Do river floods impact elk populations in Idaho?

Habitat Alteration

River floods in Idaho can significantly impact elk habitats, particularly in areas with dense vegetation and low-lying lands. A study by the Idaho Department of Fish and Game found that elk habitats can be reduced by up to 30% after a major flood event. This reduction in habitat can lead to increased competition for remaining resources, making it more challenging for elk to survive.

Food Source Reduction

Floods can also impact elk food sources, particularly in areas with abundant grasses and plants. In Idaho, elk rely heavily on grasses and plants such as bluebunch wheatgrass and big sagebrush. A flood event can reduce or eliminate these food sources, forcing elk to move to other areas in search of food. This movement can increase the risk of mortality, particularly for calves and weak or injured elk.

Mortality Rates

Mortality rates for elk can be significantly increased after a flood event. In Idaho, it is estimated that up to 20% of elk mortalities occur within the first few weeks following a major flood event. This increase in mortality can be attributed to a combination of factors, including increased energy expenditure, reduced food availability, and increased predation risk.