Ecology of the Cerulean Warbler in the Cumberland Mountains of East Tennessee
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University of Tennessee, Knoxville TRACE: Tennessee Research and Creative Exchange Doctoral Dissertations Graduate School 5-2004 Ecology of the Cerulean Warbler in the Cumberland Mountains of East Tennessee Charles Patrick Nicholson University of Tennessee - Knoxville Follow this and additional works at: https://trace.tennessee.edu/utk_graddiss Part of the Ecology and Evolutionary Biology Commons Recommended Citation Nicholson, Charles Patrick, "Ecology of the Cerulean Warbler in the Cumberland Mountains of East Tennessee. " PhD diss., University of Tennessee, 2004. https://trace.tennessee.edu/utk_graddiss/2995 This Dissertation is brought to you for free and open access by the Graduate School at TRACE: Tennessee Research and Creative Exchange. It has been accepted for inclusion in Doctoral Dissertations by an authorized administrator of TRACE: Tennessee Research and Creative Exchange. For more information, please contact [email protected]. To the Graduate Council: I am submitting herewith a dissertation written by Charles Patrick Nicholson entitled "Ecology of the Cerulean Warbler in the Cumberland Mountains of East Tennessee." I have examined the final electronic copy of this dissertation for form and content and recommend that it be accepted in partial fulfillment of the equirr ements for the degree of Doctor of Philosophy, with a major in Ecology and Evolutionary Biology. David A. Buehler, Major Professor We have read this dissertation and recommend its acceptance: H. R. DeSelem, M. Boulet, M. Remie Accepted for the Council: Carolyn R. Hodges Vice Provost and Dean of the Graduate School (Original signatures are on file with official studentecor r ds.) To the Graduate Council: I am submitting herewith a dissertation written by Charles Patrick Nicholson entitled "Ecology of the Cerulean Warbler in the Cumberland Mountains of East Tennessee." I have examined the final paper copy of this dissertation fo r fo rm andcontent and recommend that it be accepted in partial fu lfillment of the requirements fo r the degree of Doctor of Philosophy, with a major in Ecology and Evolutionary Biology. �� Davidp.-(2 A. Buehler, Major Professor We have read this dissertation And recommend its acceptance: 11-.J?. D.L dk. .. :,... Acceptance fo r the Council: Vice Provost and Dean of raduate Studies •' . .. • f�i ;:: � ' ,,:: .. ,>I-, f ,' ( • . '.• .,·"'_; : J:! ,) � ; •,. i'. 11 I • ·-' · ·.;r ... ' ,,· : .1 .. :;· ' .. : f.' : ,· .. ·.,� ; . .j/53 •i '"'.; ., ,_ ' \ ...... .. ... -- _..,._.·� .. '• ... _ ECOLOGY OF THE CERULEAN WARBLER IN THE CUMBERLAND MOUNTAINS OF EAST TENNESSEE A Dissertation Presented fo r the Doctor of Philosophy Degree The University of Tennessee, Knoxville Charles Patrick Nicholson May 2004 ACKNOWLEDGEMENTS I wish to thankthe many fieldassi stants who helped with censuses, point counts, nest-searching, andvegetation sampling. These included E. Daniel Moss, Allen J. Trendy, Troy L, Ettel, Randy Detmers, Christopher D. Kreh, Margaret Rohs Short, Nathan A. Klaus, Chris D. Newbold, David R Sams, Billy Minser, and Dave Buckles. The hospitality, access, assistancein conducting fieldwork, andinf ormation provided by several land managers was invaluable. For this I thank Superintendent Duane Wyrick, Dave Engebretson, and other staffat Frozen Head State Park and Natural Area; Stanley Stooksbury at Royal Blue Wildlife Management Area; Carlton Owen and John Flynn oflnternational Paper Company; and Richard Evans, Superintendent of the University of Tennessee Forestry Experiment Stations. Richard Evans also provided invaluable housing fo r field crews. Funding for thisstudy was provided by the U.S. Fish and Wildlife Service through a grant administered by the Tennessee Wildlife Resources Agency. Nora Murdock and Bob Hatcher were especially helpfulin arranging this funding. For assistance in producing the maps, I thank Dave Hankins and Roger Tankersley. Susan Marsden of the Tennessee Wildlife Resources Agency and Mark Young of the University ofTennessee graciously provided electronic filesof the study areas boundaries. I thank the members of my graduate committee, especially Dave Buehler, fo r assistance and guidance duringthe study. I also thank Paul Hamel for sharing his knowledge of and enthusiasm fo r Cerulean Warblers. I thank my supervisors at the Tennessee Valley Authority fo r allowing me to maintain the flexible work schedule necessary for coursework and fieldwork. Finally, I thank my wife Niki fo r her love, support, advice, and patience. II ABSTRACT The objective of this study was to describe the distribution, local breeding densities and population trends, breeding biology, and habitat selection of the Cerulean Warbler (Dendroica cerulea) in