Ada Fowler, PhD
PhD in Ecology, University of California, Davis. 2003
MS in Wildlife Ecology, Colorado State University. 1990
BA in Biology, Earlham College. 1983

fowlerAda Fowler received her PhD in Ecology at UC Davis in 2003, with a dissertation entitled, "Population genetic structure and breeding philopatric behavior of Cackling Canada Geese." [Also available online - restricted to UC campuses]

Ada had been doing ecological research, in one capacity or another, since completing her undergraduate degree in Biology in 1983. Although she worked on a variety of projects in many different settings, she eventually realized she was limited working as a technician, and this inspired her to return to school for a secondary degree. Ada completed an MS degree in Wildlife Ecology at Colorado State University in 1990; her thesis was an experimental investigation into the effects of avian predation on grasshopper populations in North Dakota grasslands. After completing her MS degree, she worked for the Alaska Science Center (USGS) as a Research Biologist until 2000.  She worked as field supervisor on a long-term project studying breeding ecology and demographics of cackling Canada geese on the Yukon Delta National Wildlife Refuge. It was during her tenure with the USGS that Ada began her Ph.D. with support from that organization. She is now a biologist with The Nature Conservancy.

Ada's research interests focused on examining patterns of philopatry and population structure in cackler. Her dissertation research involved using molecular techniques to investigate patterns of genetic population structuring and aspects of behavioral ecology of a species of migratory waterfowl.  Waterfowl provide a valuable case for studying population structuring because they exhibit a wide range of behavioral characteristics, including variation in levels of female-biased philopatry (return to previous nesting areas) and timing of pair formation, and potentially varying degrees of population structure. Genetic structuring in populations can result from ecological processes that operate across a hierarchy of scales, both spatial and temporal. Structuring in animal populations may be a consequence of geographic, behavioral or other barriers to gene flow. Subtle processes, such as a tendency of individuals to return to a specific location (philopatry) or the timing and location of mate selection, may result in restrictions in the amount of gene flow. A reduction in gene flow can increase the average relatedness within groups and lead to geographic patterns of genetic divergence or structuring among groups. Understanding how groups are structured is important to understanding their population dynamics and in turn helps inform management decisions.

microsatellitesMolecular genetic techniques can be extremely powerful tools for understanding the biology of organisms. Development of these techniques now allows biologists to address a wide variety of ecological questions pertaining to the pattern and structure of populations. With the development of polymerase chain reaction (PCR), it is possible to obtain sufficient amounts of DNA from minute samples. Most species of waterfowl deposit down and contour feathers in their nests during incubation. Using PCR techniques Ada could amplify specific DNA fragments from just a few feathers collected, noninvasively, from a goose nest. In the past, the standard protocol for collection of genetic samples from animals required trapping a large number of individuals and taking blood or tissue samples. The difficulties and disturbance associated with trapping and handling may have limited the sample size in many studies. Use of PCR techniques eliminates the need to capture and handle the study species and allows for many more genetic samples to be collected with minimal risk to the organism. 

aerial photo-wetlandsAda's goal was to use molecular techniques to address population-level questions about geographic structuring and individual-based questions concerning ecological benefits of philopatry in cacklers.  The objectives were two-fold: (1) investigating genetic structuring in cacklers hierarchically (at large and small scales) on the breeding grounds and across wintering areas, and (2) examining the relationship between philopatry, nesting success, and reproductive variance in cacklers.


  • Dennis G. Raveling Scholarship, California Waterfowl Association (1999)
  • U.S. National Biological Service Special Achievement Award (1994, 1995, 1996)
  • University of California Graduate Scholarship, Block Grant (1997 - 2001)
  • Jastro Shields Graduate Research Award (1998, 1999, 2000)
  • American Ornithologists Union Research Award (2000 )
Revised September 15, 2009