Ringed seals give birth in lairs carved out of packed snowdrifts. Which abiotic change may increase pup mortality?
a. reduced carbon dioxide
b. reduced temperatures
c. reduced polar bear population
d. reduced snowfall
d. reduced snowfall
To determine which abiotic change may increase pup mortality for ringed seals that give birth in lairs carved out of packed snowdrifts, we need to consider the requirements and adaptations of these seals.
Ringed seals rely on the stability and insulation provided by the packed snowdrifts to create their birthing lairs. This environment helps to protect the pups from predators, such as polar bears, while also providing a suitable temperature range for survival. With this in mind, we can evaluate the given options.
a. Reduced carbon dioxide: Carbon dioxide levels are not directly related to the survival of ringed seal pups in snowdrifts. Therefore, this option is not likely to be the correct answer.
b. Reduced temperatures: Ringed seals are adapted to cold environments, and reduced temperatures may not necessarily adversely affect the pups, as long as they remain within an optimal temperature range for survival. Therefore, this option is a possible answer.
c. Reduced polar bear population: While a reduced polar bear population could indirectly improve pup survival by decreasing the likelihood of predation, it is not directly related to changes in the abiotic factors affecting the pups' survival within the snowdrifts. Thus, this option is less relevant.
d. Reduced snowfall: This option is the most likely to increase pup mortality. Reduced snowfall would lead to shallower and less stable snowdrifts, potentially causing the lairs to collapse or exposing the pups to the harsher outside environment. This would reduce the chances of pup survival, making it the correct answer.
In conclusion, among the given options, the abiotic change that may increase pup mortality for ringed seals giving birth in lairs carved out of packed snowdrifts is d. reduced snowfall.
The correct answer is b. reduced temperatures.
Reduced temperatures can increase pup mortality for ringed seals because they rely on the insulating properties of the snowdrifts to protect their pups from harsh environmental conditions. If temperatures are reduced, the snowdrifts may become less insulated, leading to increased exposure and vulnerability of the seal pups to cold temperatures, which can result in higher mortality rates.