How Much Does a Squirrel’s Fur Change in the Winter?
If you’re wondering how a squirrel’s fur changes in the winter, read this article! It will explain why Red squirrels lose body heat and develop a rusty red look, while Gray squirrels keep more body fat and shiver less. This winter change in fur pattern is due to two factors: the amount of fat stored on a squirrel’s body and its shivering.
Gray squirrels develop a rusty red appearance
Gray squirrels have a rusty red appearance in the fall and winter. Their undersides are white or rusty and their ears are reddish-orange. They have two breeding seasons each year – one from late winter to early spring and one from midsummer to late fall. Mating is conducted during one of the two breeding seasons. The female gives birth to one to nine young, depending on the season. During the breeding season, multiple males compete for the female. The dominant male mates with the female. Young are born hairless and blind and dependent on their mothers for about eight weeks. They remain close to their mothers until they are about twelve weeks old and are ready to leave the nest.
Red squirrels store fat on their bodies
In the autumn, red squirrels stored their food in one location, such as the tree where they built their nest. As the winter months approached, they increased their food intake and stored fat on their bodies. This increase in body fat helps keep them warm. They can gain up to 50% of their body weight in this way. This behavior has many implications for human health. However, more research is needed to determine if red squirrels store fat on their bodies during winter.
Gray squirrels shiver to keep warm
Why do gray squirrels shiver in the winter? The short days of winter decrease the activity level of gray squirrels, causing them to shiver to maintain body heat. The vibrations from the shivering process also help maintain body heat. Unlike ground squirrels that hibernate during the cold months, gray squirrels shiver to maintain body heat. These are just two of the many reasons why gray squirrels shiver in the winter.
Rock squirrels lose less body heat
The coat of the rock squirrels is adapted for absorbing more solar heat during the winter, while its coat structure helps it produce more metabolic energy. The rock squirrel’s coat structure adjusts to changes in wind speed and temperature, so it can capture more solar heat in the winter. This thermal gain is possible because the rock squirrel’s coat is highly resistant to solar radiation. Although the color of the rock squirrel’s coat is the same as its summer coat, the thermal resistance is greatly increased.
Melanistic squirrels have lower basal metabolic rate
A recent study has revealed that melanistic squirrels lose less body heat during the winter than their gray counterparts. The study also found that the melanistic morphs have lower basal metabolic rates in the winter than the grey morphs. This difference may be due to the fact that melanistic squirrels are found in northern regions, where their annual temperatures are relatively cool. However, these findings are not definitive. More research is needed to determine whether melanistic and grey morphs share the same genetic differences.
Richardson’s ground squirrel arouses during hibernation
The reproductive phenology of Richardson’s ground squirrels was impacted by a 2012 heatwave, and the number of infertile males in the following year was comparable to other years. The heatwave resulted in early emergence of females and insufficient time for males to develop reproductive organs. The lack of adequate time to develop reproductive organs in males could explain the unusually late emergence of females in recent years.
Richardson’s ground squirrel mates only twice a year
Despite its small size, the Richardson’s ground squirrel can cause extensive damage to agricultural crops. Average populations can consume as much as 90 pounds of forage per acre in a month. In addition, their burrowing habits can destroy farm equipment and cause significant water loss in irrigated fields. Unfortunately, rodenticides are ineffective against Richardson’s ground squirrels.
Jessica Watson is a PHD holder from the University of Washington. She studied behavior and interaction between squirrels and has presented her research in several wildlife conferences including TWS Annual Conference in Winnipeg.