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  1. AU="Mortensen, Jennifer L"
  2. AU="Manthey, Helga D"
  3. AU="Baker, Susan"
  4. AU="Gunasegaram, James R"
  5. AU="Jung, Steffen"
  6. AU="Cairns, Anita"
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  1. Article ; Online: Population Viability and Vital Rate Sensitivity of an Endangered Avian Cooperative Breeder, the White-Breasted Thrasher (Ramphocinclus brachyurus).

    Mortensen, Jennifer L / Reed, J Michael

    PloS one

    2016  Volume 11, Issue 2, Page(s) e0148928

    Abstract: Social behaviors can significantly affect population viability, and some behaviors might reduce extinction risk. We used population viability analysis to evaluate effects of past and proposed habitat loss on the White-breasted Thrasher (Ramphocinclus ... ...

    Abstract Social behaviors can significantly affect population viability, and some behaviors might reduce extinction risk. We used population viability analysis to evaluate effects of past and proposed habitat loss on the White-breasted Thrasher (Ramphocinclus brachyurus), a cooperatively breeding songbird with a global population size of <2000 individuals. We used an individual-based approach to build the first demographic population projection model for this endangered species, parameterizing the model with data from eight years of field study before and after habitat loss within the stronghold of the species' distribution. The recent habitat loss resulted in an approximately 18% predicted decline in population size; this estimate was mirrored by a separate assessment using occupancy data. When mortality rates remained close to the pre-habitat loss estimate, quasi-extinction probability was low under extant habitat area, but increased with habitat loss expected after current plans for resort construction are completed. Post-habitat loss mortality rate estimates were too high for projected populations to persist. Vital rate sensitivity analyses indicated that population growth rate and population persistence were most sensitive to juvenile mortality. However, observed values for adult mortality were closest to the threshold value above which populations would crash. Adult mortality, already relatively low, may have the least capacity to change compared to other vital rates, whereas juvenile mortality may have the most capacity for improvement. Results suggest that improving mortality estimates and determining the cause(s) of juvenile mortality should be research priorities. Despite predictions that aspects of cooperative systems may result in variation in reproduction or juvenile mortality being the most sensitive vital rates, adult mortality was the most sensitive in half of the demographic models of other avian cooperative breeders. Interestingly, vital rate sensitivity differed by model type. However, studies that explicitly modeled the species' cooperative breeding system found reproduction to be the most sensitive rate.
    MeSH term(s) Animals ; Behavior, Animal ; Cooperative Behavior ; Ecosystem ; Endangered Species ; Extinction, Biological ; Female ; Male ; Models, Statistical ; Population Dynamics ; Reproduction ; Saint Lucia ; Songbirds/physiology
    Language English
    Publishing date 2016-02-09
    Publishing country United States
    Document type Journal Article ; Research Support, Non-U.S. Gov't
    ZDB-ID 2267670-3
    ISSN 1932-6203 ; 1932-6203
    ISSN (online) 1932-6203
    ISSN 1932-6203
    DOI 10.1371/journal.pone.0148928
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  2. Article: Parental incubation patterns and the effect of group size in a Neotropical cooperative breeder

    Mortensen, Jennifer L / J. Michael Reed

    Auk. 2018 July, v. 135, no. 3

    2018  

    Abstract: In many cooperatively breeding species, young (“helpers”) from one year help other adults raise offspring the following year. In contrast to helper effects during the nestling or postfledging stages of the avian breeding cycle, potential benefits from ... ...

    Title translation Patrones de incubación parental y efecto del tamaño de grupo en un ave neotropical de cría cooperativa (Ramphocinclus brachyurus)
    Abstract In many cooperatively breeding species, young (“helpers”) from one year help other adults raise offspring the following year. In contrast to helper effects during the nestling or postfledging stages of the avian breeding cycle, potential benefits from helpers during incubation are poorly studied. We analyzed 39 clutches and recorded 6,027 off-bouts to document incubation behavior in the White-breasted Thrasher (Ramphocinclus brachyurus), an endangered Neotropical facultative cooperative breeder. Our goal was to test the prediction that cooperation confers benefits during incubation in terms of increased nest attendance and hatching success. We found that 65% of active hours (0500–2100) are spent on the nest, values somewhat lower than average for a tropical passerine with uniparental incubation. Highest incubation constancy was observed at a rare 4-egg clutch, which was attended by putative joint-nesters. Excluding this clutch, differences in incubation behavior between pair and cooperative groups were subtle and context dependent. We found temporal variation in incubation behavior, whereby off-bout frequency declined as the breeding season progressed, but more quickly for cooperative groups. Maximum ambient temperature was also an influential abiotic predictor. Across both social group types, incubation constancy declined as temperature increased to ∼30°C, above which constancy remained high. As expected, we found that the behavior of birds with failed and successful clutches differed. Specifically, failed clutches experienced high early-season constancy, despite temperature data suggesting insufficient warming during that time, and successful cooperative clutches had higher late-season constancy than pairs. Other factors important in avian systems were not predictive of incubation behavior here, and in general, high individual variation for all incubation behaviors swamped most other sources of variation. Results from this work highlight the individuality in incubation behavior and suggest that breeding females in cooperative groups have more flexibility in shifting between incubation demands and maintenance behaviors than do lone pairs.
    Keywords adults ; alloparental behavior ; ambient temperature ; birds ; breeding ; breeding season ; females ; group size ; hatching ; nestlings ; nests ; Passeriformes ; prediction ; progeny ; social class ; temporal variation
    Language English
    Dates of publication 2018-07
    Size p. 669-692.
    Publishing place The American Ornithologists' Union
    Document type Article
    ZDB-ID 2065970-2
    ISSN 1938-4254 ; 0004-8038
    ISSN (online) 1938-4254
    ISSN 0004-8038
    DOI 10.1642/AUK-17-236.1
    Database NAL-Catalogue (AGRICOLA)

