Sentences with phrase «ringed seal pupping»

This paper does not document starving or dying bears but merely found some (5/9) that lost weight when they should have been gaining, given that early April is the start of the ringed seal pupping season (Smith 1987) and the intensive spring feeding period for polar bears (Stirling et al. 1981).

The bears there have had to leave the sea ice behind, along with their normal diet of ringed seal pups, earlier in the year because of warming.

As Arctic sea ice melts earlier and freezes later each year, polar bears have a limited amount of time to hunt their historically preferred prey — ringed seal pups — and must spend more time on land.

16 To illustrate the importance of ringed seal pups they wrote, «In the mid-1970s and again in the mid-1980s, ringed seal pup productivity plummeted by 80 % or more for 2 — 3 years....

In contrast during the most recent decade with more open water, the number of ringed seal pups in the western Hudson Bay tripled relative to the 1990s.4 With more seal pups the polar bears» body condition also improved.

Deep snow over birthing lairs (diagram above, see also Lydersen and Gjerz 1986) means ringed seal pups are well protected from polar bear predation — the seals do well but the polar bears do not.

Unfortunately, several bad years for ringed seal pup survival caused by shallow snow depth in spring means that in subsequent years, fewer seal pups will be produced for polar bears to eat — polar bears end up suffering after a bit of a lag.

The question is, why were Southern Beaufort Sea polar bears off Prudhoe Bay (see map of the study area below), still hunting and capturing only adult and subadult ringed seals from sea ice leads when newborn ringed seal pups and their mothers should have been plentiful and relatively easily available in their birth lairs on the sea ice (see below)?

If that occurs, the premature removal of protection offered by subnivean birth lairs may expose young ringed seal pups to high levels of predation, which may negatively affect populations of ringed seals and the polar bears that depend on them for food.

The unpublished improvements of polar bear body condition during the 2000s corresponds well with published reports that since the heavy ice years of the early 1990s reduced ringed seal body condition and reproduction, ringed seal pups tripled during subsequent lighter ice years of the 2000s.

Not exact matches

Shallow snow cover over birthing lairs, which are built against pressure ridges as shown in the diagram above (considered to be less than 25 - 32 cm over the lair, or less than 20 cm over flat ice), 1 can mean the snow caves are easier for polar bears to break into (and consume the pup)-- that's good news for polar bears (in the short term) but bad news for ringed seals.

It appears that pregnant ringed seals abandon traditional near shore pupping areas because the ice is too thick to maintain breathing holes.

Snow depth over sea ice in spring affects the hunting success of polar bears on ringed seal (Phoca hispida) pups, but the relationship is more complicated than you might think and there is less data on this phenomenon than you would believe.