Notes on a Breeding Population of Red-headed Woodpeckers in New York State. Jacob L. Berl and John W. Edwards

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1 Notes on a Breeding Population of Red-headed Woodpeckers in New York State Jacob L. Berl and John W. Edwards Division of Forestry and Natural Resources, West Virginia University Morgantown, WV The red-headed woodpecker (Melanerpes erythrocephalus) is a widely distributed yet declining species, historically occurring across much of the eastern United States (Smith et al. 2000). Throughout their range, red-headed woodpeckers are typically found in relatively open habitats, such as agricultural woodlots, pine plantations, or oak savanna. Although widely distributed, this species has seen sharp population declines across much of its range over the past 40 years (Sauer et al. 2011). Breeding Bird Survey (BBS) data reports an annual range-wide population decline of nearly 3%, invoking its listing as a Watch List Species by the National Audubon Society and Partners in Flight (Rich et al. 2004). In New York State, declines of 8.8% annually have been reported, constituting the greatest rate of decline for any state within the range of red-headed woodpeckers (Sauer et al. 2011). This decline is corroborated by New York State Breeding Bird Atlas data, which recorded red-headed woodpeckers in over 70 % fewer survey blocks during the to survey compared to (McGowan and Corwin 2008). This drastic decline resulted in the red-headed woodpecker being listed as a New York State Species of Greatest Conservation Need. Red-headed woodpeckers are sparsely distributed in the northeastern United States (Spiering 2009), and are typically found in small numbers (1 or 2 pairs) in beaver ponds, oak

2 savanna, or other habitats characterized by abundant snags and open understory. A small population of at least 9 11 adult pairs regularly breeds on Fort Drum Military Installation, in northern New York State. This small population likely represents one of the largest breeding populations in the Northeast, and occurs at the northern limit of the red-headed woodpecker s distribution. The Fort Drum population represents an important study system as further population declines in the Northeastern portion of its range will likely lead to conservation actions designed to manage habitat for this rapidly declining species. Beginning in early May 2012, a field study was initiated with objectives to quantitatively assess the breeding ecology and habitat selection of the Fort Drum red-headed woodpecker population. Methods and Preliminary Results Fort Drum is a large (43,442 ha) U.S. Army installation located in northwestern New York State. Fort Drum provides nesting habitat for over 140 bird species, many of which are listed by New York State as endangered, threatened, or of special concern (Bolsinger and Rainbolt 2006). From early May August 2012 surveys recording the abundance and distribution of red-headed woodpeckers were completed to identify individual breeding territories. Once territorial pairs were located, intensive nest searching was conducted to locate individual nest cavities and subsequently monitor nests to evaluate survival and productivity. Nests were monitored every 3 4 days using a wireless video camera affixed to a 50 ft telescoping fiberglass pole. Consistently monitoring nests throughout the nesting cycle allows for calculation of nest survival and modeling of daily survival rates (DSR) in relation to various vegetative, environmental, and temporal parameters. To evaluate nest-site selection, vegetative measurements were made at nest-sites as well as randomly located sites throughout the study

3 area. This study design allows for analytical assessment of selected versus available vegetation plot data. A total of 15 red-headed woodpecker territories were located during the 2012 field season, with the majority of territories being located in areas dominated by oak savanna (i.e., grasslands interspersed with sparse patches of red and white oak). Nest trees were found for 14 of 15 territories (Table 1). The majority of nests were located in red and white oak, 63% and 21 %, respectively. Less than half (n = 8) of the nests were located in snags, while the remaining nests (n = 11) were located in dead portions (typically limbs) of otherwise live trees. Overall, there was a high degree of variability in nest-sites, with cavities located from 3 15 m above ground, in both snags and live trees, and in limbs and trunks of trees (Table 1). A total of 22 nesting attempts (14 first nest attempts, and 8 re-nest attempts; Table 2) were monitored during the 2012 field season. Of the 22 nesting attempts monitored, only 16 could be monitored using the wireless camera affixed to a telescoping pole (i.e., usable for calculating daily survival rates). Fifteen of 22 nesting attempts monitored failed before fledging young (apparent failure rate = 68%; Table 2). Predation was the major cause of nest failure, although there was little evidence to suggest the type of nest predator (i.e., mammalian, reptile, or avian). One nest failed due to exposure, and two nests failed due to apparently infertile eggs. In almost all cases, once nests failed the adult pair would attempt to re-nest in either the same cavity or excavate a new cavity in a nearby tree. The high predation rate of nests is initially startling, especially for a cavity nesting species which are typically thought to have increased nesting success due to the advantage of nest concealment. However, it is difficult to ascertain specific mechanisms of failure. Indeed, a focal objective of the 2013 field season will be to gain a better understanding of nest predation events.

