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HARVARD UNIVERSITY Ernst Mayr Library of the Museum of Comparative Zoology u& m n »«5 unwersity Me.2 Wilson ""The Journal Ornithology of Volume 119, Number March 2007 1, Published by the Wilson OrnithologicalSociety THEWILSON ORNITHOLOGICAL SOCIETY FOUNDED 3 DECEMBER 1888 Named afterALEXANDERWILSON,the firstAmerican ornithologist. — President Doris J. Watt, Department ofBiology, Saint Mary’s College, Notre Dame, IN 46556, USA; e-mail: [email protected] — FirstVice-President JamesD. Rising, DepartmentofZoology,UniversityofToronto,Toronto,ON M5S 3G5, Canada; e-mail: [email protected] — SecondVice-President E. DaleKennedy,BiologyDepartment,AlbionCollege,Albion,MI49224,USA; e-mail: [email protected] — Editor ClaitE. Braun, 5572NorthVentanaVistaRd.,Tucson,AZ 85750, USA; e-mail:TWILSONJO@ comcast.net — Secretary JohnA.Smallwood,DepartmentofBiologyandMolecularBiology,MontclairStateUniversity, Montclair, NJ 07043, USA; e-mail: [email protected] — Treasurer MelindaM.Clark,52684HighlandDr.,SouthBend,IN46635,USA;e-mail:[email protected] — Elected Council Members Mary Bomberger Brown, Robert L. Curry, and James R. Hill, III (terms expire 2007); Daniel Klem, Jr. and Douglas W. White (terms expire 2008); Carla J. Dove, Greg H. Farley, and Mia R. Revels (terms expire 2009). Membership dues per calendar year are: Active, $21.00; Student, $15.00; Family, $25.00; Sustaining, $30.00; Life memberships, $500 (payable in four installments). The WilsonJournalofOrnithology is sentto all members not in arrears fordues. THEWILSON JOURNAL OF ORNITHOLOGY (formerly The Wilson Bulletin) THE WILSON JOURNAL OF ORNITHOLOGY (ISSN 1559-4491) is published quarterly in March, June, September, and December by the Wilson Ornithological Society, 810 East 10th St., Lawrence, KS 66044-8897. The subscriptionprice,bothintheUnitedStatesandelsewhere,is$40.00peryear. PeriodicalspostagepaidatLawrence,KS. POSTMASTER; SendaddresschangestoOSNA,5400BosqueBlvd.,Ste. 680,Waco,TX 76710. AllarticlesandcommunicationsforpublicationsshouldbeaddressedtotheEditor. Exchangesshouldbeaddressed toTheJosselynVanTyneMemorial Library, MuseumofZoology,AnnArbor, Michigan48109. Subscriptions,changesofaddress,andclaims forundeliveredcopiesshouldbesenttoOSNA, 5400 BosqueBlvd., Ste. 680, Waco,TX 76710. Phone; (254) 399-9636; e-mail; [email protected]. Back issues or single copies are available for$12.00each. Mostback issuesofthejournal areavailableandmaybeorderedfromOSNA. Specialprices willbequotedforquantityorders.Allissuesofthejournalpublishedbefore2000areaccessibleonafreeWebsiteatthe UniversityofNewMexicolibrary(http;//elibrary.unm.edu/sora/).Thesiteisfullysearchable,andfull-textreproductions ofallpapers(includingillustrations)areavailableaseitherPDForDjVufiles. ©Copyright 2007 bytheWilson Ornithological Society PrintedbyAllen Press, Inc., Lawrence, Kansas 66044, U.S.A. COVER: Wilson’s Snipe {Gallinagodelicata). Illustrationby Scott Rashid. 0 Thispapermeetsthe requirementsofANSI/NISOZ39.48-1992 (PermanenceofPaper). MCZ L/BRary MAY 1 2007 u1 niversity FRONTISPIECE. This is a reproduction of an original watercolor by George M. Sutton painted in 1952 as an illustrationforthebook,GeorgiaBirds, written byThomasD. Burleighandpublishedby UniversityofOklahoma Press. The original paintings for the book were given in friendship to Herbert Stoddard and are part of the Stoddard Collection at Tall Timbers Research Station & Land Conservancy. “When I made this painting, the nuthatches were not moving through the pine tops in noisy family groups, as they often do, but nesting quietly. This pair had a nest in a small hollowed-out cypress knee placed for them on a fence post. 1 looked a long while before finding exactly the right shortleaf pine branch for the picture. I wanted the branch, as well as the birds, to be interesting.” Wilson Journal ofOrnithology Published by the Wilson OrnithologicalSociety VOL. 119, NO. 1 March 2007 PAGES 1-150 The Wilson Journal ofOrnithology II9(1):1-8, 2007 COOPERATIVE BREEDING IN THE BROWN-HEADED NUTHATCH JAMES A. COX” AND GARY L. SLATERS — ABSTRACT. We monitored two color-marked populations ofthe Brown-headed Nuthatch {Sittapusilla) for >5 years and collected data on survival, dispersal, territoriality, and cooperative breeding. Adults {n = 284) were sedentary, maintained long-term pair bonds, and had higher apparent annual survival (66-78%) than previously reported. Territories monitored {n = 347) contained up to five adults; the percentage of territories containing >2 adults averaged —20% but varied widely. Most groups with >2 adults consisted of a breeding pair and a male helper related to at least one breeding adult {n = 8), but several exceptions were noted. The presence of helpers did not improve nest productivity. Apparent annual survival for females was lower than apparent survival for males in one population and may have influenced cooperative breeding. In the other population, apparent survival was similar between males and females. We suggest food resources and other environmental factors may have influenced cooperative breeding in this setting. Received 19 January 2006. Accepted21 July 2006. Cooperative breeding in the Brown-headed that inhabits open pine {Pinus spp.) forests in Nuthatch {Sitta pusilla) has received little at- the southeastern United States and the Baha- tention since the behavior was first described mas. Populations have declined steadily by Norris (1958). Presumably non-breeding throughout much of the species’ range (Sauer adult nuthatches spend large amounts of time et al. 2005) as a result of habitat loss from assisting in nest construction, feeding