HORNED LARKS
Identification
Horned larks ( Eremophila alpestris ) are ground-dwelling birds that are slightly larger than house sparrows. They are brown, with a yellowish face, black breast, black "whiskers," and two small black "horns." Their song is a high-pitched, sustained call given from the ground or high in the air.
Range
Horned larks breed widely throughout North America , from northern Alaska to southern Mexico . They retreat from northern latitudes and higher elevations in autumn, wintering from southern Canada southward across the United States and Mexico .
Habitat
In certain parts of California the horned lark is a serious crop pest. The damage occurs mostly in the interior valleys from Sacramento south to the Imperial Valley , and along the coast from San Francisco south to San Diego . Damage also occurs to crops in the Mojave Desert region and other desert valleys in southeastern California . Horned larks do not usually cause problems in other areas where they are present. Resident populations of horned larks are found in the stubble, grass, and fallow lands near cultivated fields. The majority of the birds live in the wide expanses of the deserts, foothills, and dry grasslands that encircle the farming areas.
Food Habits
The food of the horned lark consists largely of seeds picked up from the ground. Analysis of the food items contained in the stomachs of 259 horned larks collected in California showed the birds' annual food to consist of about 91% plant and 9% animal matter. Seeds of weeds and wild grasses averaged 51% of the total food.
General Biology, Reproduction, and Behavior
Large numbers of horned larks leave agricultural areas in the spring and migrate into foothills, dry grasslands, and desert, where nesting and rearing of the young takes place. Nests are depressions in the ground, heavily lined with grasses, weed stems, and flower heads. Usually 3 to 4 eggs are laid with an incubation period of 11 to 14 days. The nesting season extends from March to June with 2 or 3 broods commonly raised each year. In June and July the juvenile birds move from the open country into the general farming areas. Bird numbers increase throughout the remainder of the summer and early fall as additional bands move in from the foothills.
Damage and Damage Identification
Vegetable crops damaged by horned larks include beets, broccoli, carrots, lettuce, peas, spinach, and tomatoes. Other field and truck crops damaged are alfalfa, grain, sugar beets, cantaloupes, and watermelons. Flower plantlets of many varieties and commercial seed plantings are frequently damaged by horned larks.
Damage usually begins as the first plants break through the surface of the soil. Horned larks nip off parts of the tender plantlets. In the case of small seedlings such as lettuce, they may pull up the entire plant. If the seedlings are not destroyed in the early stage of growth, the secondary leaflets and adventitious buds are rapidly consumed as they appear. In irrigated fields, where the plants grow rapidly, the damage is usually of short duration. It is normally curtailed when the seedlings reach a height of 3 to 4 inches (7 to 10 cm). Plant growth is slow in dryland areas, thus the damage may extend over a long period and excessive losses may occur.
In dryland farm areas, crop damage by horned larks is closely correlated with the dry season. Most of the crop depredations occur after the natural vegetation of the surrounding range or grassland has dried up, and may continue until the first fall rains come.
The first evidence of damage by horned larks is usually the denuding of plants from a small area in the center of the field. As the damage continues, the bare spot may spread rapidly until a narrow fringe of undamaged plants remains along the borders of the field.
Legal Status
Horned larks are classified as migratory nongame birds in the Code of Federal Regulations. Depredation permits are required from the US Fish and Wildlife Service before any control activities can be initiated. Horned larks may be controlled in California , under general supervision of the county agricultural commissioner.
Damage Prevention and Control Methods
Exclusion
Not effective.
Frightening
Use propane exploders in conjunction with shotgun fire, shell crackers, bird bombs or whistles, and raptor-mimicking kites. Avitrol ®.
Repellents
Capsicum.
Toxicants
None are registered.
Trapping
Use culvert traps or foot snares; for bait use only wild animal road kills and scents.
Immobilizing and Handling
Not effective.
Shooting
Not effective.
ACKNOWLEDGEMENTS
The above information was adapted from PREVENTION AND CONTROL OF WILDLIFE DAMAGE with permission of the editors, Scott E. Hygnstrom, Robert M. Timm, and Gary E. Larson (Cooperative Extension Division, Institute of Agriculture and Natural Resources University of Nebraska-Lincoln, United States Department of Agriculture Animal and Plant Health Inspection Service, Animal Damage Control, Great Plains Agricultural Council Wildlife Committee).
