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part of the nesting season.  Later inthe season, warblers are frequent part of the nesting season.  Later inthe season, warblers are frequent

part of the nesting season. Later inthe season, warblers are frequent - PDF document

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part of the nesting season. Later inthe season, warblers are frequent - PPT Presentation

Female warbler with insect ID: 454806

Female warbler with insect

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part of the nesting season. Later inthe season, warblers are frequentlyseen foraging in Ashe juniper. Mesic(relatively moist) conditions, such asthose found on wooded slopes,canyon bottoms, and along creeks anddraws, are especially favorable for theproduction of insect foods.Depending on the location andquality of habitat, Golden-cheekedWarblers forage and nest in areas ofhabitat ranging in size from five to20 acres per pair. Within suitablenesting habitat, male Golden-cheekedWarblers occupy an area, called a ter-ritory, which is vigorously defendedagainst all other male Golden-cheekedWarblers. Nesting territories range insize from three to ten acres, depend-ing on habitat quality. Banding stud-ies show that males often occupy thesame territory in subsequent breed-ing seasons. Male warblers can oftenbe located through their territorialsong, described as a rather hurried,buzzy Òtweah-tweah-twee-sy.Ó Single,sharp ÒchippingÓ calls can frequentlybe heard as Golden-cheeks forageamong the trees.The female does most of the workof nest building and incubating theeggs. The cup-like nest is often neatlytucked into the fork of a vertical limband camouflaged to blend with thebark of the tree. Nests are constructedat an average height of 15 feet aboveground, although they have been foundas low as five feet and as high as 32feet. The male stays close by, singinghis distinctive song and defending histerritory during incubation. During April, a single clutch ofthree to four eggs is laid. Warblersusually nest only once per season,unless a nest is lost to accident or pre-dation. The eggs hatch in 12 days,and both parents care for the young.After the young hatch, male singingdeclines, although they can still beheard into June. Nestlings fledgeeight or nine days after hatching, butremain in the vicinity of the territoryfor at least four weeks while beingcared for by both parents. Golden-cheeked Warblers migrateto their wintering grounds in thepine-oak woodlands of southern Mex-ico (Chiapas), Guatemala, Honduras,and Nicaragua from late June to midAugust. They return to Texas in earlyto mid-March. Threats and Reasons for DeclineThe most serious problems facing theGolden-cheeked Warbler today, as inthe recent past, are habitat loss andfragmentation. Since warblers havelimited and specific habitat require-ments, direct habitat loss has resultedin population reduction, althoughprecise comparisons of historic andcurrent populations are not available. Recently, serious losses in nestinghabitat have occurred in counties suchas Travis, Williamson, and Bexar, whererapid urban development has spreadinto oak-juniper woodlands associatedwith canyonlands. Flood control andother impoundments have also reducedhabitat for the warbler by inundatingthe juniper-oak woodlands existing oncanyon slopes and bottoms alongsprings, streams, and rivers. Construc-tion of large reservoirs has also led toloss of warbler habitat due to develop-ment of lake-side communities.Historically, some warbler habitatwas lost as a result of clearingjuniper/oak woodlands for increasedlivestock production or improved live-stock handling. Stands of large junipertrees were also cut for sale as fenceposts and other timber products, espe-cially before 1940. Over-browsing bywhite-tailed deer, goats, and exoticungulates is believed to contribute tohabitat degradation by reducing thesurvival of seedling oaks and otherdeciduous trees, which are a vital com-ponent of warbler habitat. Also, manyof the deeper and more fertile soils inmuch of the Hill Country are found insmall floodplains along creeks or inter-mittent streams associated with hillsidedrainage. Many of these areas, someof them supporting a variety of decidu-ous trees, were cleared and convertedto forage crops and pasture, oftenresulting in a decrease in the amountof warbler habitat.Habitat loss may be obscured bythe increase in juniper on rangelandthroughout central Texas. The inva-sion of juniper on upland sites isoften the result of fire suppression,overgrazing, or a combination ofboth. These young