The ecological and physiological bases of variation in the phenology of gonad growth in an urban and desert songbird

Scott Davies, Samuel Lane, Simone L. Meddle, Kazuyoshi Tsutsui, Pierre Deviche

    Research output: Contribution to journalArticle

    5 Citations (Scopus)

    Abstract

    Birds often adjust to urban areas by advancing the timing (phenology) of vernal gonad growth. However, the ecological and physiological bases of this adjustment are unclear. We tested whether the habitat-related disparity in gonad growth phenology of male Abert's towhees, Melozone aberti, is due to greater food availability in urban areas of Phoenix, Arizona USA or, alternatively, a habitat-related difference in the phenology of key food types. To better understand the physiological mechanism underlying variation in gonad growth phenology, we compared the activity of the reproductive system at all levels of hypothalamo-pituitary-gonadal (HPG) axis. We found no habitat-associated difference in food availability (ground arthropod biomass), but, in contrast to the seasonal growth of leaves on desert trees, the leaf foliage of urban trees was already developed at the beginning of our study. Multiple estimates of energetic status did not significantly differ between the non-urban and urban towhees during three years that differed in the habitat-related disparity in gonad growth and winter precipitation levels. Thus, our results provide no support for the hypothesis that greater food abundance in urban areas of Phoenix drives the habitat-related disparity in gonad growth phenology in Abert's towhees. By contrast, they suggest that differences in the predictability and magnitude of change in food availability between urban and desert areas of Phoenix contribute to the observed habitat-related disparity in gonad growth. Endocrine responsiveness of the gonads may contribute to this phenomenon as desert - but not urban - towhees had a marked plasma testosterone response to GnRH challenge.

    Original languageEnglish
    Pages (from-to)17-25
    Number of pages9
    JournalGeneral and Comparative Endocrinology
    Volume230-231
    DOIs
    Publication statusPublished - 2016 May 1

    Fingerprint

    Songbirds
    Gonads
    songbirds
    urbanization
    phenology
    gonads
    deserts
    Ecosystem
    Growth
    Food
    habitats
    urban areas
    food availability
    leaves
    seasonal growth
    Arthropods
    reproductive system
    Gonadotropin-Releasing Hormone
    Biomass
    testosterone

    Keywords

    • Food abundance
    • Gonad cycles
    • Phenotypic plasticity
    • Reproductive neuroendocrinology
    • Urbanization

    ASJC Scopus subject areas

    • Endocrinology

    Cite this

    The ecological and physiological bases of variation in the phenology of gonad growth in an urban and desert songbird. / Davies, Scott; Lane, Samuel; Meddle, Simone L.; Tsutsui, Kazuyoshi; Deviche, Pierre.

    In: General and Comparative Endocrinology, Vol. 230-231, 01.05.2016, p. 17-25.

    Research output: Contribution to journalArticle

    @article{9f9b58b79473413eaf42f3e5e7bfb973,
    title = "The ecological and physiological bases of variation in the phenology of gonad growth in an urban and desert songbird",
    abstract = "Birds often adjust to urban areas by advancing the timing (phenology) of vernal gonad growth. However, the ecological and physiological bases of this adjustment are unclear. We tested whether the habitat-related disparity in gonad growth phenology of male Abert's towhees, Melozone aberti, is due to greater food availability in urban areas of Phoenix, Arizona USA or, alternatively, a habitat-related difference in the phenology of key food types. To better understand the physiological mechanism underlying variation in gonad growth phenology, we compared the activity of the reproductive system at all levels of hypothalamo-pituitary-gonadal (HPG) axis. We found no habitat-associated difference in food availability (ground arthropod biomass), but, in contrast to the seasonal growth of leaves on desert trees, the leaf foliage of urban trees was already developed at the beginning of our study. Multiple estimates of energetic status did not significantly differ between the non-urban and urban towhees during three years that differed in the habitat-related disparity in gonad growth and winter precipitation levels. Thus, our results provide no support for the hypothesis that greater food abundance in urban areas of Phoenix drives the habitat-related disparity in gonad growth phenology in Abert's towhees. By contrast, they suggest that differences in the predictability and magnitude of change in food availability between urban and desert areas of Phoenix contribute to the observed habitat-related disparity in gonad growth. Endocrine responsiveness of the gonads may contribute to this phenomenon as desert - but not urban - towhees had a marked plasma testosterone response to GnRH challenge.",
    keywords = "Food abundance, Gonad cycles, Phenotypic plasticity, Reproductive neuroendocrinology, Urbanization",
    author = "Scott Davies and Samuel Lane and Meddle, {Simone L.} and Kazuyoshi Tsutsui and Pierre Deviche",
    year = "2016",
    month = "5",
    day = "1",
    doi = "10.1016/j.ygcen.2016.03.013",
    language = "English",
    volume = "230-231",
    pages = "17--25",
    journal = "General and Comparative Endocrinology",
    issn = "0016-6480",
    publisher = "Academic Press Inc.",

