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Published byClaude Stewart Robinson Modified over 9 years ago
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A Changing World
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My Students and I are Studying the Responses of Birds to Such Change
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We Found a Counterintuitive Response
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But, Considering Extinction and Colonization of Different Groups of Birds Separately, The Pattern Makes More Sense
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Expected Changes
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Winners
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And Losers Pacific-slope Flycatcher
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Approaching a Tipping Point? Projected Forest Decline
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The way a crow Shook down on me The dust of snow From a hemlock tree Has given my heart A change of mood And saved some part Of a day I had rued Robert Frost In the Company of Crows and Ravens John Marzluff and Tony Angell Some Resilient Species are Powerful Cultural Motivators
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Crows
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Ravens
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A Rich Family
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Creator to some….
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…sport to others
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Influence of Ravens and Crows through History
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Cultural Coevolution Cultural coevolution: coupled changes in two or more species’ cultures that evolve in response to interactions between the species
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Major Episodes of Cultural Coevolution Hunting and Gathering War and Aggression Agricultural Intensification Urbanization Hunting and Harvest Bird Feeding
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(Knight 1984, Knight et al. 1987)
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An AgriCULTURAL Revolution
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(Nihei and Higuchi 2001) Foraging Innovations and Human Behavior
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Why Do Crows and Ravens Motivate Us? Large brains Proximity Sociality
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Feathered Apes
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Lateralization and Brain Complexity Complex neural connections and lateralization –Left hemisphere for complex integration and learning New Caledonian Crows are mostly right-billed (tilting to use right eye), using left hemisphere to guide tool making and use Song learning is also controlled from left hemisphere (Cnotka et al. 2008)
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Learning about friends and foes is necessary in a dangerous, changing environment pace of change may favor individual and social learning Sociality and Opportunity
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Can American Crows Tell the Difference? Caveman
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Can American Crows Tell the Difference? CavemanCheney
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Yes, Crows Know Their Enemies
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Memory of Extraordinary Face is Long-term (and still continues)
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What About Ordinary Faces? LindaVivianMichelle HirooJoeScott
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The Dangerous Face is Always Recognized, and Especially Likely to Attract a Mob But not Perfectly
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Who is Scolding?
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Social Learning
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Tool Use by New Caledonian Crows Betty, a female crow was successful at making hooks to retrieve a bucket of meat 9 / 10 times In wild, most are right-handed, indicating importance of the brain’s left hemisphere in solving non-spatial problems (language in people, tool making in crows) (Weir et al. 2002. Science 297:981)
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Courtesy of Alex Weir, Oxford
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What About Gifting? Gary Clark, 2006, Marysville, WA
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Hypotheses: 1.Crows understand the spoken and written word 2.Someone pulled Gary’s chain 3.Gary pulled my chain 4.The crow was trained / imprinted 5.Gifting is a mistake 6.Gifting is adaptive
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Gary’s Chain is Hard to Pull Wife is handicapped No kids Fenced yard
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Independent Accounts Suggest My Chain Was Not Pulled and the Crow was not Trained 2005, Nancy from Bristol, Indiana reports on national radio that a crow lands on her lap and leaves a wooden bead
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Independent Accounts Suggest My Chain Was Not Pulled and the Crow was not Trained 2005, Gail also calls in to say a crow dropped her a red / white rocket
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Independent Accounts Suggest My Chain Was Not Pulled and the Crow was not Trained 2005, Leona from Missouri receives glass shards in her feeder
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Independent Accounts Suggest My Chain Was Not Pulled and the Crow was not Trained 2008, Eric from Kuna, Idaho leaves mice for magpies in his barn, and gets shiny objects
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Independent Accounts Suggest My Chain Was Not Pulled and the Crow was not Trained 2008, Beth from Seattle feeds crows and watches them drop a key as they go for the dog kibble she is leaving
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Crows Gift Without Being Asked In all other cases of gifting, nothing was asked of crows and no writing was exchanged
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Gifting Could Be a Mistake A stolen object might be dropped for a better meal –Why not return to get it later? Predictions: –Items left should be irrelevant to people Some are: bones, feathers, nuts, twigs –Anyone should receive a gift Most recipients are habitual feeders Delivering a nestling to a crow statue sounds like mistaken identity, but purposeful
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Could Gifting be Adaptive? It could pay to engage people –Easily learned; most gifts are relevant rewards for helpful people It has natural predecessor –Courtship feeding –Bowerbird courts It is seen in another setting –Dolphins give fish to birds and humans
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Sometimes People Get Too Much Nature Cultural Carrying Capacities Can Be Exceeded People respond with a host of cultural shifts Shooting crows in Chatham, ON and Singapore Changed garbage handling in Tokyo Chili-flavored or Yellow garbage bags
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Our Actions are Reflected in the Diversity of Crows and Ravens
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Thanks and Best Wishes
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