School Ground Invasion by Voles, Pocket Gophers, Ground Squirrels, or Moles
University of Nebraska
Cooperative Extension
IPM and Vertebrate Pests
Determine what animal is causing the problem
Learn the habits and lifestyle of the pest
Determine a threshold level for control actions
Create a management plan that uses the best control methods
Wildlife Integrated Pest Management
Successful Damage Management
Habitat Modification
Control Methods
Timing and Monitoring
Voles
Used with permission from University of California Statewide IPM Program,
J.K. Clark, photographer
Voles: General Background
AKA Meadow Mice
Rodents: They gnaw
Vegetarian: seeds, roots, grasses, bark
Three Vole Species Reside in Nebraska
Prairie Vole: most common and statewide
Meadow Vole: almost statewide
Pine Vole: S.E. corner of the state
Fortunately, control methods are essentially identical for all three
Nebraska's Voles
Prairie and Meadow Voles
Large: 3.5-7.0 inches
Nests: surface or shallow burrows
Reproduction: Explosive: 5-10 litters/yr; 3-5 yg/litter
Photo: USDA-APHIS
Photo: Steve Hahus, All Wild About
Kentucky's Environment
Nebraska's Voles
Pine Voles
Small: 2.8-4.2 inches
Nests: burrows < 1 ft deep
Reproduction: Steady, 1-6 litters/yr; 2-4 yg/litter
Photo: ©2004 Vole Control, Inc.
Vole Damage Identification
Trails in grass
Photo: University of Nebraska
Vole Damage Identification
Subnivean "Under the Snow" clues
Voles don't hibernate
Photo: University of Nebraska
Photo: University of Nebraska
Vole Damage Identification
Debarking/Girdling
Tooth marks approx. 1/16" wide
Photo: M.E. Tobin. Copyright New York State
Integrated Pest Management Program, Cornell University
Vole Damage Control: Non-Lethal
Habitat Modification
Reduce ground cover
Remove crawling ivies
Lawn debris
Keep grass mowed
Replace grass with gravel
Photo: University of Nebraska
Photo: University of Nebraska
Vole Habitat Modification
Reduce Food Sources
Bird feeders
Voles will eat the spilled food
Well fed animals reproduce more rapidly
Photo: University of Nebraska
Vole Control: Barriers
Fencing: at least 12" high and buried 6"
Fencing mesh should be ¼" weave
Include weed free zone
Photo: Used with permission from University of California
Statewide IPM Program, W.P. Gorenzel, photographer
Vole Control: Barriers
Solid plastic tubes should extend above the snow line. Secure the top of the tube with mesh to prevent entrapping birds
Photo: University of Nebraska
Vole Control: Repellents
Active ingredients
Thiram
Capsaicin
Can't use for plants destined for human consumption
Can be expensive $$$
Effectiveness weakened by rain
Trapping Safety
Wear appropriate safety equipment, such as gloves, when handling traps and animals
Avoid setting traps in areas with high human/pet traffic
Check traps daily. Don't set them if you can't check them the next day.
Vole Damage Control: Lethal
Trapping with snap traps
Place trap perpendicular to trail so that vole must walk over trigger
Cover traps with boxes to prevent non-target capture
Baiting is optional
Photo: University of Nebraska
Vole Control: Trapping
Trapping with snap traps
Make sure boxes don't interfere with trap or animal movements
Use only mouse sized snap traps
Traps in photo have expanded trigger. However, traditional triggers are also effective
Photo: University of Nebraska
Vole Control: Trapping
Multi-catch mouse traps
All varieties will work
Place opening in line of trail
Baiting is optional
Photo: University of Nebraska
Vole Trapping Baits
Peanut butter - be careful around those with allergies to peanut butter
Bird seed - just glue seed to trap trigger (keep out of view of birds)
Oats and molasses (keep out of view of birds)
Vole Control: Toxicants
Follow Label Instructions
THE LABEL IS THE LAW!
