Livestock Grazing Harms Native Bees

There are thousands of native bee specie and they are critical pollinators. They are declining in part due to livestock impacts.

Most people know that bees are critical for the pollination of shrubs, trees, and flowers. Though honey bees are often used for pollination of agricultural crops, native bees are essential for pollination of native vegetation. Bees pollinate 80% of all flowering plants. Most native bees live in the soil and in rotten logs.

Wasp-like bee on goldenrod. Photo By Ralph Maughan.

High severity fire tends to increase native bees, in part, because wildfires create more downed wood nest habitat, and there is often an increase in flowers after a burn.

High severity wildfires create both an abundance of wildflowers and dead snags that provide habitat for native bees.

There are hundreds of native bees living across the West. For instance, Oregon has more than 700 native bee species. Some are so rare that they are candidates for listing under the Endangered Species Act.

Cattle grazing Agua Fria NM, AZ. Many native bees live in the soil, and heavy livestock use can compact soils, impacting bee populations. Photo by George Wuerthner

What is not recognized by most people is that livestock grazing has a significant impact on native bees.

Native bees like the bumble bee are critical pollinators of wild flowers.

In desert regions, soil compaction from livestock hooves can collapse tunnels. However, the most significant impact is from forage competition. Livestock eat many of the flowering plants that bees depend upon for food. Cattle, along with native herbivores like elk, consume 60% or more of the same flowering species that bees depend upon for food.

Cattle damage riparian areas that harbor critical bee forage plants like willows. Photo by George Wuerthner

But what may be surprising to some is that many bee species focus on shrubs, some exclusively. In particular, shrubs like nine bark, willow, and wax currant are particularly important to bees in early spring. In one study, shrubs made up 7% of the available blooms, but made up 57% of the plants visited by bees.

Cows trash riparian area on West Fork Blacktail Creek Beaverhead Deerlodge NF, Montana. Photo by George Wuerthner

l bee habitat. For example, many bees depend on willow flowers found along riparian areas. Since livestock is one of the major factors in the loss of western riparian habitat where willows are most abundant, this loss can lead to local bee population declines.

In all my years of reviewing federal grazing allotment permits, I’ve never seen any range conservationist discuss livestock impacts on native bees, but domestic livestock can and do pose a threat to these insects, which are critical for pollination of both crops as well as native flowering plants. I presume the loss of flowering plants due to livestock grazing likely harms other species like hummingbirds.

Livestock grazing was terminated on hundreds of thousands of acres in the Boulder White Cloud Mountains of Idaho by grazing permit retirement. Photo by George Wuerthner

Once more, the ideal solution is to close livestock grazing allotments on public lands. The most effective way is through the Voluntary Grazing Permit Retirement Act, which has been introduced into Congress repeatedly. The retirement of grazing privileges has also been used in local situations, such as the Boulder White Cloud Wilderness legislation, and elsewhere to remove domestic livestock from public lands.