juniper standsinvading open rangelands generallylack the kinds and numbers of hard-wood trees required by warblers.Warblers are usually not found inmonocultures (pure stands) wherejuniper comprises over 90% of thecomposition throughout a large area. Poor grazing management practices and fire suppression resultin a decline in the diversity and pro-ductivity of rangeland. The declinein range condition associated withimproper management has led toincreases in juniper throughout theHill Country. Brood parasitism by Brown-headed Cowbirds may threaten success-ful reproduction of Golden-cheekedWarblers, although the degree of2Golden-cheeked Warbler Female warbler with insect © TPWD Dean Keddy-HectorWarbler at a nest© TPWD Dean Keddy-HectorGolden-cheeked Warbler habitat© TPWD David Riskind Golden-cheeked Warbler3impact of cowbird parasitism on war-bler productivity is not fully under-stood. Cowbirds lay their eggs inother birdsÕ nests, leaving the host birdto raise the cowbird young. Golden-cheeked Warblers apparently willeither abandon parasitized nests, orraise young cowbirds in addition to orin place of their own young. Warblersthat abandon parasitized nests mayrenest later in the season. However,abandonment of first clutches, or rais-ing cowbird young in addition to theirown, decreases the total number andsurvivability of Golden-cheeked war-bler young produced. Habitat fragmentation reducesthe quality and quantity of warblerhabitat. In small woodland patches,the increased proportion of habitatedge to interior area may increaserates of brood parasitism and preda-tion, so that the surviving popula-tions cannot maintain themselves.Also, increased distances betweenpatches may make recolonization ofvacated habitat more difficult.In Texas, Mexico and CentralAmerica, habitat management and pro-tection, responsible land stewardship,and incentives for landowners tomaintain and develop habitat, are keysto the survival and recovery of theGolden-cheeked Warbler. The diversemix of hardwoods and junipers incanyons, and on slopes and adjacenthilltops, provide ideal habitat for thewarbler. Numerous beautiful andinteresting native plants and animalsare also found in these canyons. Recovery EffortsResearch is underway to better under-stand the life history, habitat require-ments, limiting factors, and landmanagement practices affecting theGolden-cheeked Warbler. Populationsurveys during the breeding seasonare being conducted in known andpotential habitat areas. Efforts to pro-vide information and educationalopportunities to landowners and thepublic regarding life history and habi-tat requirements of the warbler arealso a vital part of the recovery effort.Major recovery efforts are being con-ducted on Department of DefenseÕsFort Hood and Camp Bullis, TravisCounty and the City of AustinÕs Bal-cones Canyonlands Preserve, the U.S.Fish and Wildlife ServicesÕ BalconesCanyonlands National Wildlife Refuge,and many properties owned and/ormanaged by the Nature Conservancy.Additionally, Environmental Defensethrough their Safe Harbor Agreementwith the U.S. Fish and Wildlife Serviceis assisting many landowners to man-age and/or create habitat for the ben-efit of the warbler. Voluntary cowbird Closed canopy habitat© Carol Beardmore Juniper with peeling bark© TPWD D. Keddy-Hectortrapping is being conducted by morethan 400 landowners in countiesthroughout the range of the warbler.Recently, a consortium ofresearchers in governmental and non-governmental agencies has proposeda multinational effort to better under-stand and coordinate approaches tomanaging and recovering the Golden-cheeked Warbler. Additional researchin Mexico and Central America isplanned to gather information con-cerning life history and habitatrequirements on the wintering range.Studies are needed to assess thepotential for income generating activ-ities, such as selective harvest ofjuniper, which may be compatiblewith habitat protection. Where To See the Golden-cheeked WarblerA number of state lands, including Colorado Bend State Park (SP),Dinosaur Valley SP, Garner SP,Guadalupe River SP, Honey Creek StateNatural Area (SNA), Hill Country SNA,Kerr Wildlife Management Area, Long-horn Cavern SP, Lost Maples SNA,Meridian SP, Pedernales Falls SP, andPossum Kingdom SP offer opportuni-ties for people to see Golden-cheekedWarblers and their habitat. Other locations include the Balcones Canyon-lands National Wildlife Refuge, TravisAudubon Sanctuary, Wild Basin Preserve, and Emma Long City Park inthe Austin area; and Friedrich Wilder-ness Park near San Antonio. Onceopen to the public, GovernmentCanyon State