Tree Squirrels

There are three species of tree squirrel found in Oklahoma. The fox squirrel is found across the state while the Eastern gray squirrel is found in the eastern portions of the state. Southern flying squirrels are also present, but are generally not common, and except for occasionally entering at- tics, do not cause significant damage. Both the fox and gray squirrel feed on a variety of food. In the garden, they cause damage to nut-bearing trees, various fruits, corn and consume bird seed. They sometimes dig in lawns to bury food and can enter openings in attics. They also evict birds from nest boxes at times.

Lethal Control While both the fox and gray squirrel are legal game species, seasons are very liberal and they may be killed most of the year (http://wildlifede- Figure 11.12. Cones placed below bird feeders partment.com). Where legal, shooting is effective or trees help reduce squirrel damage. Metal to control squirrels under low population densi- cones are preferred over plastic as plastic can ties. However, with high densities, animals will be be damaged by the squirrel as shown in this photo. quickly replaced.

Repellents Various repellents such as moth balls and cap- saicin can reduce damage in some instances, but will generally not be effective alone and must be reapplied often.

Frightening Not generally effective for reducing squirrel damage.

Exclusion If squirrels are entering attics or other struc- tures, cover the entrance(s) with wire mesh, alumi- num flashing and other materials as appropriate. Be cautious about trapping squirrels inside, as they can do significant damage attempting to escape and will smell once dead. If animals are suspected to be inside the structure, place a live catch trap (baited with peanut butter, nuts or fruit) inside the Figure 11.13. This squirrel guard prevents the enclosed space, or create a temporary one-way nesting birds from being destroyed. The hole door over the opening. Use a metal (preferable) should be appropriate for the target bird but or plastic collar to prevent squirrels from climb- ing trees or bird feeders (Figure 11.12). The collar small enough to limit squirrel entrance (more than 2 inches). If using metal flashing, be sure should be 2 feet wide and 6 feet off the ground to to file edges to ensure birds entering will not be fully exclude squirrels. If placing on a tree, ensure injured. there is space between the collar and tree to pre- ment.com/laws_regs/nco.htm). Raccoons can be vent damage to the tree. Woven wire (1-inch mesh) trapped using live catch traps (10 x 12 x 32 inches) fence topped with a single strand electrical wire baited with sardines, chicken, or cat food. Howev- (within 1 inch of top of fence) can be installed to er, the use of smaller mesh (1/2-inch) wired to the protect small garden plots. If sweet corn is being cage may be needed to prevent raccoons from damaged, use a piece of reinforced filament tape pulling out the bait through the trap walls. In most wrapped several times around the end of each ear cases, lethal control will not be necessary for rac- of corn to inhibit squirrels from opening the husk. coons. An exception may be in the rare case when This should be done prior to the corn becoming raccoons enter attics or crawl spaces of structures. ripe. If squirrels are raiding bird houses, a metal or hard plastic collar can be placed around the Repellents opening that will restrict their entry by preventing No known repellents are effective for raccoons. them from chewing the entrance hole larger (Fig- ure 11.13). Frightening While frightening may temporarily lessen dam- Habitat Modification age from raccoons, it is not generally effective and Tree limbs can be trimmed to prevent squirrels not recommended. from accessing structures, gardens, bird feeders, other trees, etc. Limbs should be trimmed 8 feet Exclusion from the object protected as squirrels can jump Exclusion is the most effective way to reduce several feet. most raccoon damage. For garbage cans, tightly restrain lids with bungee cords. Consider using Northern Raccoon metal containers for any food item to discourage raccoons from chewing into the container. For rac- The Northern raccoon is a widespread mam- coons entering structures, seal any holes where mal found throughout Oklahoma. They consume a entry is possible immediately upon discovering the wide variety of foods (omnivorous), are intelligent entry. Trap any raccoons that may be present after and have good dexterity. These traits sometimes the entry is sealed or by blocking the entry with a lead to conflicts with homeowners and gardeners. trap. Ensure chimneys are covered with wire mesh While they prefer areas near forests and water, and/or capped to prevent entry. For small corn they can be found far from either. They are pri- crops, use filament reinforced tape wrapped sev- marily nocturnal, thus often not seen. They cause eral times around the end of each ripening ear of damage by raiding garbage cans, bird feeders, corn. For larger areas, use an electric fence with and bird houses; entering attics; consuming veg- two hot wires, with the first wire at about 6 inches etable crops (especially corn); and occasionally above the ground. Poultry should be well fenced pulling up fresh sod. If raccoons are present in an with all doors and windows secured at night. A sin- attic, they generally make considerable noise by gle electric wire along the top of the poultry fence running, scratching and snarling. Other species of will greatly reduce raccoon damage. If raccoons wildlife that sometimes enter attics are generally are raiding bird nest boxes, install a predator shield more subtle. (cone) to limit access (Figure 11.12). Metal, rath- er than plastic should be used if raccoons are a Lethal Control problem. Raccoons are a regulated furbearer in Oklaho- ma. The Oklahoma Department of Wildlife Conser- Habitat Modification vation sets seasons and legal methods of harvest There are few instances where habitat modifi- (http://wildlifedepartment.com). Raccoons can be cation is practical. If fresh sod is being damaged killed if they are harming livestock or poultry at any by raccoons, consider pinning down the corners time. For nuisance issues which require trapping with pins or stakes until the grass has firmly estab- outside of an established hunting season, con- lished roots. Overhanging limbs can be trimmed to tact a NWCO in your area (http://wildlifedepart- prevent access to the roof of a structure or to bird houses. Repellents Striped Skunk Not generally effective. Mothballs may work for enclosed spaces, but should be used cautiously Oklahoma has two species of skunk. The spot- where people reside. ted skunk is very uncommon and is a protected species. It will seldom, if ever, cause problems for Frightening the Oklahoma gardener. The striped skunk is a Lights and loud noises may provide some common mammal found statewide. They are most relief. common in open areas near forests and streams, but are quite adaptable. Skunks eat a wide variety Exclusion of foods, but insects are eaten during the summer Exclusion is the most effective way to reduce months. Skunks occasionally raid poultry eggs, most skunk damage. For garbage cans, tightly re- eat low hanging vegetables and get into garbage. strain lids with bungee cords. Consider using metal However, most complaints from skunks involve ei- containers for any food items. For skunks entering ther damage to turf because they seek soil insects structures, seal any holes where entry is possible or when skunks enter the crawl spaces of homes. immediately upon discovery. Trap any skunks that Skunk damage in lawns can look similar to tree may be present at the entry point using sardines squirrels and armadillo. Tracks or visual sighting or cat food as bait. Poultry should be well fenced are the best ways to differentiate between species with all doors and windows secured at night. Fenc- causing turf damage. Note that most turf damage es should be buried about 12 inches if skunks are in Oklahoma gardens will be from armadillo and digging under them. not from skunk.

