Animals Adapting to Winter

Little River Wetland Projects hosts a monthly program, Breakfast on the Marsh. This month the speaker was Jessica Merlking. She is an urban wildlife biologist for the Indiana Fish and Wildlife division of the Indiana Department of Natural Resources. Jessica’s service area covers Elkhart, South Bend and Fort Wayne. She spoke on Winter Wildlife.  
 
Jessica said the urban wildlife biologist program was needed because people think nature happens “out there” and in fact it happens “here.” That being the case then addressing the interactions of animals and their environments and animals and humans becomes important. The Urban Biologist program was created in 2015. Jessica stated that there were 890 species of wildlife in Indiana. That keeps a small government department busy. Unlike some Western states, 97% of Indiana land is privately owned. That means much of her work is consultive. 
 
The Urban Wildlife Biologist program is guided by four pillars: 

• Living with wildlife 
• Developing/improving/acquiring urban wildlife habitat  
• Education and outreach 

• Addressing green infrastructure and sustainability  

 
Jessica then focused on the impact of winter on animal behavior. For Indiana winter changes can be seen occurring from October to March. The environmental changes include cold, snow, dormant vegetation, less daylight, and frozen water. The behavioral changes are part of a circannual rhythm (yearly changes). Behavioral changes may be seen in terms of hibernation or slowing down, breeding, and migration. The changes are tied to the changing amount of sunlight or photoperiod, changes in food sources, and climate conditions. This may also result in hormonal changes in the animals.   
 
The challenges for fish and wildlife during winter are to keep warm, find shelter, and to find food.  Strategies for getting through the season include migration, dormancy of some sort and simply “toughing it out”.   
 
There are a number of adaptations. Migration is seen in monarch butterflies, some birds, and some bats. 
 
Dormancy is another adaptation. This is a continuum from decreased activity, to hibernation, to diapause. Hibernation is unique to mammals. However, brumation is a type of inactivity that is unique to reptiles.  The speaker pointed out that bears are not true hibernators, they can awaken and become active. Jessica gave numerous examples of behavioral changes. They included:  

• Insects in diapause. They may be found in standing dead vegetation and using vegetive debris as cover. 
• Brown bats may be found in caves. Their body temperatures and heart rate drops. 
• Turtles borrow into mud. 

• Frogs hibernate in burrows, leaf litter, and logs. 
• Snakes and lizards seek refuge where they can remain dormant until spring. 
• Fish need to move to where water is warmer and well oxygenated. 

 
“Toughing it out” referred to behavioral changes that did not include any of the continuum of hibernation or dormancy. This may include communal nesting. Flying squirrels demonstrate this behavior as do racoons and skunk. Deer may exhibit behavior referred to as “deer yards” in which the crowded conditions trap the heat of the deer together. More interesting is the phenomena of beaver and muskrat sharing lodges to increase the temperature.  
 
Food hording is also seen among some animals. This includes grey and red squirrels and beavers.  Other animals will shift their diets. Coyotes are opportunistic foragers. Canada Geese may shift from eating grass to eating waste grass.   
 
The environment may have a direct impact on the animals. Snow acts as an insulator and may protect borrowing animals from the cold. A lack of snow during periods of mild winters may lead to increased deaths. A balance to this is the fact that mild winters may lead to increased litters.  
 
 Jessica had a display of furs from local animals. She asked the audience to identify each animal by the fur being held up. It was clear that many in attendance have been involved in nature for a long time. She also talked about diverse ways fur adapted to protect an animal from the cold. This included fluffing up to increase insulation, oils to protect the animal from the wet, multiple types of fur on an animal to increase insulation and increasing the amount of fur. She pointed out that coyote fur becomes two inches thicker in winter. This increased retention of body heat by 87%. 
 
Jessica provided many more examples of adaptation to the winter by mammals, birds, reptiles, and amphibians. She then talked about what humans can do to help. This included providing diverse and native plant habitats. It included “being messy” or not raking the leaves but rather leaving natural ground cover. This included combating invasive species.  
 
She also clearly recommended that we not feed wildlife in the winter. Feeding wildlife in the winter may increase the spread of disease. It may increase animal conflict. It may disrupt natural behavior that serves the animals to survive in the winter.  
 
Merkling gave examples of how we could be involved in helping wildlife. This included: 

• Hunting, fishing, and trapping. The license provides funding for wildlife programs. 
• Participate in winter bird watching. 
• Participate in winter plant identification. 
• Participate in winter track identification. 
• Use wildlife boxes. 
• Participate in salamander spotting. 

 
This was a well-researched and organized presentation. There was information for the experienced naturalist as well as the rookie naturalist. The speaker was engaging. I am never disappointed when I attend a LRWP Breakfast on the Marsh talk.