    }

    TY - JOUR

    T1 - The ecological and physiological bases of variation in the phenology of gonad growth in an urban and desert songbird

    AU - Davies, Scott

    AU - Lane, Samuel

    AU - Meddle, Simone L.

    AU - Tsutsui, Kazuyoshi

    AU - Deviche, Pierre

    PY - 2016/5/1

    Y1 - 2016/5/1

    N2 - Birds often adjust to urban areas by advancing the timing (phenology) of vernal gonad growth. However, the ecological and physiological bases of this adjustment are unclear. We tested whether the habitat-related disparity in gonad growth phenology of male Abert's towhees, Melozone aberti, is due to greater food availability in urban areas of Phoenix, Arizona USA or, alternatively, a habitat-related difference in the phenology of key food types. To better understand the physiological mechanism underlying variation in gonad growth phenology, we compared the activity of the reproductive system at all levels of hypothalamo-pituitary-gonadal (HPG) axis. We found no habitat-associated difference in food availability (ground arthropod biomass), but, in contrast to the seasonal growth of leaves on desert trees, the leaf foliage of urban trees was already developed at the beginning of our study. Multiple estimates of energetic status did not significantly differ between the non-urban and urban towhees during three years that differed in the habitat-related disparity in gonad growth and winter precipitation levels. Thus, our results provide no support for the hypothesis that greater food abundance in urban areas of Phoenix drives the habitat-related disparity in gonad growth phenology in Abert's towhees. By contrast, they suggest that differences in the predictability and magnitude of change in food availability between urban and desert areas of Phoenix contribute to the observed habitat-related disparity in gonad growth. Endocrine responsiveness of the gonads may contribute to this phenomenon as desert - but not urban - towhees had a marked plasma testosterone response to GnRH challenge.

    AB - Birds often adjust to urban areas by advancing the timing (phenology) of vernal gonad growth. However, the ecological and physiological bases of this adjustment are unclear. We tested whether the habitat-related disparity in gonad growth phenology of male Abert's towhees, Melozone aberti, is due to greater food availability in urban areas of Phoenix, Arizona USA or, alternatively, a habitat-related difference in the phenology of key food types. To better understand the physiological mechanism underlying variation in gonad growth phenology, we compared the activity of the reproductive system at all levels of hypothalamo-pituitary-gonadal (HPG) axis. We found no habitat-associated difference in food availability (ground arthropod biomass), but, in contrast to the seasonal growth of leaves on desert trees, the leaf foliage of urban trees was already developed at the beginning of our study. Multiple estimates of energetic status did not significantly differ between the non-urban and urban towhees during three years that differed in the habitat-related disparity in gonad growth and winter precipitation levels. Thus, our results provide no support for the hypothesis that greater food abundance in urban areas of Phoenix drives the habitat-related disparity in gonad growth phenology in Abert's towhees. By contrast, they suggest that differences in the predictability and magnitude of change in food availability between urban and desert areas of Phoenix contribute to the observed habitat-related disparity in gonad growth. Endocrine responsiveness of the gonads may contribute to this phenomenon as desert - but not urban - towhees had a marked plasma testosterone response to GnRH challenge.

    KW - Food abundance

    KW - Gonad cycles

    KW - Phenotypic plasticity

    KW - Reproductive neuroendocrinology

    KW - Urbanization

    UR - http://www.scopus.com/inward/record.url?scp=84961126653&partnerID=8YFLogxK

    UR - http://www.scopus.com/inward/citedby.url?scp=84961126653&partnerID=8YFLogxK

    U2 - 10.1016/j.ygcen.2016.03.013

    DO - 10.1016/j.ygcen.2016.03.013

    M3 - Article

    C2 - 26972152

    AN - SCOPUS:84961126653

    VL - 230-231

    SP - 17

    EP - 25

    JO - General and Comparative Endocrinology

    JF - General and Comparative Endocrinology

    SN - 0016-6480

    ER -