• Arctic seabirds are less heat tolerant,

    From ScienceDaily@1:317/3 to All on Wed Jul 7 21:30:38 2021
    Arctic seabirds are less heat tolerant, more vulnerable to climate
    change
    Arctic species poorly adapted for coping with rising temperatures as the Arctic continues to warm

    Date:
    July 7, 2021
    Source:
    McGill University
    Summary:
    The Arctic is warming at approximately twice the global rate. A new
    study finds that cold-adapted Arctic species, like the thick-billed
    murre, are especially vulnerable to heat stress caused by climate
    change.



    FULL STORY ==========================================================================
    The Arctic is warming at approximately twice the global rate. A new study
    led by researchers from McGill University finds that cold-adapted Arctic species, like the thick-billed murre, are especially vulnerable to heat
    stress caused by climate change.


    ==========================================================================
    "We discovered that murres have the lowest cooling efficiency ever
    reported in birds, which means they have an extremely poor ability to
    dissipate or lose heat," says lead author Emily Choy, a Postdoctoral
    Fellow in the Natural Resource Sciences Department at McGill University.

    Following reports of the seabirds dying in their nests on sunny days,
    the researchers trekked the cliffs of Coast Island in northern Hudson
    Bay to study a colony of 30,000 breeding pairs. They put the birds'
    heat tolerance to the test and found that the animals showed signs of
    stress at temperatures as low as 21C.

    Until now few studies have explored the direct effects of warming
    temperatures on Arctic wildlife. The study, published in Journal of Experimental Biology, is the first to examine heat stress in large
    Arctic seabirds.

    Bigger not always better By measuring breathing rates and water loss as
    the murres were subjected to increasing temperatures, the researchers
    found that larger birds were more sensitive to heat stress than smaller
    birds.

    Weighing up to one kilogram, murres have a very high metabolic rate
    relative to their size, meaning when they pant or flap their wings to cool
    off, they expend a very high amount of energy, producing even more heat.

    These seabirds nest in dense colonies, often breeding shoulder to
    shoulder along the narrow ledges of cliffs. Male and female birds
    take turns nesting on 12-hour shifts. According to the researchers, the thick-billed murres' limited heat tolerance may explain their mortalities
    on warm weather days.

    "Overheating is an important and understudied effect of climate
    change on Arctic wildlife," says Choy. "Murres and potentially
    other Arctic species are poorly adapted for coping with warming
    temperatures, which is important as the Arctic continues to warm." ========================================================================== Story Source: Materials provided by McGill_University. Note: Content
    may be edited for style and length.


    ========================================================================== Journal Reference:
    1. Emily S. Choy, Ryan S. O'Connor, H. Grant Gilchrist, Anna
    L. Hargreaves,
    Oliver P. Love, Franc,ois Ve'zina, Kyle H. Elliott. Limited heat
    tolerance in a cold-adapted seabird: implications of a warming
    Arctic.

    Journal of Experimental Biology, 2021; 224 (13) DOI:
    10.1242/jeb.242168 ==========================================================================

    Link to news story: https://www.sciencedaily.com/releases/2021/07/210707133024.htm

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