Threats to Birds - Leafy Spurge (Euphorbia esula)

Photo: USGS

Overview

Introduced in 1827 from Eurasia to Massachusetts with a seed delivery, leafy spurge blazed west to California. Leafy spurge now infests more than five million acres of rangeland and farmland in 35 states and the prairie provinces of Canada, doubling in acreage every ten years since the early 1900s. The states of Montana, South Dakota, North Dakota, Nebraska, and Wyoming are especially hard hit. Infestations are most severe on undisturbed lands. This weed crowds out native grasses, reducing species diversity and habitat for wildlife. With its long taproot, it usurps available moisture and nutrients, especially in arid regions of the West where it is most aggressive. Its extensive root system allows it to recover quickly from physical and most chemical damage. Leafy spurge also releases plant toxins that prevent the growth of other plants beneath it, and it has extraordinary seed dispersal ability. Leafy spurge has little value to birds. It is now found throughout the world with the exception of Australia.

Description

Grows about 3 feet tall and has an extensive root system extending up to 20 feet. Stems are erect and thickly clustered. Leaves are narrow, alternate, and 1 - 4 inches long. Flowers are yellowish-green in numerous small clusters; petals are fused into a cup-like structure enclosed by paired, heart-shaped green-yellow bracts. The entire plant produces a milky latex which is poisonous to some animals and can cause irritation, blotching, blisters, and swelling in sensitive people.

Birds Affected

Especially impacting Sage Grouse and other grassland birds including Grasshopper Sparrow and Savannah Sparrow.

Control

Control efforts have included mowing, burning, plowing, chemical herbicides, insect bio-controls, grazing goats and sheep. Hand-pulling and cutting are ineffective and could actually increase the spread. Several species of insects, notably a few root-eating beetles, are helping to control along with goats and sheep. TEAM Leafy Spurge, a division of the U.S. Department of Agriculture, is researching more ecologically based integrated pest management strategies that landowners and land managers can use to achieve effective, affordable leafy spurge control.