Wilson Bull., 1 13(2), 200 1, pp. 2562.53
Interactions Between Nesting Pileated Woodpeckers and Wood Ducks
Richard N. Conner.‘,’ Clifford E. Shackelford,’ Daniel Saenz,’ and Richard R Schaefer’
ABSTRACT-We observed interactions between a demand by Wood Ducks during the nesting season. nesting pair of Pileated Woodpeckers (i3ryoco~1u.s pi- Our observations suggest that some Pileated Wood- 1eatu.s) and what appeared to be four pairs of Wood pcckers may be able to resist attempts by Wood Ducks Ducks (Aix .spon.sa). Wood Ducks regularly ap- to usurp nesl cavities during the breeding season. Ke- proached and attempted to enter an active Pileated ceivrd 27 Oct. 2000, crccrpted 25 Apr. 2001. Woodpecker nest cavity that contained three fully feathered young Pileated Woodpeckers. The male Pi- leated Woodpecker often perched on a snag near their nest cavity to guard the entrance from Wood Ducks. Pileated Woodpeckers (Dtyocc~pu.s pileatus) Female Wood Ducks attempted to enter the Pilented are unique among North American woodpeck- Woodpecker nest cavity on at least 12 occasions and ers because they are the only extant species typically were intercepted by the male Pileated Wood- that excavates large (>45 cm deep) cavities pecker before they reached the lip of the nest cavity. for nest and roost sites (Conner 1974, Bull and On two occasions the male Pileated Woodpecker cn- Jackson 1995). Their large cavities are used tered his nest cavity and forcibly evicted female Wood Ducks that had slipped into the cavity. These incidents by a wide variety of both small and large birds suggest that large cavities in snags may be in high and mammals that are primary and secondary cavity users throughout the species range ’ Wildlife Habitat and Silviculture Laboratory, (Hoyt 1948, Hoyt 1957, Conner 1978, Evans Southern Research Station, USDA Forest Service, Ste- and Conner 1979, McClelland 1979, Bonar phen E Austin State Univ., Nacogdochcs, TX 75962 2000). Historically, Ivory-billed Woodpeckers USA. (Cumnpphihs principdis) also provided large ? Texas Parks and Wildlife Dept., Austin, TX 78704 USA. cavities (Tanner 1942) for secondary cavity 7 Corresponding author: E-mail: c_connerrn<~titan. users in the southern U.S., particularly in sfasu.edu hardwood forests within and adjacent to wel-
SHORT COMMUNICATIONS 2.51
lands. Ivory-billed Woodpeckers, however, During 20 h of observation over seven sep- probably now are extinct (U.S. Fish and Wild- arate days between 24 April and 5 May 1996, life Service 1980, Lammertink and Estrada we observed Wood Ducks (four male and four 1995). female Wood Ducks were present) attempting Demand for large cavities has the potential to usurp a Pileated Woodpecker nest cavity to cause secondary cavity users to compete that contained three woodpecker nestlings. with Pileated Woodpeckers for the cavities the The cavity was located in a 60-cm dbh, 25-m woodpeckers excavate. Conner (1973) ob- loblolly pine (Pinus turd(z) snag within a near- served an interaction where an Eastern ly pure stand of loblolly pines on the Stephen Screech-Owl (Otus LI.+) displaced a pair of E Austin Experimental Forest (3 I” 29’ N, 94” Pileatcd Woodpeckers that were attempting to 47’ W) in southern Nacogdoches County, Tex- nest in a snag in Virginia. Pileated Wood- as. Most major limbs were still present WI the peckers appear to tolerate the presence of snag and the nest cavity had been excavated some potential cavity competitors, particularly about 10 m above the ground, where the bole smaller species, and there are reports of was 52 cm in diameter. The Pileated Wood- Northern Flickers (Coluptc~s aurutus), Red- pecker nest tree was 450 m from relatively breasted Nuthatches (Sittcl canrrd~nsis), and permanent water in a small stream. Other Mountain Chickadees (Poccile gamheli) si- ephemeral streams were about 300 m from the multaneously nesting in the same snags as Pi- nest tree. leated Woodpeckers, but in different cavities During our observations female Wood (Hoyt 1948, McClelland and McClelland Ducks typically perched with their mates in 1999). However, a Pileated Woodpecker was the vicinity (50 m) of the Pileated Woodpeck- observed driving a Northern Flicker away er nest tree, and flew toward the woodpecker from its nest cavity (J. 7: Tanner in Hoyt nest cavity as the Pileated Woodpeckers left 1957). Pileated Woodpeckers also have been to obtain food to provision their nestlings. In reported to remove young and nest material of 10 of I 1 instances, as a female Wood Duck Eastern Bluebirds (Sialiu siulis) from a cavity approached the nest cavity, the male Pileated the woodpeckers used during a previous Woodpecker intercepted the Wood Duck with- breeding season, further enlarge the cavity in 1 m of the cavity entrance, before it could chamber, and subsequently use the cavity for enter the cavity. When intercepting female a second nesting season (Baird et al. 1875). Wood Ducks, the male Pileated Woodpecker The Wood Duck (Aix .sponsu), a large sec- often vocalized a short duration “kuk, kuk, ondary cavity user, requires large cavities for kuk, kuk, kuk” (High call, Kilham 1959; nesting (Bellrose et al. 1964, Ryan et al. 1998) “Wok” call, Short 1982) that decreased in