Habitat Modification Lethal Control Keep brush, debris and garbage picked up to Striped skunks are not protected in Oklahoma reduce the attractiveness to skunks. and may be killed at any time. They can be easily trapped using live catch traps (7 x 7 x 24 inch- Additional References es). The trap should be baited with cat food or sar- The Internet Center for Wildlife Damage Manage- dines. While skunks are not eager to spray and are ment contains information on many wildlife very docile animals, it is still advisable to cover the species (http://icwdm.org). trap with canvas or some other covering to reduce The following Oklahoma State University fact the chance of spray. As it is illegal to move wild- sheets can be found at osufacts.okstate.edu life, humanely kill any trapped skunks. Approach Ornamental and Garden Plants: Controlling Deer the trap calmly, pull back the cover and shoot the Damage, HLA-6427 animal in the head. Many skunks will spray when Controlling Pocket Gophers, NREM-9001 shot, but shooting the brain will reduce the chance The USDA Animal and Plant Health Inspection Ser- and will kill the animal instantly. Shooting the ani- vice is a good resource for wildlife damage im- mal from a distance (to avoid the possibility of get- pacting agriculture or human health and safety ting sprayed) will almost certainly cause the ani- (http://www.aphis.usda.gov/wildlife_damage). mal to spray the trap. If the skunk does spray, use The Oklahoma Department of Wildlife Conserva- a mixture of one quart hydrogen peroxide, ¼ cup tion sets regulations for resident wildlife spe- baking soda, and two teaspoons liquid dish soap cies and also manages the Nuisance Wildlife to clean the trap. Note: do not seal this mixture in a Control Operator Program (http://wildlifede- container as the hydrogen peroxide releases gas partment.com) which can cause a closed container to explode.

Alternatively, call a NWCO to trap for you (http:// wildlifedepartment.com/laws_regs/nco.htm).

This is an excerpt from OSU OCES publication E-1034 “Master Gardener’s Manual”