Navigation Links
Goose eggs may help polar bears weather climate change
Date:12/15/2008

As polar bears adapt to a warming Arctica frozen seascape that cleaves earlier each springthey may find relief in an unlikely source: snow goose eggs. New calculations show that changes in the timing of sea-ice breakup and of snow goose nesting near the western Hudson Bay could provide at least some polar bears with an alternative source of food. This new analysis appears in Polar Biology.

"Over 40 years, six subadult male bears were seen among snow goose nests, and four of them were sighted after the year 2000," says Robert Rockwell, a research associate in Ornithology at the American Museum of Natural History and a Professor of Biology at City College at City University of New York. "I've seen a subadult male eat eider duck eggs whole or press its nose against the shell, break it, and eat the contents. This is similar to a different research group's observations of polar bears eating Barnacle Goose eggs on Svalbard, an island near Norway."

Polar bears, Ursus maritimus, are listed as a threatened species under the United States' Endangered Species Act and are classified as "vulnerable with declining populations" under IUCN's Red List. Polar bears' habitat rings the Arctic south of 88˚ latitude. Most of this area is sea ice from which bears hunt seals, although the breakup of sea ice over the summer forces some bears to move north, to pack ice, or onto land. More often, it is subadult males that are pushed to these less ideal conditions, where they live, in part, off stored fat reserves.

When bears switch to the tundra in some areas, they may enter the nesting grounds of snow geese. Goose eggs and developing embryos are a highly nutritious source of food to opportunistic foragers. Although geese populations were in decline in the early 1900s, the population rebounded and expanded. There are now too many geese for the Arctic to support in the summer, mainly because their over-wintering habitat has increased to cover the northern plains, where they eat waste corn and forage in rice fields.

Polar bear and snow geese populations come into contact in the Hudson Bay. Here, some bears routinely live on land for 4-5 months of the year, subsisting on fat reserves. The new research shows that the effects of climate change will bring additional sources of food as the movement of both populations begins earlier each spring. Rockwell and his graduate student, Linda Gormezano, calculated that the rate of change in ice breakup is, on average, 0.72 days earlier each year, and that hatching time is also moving forward by 0.16 days each year. Current trends indicate that the arrival of polar bears will overlap the mean hatching period in 3.6 years, and egg consumption could become a routine, reliable option. At this point, a bear would need to consume the eggs of 43 nests to replace the energy gained from the average day of hunting seals. But within a decade, because timing changes would put bears in contact with even more nests with younger embryos (younger embryos are more nutritious), a bear would only need to consume the eggs of 34 nests to get the same amount of energy.

"Polar bears went through the Eemian 125,000 years ago, when sea level was 4-6 meters higher than it is now and trees lived above the Arctic Circle. They've been through warming before," says Rockwell. "I just read a piece in Natural History with a quote from Ilkoo Angutikjuak that sums this up: 'If the changes continuethe animals will adapt. I've heard that because they depend on sea ice, polar bears will go extinct, but I don't believe itPolar bears might get skinnier and some might die, but I don't think they will go extinct.'"


'/>"/>

Contact: Kristin Elise Phillips
kphillips@amnh.org
212-496-3419
American Museum of Natural History
Source:Eurekalert  

Related biology news :

1. Drug commonly used to treat bipolar disorder dramatically increases lifespan in worms
2. Half time in the International Polar Year 2007-2008
3. Arctic climate models playing key role in polar bear decision
4. NASA expert to address Earths vanishing polar ice, April 10, at UD
5. Vanishing polar ice talk to be Webcast live, April 10
6. Federal polar bear research critically flawed, says study in INFORMS journal
7. Rare Antarctic fossils reveal extinction of tundra before full polar climate arrived
8. Dartmouth awarded NSF grant for new polar sciences, engineering grad program
9. Largest study of its kind implicates gene abnormalities in bipolar disorder
10. RV Polarstern on its way to East Siberian Sea
11. Experts meet on need for new rules to govern worlds fragile polar regions
Post Your Comments:
*Name:
*Comment:
*Email:
Related Image:
Goose eggs may help polar bears weather climate change
(Date:6/20/2016)... June 20, 2016 Securus Technologies, a ... solutions for public safety, investigation, corrections and monitoring ... involved, it has secured the final acceptance by ... for Managed Access Systems (MAS) installed. Furthermore, Securus ... to be installed by October, 2016. MAS distinguishes ...
(Date:6/9/2016)... 2016 Paris Police Prefecture ... security solution to ensure the safety of people and operations ... the major tournament Teleste, an international technology group ... announced today that its video security solution will be utilised ... up public safety across the country. The system roll-out is ...
(Date:6/2/2016)... YORK , June 2, 2016   The Weather ... is announcing Watson Ads, an industry-first capability in which consumers ... by being able to ask questions via voice or text ... Marketers have long sought ... the consumer, that can be personal, relevant and valuable; and ...
Breaking Biology News(10 mins):
(Date:6/24/2016)... ... June 24, 2016 , ... Researchers at the Universita Politecnica delle Marche in ... peritoneal or pleural mesothelioma. Their findings are the subject of a new article on ... biomarkers are signposts in the blood, lung fluid or tissue of mesothelioma patients that ...
(Date:6/23/2016)... , June 23, 2016 /PRNewswire/ - FACIT ... Ontario biotechnology company, Propellon Therapeutics ... development and commercialization of a portfolio of first-in-class ... Epigenetic targets such as WDR5 represent an exciting ... significantly in precision medicine for cancer patients. Substantial ...
(Date:6/23/2016)... , June 23, 2016  The Prostate Cancer Foundation (PCF) ... precise treatments and faster cures for prostate cancer. Members of the Class of ... 15 countries. Read More About the Class of 2016 ... ... ...
(Date:6/23/2016)... (PRWEB) , ... June 23, 2016 , ... STACS DNA ... Technical Leader at the Arkansas State Crime Laboratory, has joined STACS DNA as a ... STACS DNA team,” said Jocelyn Tremblay, President and COO of STACS DNA. “In further ...
Breaking Biology Technology: