Friday, June 05, 2009

Research Proposal - Correlated fall migratory timing between avian predators and avian prey

Some of my readers have asked what my research will be focused on. Here is the work in progress proposal that should provide some good background.

Research Proposal

Robert Miller
Boise State University
June 2009
Research Adviser: Jay Carlisle; Academic Adviser: Jim Belthoff
Revision: 0.2

This document provides a foundation for a proposed undergraduate research project in the area of Biology/Ecology.

Purpose of Research

This research project was chosen to meet a number of personal and educational objectives including:
  • Build knowledge and experience in conducting self directed research.
  • Build experience and demonstrate proficiency in biological research.
  • Contribute meaningfully to the base of scientific knowledge.
  • Achieve educational credit for research (2-3 credits in Fall 2009).
  • Pursue publication and presentation of research results.

Research Topic

Correlated fall migratory timing between avian predators (specifically accipiter hawks) and avian prey (specifically songbirds).


Avian predators pace their fall migratory speed based on the speed of their primary food source, songbirds. This causes a strong correlation between peak songbird numbers and peak accipiter numbers, that cannot be explained by other phenomenon.


The data for the study has or will all be collected at the Idaho Bird Observatory. Historical data from the past 12 years combined with new data for 2009 will be included in the analysis.

The focal species of this study will be Sharp-shinned Hawks (Accipiter striatus) and Cooper's Hawks (Accipiter cooperii) as the avian predators of interest, along with total numbers of songbirds (unless I later find specific species relevancy).

The predator data source will be the hawk watch counts, not capture data. Songbird data will consist of capture data.

Attempts will be made to show a stronger correlation between accipiters and songbirds than with any other possible contributing factors - non-accipiter timing, weather (cold front passage, temperature, wind speed/direction), Julian date, etc.

Multiple statistical methods are required and are still under investigation.

Implications of Research

A great deal of research has been performed on the migratory processes and ecology of avian species, yet significant gaps in our knowledge still exist. Migration is a very significant event in the annual cycle of avian species increasing their metabolic requirements to 10-25 times the basal rate (Gill 2007).

Migratory birds make great biological indicators. Migrating Raptors meet or exceed 13 of the 14 "ideal" indicators of environmental health (Bildstein 2001). Through human development (loss of habitat, pollution, and anthropogenic climate change), migrating birds face greater challenges than ever before. According to Birdlife International (2009), "there has been a steady and continuing deterioration in the threat status (relative projected extinction risk) of the world’s birds since 1988." Increasing our overall understanding of the ecology of avian species can help in the conservation and management of these species to decrease the threat against them.

This research builds on the fundamental research of others. Aborn (1994) has illustrated the correlation of accipiter and songbird numbers passing through Southern Mississippi. Cimprich, et al (2005), has analyzed predator prey behavioral relationships between songbirds and accipiters. Allen, et al, (1996), have shown the correlation of accipiter volumes related to regional cold fronts at Hawk Mountain Pennsylvania, while Titus & Mosher (1982) analyzed the impact of wind direction, speed, and visibility on raptor volumes. Bringing this work together with a focus on the predator prey timing relationships is novel.

Expected Timeline

Background Research

IBO data collection

Core analysis


First Draft Paper

Resources Required

The following resources are required to be successful.
  • Personal time - Committed.
  • Access to the IBO data - Committed.
  • Peer consultation and review - Committed.
  • Regular advising and consultation (1 hour every 2 weeks) - Not committed.
  • Statistical consulting and review - Not committed.

Initial Literature Review

Aborn, DA. 1994. Correlation between raptor and songbird numbers at a migratory stopover site. The Wilson Bulletin 106:150-154.

Allen, PE., Goodrich, LJ., Bildstein, KL. 1996. Within- and Among-Year Effects of Cold Fronts on Migrating Raptors at Hawk Mountain, Pennsylvania, 1934-1991. The Auk 113:329-338.

Bednarz, JC., Klem, D Jr., Goodrich, LJ., Senner, SE. 1990. Migration Counts of Raptors at Hawk Mountain Pennsylvannia, as Indiciators of Population Trends, 1934-1986. The Auk 107:96-109.

Bildstein, KL. 2001. Why Migratory Bids of Prey Make Great Biological Indicators. Pages 169-179 in Bildstein and Klem, Eds. Hawkwatching in the Americas.

BirdLife International, Global Species Programme. IUCN Red List (updated 2009).

Cimprich, DA., Woodrey, MS., Moore, FR. 2005. Passerine migrants respond to variation in predation risk during stopover. Animal Behavior 69:1173-1179.

DeLong, J., Hoffman, SW. 1999. Differential Autumn Migration of Sharp-Shinned and Cooper's Hawks in Western North America. The Condor 101:674-678.

Gill, FB. 2007. Ornithology (Third Edition). W. H. Freeman and Company, New York, NY, USA.

Kjellen, N. 1992. Differential Timing of Autumn Migration between Sex and Age Groups in Raptors at Falsterbo, Sweden. Ornis Scandinavica 23:420-434.

Mueller, HC., Berger, DD. 1967. Wind Drift, Leading Lines, and Diurnal Migration. The Wilson Bulletin 79:50-63.

Titus, K., Mosher, JA. 1982. The Influence of Seasonality and Selected Weather Variables on Autumn Migration of Three Species of Hawks through the Central Appalachians. The Wilson Bulletin 94:176.184.

Smith, JP., Farmer, CJ., Hoffman, SW., Kaltenecker, GS., Woodruff, KZ., Sherrington, PF. 2008. Trends in autumn counts of migratory raptors in western North America. The State of North American Birds of Prey, ed. by K.L. Bildstein, J.P. Smith, E. Ruelas I., vol. Series in Ornithology(3), pp. 217-252, American Ornithologists' Union and Nuttall Ornithological Club, Cambridge, MA.

Viverette, CB., Struve, S., Goodrich, LJ., Bildstein, KL. 1996. Decreases in Migrating Sharp-shinned Hawks (accipter striatus) at Traditional Raptor Migration Watch Sites in Eastern North America. The Auk 113:32-40.

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