Friday 8 February 2019

Pika survival rates dry up with low moisture

February 4, 2019 by Zoe Gentes, Ecological Society of America
Although it has been ranked as the cutest creature in US National Parks, the American pika is tough, at home in loose alpine rocks in windswept mountain regions. Related to rabbits and hares, pikas live in cold, wet climates and high terrain, spending winters in snowy homes living off of stored grasses and other forage they have gathered, only venturing out for more when weather permits.
Unfortunately for these adorable little mammals, they have a fairly severe sensitivity to overheating—they die if they are exposed to temperatures above 77°F for longer than six hours. Due to their lethal threshold for heat stress, pikas are indicators of how changing environmental conditions can affect mountain-dwelling species.
It might appear that the danger for pikas lies mostly with increasing temperatures and summer heat extremes. In some cases, however, decreased snowpack and lower air moisture may threaten pikas more.
Vapor-pressure deficit (VPD) can be likened to air's aridity—higher VPD is drier. VPD governs the growth of many plants that pikas depend on for food, and controls cloud formation and snow. If VPD becomes higher, it will inhibit the growth of plants that pikas depend on for food, and will shrink snow packs which they use for insulation against extreme temperature. The snowpack also stores water until springtime, when it provides water for forage plants that pikas eat.

No comments:

Post a Comment

You only need to enter your comment once! Comments will appear once they have been moderated. This is so as to stop the would-be comedian who has been spamming the comments here with inane and often offensive remarks. You know who you are!

Related Posts with Thumbnails