Polar bears hunt for ringed seals by waiting for them to emerge from breathing holes in the ice. Which abiotic change may decrease a polar bear’s ability to hunt?
a. increased ice cover
b. increased temperatures
c. increased competition
d. increased seal population
b. increased temperatures
The correct answer is b. increased temperatures.
Polar bears rely on the presence of ice to hunt for ringed seals. They wait near breathing holes in the ice, from which seals emerge to breathe. If temperatures increase, it can lead to melting of the ice, resulting in reduced ice cover. This can make it more difficult for polar bears to locate and hunt seals. Therefore, increased temperatures can decrease a polar bear's ability to hunt.
To determine which abiotic change may decrease a polar bear's ability to hunt, let's analyze each option:
a. Increased ice cover: This would likely have a positive effect on polar bears' hunting ability since more ice cover means more breathing holes for seals, which in turn provides more opportunities for the polar bears to catch them. Therefore, this option is unlikely to be the correct answer.
b. Increased temperatures: This option could potentially decrease a polar bear's ability to hunt. As temperatures increase, the ice will melt, reducing the amount of available ice cover and potential seals. With less ice, polar bears have fewer opportunities to wait for seals to emerge from breathing holes. Therefore, increased temperatures could adversely affect a polar bear's hunting ability.
c. Increased competition: While increased competition among polar bears may impact an individual bear's success in hunting, it does not directly relate to abiotic changes. Competing for resources like breathing holes and seals is a biotic factor (related to living organisms) rather than an abiotic factor (related to non-living factors such as temperature or ice cover). Therefore, this option is unlikely to be the correct answer.
d. Increased seal population: An increased seal population would actually benefit a polar bear's ability to hunt. More seals mean a greater availability of prey, providing more opportunities for successful hunts. So, this option is unlikely to decrease a polar bear's hunting ability.
Based on the above analysis, the correct answer is likely to be option b, increased temperatures. However, it's essential to remember that this is not a conclusive answer but rather a probable explanation based on the given information.