Vole Control: Toxicants
Zinc Phosphide
Most effective in Spring and Fall
Use during fair weather
Mow grass prior to baiting
Place in runs/burrows or bait stations
Never place in piles/bare soil
Vole Control: Fumigants
Not recommended
Vole tunnels are too difficult to fumigate effectively
Photo: University of Nebraska
Resources/Information
Internet Center for Wildlife Damage Management
wildlifedamage.unl.edu
Prevention and Control of Wildlife Damage
Local Cooperative Extension/Pesticide Education Office
Learn more about becoming a Licensed Pesticide Applicator. Only necessary for Restricted Use Pesticides (Wildlife Damage Control Category 14)
Pocket Gophers
Used with permission from University of California Statewide
IPM Program, J.K. Clark, photographer
Pocket Gophers are rodents
Up to 12 inches long and average ½ to ¾ pound
Nebraska has two species
Plains (Geomys bursarius)-most of Nebraska
Mountain (Thomomys talpoides)-extreme NW and SW Nebraska
Photo: University of Nebraska
Pocket Gopher Biology
Solitary except for mating and raising young
Mating 1-2 times a year
Litter sizes 3-4 young/Spring
Young disperse above ground in fall and usually at night
Pocket Gopher Biology
Senses
Poor hearing and eyesight
Highly developed sense of touch
Fossorial-live underground
Habitat
Soil firm enough to maintain tunnels
Avoids rocky soils and swampy soils
The "Pocket" Gopher
On either side of the mouth lies a fur-lined pouch that is used to carry stems, leaves, and roots
Some people misapply the word "gopher" to ground squirrels
Drawing: University of Nebraska
Underground Bulldozers
Pocket gophers have oversized front limbs and claws
More than a ton of soil can be moved each year
Photo: University of Nebraska
Drawing: University of Nebraska
Photo: University of Nebraska
ID of Pocket Gopher Mounds
Gophers create mounds 12-20 inches in diameter
Drawing: University of Nebraska
Photo: University of Nebraska
Mole vs. Gopher Mounds
Only Moles Create Surface Runs
Gophers DON'T create runs
Gophers ONLY create mounds
Photo: Thomas Olander
Signs of Pocket Gophers
Mounds of soil occur most often during early Spring and Fall
Sizes of mounds are 10 to 20 inch in diameter
One gopher can build over 200 mounds in a year!
Photo: University of Nebraska
A Pocket Gopher has a complex underground system
Root Zone
Frost-free zone
Top View
Side View
75 to 100 feet
Drawing: University of Nebraska
Winter Soil Castes
Caused when a gopher excavates soil to the surface into snow tunnels
This usually occurs under deep, long-lasting snow
Photo: University of Nebraska
Damage to Lawns and Equipment
Mounds cover grass
Destroy plastic and rubber piping 2.8" in diameter or smaller
Photo: University of Nebraska
Photo: University of Nebraska
Damage to Plants
Underground roots up to 4 inches in diameter can be severed
Girdling may occur at or below ground
Photo: University of Nebraska
Excluding Pocket Gophers Around Flower Beds, Trees, or Shrubs
Build an underground fence of ¼ or ½ inch galvanized wire mesh
Bury at least 18 inches
Excluding Pocket Gophers Around Buried Utility Cables or Irrigation Tubes
Trenches can be filled to surround the pipe with 6 inches of large gravel (> 1 inch diameter)
Use conduit or pipe diameters > 2 7/8 inches
Cultural Practices to Deter Gophers
Flooding often kills gophers or sometimes discourages them from digging
Apply weed control to those species that produce large, attractive roots
Best if done for 2 straight years
Repellents for Gophers
None
Questionable effectiveness of predator odors, sonic devices, and botanicals
Trapping Safely
Wear appropriate safety equipment, such as gloves when handling traps and animals
Avoid setting traps in areas with high human/pet traffic
Check traps daily. Don't set them if you can't check them the next day
Pocket Gopher Control Solutions
There are a wide variety of traps on the market
Place them below mound in opened tunnel. They can then be left open or closed, depending on preference
Drawing: University of Nebraska
Gopher traps: A. Macabee® type; B. Victor®Gopher Getter; C. Death-Klutch®-1; D. Box-type
Setting Gopher Traps
Look for the freshest mound
Find the soil plug in it
Now remove the soil with a trowel
Photo: University of Nebraska
Photo: University of Nebraska
Photo: University of Nebraska
Setting Gopher Traps
Always place traps below ground
Always wire-tie them to a stake
You may use lure baits (carrots, fresh alfalfa) behind traps
Drawing: University of Nebraska
Pocket Gopher Control: Toxicants
Follow Label Instructions
THE LABEL IS THE LAW!
Methods of Poisoning Pocket Gophers
Alternative 1 - toxicants placed below mound in tunnel through hand baiting
OR
Alternative 2 - fumigants placed below mound in tunnel
Probes for Pocket Gophers
Probes are rods used to help find gopher tunnels
Probes can be simple homemade rods or professionally manufactured ones
Photo: University of Nebraska
Three Methods of Hand Baiting
Hand baiting through mound
Use of probe with bait applicator
Probing and baiting
Drawing: University of Nebraska
Hand Baiting Tools
Tools may include:
A probe to locate the mound plug
12-inch No. 9 wire
Long-handle screwdriver
A garden trowel
A small funnel with tube extension to dispense bait
A flag to mark the mound
Photo: University of Nebraska
Choosing Toxicants for Pocket Gophers
Zinc phosphide has been shown to be slightly less effective than strychnine
Photo: University of Nebraska
Gopher Toxicant Types
Anticoagulants, chlorophacinone (RoZol®) and diphacinone (Eaton's Answer®)
These multiple-dose toxicants require a greater amount of bait than zinc phosphide or strychnine
Fumigants for Pocket Gophers
Most effective when
Soil is moist
Soil is a loam or clay
Tunnel system is small (new)
Gophers may sense gas and push soil between it and them
Retreating tunnels are often necessary
Resources/Information
Internet Center for Wildlife Damage Management
wildlifedamage.unl.edu
Prevention and Control of Wildlife Damage
Local Cooperative Extension/Pesticide Education Office
Learn more about becoming a Licensed Pesticide Applicator. Only necessary for Restricted Use Pesticides (Wildlife Damage Control Category 14)
13-Lined
Ground Squirrel
Photo: University of Nebraska
Drawing: University of Nebraska
13-Lined Ground Squirrel
Size: 11" long (including tail)
Weight: 4-5 oz.
