Ground Squirrels Thrive Year-Round in Avocado Orchards

Ground squirrels eat a variety of fresh greens as well as seeds and dried nuts. In spring, ground squirrels prefer greens over seeds and nuts.  Once the natural grasses begin to dry and wither, squirrels will actively forage for seeds. 

As foragers, squirrels are well-adapted to find sparsely dispersed food, one seed at a time. Once squirrels have had their fill, they will

collect food in their cheek pouches and take it back to the nest to form a cache for later use. Squirrels tend to forage close to their burrow, although they will travel for desirable foods.

How Biology relates to control:

The California ground squirrel prefers to forage for food in the early morning or late afternoon/early evening to avoid the day's heat. In some crop situations, especially nut crops, squirrels may prefer the crop to the point where they will not eat any bait. If the squirrel won't eat the bait, the poison bait method will not work. In this case, an alternative control approach may be necessary (trapping or fumigation).

Understanding these feeding preferences is extremely important when using baits since they are seed based. Also, in irrigated crops or landscape areas, squirrel feeding preferences are influenced by what food is available. For example, the natural vegetation may be dry in early summer and squirrels are actively foraging for seed. If newly sprouted crops are available however, the squirrels may take them with great delight.

The calendar of ground squirrel diet, activity and control measures is adapted from the Best Management Practices for Ground Squirrel Control website http://ipm.ucanr.edu/PMG/PESTNOTES/pn7438.html.  Calendar dates are merely an estimation of time; actual time frames may vary according to the weather and location. 

Ground squirrels - Spenrophilus sp. of which there are 17 species may cause damage to avocado orchards by eating fruit, branches, and making burrows near or under trees which expose roots and redirect irrigation water. The most common ground squirrel is the California or Beechey ground squirrel Spermophilus beecheyi.

*An adult will weigh from 1 to 2 ½ pounds and is tan in color with flecked or mottled fur.

*Females produce one litter each year, averaging six to eight offspring.

*They are active in the daytime.

*Their diet may consist of green herbage in winter and spring and seeds during the summer and fall.

*They hibernate during cold winters, but are active year-round in avocado growing areas

*Ground squirrels are not repelled by any chemical or physical means. Thus, control through the use of toxic fumigants, poison baits, traps, or shooting is the only effective control measures available

*They are also preyed on by eagles, raccoons, foxes, badgers, weasels, rattlesnakes and clever dogs

more on those cute animals:

http://ipm.ucanr.edu/PMG/PESTNOTES/pn7438.html

ground squirrel

Read more