study large carnivorous mammals is not without its challenges , especially when they live in remote locations . Whilefootprintshave been used antecedently , using GPS collar combined with cameras has given researchers the opportunity to find out more about how polar bears ( Ursus maritimus ) are using land to hunt , and the impact that this will have on their health and populations as thesea icecontinues to decline .
Typically diametric bears in this region of western Hudson Bay in Canada Leigh Hunt ringed ( Pusa hispida ) and bearded seal ( Erignathus barbatus ) from the ice sheet , most often in the tardy spring and early summer when the seals are giving nascence . As the sea glass declines , polar bears are forced to spend more fourth dimension on ground hound for different prey . Researchers take 20 individual frigid bears for three hebdomad during August and September each year from 2019 to 2022 .
The Arctic marine ecosystem is have bothloss of ocean icebut also reduced extent and heaviness , leading the bear to pass more prison term on commonwealth . Current research has show that the meth - gratuitous period in Hudson Bay increase by three weeks in the full stop from 1979 - 2015 , intend the polar bears are on land for around 130 days .
A polar bear snoozes on land in Western Hudson Bay, with its collar camera attached.Image credit: Anthony Pagano
Some prediction advise that 24 percent of adult male polars would croak of famishment if that menstruum increase to 180 mean solar day .
“ As polar bear are forced on realm to begin with , it cuts into the period that they ordinarily acquire the majority of the energy they need to survive , ” say lead author Anthony Pagano , research wildlife biologist with the U.S. Geological Survey Polar Bear Research Program and former Washington State University postdoctoral researcher , in a statement seen by IFLScience . “ With increased realm usance , the first moment is that we ’ll in all likelihood see increases in starving , particularly with teenager andfemales with cubs . ”
The squad wanted to find out if the diametrical bear reduce their vigor expenditure on land during this deoxyephedrine - free period . They measure the energy expenditure , dieting , behavior , activeness , movement rate , blood chemistry , and dead body composition of eight adult females , five grownup male , four subadult female , and three subadult Male .
The team found bombastic mutant across each of the polar bears . Adult and subadult female spent around 13 percentage of their time eat up , most often consuming berries . Three individual bears spent 10 - 16 percent of their fourth dimension swim , and while two of the three institute carcasses to fee on during these swim periods , they each spent minimal time feeding from them despite the in high spirits up-and-coming demand of swimming .
This suggests that the bears struggle to feed while in the piddle , and one bear was detect via the camera footage sample to take a seal carcass back to shore , but dropped it during the swim .
Recently , apolar bear diedin Alaska after consuming a bird carcass infect with avian flu .
“ Neither strategy will allow polar bear to exist on land beyond a sure amount of time . Even those bear that were forage fall behind body weight at the same rate as those that laid down , ” enounce Charles Robbins , director of the Washington State University Bear Center and co - source of the study .
Overall despite different strategies to foraging and resting , 19 of the 20 bear studied drop off weight – between 8 and 36 kilo ( 17 - 79 Sudanese pound ) over the three - week period . On median , this indicated a weight loss of around 1 kilogram per day ( 2.2 punt ) . Only one bear gained weight after receive a all in maritime mammal carcass on land . This indicates that as ocean ice further declines and the bears spend longer on land , they will be at increase risk of starvation .
This problem is not just present in Canada . In Norway , the look-alike of a polar bear sleeping haswon an awardand work brightness to the simplification of sea ice across the populace .
The study is put out inNature Communications .
