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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