UC ANR Broadcasts New Information Helps Natural Growers Handle Burrowing Rodents

A pocket gopher emerges from a burrow. The holes and mounds created by digging rodents pose a threat to farm workers and farm equipment. Photo by Jack Kelly Clark

June 9, 2021 – Posted by Pamela Kan-Rice – Rodents digging can cause extensive and costly damage to orchards and fields. To get rid of the pests without the chemicals used in conventional farms, organic farmers can consult a new publication from scientists at UC Agriculture and Natural Resources.

“Burrowing Rodents: Developing a Management Plan for Organic Agriculture in California” outlines the management with biologically acceptable methods using an integrated pest control approach.

California ground squirrels, pocket squirrels, and meadow voles are the three most common types that cause damage. Squirrels chew on seedlings, fruits and nuts, kill young trees and reduce crop yields. In addition to plants, ground squirrels, pocket squirrels, and voles can chew on irrigation pipes, and their building systems can divert water from plants and erode the soil. The holes and mounds created by digging rodents pose a threat to farm workers and farm machinery.

This publication will help breeders identify the rodent species based on their characteristics, life cycle and the tools available to control them.

California ground squirrels chew on seedlings, fruits and nuts, killing young trees and reducing crop yields. Photo by Roger Baldwin

“Breeders can read how to effectively select and set up a series of traps for burrowing rodents,” said co-author Margaret Lloyd, UC Cooperative Extension small farm advisor for the Capitol Corridor. “Traps are an important tool for environmental management, but maximizing control comes from integrating knowledge. Here we present information on rodent biology, trap effectiveness, biological control, habitat management, crop protection and other approaches to jointly address the pest problem. “

In the publication, Lloyd and Roger Baldwin, UC Cooperative Extension Wildlife Specialists in the Department of Wildlife, Fish and Conservation Biology at UC Davis, review the effectiveness of commercially available traps – where to place the traps, whether attractants are used, and methods of euthanasia Animals.

Traps are an important tool for rodent management on organic farms, but the integration of traps with other tools is necessary for effective management, according to the authors. Photo by Roger Baldwin

They also offer culture techniques to deter rodents, such as flooding fields and digging deep soils to destroy building systems. Plants for orchards or catch crops can be selected and managed to minimize the habitat that protects and promotes ground squirrels and voles.

For biological control, they suggest that barn owls, birds of prey, and snakes could help, but warn breeders that predators alone won’t be able to eat enough of the rodents to keep the high populations to manageable levels for many breeders to reduce.

“Effective management relies on a number of tools,” said Baldwin.

The 15-page publication can be downloaded free of charge from https://anrcatalog.ucanr.edu/Details.aspx?itemNo=8688.
Source: UC ANR