Gitanjali Gnanadesikan

Princeton University’s Ecology and Evolutionary Biology Department.

Working with Allison Shaw in Simon Levin’s theoretical ecology lab.

Original internship title: “What factors ultimately drive migration?”

Often applied definition: long distance, round trip, seasonal movements between two “worlds”: breeding grounds and wintering grounds (as studied in birds).

Problems with this definition: What is “long” distance? What if the trip is made on a different

timescale: multiple times a year or once a lifetime?

What about distinct locations that are not wintering or breeding grounds?

As described by Dingle (2007):Migration is movement that…1) Is persistent, undistracted, and directed.2) Is of greater scale and longer duration

than normal daily activities.3) Is a seasonal back-and-forth between

regions which are temporarily favorable.4) Results in geographic redistribution

within a widespread population.

Dingle, Hugh. What is Migration? Bioscience. Vol. 57, Iss. 2. Pp 113-121. Feb 2007.

Most information about migration is species-specific.

Look at migration as phenomenon across taxa.

Focused on mammals to start.

Task: conduct extensive literature –based research to compile a database of migratory behaviors using new definition.

Synthesize collected to data and look for patterns.

A-to-B: Directed movement by a group of animals between two distinct locations.

Examples: Humpback whales, Arctic Terns, and many iconic migrations.

Dispersal-recongregation: movement away from some location and then returning to some common location. Involves individuals utilizing different resources and paths.

Examples: many bats (caves), pinnipeds (breeding territories).

Confirmation of major choice. Valuable research experience and

familiarity with the field and current research.

Basis of research to be continued this year: Continue researching species (about ¼ of

mammals done). Look at more geographic data for patterns

and relationships to climate, resources, etc.

To PEI, the EEB department, and especiallyAllison Shaw for a great summer internship experience. Also the AOS department for collaborations and journal club.