the Cumberland Mountains of Morgan, Campbell, Scott, and Anderson Counties, Tennessee. Point counts were conducted during three years at six study sites. The Cerulean Warbler was detected at 50% of the point counts and was the sixth most frequently encountered bird. Spot-map censuses were conducted on five plots at three study sites. Cerulean Warblers occurredon all census plots at an average density of84.9 pairs/100 ha. Average density on individual plots ranged from 21.3 to 137.6 pairs/100 ha. Although population trends on the census plots were not unifonn, there was an overall decline during the late 1990s. The breeding biology of the Cerulean Warbler was studied by observing courtship behavior and nest-building, and monitoring a total of 52 nests. Female warblers built nests, incubated eggs, and brooded nestlings. Females fe d nestlings more often than males; the rate at which males and fe males removed fe cal sacs from the nest did not differ. Mean clutch size was 3.7± 0.13 SE. For the years 1996-1999, nest success, measured by the Mayfieldmethod, averaged 0.3708; the daily nest success rate averaged 0.9685 ± 0.0057 SE. The major cause of nest failure appeared to be weather events, including presumed nestling starvation during unusually cool and wet weather. Nests were built in 12 taxa of deciduous trees. Although there were some plot specificpref erences, most tree taxa were selected in proportion to their availability. Nests averaged 15.9 m ± 0.81 SE (range 7.0 - 36.3m) above ground. Nest treesaveraged 23.6 m± 0.90 SE (range 10.2-42.2 m) tall and 39.6 em± 2.53 SE (range 12.3- 76.2 em) in diameter at breast height. Habitat characteristics were sampled at nest sites, territory sites, and random sites on census plots, and at point count locations. Basal area was consistently greater, and both shrub cover and canopy cover consistently less, at nest sites than at random sites, at territory sites than at random sites, and at nest sites than at territory sites. Point count locations where Cerulean Warblers were present had larger diameter live trees and more lll sapling cover than locations where the warbler was absent. Logistic regression models successfully classifiedover 70% of sites on census plots but were less successful in predicting Cerulean Warbler presence at point count locations. iv TABLE OF CONTENTS Chapter .............................................................................................................. Page 1 INTRODUCTION ...... ................ ........... ..................... ....... ......................... 1 2 STUDY AREAS.. ................................................................... .. ................. 4 Regional Vegetation.................. ........ ..........................................................4 Frozen Head State Park and Natural Area ....... .................. .................... ...... 6 Royal Blue Wildlife Management Area .... .................................................. 8 University of Tennessee Cumberland Forestry Station, Morgan County Tracts ................................ ..... ... ....... ....................................... ......... 9 University of Tennessee Cumberland Forestry Station, Scott County Tract ..................... .. .......................... .............. ....... ..... ...... ............ 11 Lone Mountain State Forest. .... .................................. .. ......................... ... 11 Champion InternationalCumberland Forest .............................................. 12 3 DISTRIBUTION, DENSITY AND POPULATION TRENDS OF THE CERULEAN WARBLER IN THE CUMBERLAND MOUNTAINS OF TENNESSEE ............................................................................................. 13 Methods....... ... .. ...... .. ................... ................... .. ...... ..... ........ ... ... ...... ......... 13 Results .. ......................... ....... ..................... ... .. ......................................... 18 Discussion ............. .. ...... .. ... ......... ....... .......... ... ..................................... ...27 4 HABITAT SELECTION BY THE CERULEAN WARBLER IN THE 34 CUMBERLAND MOUNTAINS OF TENNESSEE ...... ...... .... ... .... ...... .. Methods................ ........... .. ........... ........................... ..... .. ........ ..... ...... ...... .. 35 Results ... .............................. .... ............................................................ ....... 39 Discussion ...................................., .............................................................54 5 BREEDING BIOLOGY OF THE CERULEAN WARBLER IN EASTERN TENNESSEE ........... .... ......... ...................... ................ ...........60 Methods............ .............. ...... ....... ........ ....... ................. ............... ................60 Results