4 Discussion and Future Prospects At first glance, the Fort Drum red-headed woodpecker population appears to be highly dependent on oak savanna habitats to accommodate their nesting and foraging requirements, as nearly all territories were located in this habitat type. Red-headed woodpeckers utilize a diversity of foraging methods (Smith et al. 2000) that includes aerial flycatching. The Fort Drum population may respond well to oak savanna habitats because they offer a combination of nesting substrate (e.g., abundant snags) and foraging habitat (i.e., open understory and abundant insects). Unfortunately, oak savanna is a very rare habitat type in the northeastern U.S., and is decreasing due to changes in land use and disturbance regimes. This reduction of available habitat may be a potential factor leading to the decline of this species in the Northeast (Smith et al. 2000). As reported previously, the observed nesting success is seemingly low and of particular interest in this breeding population. Population growth (or decline) results from the combination of several demographic parameters (e.g., adult survival and productivity), yet in short-lived species, productivity is often considered an important factor influencing population dynamics (Rodriguez 2002). Indeed, if red-headed woodpeckers are experiencing below-replacement rates of productivity, this factor alone may be a potential cause of decline. The extreme paucity of information on red-headed woodpecker breeding ecology and habitat selection in the Northeastern portion of its range is surprising, especially given the observed population declines. More study of demographic parameters (e.g., adult survival) and habitat selection (e.g., in different habitat types and spatial scales) is certainly warranted. In order to develop conservation strategies for this species in the Northeast, management guidelines should be based on rigorously tested scientific data. Thus, the ultimate goal of this project

5 (continuing through the 2013 summer field season) is to provide resource managers with the first quantitative assessment of red-headed woodpecker breeding ecology and habitat selection in the Northeast. Acknowledgments This work was partially supported by a research grant from the Buffalo Ornithological Society. I would like to sincerely thank the Buffalo Ornithological Society for graciously providing support for this research project, and for offering small grant opportunities to budding ecologists such as myself. Literature Cited Bolsinger, J. S., and R. E. Rainbolt Birding on DoD lands: Fort Drum, New York. Winging It 18:3 5. McGowan, K. J., and K. Corwin The second atlas of breeding birds in New York State. Cornell University Press, Ithaca, New York. Rich, T. D., C. J. Beardmore, H. Berlangna, P. J. Blancher, M. S. W. Bradstreet, G. S. Butcher, D. W. Demarest, E. H. Dunn, W. C. Hunter, E. E. Inigo-Elias, J. A. Kennedy, A. M, Martell, A. O. Panjabi, D. N. Pashley, K. V. Rosenberg, C. M. Rustay, J. S. Wendt, and T. C. Will Partners in flight North American landbird conservation plan. Cornell Lab of Ornithology, Ithaca, New York, USA. Rodriguez, J. P Range contraction in declining North American bird populations. Ecological Applications 12:

6 Sauer, J. R., J. E. Hines, J. E. Fallon, K. L. Pardieck, D. J. Ziolkowski, Jr., and W. A. Link The North American breeding bird survey, results and analysis Version USGS Patuxent Wildlife Research Center, Laurel, MD. Smith, K. G., J. H. Withgott, and P. G. Rodewald Red-headed woodpecker (Melanerpes erythrocephalus). In A. Poole and F. Gill eds. The Birds of North America No The Birds of North America, Inc., Philadelphia. PA. Spiering, D. J Woodpeckers at Tifft Nature Preserve (and beyond): a brief review of the habitats and conservation of the woodpeckers in eastern North America. Bulletin of the Buffalo Society of Natural Sciences 38:55 66.

7 Table 1. Characteristics of nest trees selected by red-headed woodpeckers on Fort Drum. Nest Trees Located Territory Nesting Attempt Tree Species Tree Condition 1 1 First Red Oak Snag 2 2 First White Oak Snag 3 3 First Red Oak Live 4 4 First Red Oak Snag 5 5 First Red Pine Live 6 6 First Red Oak Live 7 7 First Red Oak Snag 8 8 First Red Oak Live 9 9 First Red Oak Snag First Red Oak Snag 11 6 Second Red Oak Live First Red Pine Snag First E. Cottonwood Live First Red Oak Snag First White Oak Live 16 5 Second White Oak Live 17 1 Second White Oak Snag 18 3 Second Red Oak Live 19 8 Second Red Oak Live

8 Table 2. Characteristics of red-headed woodpecker nesting attempts monitored during the 2012 field season. Nest Monitored Territory Monitored w/ Camera Nesting Attempt Success No. Fledged Cause of Failure 1 1 Y First Failed 0 Predation 2 2 Y First Fledged N First Failed 0 NA 4 4 Y First Failed 0 Predation 5 5 Y First Failed 0 Predation 6 6 N First Failed 0 Predation 7 7 N First Failed 0 NA 8 8 Y First Failed 0 Exposure 9 9 Y First Failed 0 Predation N First Failed 0 Predation 11 6 Y Second Fledged N First Failed 0 NA N First Fledged Y First Failed 0 Predation Y First Failed 0 Infertile Eggs 16 5 Y Second Fledged Y Second Fledged Y Second Failed 0 Predation 19 8 Y Second Failed 0 Predation 20 4 Y Second Failed 0 Infertile Eggs Y Second Failed 0 Predation Y Second Fledged 1 -

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