Monitoring nests in Sapsucker Woods
Throughout the 2012 breeding season, Jason Martin (NestWatch Project Leader) and Suzanne Beyeler (Research Associate, Department of Natural Resources, Cornell University) have roamed Sapsucker Woods, home of the Cornell Lab of Ornithology, in search of bird nests. Armed with a mirror attached to the end of an extendable pole, they were able to look into nests that were up to 20 feet high. Why? In addition to field-testing the NestWatch protocols and putting our new data entry system through its paces, they were piloting a study examining the impact of recreational trails on bird nesting success.
This summer, Jason and Suzanne monitored 41 open cup nests in Sapsucker Woods. Preliminary results indicate that nests near more heavily used trails were more likely to successfully produce fledglings than those near lightly used trails. This trend was apparent for all species lumped together (11 out of 24 nests were successful near heavily used trails; 3 out of 17 nests were successful near lightly used trails) and for nests of the most common species found, American Robin (heavy: 8 out of 15 successful; light: 1 out of 6 successful). Using trail counters, they determined that the heavily used trails in Sapsucker Woods averaged approximately 140 people per day during the summer, while the more lightly traveled trails were used by about only 20 people per day. Other studies on this topic have found mixed results, but some have suggested that frequent foot traffic can interfere with the activities of nest predators and thus allow more chicks to hatch and grow to maturity. Chipmunks appear to be the most common nest predators in Sapsucker Woods. Nesting success for various species can range widely depending on lots of factors, such as predator density, habitat quality, weather, and the abundance of Brown-headed Cowbirds.