravens would show apparent unselfish behavior<\/p>\n
The paradox was resolved only after Heinrich began to capture ravens and tag them with numbered plastic wing tags.\u00a0 This tagging allowed him to recognize individual ravens from day to day.<\/p>\n
This biological mystery was solved by first noting that a mated pair of ravens (they pair for life) defend a territory throughout the year, not just in the summer as most of our perching birds do.\u00a0 This territorial pair defends their turf vigorously and will chase off any intruding raven.<\/p>\n
From this observations of banded birds, Heinrich realized that the ravens which called to alert other ravens to the presence of an animal carcass were unmated juveniles.\u00a0 These birds did not have a breeding territory and wandered widely.<\/p>\n
If a wandering juvenile located an animal carcass in the territory of a mated pair, the territorial birds would soon locate the intruder and the food and chase the intruding raven off.\u00a0 That observation is the key to the story.\u00a0 By advertising the presence of the carcass to other juveniles, the number of juveniles at the food overwhelms the territorial pair.\u00a0 The mated pair cannot chase off all the juveniles.\u00a0 As soon as one is scared off, others are back feeding on the carcass.<\/p>\n
Behavior which appears at first to be unselfish is, in fact, self-serving behavior.\u00a0 If a juvenile raven found a carcass and kept quiet, it would be evicted as soon as the territorial ravens found it.\u00a0 By recruiting other juveniles to the carcass, the juveniles can have the food for themselves because their numbers prevent the resident pair from chasing the juveniles away.\u00a0 It is only by sharing that the juveniles can be assured of a feast, not unselfish behavior at all.<\/p>\n
Sadly, the book is now out of print but is commonly available from used book-sellers.\u00a0 However, a more recent book, The Mind of the Raven, is still in print.\u00a0 In this book, Heinrich explores the remarkable intelligence of ravens.\u00a0 Ravens use tools and have remarkable abilities in problem-solving.\u00a0 Their vocal communication is complex.<\/p>\n
Years ago, researchers described Common Ravens repeatedly sliding on their backs down a muddy embankment.\u00a0 The authors could not explain this behavior except as a form of entertainment.\u00a0 You have to love birds that like to play!<\/p>\n
[Originally published on January 22, 2011]<\/p>\n\n
One of the joys of Maine is seeing or hearing a Common Raven.\u00a0 These massive birds belong to the perching birds or passerines, the largest order of the birds.\u00a0 All passerines have three toes pointing forward and one pointing backward, adapted to hold on to a branch or other support for perching.\u00a0 We normally think […]<\/p>\n","protected":false},"author":146,"featured_media":0,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_s2mail":"","ngg_post_thumbnail":0,"footnotes":""},"categories":[420],"tags":[],"builder_content":"","_links":{"self":[{"href":"https:\/\/web.colby.edu\/mainebirds\/wp-json\/wp\/v2\/posts\/369"}],"collection":[{"href":"https:\/\/web.colby.edu\/mainebirds\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/web.colby.edu\/mainebirds\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/web.colby.edu\/mainebirds\/wp-json\/wp\/v2\/users\/146"}],"replies":[{"embeddable":true,"href":"https:\/\/web.colby.edu\/mainebirds\/wp-json\/wp\/v2\/comments?post=369"}],"version-history":[{"count":1,"href":"https:\/\/web.colby.edu\/mainebirds\/wp-json\/wp\/v2\/posts\/369\/revisions"}],"predecessor-version":[{"id":370,"href":"https:\/\/web.colby.edu\/mainebirds\/wp-json\/wp\/v2\/posts\/369\/revisions\/370"}],"wp:attachment":[{"href":"https:\/\/web.colby.edu\/mainebirds\/wp-json\/wp\/v2\/media?parent=369"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/web.colby.edu\/mainebirds\/wp-json\/wp\/v2\/categories?post=369"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/web.colby.edu\/mainebirds\/wp-json\/wp\/v2\/tags?post=369"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}