Fact Sheets: Fire Effects on Wildlife/Fauna

The effect of fire on animals depends on the type of fire and type of vegetation. Fire in areas of heavy fuel loading tends to be more intense and kills more animals, especially invertebrates and micro–organisms. Generally, vertebrates are rarely killed in fires and where death does occur, it usually has a negligible effect on the species population.

Fire releases minerals into the soil which stimulates plant growth. Animals, in turn, benefit from additional minerals when they eat the new plant growth or the charcoal and ash. For example, snowshoe hares and white–tailed deer have been observed eating the charred bark or ash after a fire.

Unlike those who eat foods found only in mature forests, animals with flexible habits and diets thrive. Birds and animals which require old–growth conditions decrease.

Fire provides habitat for a wide variety of animals by creating a burn pattern (mosaic) that provides diversity in vegetation for wildlife use. The surviving elk, pronghorn antelope, deer, and similar animals will find new pathways for moving to and from water, calving areas, and summer/winter ranges.

Effects of fire on stream habitats:

Removal of streamside vegetation often increase erosion (sedimentation) which reduces available habitat and raises stream temperatures.

• Increased sedimentation has several affects on fish habitat:
  • reduces the size of spawning beds
  • deposits fine materials that smother eggs
  • prevents emergence of fry
  • increased turbidity causes fish to have trouble seeing their food
  • reducing resting places as sediment fills up pools
• Increased stream flow may crush or dislodge eggs.
• Higher stream temperatures will decrease oxygen content, increase incidence of fish disease and increase oxygen demand on fish.
• Increased nutrient loading causes increased algae production which results in a more diverse population of insect larvae. This is beneficial if toxic levels aren't reached.

Effects of fire on invertebrates:

• Invertebrates tend to decrease because the animals or their eggs are killed by flames or heat.
• Fire destroys the sap that keeps bark insects away. These insects soon move into a burned forest followed by woodpeckers and other birds, especially those who nest in cavities.
• Flying insects are attracted to heat and smoke and to killed or damaged trees. Populations of certain species may increase during and after a fire.
• Fire provides immediate food for some insect pests while destroying food that many rely on in the "long run."

BIBLIOGRAPHY

¹EFFECTS OF FIRE ON FAUNA, U.S. Department of Agriculture/Forest Service. General Technical Report WO-6, 1978.

²Fuller, Margaret, FOREST FIRES, New York: Wiley & Sons, Inc., 1991.