A Changing World. My Students and I are Studying the Responses of Birds to Such Change.
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Transcript of A Changing World. My Students and I are Studying the Responses of Birds to Such Change.
My Students and I are Studying the Responses of Birds to Such Change
Mixed urban andother non-forest
Urban
Forest
Water
1 kmLandscape
Study Sites2
Songbird MappingAreas (to scale)
Kilometers
Seattle
N
2 0 2 4 6
• But, Considering Extinction and Colonization of Different Groups of Birds Separately, The Pattern Makes More Sense
And Losers
Pacific-slope Flycatcher
The way a crowShook down on meThe dust of snowFrom a hemlock treeHas given my heartA change of moodAnd saved some partOf 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
Cultural Coevolution
• Cultural coevolution: coupled changes in two or more species’ cultures that evolve in response to interactions between the species
Major Episodes of Cultural Coevolution
• Hunting and Gathering
• War and Aggression• Agricultural
Intensification• Urbanization• Hunting and Harvest• Bird Feeding
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)
Learning about friends and foes is necessary in a dangerous, changing environment
pace of change may favor individual and social learning
Sociality and Opportunity
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)
Hypotheses:
1. Crows understand the spoken and written word
2. Someone pulled Gary’s chain
3. Gary pulled my chain4. The crow was trained /
imprinted5. Gifting is a mistake6. Gifting is adaptive
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
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
Independent Accounts
Suggest My Chain Was Not Pulled and the Crow was not
Trained
• 2005, Leona from Missouri receives glass shards in her feeder
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
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
Crows Gift Without Being Asked
• In all other cases of gifting, nothing was asked of crows and no writing was exchanged
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
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
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