November 19, 2012

Blue Jay Project

By Dave Erler, Senior Naturalist

The first year of our Blue Jay Project got off to a good start thanks to all of the volunteers who participated in observations and recording data.

Blue Jays are intelligent social omnivorous songbirds that utilize on a wide variety food resources. The goal of the project was to determine if social hierarchy in blue jays affected their use of novel foods. Using the Science Center’s vacant songbird aviary a captive “flock” of 10 blue jays were introduced to the aviary to observe their feeding behavior. Volunteers observed and recorded their observations for two hour periods, usually in the morning. Observations focused on identifying each individual blue jay by the small colored band combinations on the bird’s right leg. This might sound fairly easy but observation proved to be quite challenging depending on the light conditions, the position and posture of the bird and the speed of the jays as they arrived and departed from the feeding platforms. It was also fun!

The project involved two phases. The first phase focused on observing interactions between the blue jays at a feeding station to determine who the dominant/aggressor was and who the subordinate/aggresse was. After over 100 hours of observation time on 46 days and nearly 6000 blue jay visitations to the feeders, we were ready to move on to phase two.

Phase two covered 62 days with observations focused on the use of a different novel food on each observation day (a novel food was anything potentially edible but something blue jays would not normally have been exposed to such as a piece of tropical fruit, nut, mini marshmallow, snack cracker etc). Birds were given a choice in phase two of either feeding on the normal diet provided or the other feeder presenting the novel food. Use of the novel foods varied widely from a low of 6 total feeder visits by 3 jays (dried mango bits) to a high of 129 visits in 2 hours by all 10 jays (green cat crunchies).

At the time of this writing, data collection for 2012 season is complete, but final statistical evaluation is still pending (there are a lot of numbers to crunch and variables to consider). As the sample size is quite small. The project will hopefully continue over the next two years. Like most research projects more questions have come to mind since initiating the project such as; are subordinate birds more likely to steal cached food than dominant birds, does the size, shape or color of the novel food affect use, how does weather affect activity level, how often during the course of the day do resident Cooper’s Hawks come “visit” the aviary and how do the individual birds react. Although it is still too early to tell with any certainty a quick look at all the data suggests that the more dominant blue jays were most likely to be the first to investigate a novel food and also most likely to make the most use of the novel food. It will be interesting to see if that trend continues.

The first year went better than I expected, I was greatly surprised by the amount of time and commitment volunteers gave and with the knowledge gained next year will be even better. Again I would like to thank all the volunteers who made this project possible without whose efforts this could not have been done. I hope everyone involved enjoyed the experience and if nothing else I am sure they will never look at blue jays quite the same.

Volunteers who were part of this year’s team include:
  • Pat James *
  • Sarah Kelley
  • Mary Kuhn 
  • Kathy Letsky
  • Dom & Irene Morocco
  • Peggy Martin
  • Missy Mason*
  • Denise Moulis
  • Ron Piro
  • Nance Ruhm*
  • Olivia Saunders
  • Bill Sharp*
  • Lisetta Silvestri
  • Rob & Carol Stewart*
  • Marc White*
  • Betsy Whitmore 
*denotes 20 or more hours of observation time

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