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  3. Article: Habitat suitability models indicate the White-breasted Thrasher Ramphocinclus brachyurus occupies all suitable habitat in Saint Lucia

    SASS, EMMA M / MORTENSEN, JENNIFER L / REED, J. MICHAEL

    Bird conservation international. 2017 Mar., v. 27, no. 1

    2017  

    Abstract: Habitat suitability models can guide species conservation by identifying correlates of occurrence and predicting where species are likely to occur. We created habitat suitability models for the White-breasted Thrasher Ramphocinclus brachyurus, a narrowly ...

    Abstract Habitat suitability models can guide species conservation by identifying correlates of occurrence and predicting where species are likely to occur. We created habitat suitability models for the White-breasted Thrasher Ramphocinclus brachyurus, a narrowly distributed endangered songbird that occupies dry forest in Saint Lucia and Martinique. Eighty-five percent of the global population inhabits two ranges in Saint Lucia, both of which are largely unprotected and threatened by development. We developed three habitat suitability models using Maxent techniques and published occupancy datasets collected from the species’ two Saint Lucian ranges, and used abiotic, land cover, and predator distribution predictors. We built one model with occupancy data from both ranges, and two others with occupancy data specific to each range. The best full-range model included 11 predictors; high suitability was associated with close proximity to Saint Lucia fer-de-lance Bothrops caribbeaus range, moderately low precipitation, and areas near streams. Our assessment of suitable sites island-wide was more restricted than results from a recent model that considered older land cover data and omitted predator distributions. All sites identified in our full-range model as highly suitable were in or adjacent to the species’ current designated range. The model trained on southern range occurrences predicted zero suitable habitat in the northern range, where the population is much smaller. In contrast, the model trained on northern range occurrences identified areas of moderate suitability within the southern range and patches of moderately suitable habitat in the western part of the island, where no White-breasted Thrashers currently occur. We interpret these results as suggesting that White-breasted Thrashers currently occupy virtually all suitable habitat on the island, that birds in the northern range occupy marginal habitat, or that an important correlate of suitability is missing from the model. Our results suggest that habitat management should focus on currently occupied areas.
    Keywords Bothrops ; data collection ; dry forests ; endangered species ; habitat conservation ; habitats ; land cover ; models ; Passeriformes ; prediction ; rain ; songbirds ; streams ; Martinique ; Saint Lucia
    Language English
    Dates of publication 2017-03
    Size p. 96-110.
    Publishing place Cambridge University Press
    Document type Article
    ZDB-ID 2037673-X
    ISSN 1474-0001 ; 0959-2709
    ISSN (online) 1474-0001
    ISSN 0959-2709
    DOI 10.1017/S0959270915000374
    Database NAL-Catalogue (AGRICOLA)

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  4. Article ; Online: Phylogenomics clarifies biogeographic and evolutionary history, and conservation status of West Indian tremblers and thrashers (Aves: Mimidae).

    DaCosta, Jeffrey M / Miller, Matthew J / Mortensen, Jennifer L / Reed, J Michael / Curry, Robert L / Sorenson, Michael D

    Molecular phylogenetics and evolution

    2019  Volume 136, Page(s) 196–205

    Abstract: The West Indian avifauna has provided fundamental insights into island biogeography, taxon cycles, and the evolution of avian behavior. Our interpretations, however, should rely on robust hypotheses of evolutionary relationships and consistent ... ...

