Navigation Links
Polar bears can't eat geese into extinction
Date:11/4/2010

As the Arctic warms, a new cache of resourcessnow goose eggsmay help sustain the polar bear population for the foreseeable future. In a new study published in an early online edition of Oikos, researchers affiliated with the Museum show that even large numbers of hungry bears repeatedly raiding nests over many years would have a difficult time eliminating all of the geese because of a mismatch in the timing of bear arrival on shore and goose egg incubation.

"There have been statements in popular literature indicating that polar bears can extirpate snow geese quickly once they start to eat eggs," says Robert Rockwell, a research associate in the Division of Vertebrate Zoology at the Museum and a professor at the City University of New York. "However, there will always be the occasional mismatch in the overlap between the onshore arrival of bears and the incubation period of the geese. Even if the bears eat every egg during each year of complete 'match,' our model shows that periodic years of mismatch will provide windows of successful goose reproduction that will partially offset predation effects."

In the last few years, work along the Cape Churchill Peninsula of western Hudson Bay by Rockwell and colleagues has suggested that polar bears are not as hamstrung by their environment as many biologists believe. One new nutritional option for polar bears is the bounty of goose eggs which had previously hatched into goslings that were gone by the time bears came ashore. In recent years, 'early' bears have left breaking sea ice to come ashore and consume eggs. In fact, the earlier the bears come ashore, the better: eggs are higher in nutrients when the embryo is younger.

In the new Oikos paper, Rockwell and coauthors Linda Gormezano (also affiliated with the Museum) and David Koons (a researcher at Utah State University in Logan) simulated the timing of events during the Arctic spring: the break-up of sea ice, the movement of bears onto shore, the migration of geese to the North, and the laying of eggs. Results from the computer model show that the mismatch of timing is something that both the bears and geese can use to their advantage. The timing of geese migration is primarily based on photoperiod (the amount of light in 24 hours), which will not change as quickly as polar bear movements, which are based on the melting of sea ice.

Results show that the advance in mean overlap of the two species gives an advantage to polar bears. But increased variability, also the result of global climate change, leads to an increased mismatch that is good news for snow geese.

"Mismatch is often thought to be bad, but in this case periodic mismatch is good because it keeps geese from going extinct and allows polar bears to eat," says Rockwell. "Are polar bears adaptable? Of course. This could be a nice stable system. The geese aren't going to go away, and they are a nutrient resource for the bears."


'/>"/>

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

Related biology news :

1. Study of polar dinosaur migration questions whether dinosaurs were truly the first great migrators
2. Polarized light guides cholera-carrying midges that contaminate water supplies
3. Bipolar disorder genes, pathways identified by Indiana University neuroscientists
4. Goose eggs may help polar bears weather climate change
5. Polarstern expedition LOHAFEX can be conducted
6. Polar research reveals new evidence of global environmental change
7. Research plane Polar 5 on Arctic campaign
8. New light on bipolar treatment drugs
9. Research vessel Polarstern starts 24th Arctic season
10. New tracking approach will help protect polar bears
11. ESHRE launches international study of polar body screening
Post Your Comments:
*Name:
*Comment:
*Email:
Related Image:
Polar bears can't eat geese into extinction
(Date:5/3/2016)... , May 3, 2016  Neurotechnology, a ... the MegaMatcher Automated Biometric Identification System (ABIS) ... large-scale multi-biometric projects. MegaMatcher ABIS can process multiple ... using any combination of fingerprint, face or iris ... MegaMatcher SDK and MegaMatcher Accelerator , ...
(Date:4/28/2016)... 2016 First quarter 2016:   ... with the first quarter of 2015 The gross margin ... (loss: 18.8) and the operating margin was 40% (-13) ... Cash flow from operations was SEK 249.9 M (21.2) , ... unchanged, SEK 7,000-8,500 M. The operating margin for 2016 ...
(Date:4/26/2016)... 27, 2016 Research and ... Biometrics Market 2016-2020"  report to their offering.  , ... The analysts forecast the global multimodal biometrics ... during the period 2016-2020.  Multimodal biometrics ... such as the healthcare, BFSI, transportation, automotive, and ...
Breaking Biology News(10 mins):
(Date:6/27/2016)... 27, 2016  Global demand for enzymes is ... 2020 to $7.2 billion.  This market includes enzymes ... products, biofuel production, animal feed, and other markets) ... biocatalysts). Food and beverages will remain the largest ... consumption of products containing enzymes in developing regions.  ...
(Date:6/27/2016)... ... June 27, 2016 , ... Cancer experts from ... believe could be a new and helpful biomarker for malignant pleural mesothelioma. Surviving ... to read it now. , Biomarkers are components in the blood, tissue ...
(Date:6/27/2016)... ... June 27, 2016 , ... ... will join the faculty of the University of North Carolina Kenan-Flagler Business ... strategy and entrepreneurship at UNC Kenan-Flagler, with a focus on the school’s international ...
(Date:6/24/2016)... 24, 2016  Regular discussions on a range of subjects ... the two entities said Poloz. Speaking at a ... , he pointed to the country,s inflation target, which ... "In certain areas ... have common economic goals, why not sit down and address ...
Breaking Biology Technology: