Investigation of red-cockaded woodpeckers in Virginia: 2016 report
Abstract
The Virginia population of red-cockaded woodpeckers is the northernmost throughout the species range and has been in eminent danger of extinction for more than 30 years. The Piney Grove Preserve represents a nucleus for recovery in the state and the focus of a multi-organizational partnership designed to increase the population to a sustainable level. The partnership has executed a program of aggressive habitat management, cavity-tree management and woodpecker population monitoring and management that has resulted in a tripling of the breeding population since the early 2000s. During the 2016 breeding season, Piney Grove Preserve supported 13 potential breeding groups that produced 16 fledglings. All groups made breeding attempts except for cluster 12. Four of the remaining 12 clusters failed to produce fledglings. The population as a whole had a reproductive rate of 1.2±0.34 (mean±SE). The 12 groups that made breeding attempts had a success rate of 67% (8 of 12). Fledging rate for the 8 productive pairs was 2.0±0.33. Of the 41 eggs produced in 2016, 22 (53.7%) hatched, 20 (48.8%) survived to banding age, and only 16 (39.0%) fledged. Birds that fledged included 11 females and 5 males. Eight of these birds were retained and detected during the winter count. During the calendar year of 2016, 84 individual red-cockaded woodpeckers were identified within Piney Grove preserve including 64 birds produced during previous years and 20 nestlings produced in 2016. Thirty-three birds (39%) were in their fourth year or more and three (3.6%) were in their tenth year or more. Moving into the breeding season there were 64 birds identified within Piney Grove Preserve distributed among 14 clusters. This is the highest number of adults that Piney Grove has ever carried into the breeding season and compares to 60 birds in 2015 and 56 birds in 2014. The number of birds per cluster varied from two to nine with a mean of 4.4+0.57 (mean+SE). Fifty-four birds were detected during the 2016 winter survey. This represents a 20% reduction (54 vs 68) from the winter of 2015 and is the lowest number carried into the winter since 2012. Winter group size ranged from one to eight birds and averaged 3.6+0.47 (mean±SE) birds per group. Birds present include ten of the 16 birds fledged in 2016 and 44 adult birds hatched in previous years. There were 20 adult birds detected during the spring survey that were not detected during winter survey including three breeding males and one breeding female.