Natural Area, locatednorthwest of San Antonio, will offeradditional opportunities to seeGolden-cheeked Warblers.Because the Golden-cheeked Warbler is an endangered species,birders and other observers shouldcarefully follow certain viewingethics. Recorded calls of the Golden-cheeked Warbler or Screech Owlshould not be used to attract birdsand observers should be careful notto disturb or stress birds.How You Can HelpYou can help by providing encourage-ment and support for privatelandowners who are managing their land to protect natural diversityand endangered species habitat.Landowners are encouraged to learnthe facts about the Golden-cheekedWarbler and its habitat needs, and toprotect areas of habitat found ontheir property. Creek bottom habitat 4Golden-cheeked WarblerThe Golden-cheeked Warbler is abeautiful songbird, and is much soughtafter among people who enjoy bird-watching and nature study. Possibili-ties exist for landowners to takeadvantage of the growing demand fornatural history tours and vacations.Landowners interested in more infor-mation concerning nature tourismopportunities should contact theNature Tourism Coordinator, TexasParks and Wildlife Department, Austin(512) 389-4396; EnvironmentalDefense, Austin (512) 478-5161; or theNature Conservancy, San AntonioFinally, you can be involved inthe conservation of TexasÕ nongamewildlife resources by supporting theSpecial Nongame and EndangeredSpecies Conservation Fund. Specialnongame stamps and decals are avail-able at Texas Parks and WildlifeDepartment (TPWD) field offices,most state parks, and the LicenseBranch of TPWD headquarters inAustin. Conservation organizationsin Texas also welcome your participa-tion and support. For More Information ContactTexas Parks and Wildlife DepartmentWildlife Diversity Branch4200 Smith School RoadAustin, Texas 78744U.S. Fish and Wildlife ServiceEcological Services Field Office10711 Burnet Road, Suite 200Austin, Texas 78758Management guidelines are availablefrom the Texas Parks and WildlifeDepartment and U.S. Fish andWildlife Service for landowners andmanagers wishing to maintain andimprove habitat for the Golden-cheeked Warbler. Funds for the production of this leaflet were provided by the U.S. Fish and Wildlife Service, under Section 6 of the Endangered Species Act. Urban expansion© USFWS Wyman MeinzerWarbler with identification band Golden-cheeked Warbler habitat© TPWD Bill Reaves ReferencesArnold, K.A., C.L. Coldren, and M.L. Fink. 1996. The interactions between avianpredators and golden-cheeked warblers in Travis County, Texas. Researchreport 1983-2 for Texas Department of Transportation.Coldren, C.L. 1998. The effects of habitat fragmentation on the golden-cheeked. Ph.D. Dissertation, Texas A&M University, College Station, Texas.Engels, T.M. 1995. Conservation biology of the golden-cheeked warbler. Ph.D.Dissertation, University of Texas, Austin, Texas Fink, M.L. 1996. Factors contributing to nest predation within habitat of thegolden-cheeked warbler, Travis County, Texas. M.S. Thesis, Texas A&M Uni-versity, College Station, Texas.Huss, D.L. 1954. Factors influencing plant succession following fire in ashejuniper woodland types in Real County, Texas.MS Thesis, Texas A&M Univer-sity, College Station, Texas. 77pp.Ladd, C. and L. Gass. 1999. ÒGolden-cheeked warbler (Dendroica chrysoparia).ÓIn The Birds of North America, No. 420. (A. Poole and F. Gill, eds.). The Birdsof North America, Inc., Philadelphia, PA.Mass, D.S. and G.D. Schnell. 1998. ÒEffects of habitat fragmentation on demograph-ics of golden-cheeked warblers (Dendroica chrysoparia).Ó Masters Thesis, Part 1 of 2, University of Oklahoma, Norman, Oklahoma.Oberholser, H.C. 1974. The bird life of Texas. University of Texas Press, Austin,Texas.Pulich, W. 1976. The golden-cheeked warbler, a bioecological study. Texas Parksand Wildlife Department, Austin, Texas. 172pp.U.S. Fish and Wildlife Service (USFWS). 1992. Golden-cheeked warbler recovery. USFWS, Endangered Species Office, Albuquerque, NM. 88pp.U.S. Fish and Wildlife Service (USFWS). 1996. Golden-cheeked warbler populationand habitat viability assessment report.Compiled and edited by Carol Beard-more, Jeff Hatfield, and Jim Lewis in conjunction with workshop participants.Report of an August 21-24, 1995 workshop arranged by the U.S. Fish andWildlife Service in partial fulfillment of U.S. National Biological Service GrantNo. 80333-1423. Austin, Texas. xii+48pp.+Appendix.Wahl, R., D.D. Diamond, and D. Shaw. 1990. The golden-cheeked warbler: a statusreview. U.S. Fish and Wildlife Service, Ecological Services Office, Austin, Texas.