nest- human development and habitat degradation lings, and defending territories (Norris 1958, through fire suppression and logging (With- Thompson 2000), but recent studies of coop- gott and Smith 1998). The species also has erative breeding in this species are limited to exhibited range contraction in some regions two unpublished theses (Slater 1997, Thomp- (e.g.. South Florida and Missouri), and With- son 2000) and a study based on 15 territories gott and Smith (1998) noted that nuthatches (Miller and Jones 1999). disappeared from some areas before the en- The Brown-headed Nuthatch is a primary dangered Red-cockaded Woodpecker (Picoi- cavity-nesting species (McComb et al. 1986) des borealis; U.S. Department of Interior 2003) disappeared from those same areas. Ac- cordingly, the Brown-headed Nuthatch has el ‘DrT.a,llTaTlilmabheasrsseeR,esFeLar3c2h3S1t2a,tiUonS,A.13093 Henry Bead- been designated a species of management 2Ecostudies Institute, P. O. Box 703, MountVernon, concern in several evaluations (Hunter et al. WA 98273, USA. 1993, Carter et al. 1998, U.S. Department of Corresponding author; e-mail: [email protected] Interior 2002), and the Bahamian subspecies 1 ) 2 THE WILSON JOURNAL OF ORNITHOLOGY • Vol. 119, No. 1, March 2007 {S. p. insularis; Bond 1931) is thought to be glades. Nuthatches disappeared from ENP in highly imperiled (Smith and Smith 1994, the early 1940s apparently as a result of ex- Hayes et al. 2004). tensive logging (Robertson and Kushlan Characteristics of social breeding systems 1984), and data collected here stemmed from have been used to develop management pro- a reintroduction program initiated in 1997. grams for some cooperative breeders that have Most prescribed burns in BCNP and ENP undergone population declines (Walters et al. were conducted during the early wet season 1992, Mumme and Below 1999). Information (May-Jun) at 3 to 5-year return intervals. — on cooperative breeding in the Brown-headed Fieldwork and Data Analysis. Area Nuthatch could have a similar role and also searches were initiated in February to locate broaden our understanding of social breeding territories and find nests. Nests were identified systems (Boland and Cockburn 2002); how- by worn or freshly exposed wood at cavity ever, data regarding the extent and frequency entrances, observing birds excavating cavities, of cooperative breeding, gender of auxiliary or by finding completed nests with eggs or adults, territory establishment and mainte- young. Nest locations were geographically nance, and adult and natal dispersal are gen- referenced using hand-held global positioning erally lacking (Norris 1958, Withgott and systems. Dispersal distances, nest displace- Smith 1998). ments, and territory densities were estimated The objectives of our study were to (1 using ArcView (ESRI 1998) and the straight- quantify and compare demographic parame- line distance between nest locations. ters, population densities, and characteristics Nests were visited every 3-4 days to as- of cooperative breeding between two popula- certain status and gather information on adults tions of Brown-headed Nuthatch in Florida, associated with nests. Nest height at TTRS (2) develop hypotheses for factors influencing generally was <3 m and nesting status was cooperative breeding in this species, and (3) monitored using step ladders, flash lights, and consider how our information regarding co- dental mirrors. In south Florida, nest height operative breeding and other life history traits averaged >10 m and status was monitored us- may contribute to population conservation and ing behavioral observations (typically <30 management. min/visit). A breeding attempt was defined as the presence of eggs or behavioral cues indi- METHODS cating nesting was underway (used for tall — StudyAreas. We studied nuthatches at Tall nests). Timbers Research Station (TTRS; 30.66° N, Nestlings were banded 13-16 days after 84.22° W) in north Florida (2001-present) and hatching at TTRS by removing the front of at two sites in south Florida ( 1998-2003): Big nesting cavities using a small saw. The cavity Cypress National Preserve (BCNP; 26.03° N, face was secured after banding using wood 81.20° W) and Everglades National Park putty, staples, and masking tape. A single fed- (ENP; 25.37° N, 80.59° W). TTRS encom- eral band was affixed to nestlings. All adults passes 1,630 ha and is dominated by upland were color banded. The height of nests in pine habitats consisting primarily of loblolly South Florida precluded banding of young, {Finns taeda) and shortleaf pines {F. echina- and data on dispersal for second-year (SY) ta). Dominant trees are >100 years old, and birds and nestlings stemmed exclusively from prescribed burns are conducted from March to the TTRS population. We compared produc- April at two-year return intervals. Historically, tivity between pairs and cooperative groups upland forests at TTRS were dominated by within populations using (1) the number of longleaf pine (P. palustris), but the original nestlings banded per nest (TTRS) and (2) the forests were cleared for agriculture many de- number of fledglings counted on at least two cades ago (Frost 1993). In south Florida, the visits (south Florida) less than two weeks after BCNP site is associated with an old-growth young left the nest. slash pine (P. elliottii var. densa) forest sur- Most adults were captured using mist nets rounded by a cypress {Ta.xodium sp.) mosaic. placed near nests, but a few individuals were ENP contained even-aged slash pines inter- lured into mist nets using recorded vocaliza- spersed with hardwood forests and grassy tions of nuthatches or Eastern Screech-owl