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.

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New tool to aid in dolphin strandings

Date:

May 1, 2014

Source:

Tufts University

Summary:

The cause of dolphin strandings has long been a mystery but a new study shows that clues about survival rates after release may be found in the sea mammal’s blood. The study analyzed blood work and body condition values from stranded common dolphins and compared them with survival rates after release. Responders in the field are now using the blood and health data to make better release decisions and predict survival outcomes. "The establishment of these blood values provides a window into the overall health of the dolphin," said the paper's lead author. "Now we have a way to predict which stranded dolphins have a better chance of survival after release and this can help triage care."

Continued

Lobster Farming Breakthrough: Doubling Survival Rates Among Lobster Larvae Under Farmed Conditions

ScienceDaily (Dec. 4, 2012) — Researchers in Norway have recently succeeded in doubling survival rates among lobster larvae under farmed conditions. This could boost populations of a species threatened in the wild.

In the early 1950s the Norwegian wild lobster catch amounted to about 1000 tonnes per year. Today this figure has been reduced by 95 per cent. This drastic decline has resulted in the release of juvenile lobsters as part of sea-ranching programmes.

The animals come from Norsk Hummer AS' facility at Tjeldbergodden. The company has been working for something over 20 years, together with SINTEF among others, to find the best system of farming this unique species.

Heat is the key

"In nature, development rates among lobster larvae are determined by water temperature," explains SINTEF researcher Jan Ove Evjemo. "In spite of the fact that a female lobster can produce as many as ten thousand larvae, total production along the Norwegian coast is relatively low. This is due to low water temperatures and high predation rates by other crustaceans and fish," he says.

This is why at Tjeldbergodden surplus heat from the methanol plant is used to create optimal conditions for these fastidious creatures. If all goes to plan, they will end their lives as well-nourished wild lobsters.

Read on:  http://www.sciencedaily.com/releases/2012/12/121204081144.htm