IN THIS ISSUE...
- Renew Your Membership
- Save the Date for Auction & Golf
- Bird Notes
- Shortleaf Pine/Oak/Hickory Forest Community
- 2011 Longleaf Cone Crop
- Congressman Southerland Visits Tall Timbers
- Tall Timbers Photography Exhibit
- Management Recommendations
- Public Lands Summit
- Quail Hatch
Vol. 4 | No. 4 | June 2011
By Jim Cox, Vertebrate Ecology Scientist
Thanks to a grant from the Florida Fish and Wildlife Conservation Commission, the Vertebrate Ecology Program recently completed genetic sampling of the brown-headed nuthatch population on Babcock-Webb Wildlife Management Area (WMA) in southwest Florida. Babcock-Webb supports one of the largest expanses of nuthatch habitat remaining south of Orlando, but the nuthatch population is isolated from other neighboring populations, so genetic information will help to determine whether genetic variation within this population has changed as a result of its isolation. Tall Timbers’ staff has developed some impressively efficient netting procedures for this bird that normally spends most of its time high up in the canopy — 35 individuals were netted in only 2.5 days of work!
Jim Cox holds a young nuthatch netted on the Babcock-Webb Wildlife Management Area.
Vertebrate Ecology has initiated new breeding bird counts on Arcadia Plantation that are similar to the counts conducted on Tall Timbers for six years. The expanded work on Arcadia provides a chance to compare subtle differences in the breeding bird communities associated with old-field pinelands on Tall Timbers versus the more extensive area of longleaf pine and native ground cover on Arcadia. The most common bird observed on Arcadia is Bachman’s Sparrow (2.3 individuals per count), which checks in as the eighth most common bird on Tall Timbers (1.6 individuals per count). On the other hand, Northern Cardinal is the most common bird observed on Tall Timbers (2.1 per count) and checks in as the fourth most common bird on Arcadia (1.3 per count). Cardinals are more common on Tall Timbers because of their preference for brushier ground cover. Counts on Tall Timbers also show continued declines for several neotropical migrants that once occurred more regularly on the property (Kentucky Warbler, Wood Thrush, and Louisiana Waterthrush).
Finally, new methods for measuring Bachman’s Sparrow breeding-season productivity are being assessed on the Wade Tract. Young sparrows give distinctive call notes that can be used to estimate the number of young per unit area, just as easily as counts of singing males often are used to estimate the abundance of adults. We are comparing efficient line transect procedures with two more intensive forms of plot-based surveys in hopes of recommending some simple field procedures for measuring productivity for this declining species. Productivity may be a key measure of habitat quality in this species, because other data suggest that well over half the singing males never secure mates.