Investigation of red-cockaded woodpeckers in Virginia: 2015 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 2015 breeding season, Piney Grove Preserve supported 13 potential breeding groups that produced 21 fledglings. All groups made breeding attempts except for cluster 13. Four of the remaining 12 clusters failed to produce fledglings. Remaining groups produced a mean fledging rate of 2.63 + 1.06 (mean + SE). Of the 33 eggs that could be tracked through the nesting period, 22 (73.3%) hatched, 20 (66.7%) survived to banding age, and only 14 (46.7%) fledged. Of the overall 21 birds that fledged, 12 were males and 9 were females. Sixteen of these birds were retained and detected during the winter count. During the calendar year of 2015, 92 individual red-cockaded woodpeckers were identified within Piney Grove preserve including 66 birds produced during previous years and 26 nestlings produced in 2015. Thirty-five birds (38%) were at least four years old and three (3.3%) were at least ten years old. Moving into the breeding season there were 60 birds identified within Piney Grove Preserve distributed among 13 clusters. This is the highest number of adults that Piney Grove has ever carried into the breeding season and compares to 56 birds in 2014 and 52 birds in 2013. The number of birds per cluster varied from two to nine with a mean of 4.6+0.62 (mean+SE). Sixty-eight birds were detected during the 2015 winter survey which exceeds the record number of 66 recorded during the previous winter. Winter group size ranged from 2-10 birds and averaged 4.9+0.71 (mean±SE) birds per group. As in past years, cluster 8 supported the largest foraging group with ten birds. At the close of the 2015 breeding season, Piney Grove supported 243 cavities in 210 live trees including 77 start cavities, 91 completed natural cavities, and 75 artificial inserts. Seven cavities were located within shortleaf pines and the remaining 266 were in loblolly pines. Twelve cavities or starts were added in 2015 and two were lost. A total of 18 southern flying squirrels were encountered in clusters 1, 9, 10, 15, and 19. Two instances of southern flying squirrels occurred in one cavity on separate dates. Six of the seven cavities utilized by flying squirrels and two of the three cavities with nest material were in artificial inserts. Two bird nests with eggs or nestlings (not including RCW nests) were found in cavities. Both were shite-breasted nuthatches.
