Should We Feed Wildlife During Extremely Cold Weather?
It’s early January 2020 and, according to the weather forecast, western Canada is about to experience record cold temperatures. For those that care about wildlife, it’s natural to be concerned for them with this sort of winter weather looming on the horizon. Within your concern, you may be wondering if humans should feed wildlife to help them through extreme cold winter conditions.
Well, to answer this question, let’s first look at how different kinds of wildlife are adapted to survive extreme cold.
Extremely low temperatures can negatively affect wildlife. They can get impaired from frost bite and wildlife can die from hypothermia just like people. The most effective adaption to survive extreme low winter temperatures is to simply to avoid being around it when the cold arrives. Waterfowl and shorebirds make epic journeys to avoid the inhospitable temperatures of winter. The black brant, for example, can migrate up to 4800 kms non-stop from Alaska to Baja California in 60 to 72 hours.
Wildlife will also change their behavior by moving to different habitats to guard against the effects of cold temperatures. Moving from exposed open grasslands into old growth forests, migrating from higher elevations to lower elevations, moving from windswept slopes to leeward slopes and moving from shaded hillsides to sunny slopes are all examples of changes wildlife make to avoid the cold.
Some wildlife will go into a state of torpor when it gets cold. When in torpor, an animal’s body slows itself down and focuses on maintaining its internal core body temperature. Torpor is thought to be an involuntary reaction of some wildlife to cold temperatures. Some wildlife species can go in and out of torpor at any time of the year or at any time of the day depending on the conditions. Torpor is an important cold survival strategy for birds, bats and rodents.
Hibernation is another way some wildlife species survive extreme cold. Hibernation is like torpor in the sense that the animals go into a state of reduced metabolic activity and experience a lower body temperature and lower breathing rates to conserve energy and maintain their core body temperature. Unlike torpor, hibernation is a voluntary reaction triggered by changes in hormones that is linked to the diminishing length of the days as winter approaches. Hibernation usually last long periods of time, whereas torpor is often short in duration.
Some mammals hibernate but reptiles bruminate. The main differences between mammal hibernation and bruminating reptiles are that reptiles need to absorb water while they are in this state; some species of reptiles can survive with minimal oxygen and reptile’s “sleep” can be punctuated by periods of normal activity.
Some wildlife uniquely exchange heat between the warm blood moving away from the heart with the cooler blood moving back toward the heart. This heat exchange system ensures warm blood always enters the heart, which helps save energy. Transferring heat in the blood like this is the reason why the feet of ducks and geese and seal’s flippers don’t freeze.
Whether wildlife migrate, hibernate or stay put for the winter, they all build up their fat reserves prior to winter. The bufflehead can store up to 25% of its body weight in fat prior to its migration. Migratory birds need enough fat to last them until them reach the warm climates where they will find good quality food. Most food that ungulates eat in the winter is low in quality so their fat reserves must last them until spring when better food comes along.
As winter approaches, the fur and hair of mammals and the plumage of birds will thicken so that more air can be trapped close to their bodies. Animals such as bison develop thicker skin prior to winter. Their thicker skin stores energy that the bison’s can use later in the winter, and their thick skin acts as another layer of insulation.
Some wildlife species have a high level of adipose fat, which helps them survive extreme cold temperatures. Adipose fat, also known as brown fat, is a type of fat that can provide energy to the body without the need of any muscle action. This makes adipose fat a more energy-efficient type of fat than white fat. The blubber of a seal is all brown fat.
Wildlife in northern latitudes have evolved to have larger bodies and shorter appendages compared to species in lower latitudes. A larger bodied mammal has less surface area relative to its body mass than a smaller-bodied animal. This means it is easier for large-bodied animals to maintain their core body temperature in cold temperatures when the quality of their food is not so great.
Moose are a heat intolerant species and their large body mass is a survival adaption to living in cold climates. Moose aren’t impacted as much by the cold as they are by warm weather. In one study in Minnesota, the survival of moose was reported to be lower after a warm winter.
Many ungulate species go into a state of reduced metabolic activity during the winter to conserve their stores of fat and protein. Ungulates don’t become lethargic like the species that go into torpor, but they do mellow out for the winter. Increased harassment from predators and humans during the winter can be detrimental for ungulates trying to live the mellow-yellow lifestyle. However, deep snow will claim more ungulate lives than cold temperatures. Snow depth approaching 40 cm deep will cause most ungulates to burn more of their energy reserves.
For ungulates, it’s not the quality of their winter forage that guarantees their winter survival. Rather it is their body mass going into winter that is most important to their survival. For female ungulates and their offspring, the quality of food in their spring and early summer habitats determines how big they will be heading into winter. For males, the quality of forage in the habitats they are living in right after the rut determines how much mass they can put back on their bodies before winter.
Winter is a time some people might feel sorry for wildlife because they think the animals are cold and starving. This empathy will often compel people to feed wildlife in the winter. For some wildlife, especially ungulates, artificial feeding can be counter productive to the way their bodies are programed to survive winter. Intermittent or improper artificial feeding increases ungulates risk of dying before winter is over because it can cause them to use up their internal fat reserves faster than normal.
The fallacy of non-regulated wildlife feeding programs lies in the misconception that just because people can see animals eating the supplemental food doesn’t mean they are all getting the necessary number of calories each day to survive the winter. When left to their own ways, most ungulates coast along through the winter judiciously using their stores of energy even when the temperatures get extremely cold.
For many wildlife species, dense-canopied old growth forests are the habitats that will give them refuge from severe winter conditions when the snow is deep, the temperatures are extremely cold, and when the presence of predators or humans is stressing them out.
So, to answer the question posed at the start of this article – no, humans do not need to feed wildlife to help them survive extremely cold temperatures. Winter is tough for wildlife, but they are adapted to survive most of what mother natures dishes out. Populations eb and flow from year to year based on the winter severity, but generally wildlife populations endure most winters just fine – even the winters with extremely cold temperatures.
Whether you are hunter who is concerned about game animals like elk, moose and deer or whether you are concerned for all species of wildlife, you can take solace in the fact the winter of 2020 is not wildlife’s first rodeo.
As a hunter conservationist, understanding that wildlife must persevere through winter is not a source of concern for me but rather it is a source fascination and appreciation for the resiliency and power of nature.
If you want to help wildlife have the best chance of surviving winter, the best thing you can do is get involved in protecting your public lands so that the most critical winter habitats are looked after in a way that puts the needs of wildlife first.
Cover Image Copyright © Robert Kelsey / Adobe Stock