and regularly uses Pileated Woodpecker cav- volume and frequency as the call ended. This ities (Kilham 1979, Bull and Jackson 1995). vocalization usually is associated with excite- Bellrose et al. (1964) and Ryan ct al. (199X) ment or alarm (Kilham 1959). During one in- noted that Wood Ducks achieve higher nest stance, both the male and female woodpecker success in cavities that are high above the simultaneously intercepted a female Wood ground, likely because of lower predation risk. Duck and prevented her from entering the Pi&ted Woodpcckcr cavities typically are cavity. On two other occasions the male Pi- IO-20 m above the ground (Conner et al. leated Woodpecker, while inside the nest cav- 1975) and thus may be highly attractive to ity, pecked at an approaching female Wood Wood Ducks as potential nest sites. Wood Duck as it flew to within S-IO cm of the en- Ducks also are known to nest in Red-cock- trance. aded Woodpecker (Picoicks horcwlis) cavities During 4 h of our observations, the male that have been enlarged by Pileated Wood- Pi&ted Woodpecker perched in the same po- peckers (Conner et al. 1997). Observations of sition on a snag about 20 III distant from his potentially competitive interactions between nest cavity and attentively followed the aerial Pileated Woodpcckcrs and other cavity users movements of Wood Duck j3airs. It was from are rare, likely because of the wariness of the this perch that he typically flew to intercept large woodpeckers around their nest site an approaching Wood Duck. During the 2-wk (RNC pcrs. obs.). period when we observed the nest cavity, at- 252 THE WlI.SON BULI.ETIN * Vol. Il.?, No. 2, .///rw 2001
tempts to usurp the cavity appeared to inten- One female Wood Duck repeatedly flew to the sify and the male Pileated Woodpecker often cavity entrance and perched OII the entrance guarded the nest from inside the nest cavity. lip for approximately I tnin while she peered On two occasions a fetnale Wood Duck into the cavity every 3-4 s. A tnale Wood successfully entered the Pileated Woodpecker Duck remained perched above the cavity on a nest cavity while it contained three Pileated lateral branch of the cavity tree while the fe- Woodpecker nestlings. We did not see the tnale examined the cavity. After 20 min of Wood Duck enter the cavity in the first in- repeated brief visits to peer into the cavity, the stance. We had been observing the cavity for fetnale Wood Duck entered and remained in approximately 1 h on 26 April 1996 without the cavity for 1 h, after which our observation seeing any adult Pilcated Woodpeckers around ceased. the nest cavity. Five Wood Ducks wet-e These incidents suggest that large cavities perched in live pines within 40 m of the cavity in snags on our study area may be in high tree. When the tnale Pileated Woodpecker re- demand by Wood Ducks during the nesting turned to the nest cavity to feed the three nes- season. Our observations suggest that some tlings, it appeared very agitaled while pcrch- Pileatcd Woodpeckers tnay be able to resist ing at the cavity entrance. The male fanned its attetnpts by Wood Ducks to usurp nest cavi- tail feathers and erected its red crest feathers ties during the breeding season. and repeatedly peered inlo the cavity by quickly insct-ting its head and withdrawing it. ACKNOWLEDGMENTS After 5 min of peering into the cavily, the tnale Pileated Woodpecker entered the cavity and we heard what we interpreted as sounds of him pecking something in the cavity, with LITERATURE CITED his bill occasionally striking the side of the UAIIII), S. F;, T. M. BI
EVANS, K. E. AND R. N. CONNER. 1979. Snag manage- MCCLELLAND, B. R. 1979. The Pileated Woodpecker. ment. Pp. 2 14-225 Management of northcentral Pp. 2X3-299 in The role of insectivorous birds in and northeastern forests for nongame birds (R. M. forest ecosystems (J. G. Dickson, R. N. Conner, DeGraaf and K. E. Evans, Eds..). U.S. For. Serv. R. R. Fleet, J. A. Jackson, and J. C. Kroll, Eds.). Gen. Tech. Rep. NC-51. Academic Press, New York. Hovr, J. S. Y. 194X. Further studies of the Pileated MCCLELLAND, B. R. AND I? T MCCLELLAND. 1999. Pi- Woodpecker, Hylatomi,s pileutus (Linnaeus). leated Woodpecker nest and roost trees in Mon- Ph.D. diss., Cornell Univ., Ithaca, New York. tana: links with old-growth and forest “health.” HOYT, S. E 1957. The ecology of the Pileated Wood- Wildl. Sot. Bull. 27:846-857. pecker. Ecology 3X:246-256. RYAN, D. C., R. J. KAWULA, AND R. J. GATES. 1998. Breeding biology of Wood Ducks using natural KIL~AM, L. 1959. Behavior and methods of commu- cavities in southern Illinois. J. Wild]. Manage. 62: nication of Pileated Woodpeckers. Condor 61: 112-123. 377-387. SHOKT, L. L. 1982. Woodpeckers of the world. Dela- KILMAM, L. 1979. Courtship and the pair-bond of Pi- ware Mus. Nat. Hist. Monogr. Ser. 4:1-676. leated Woodpeckers. Auk 965X7-594. TANNER, J. T. 1942. The Ivory-billed Woodpecker. Nat. LAMMERTINK, M. ANI) A. R. ESTRADA. 1995. Status of Aud. Sot. Res. Rep. No. I. the Ivory-billed Woodpecker (Cumpephilus prin- U.S. Ftstr AND WILDLIFE SERVICE. 1980. Ivory-billed cipalis) in Cuba: almost certainly extinct. Bird Woodpecker. USFWS Biol. Serv. Prog. FWS- Conserv. Internat. 5:53-59. OBS-80-01 .x.