Breeding Bird Surveys at HRNA

Since 2010 during the Spring and Summer the Western Foundation of Vertebrate Zoology (WFVZ) under the direction of Linnea Hall, Ph.D., has conducted standardized surveys for breeding bird species occurring on the Hedrick Ranch Nature Area (HRNA). These surveys represent an important measure of the success of restoration and habitat enhancement efforts undertaken by FSCR since assuming stewardship of the property in 2001. In April 2018, the WFVZ presented a summary of its report on survey results for the 2017 season. The 2017 survey was conducted on May 9, 2017. A total of 53 bird species were detected at 15 separate point counts on HRNA. The 10 most frequently observed bird species noted during the 2017 survey are as ranked in the following listing:

1. Common Yellowthroat 
2. Yellow Warbler
3. Song Sparrow
4. Spotted Towhee
5. Least Bell’s Vireo
6. American Crow
7. Black-headed Grosbeak
8. Pacific-slope Flycatcher
9. Yellow-breasted Chat
10. Orange-crowned Warbler

With the exception of the American Crow, all of these species are typically found nesting in a healthy riparian habitat. The relatively frequent occurrence of Crows in the area could be due to the bordering agricultural and orchard land uses, as well as possible predatory behavior on the nesting birds. It is of significance that Least Bell’s Vireo reached number 5 on the most frequently occurring list. This species is still listed as endangered due to the loss of its breeding habitat in recent decades. Prior to restoration and enhancement efforts on HRNA, only 2 or 3 pairs have been known to attempt nesting in the area. In 2017, as many as 17 pairs of Least Bells Vireo’s were identified as probably breeding on the HRNA.

For biologists, ecologists, and birding enthusiasts there is much information of interest in the full survey report. We will post the entire survey results on the FSCR website after publication of the results.