Ecology Of Non-Breeding And Breeding Crested Caracaras (Caracara cheriway) In Florida

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dc.contributor.authorDwyer, James F.en
dc.contributor.committeecochairMorrison, Joan L.en
dc.contributor.committeecochairFraser, James D.en
dc.contributor.committeememberWalters, Jeffrey R.en
dc.contributor.committeememberPrisley, Stephen P.en
dc.contributor.committeememberHopkins, William A.en
dc.contributor.departmentFisheries and Wildlife Sciencesen
dc.date.accessioned2014-03-14T20:11:46Zen
dc.date.adate2010-06-14en
dc.date.available2014-03-14T20:11:46Zen
dc.date.issued2010-05-06en
dc.date.rdate2010-06-14en
dc.date.sdate2010-05-09en
dc.description.abstractLike many species, Florida's population of Northern Crested Caracaras (Caracara cheriway, hereafter "caracara") is likely declining due to loss of breeding habitat. Consequently, management-oriented restrictions on landscape modification are applied where breeding occurs, but management rarely is extended beyond breeding areas. Focusing management on breeding areas can be effective if all caracaras occupy breeding areas, all breeding areas are detected, and no intermittent breeding occurs. Management may not operate as intended if any of these criteria are unmet. To explore this possibility, I investigated the movement, habitat, survival, and social biology of non-breeding caracaras. I also investigated long-term occupancy of breeding habitat, and factors contributing to detection of breeding. Non-breeding caracaras occupy areas much larger than individual breeding territories, particularly during breeding seasons. Pastures occupied by cattle were the most used habitat, but non-breeding caracaras also occupied habitats atypical of breeding areas. Specifically, citrus groves were occupied extensively, and row crops were used particularly during breeding seasons. Non-breeding caracaras also shared communal roosts, sometimes with hundreds of conspecifics, and roosts were occupied year-round. Survival of non-breeding caracaras was lowest during breeding seasons. Adult non-breeding caracaras persisted in groups for multiple years without establishing breeding territories. This implies that breeding habitat is limited and saturated. Given the proportion of adults in groups, adults also were the first to find carrion more often than expected. Apparently, young caracaras benefit from grouping by following adults. I found caracaras at all sampled breeding areas where nests were originally documented during the 1990s, and found nests at 83% of territories where nests likely existed. I also found that observer experience, visit start time, and weather affected the probability that a nest would be detected. Thus, not all caracaras occupy breeding areas, and not all breeding attempts are likely to be detected. Long-term occupancy of breeding areas should render annual verification of nesting unnecessary as a trigger for maintaining management actions. Rather management should persist even without confirmation of annual breeding. Caracara management also may be optimized through supporting the non-breeding population by maintaining a matrix of cattle pasture and citrus groves, particularly around roosts.en
dc.description.degreePh. D.en
dc.identifier.otheretd-05092010-132909en
dc.identifier.sourceurlhttp://scholar.lib.vt.edu/theses/available/etd-05092010-132909/en
dc.identifier.urihttp://hdl.handle.net/10919/27618en
dc.publisherVirginia Techen
dc.relation.haspartDwyer_JF_D_2010.pdfen
dc.rightsIn Copyrighten
dc.rights.urihttp://rightsstatements.org/vocab/InC/1.0/en
dc.subjectCrested Caracaraen
dc.subjectcore areaen
dc.subjectCaracara cheriwayen
dc.subjectbirden
dc.subjectavianen
dc.subjectroosten
dc.subjectraptoren
dc.subjectrangeen
dc.subjectprogram MARKen
dc.subjectNorthern Crested Caracaraen
dc.subjectsurvivalen
dc.subjectsocial biologyen
dc.subjectseasonen
dc.subjectthreatened speciesen
dc.subjectpopulation monitoringen
dc.subjectoccupancyen
dc.subjectnon-breedingen
dc.subjectfloateren
dc.subjectFloridaen
dc.subjecthabitaten
dc.subjecthome rangeen
dc.subjectimmatureen
dc.subjectintermittent breedingen
dc.subjectModelingen
dc.subjectmovementen
dc.titleEcology Of Non-Breeding And Breeding Crested Caracaras (Caracara cheriway) In Floridaen
dc.typeDissertationen
thesis.degree.disciplineFisheries and Wildlife Sciencesen
thesis.degree.grantorVirginia Polytechnic Institute and State Universityen
thesis.degree.leveldoctoralen
thesis.degree.namePh. D.en

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