    Abstract The West Indian avifauna has provided fundamental insights into island biogeography, taxon cycles, and the evolution of avian behavior. Our interpretations, however, should rely on robust hypotheses of evolutionary relationships and consistent conclusions about taxonomic status in groups with many endemic island populations. Here we present a phylogenetic study of the West Indian thrashers, tremblers, and allies, an assemblage of at least 5 species found on 29 islands, including what is considered the Lesser Antilles' only avian radiation. We improve on previous phylogenetic studies of this group by using double-digest restriction site-associated DNA sequencing (ddRAD-seq) to broadly sample loci scattered across the nuclear genome. A variety of analyses, based on either nucleotide variation in 2223 loci recovered in all samples or at 13,282 loci confidently scored as present or absent in all samples, converged on a single well-supported phylogenetic hypothesis. Results indicate that the resident West Indian taxa form a monophyletic group, exclusive of the Neotropical-Nearctic migratory Gray Catbird Dumetella carolinensis, which breeds in North America; this outcome differs from earlier studies suggesting that Gray Catbird was nested within a clade of island resident species. Thus, our findings imply a single colonization of the West Indies without the need to invoke a subsequent 'reverse colonization' of the mainland by West Indian taxa. Additionally, our study is the first to sample both endemic subspecies of the endangered White-breasted Thrasher Ramphocinclus brachyurus. We find that these subspecies have a long history of evolutionary independence with no evidence of gene flow, and are as genetically divergent from each other as other genera in the group. These findings support recognition of R. brachyurus (restricted to Martinique) and the Saint Lucia Thrasher R. sanctaeluciae as two distinct, single-island endemic species, and indicate the need to re-evaluate conservation plans for these taxa. Our results demonstrate the utility of phylogenomic datasets for generating robust systematic hypotheses.
    MeSH term(s) Animals ; Base Sequence ; Conserved Sequence ; DNA, Mitochondrial/genetics ; Passeriformes/classification ; Passeriformes/genetics ; Phylogeny ; Phylogeography ; Restriction Mapping ; Sequence Analysis, DNA ; Species Specificity ; West Indies
    Chemical Substances DNA, Mitochondrial
    Language English
    Publishing date 2019-04-15
    Publishing country United States
    Document type Journal Article ; Research Support, Non-U.S. Gov't ; Research Support, U.S. Gov't, Non-P.H.S.
    ZDB-ID 33610-5
    ISSN 1095-9513 ; 1055-7903
    ISSN (online) 1095-9513
    ISSN 1055-7903
    DOI 10.1016/j.ympev.2019.04.016
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  5. Article: Phylogenomics clarifies biogeographic and evolutionary history, and conservation status of West Indian tremblers and thrashers (Aves: Mimidae)

    DaCosta, Jeffrey M / Miller, Matthew J / Mortensen, Jennifer L / Reed, J. Michael / Curry, Robert L / Sorenson, Michael D

    Molecular phylogenetics and evolution. 2019 July, v. 136

    2019  

    Abstract: The West Indian avifauna has provided fundamental insights into island biogeography, taxon cycles, and the evolution of avian behavior. Our interpretations, however, should rely on robust hypotheses of evolutionary relationships and consistent ... ...

    Abstract The West Indian avifauna has provided fundamental insights into island biogeography, taxon cycles, and the evolution of avian behavior. Our interpretations, however, should rely on robust hypotheses of evolutionary relationships and consistent conclusions about taxonomic status in groups with many endemic island populations. Here we present a phylogenetic study of the West Indian thrashers, tremblers, and allies, an assemblage of at least 5 species found on 29 islands, including what is considered the Lesser Antilles’ only avian radiation. We improve on previous phylogenetic studies of this group by using double-digest restriction site-associated DNA sequencing (ddRAD-seq) to broadly sample loci scattered across the nuclear genome. A variety of analyses, based on either nucleotide variation in 2223 loci recovered in all samples or at 13,282 loci confidently scored as present or absent in all samples, converged on a single well-supported phylogenetic hypothesis. Results indicate that the resident West Indian taxa form a monophyletic group, exclusive of the Neotropical–Nearctic migratory Gray Catbird Dumetella carolinensis, which breeds in North America; this outcome differs from earlier studies suggesting that Gray Catbird was nested within a clade of island resident species. Thus, our findings imply a single colonization of the West Indies without the need to invoke a subsequent ‘reverse colonization’ of the mainland by West Indian taxa. Additionally, our study is the first to sample both endemic subspecies of the endangered White-breasted Thrasher Ramphocinclus brachyurus. We find that these subspecies have a long history of evolutionary independence with no evidence of gene flow, and are as genetically divergent from each other as other genera in the group. These findings support recognition of R. brachyurus (restricted to Martinique) and the Saint Lucia Thrasher R. sanctaeluciae as two distinct, single-island endemic species, and indicate the need to re-evaluate conservation plans for these taxa. Our results demonstrate the utility of phylogenomic datasets for generating robust systematic hypotheses.
    Keywords Mimidae ; avifauna ; biogeography ; birds ; breeds ; conservation status ; data collection ; gene flow ; genetic variation ; geographical distribution ; indigenous species ; islands ; loci ; migratory behavior ; monophyly ; nuclear genome ; sequence analysis ; Caribbean ; Martinique ; North America ; Saint Lucia
    Language English
    Dates of publication 2019-07
    Size p. 196-205.
    Publishing place Elsevier Inc.
    Document type Article
    ZDB-ID 33610-5
    ISSN 1095-9513 ; 1055-7903
    ISSN (online) 1095-9513
    ISSN 1055-7903
    DOI 10.1016/j.ympev.2019.04.016
    Database NAL-Catalogue (AGRICOLA)

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