Coevolution of Humans and Animals in Urbanizing Landscapes. Documentation and investigation of connections between human and bird behaviour in Berlin and Seattle
Stipendiat:
Antragsteller: Marzluff (College of Forest Resources, University of Washington, Seattle)
Kennwort: Avifauna
Aim
This project aims to document and investigate connections between human and bird behavior in Berlin and Seattle. The general hypothesis that humans and animals coevolve in cities because human attitudes select for social learning in animals, and vice versa, will be tested. The project will have 4 phases:
- A general literature survey of synanthropic birds and mammals will describe behavioral changes and their ecological correlates that are associated with city life. Special emphasis will be placed on documenting the extent to which social learning (a known route to cultural development in animals) appears important to animals living with people.
- A spatially-explicit depiction of human attitudes toward crows, ravens, and magpies (birds of the Corvid family) will be done in randomly selected urban and rural neighborhoods in Berlin, Seattle, and surrounding hinterlands.
- Field observations of crow, raven, and magpie responses to the variety of human attitudes discovered in Phase 2.
- Design and testing of field experiments to determine the role of social learning in the responses of corvids to people discovered in Phase 3.
Method
Human settlements bring corvids and humans together. This interaction is ancient and has likely shaped aspects of human and corvid behavior. Carrion Crow, Common Raven, and human remains are commingled in ancient (4,000 - 10,500 years ago) settlements of Syria, Poland, Troy, Mesopotamina, and western Canada (e.g., Cavallo 2000, Krönneck 1995). We know, for example, that city crows and ravens are more aggressive around their nests than country birds, in part because hazing and shooting birds is rare in the city relative to the country (Knight 1984, Knight et al. 1987). The cultural basis of persecution will be studied in humans and related to corvid demeanor by documenting the acquisition, geographical distribution, and covariation of human attitudes and corvid nest defense, roosting, and foraging behavior.
We will determine the geographical distribution of human attitudes toward corvids with extensive surveys of people in randomly selected neighborhoods of Berlin, Seattle, and their surrounding rural hinterlands. People will be querried as to their knowledge of corvids, their provisioning of corvids, and their harassment of corvids. We will also survey land directly for food, nest site, and water availability to corvids. Land parcels will be scored based on these surveys as being supportive, unsupportive, or neutral to corvid use.
By observing corvids in the same areas where we map human attitudes, we will determine how corvid resource use correlates with human attitude. We will map corvid occurrence, determine utilization distributions of corvid use, and relate use to human attitude (for example following the landscape ecological methods detailed in Marzluff et al. 2004). We expect to document differences in foraging behaviors, roost sites, nest defense behaviors, enemy recognition and communication behaviors, and parental care strategies among corvids living among supportive versus unsupportive people.
Depending on behavioral differences discovered to co-vary with human attitude, we will design and pilot-test interviews (for people) and experiments (for corvids) that would enable us to understand: (1) the relative roles of genetic, individually-acquired, and socially-learned information to human attitude and corvid behavior; (2) modes (horizontal, vertical, oblique) of acquiring social knowledge; (3) individual innovation; and (4) occurrence of parental shaping of social learning.
Urban subsidies offer experimental opportunities to test cultural coevolutionary theory. Innovative adoption and subsequent spread of unique nest materials (e.g., clothes hangers; Kubota 2004), if discovered, will be related to human behavior. The nature of apparent positive feedbacks between some people and the corvids they actively feed will be quantified, and the degree to which feeding and foraging are socially-transmitted will be investigated. Exploitation of new foods will be linked to human culture. For example, garbage use by corvids affects their diet and scrounging behavior, and also causes rapid evolution of human waste disposal culture (Shida 2001), may reinforce language ("to eat crow"), and can affect culinary practices (few modern societies actually eat crow).