Climate Changes Poses Risk to Antarctic Fur Seal Pups
26.03.2012 - Flora & Fauna, Antarctic
A study published in the journal Physiological and Biochemical Zoology has found that changing weather conditions predicted by climate models might affect the metabolic rates and thus the survival rates of fur seal pups. Windier and wetter conditions predicted in the Antarctic in the coming years could force young seals to devote more energy to thermoregualtion, which may leave less energy available for growth and development.
A team led by Dr. Birgitte McDonald from the University of California, Santa Cruz, collected data on how much energy seal pups get from their mothers’ milk and how they use it. Looking at a sample population of 48 seal pups, data the team colleted found that in newborn pups, about 60% of the milk energy they get from their mothers goes to growth; however this percentage declines to 25% by the age of one month, as their mothers begin to periodically leave the seal pups alone to forage on their own.
While the biggest predictor of a seal pup’s growth rate was the amount of milk they ingested, other factors important in determining how a pup’s energy is used include the size and condition of the pup at birth as well as environmental conditions like weather. If climate models – which predict higher precipitation and more wind – are correct, this might make it difficult for seal pups to stay warm, as wind and water drain heat from animals.
As they lack the insulation of adult seals, pups are particularly susceptible to heat loss. The researchers found that when wind chills were higher, pups were required to devote more energy to maintain the metabolism and body temperature. This could have a negative impact on pups developing foraging skills, or force them to wean at a lower body mass, which in turn could have a negative impact on survival rates.