Diet: grains, grasshoppers, mice, etc.
Hibernates: October-Mar/April
Reproduction: 1 litter/yr/3-14 young
Ground Squirrel Hole
Clean
Often a second hole 20 feet away
Photo: University of Nebraska
2-3 inch burrow opening
13-Lined Ground Squirrel
Trails through grass; note brown grass line
Photo: University of Nebraska
Ground Squirrel Habitat Modification
Allow grass to grow long and thick
Deep soil cultivation can disrupt their activities as well
Photo: University of Nebraska
Ground Squirrel Exclusion
Check for underground pipes and power lines
Dig an 18" X 18" trench around area you wish to protect
Install 0.5" galvanized hardware cloth on the bottom and up the side extending 3 ft above the ground
Ground Squirrel Exclusion
Install 2-3 ft of sheet metal above the hardware cloth
Gates should permit gaps no larger than 0.5"
Prevent digging under threshold with cement
Trapping Safety
Wear appropriate safety equipment, such as gloves when handling traps and animals
Avoid setting traps in areas with high human/pet traffic
Check traps daily. Don't set them if you can't check them the next day
Ground Squirrel Control Through Trapping
Rat sized snap traps inside protective container
Baited with peanut butter, apple, or nutmeat
Photo: University of Nebraska
Burrow Cage Traps
Place trap door up against burrow entrance
Prop trap in place
Check traps daily
Wear gloves when trapping!!
Drawing: University of Nebraska
Photo: University of Nebraska
Ground Squirrel Control through Flooding
Two gallon milk jugs, fill with water
Have you and partner pour water down into holes simultaneously
Keep jugs inserted into holes. Squirrel will run inside, then secure with screw top cap
Two clean den holes will be approx 20 ft apart
Drawing: OSHA
Ground Squirrel Repellents
There are no repellents registered for 13-Lined Ground Squirrels
Ground Squirrel Control: Toxicants
Follow Label Instructions
THE LABEL IS THE LAW!
Ground Squirrel Fumigants
Fumigants
Sodium Nitrate
Sulfur-Sodium Nitrate
Aluminum Phosphide: Restricted use pesticide
Photo: University of Nebraska
Ground Squirrel Toxicants
Baits
Zinc Phosphide: Restricted use pesticide
Pest Control Applicators License will be needed
Contact local extension educator to learn how to obtain one
Resources/Information
Internet Center for Wildlife Damage Management
wildlifedamage.unl.edu
Prevention and Control of Wildlife Damage
Local Cooperative Extension/Pesticide Education Office
Learn more about becoming a Licensed Pesticide Applicator. Only necessary for Restricted Use Pesticides (Wildlife Damage Control Category 14)
Moles
Photo: Steve Hahus, All Wild About
Kentucky's Environment
Drawing: University of Nebraska
Photo: University of Nebraska
Eastern Mole
Short, velvet fur
Black, gray, or brown
4-7 inches long
Short tail
Very small eyes and ears
Long naked snout
Wide mitt like front paws
Large claws in front only
Small pointed teeth
Photos: University of Nebraska
Drawing: University of Nebraska
The Eastern Mole
Life Style
Tolerate low oxygen levels
Fossorial-live underground
Habitat
Prefer moist, loose soil
Prefer less disturbed areas
Reproduction
Once/year (May-June)
2-5 young in deep nest
Drawing: University of Nebraska
Photo: University of Nebraska
The Eastern Mole
Feeding
Insectivorous
70% Earthworm
Consume 45-50 lbs annually
Foraging
50 75 ft of surface tunnels per day
Moist, shaded areas
Movement
Travel 80 ft per minute in burrows
Males - 3A Females - 0.66A
Photo: University of Nebraska
Mole Signs and Damage
Burrowing
Runs: Moles push up sod just under the surface; tear turf roots
Mounds: Made when moles go deep, round and conical about 8" across and 6" high. Cover and smother grass
Nests: In deep burrows 18-24" below the surface
Photo: University of Nebraska
Used with permission by University of California Statewide IPM Program, J.K. Clark, photographer
Mole Damage Identification
Mole Mounds
Caused by moles digging deep tunnels
They literally carry the dirt to the surface
Drawing: University of Nebraska
Used with permission by University of California Statewide IPM Program, Larry L. Strand, photographer
Mole Damage Identification: Mole vs. Gopher Mounds
Mole Damage Identification
Runs
Travel Runs
Long
Straight
Connect feeding areas and living areas
Feeding
Short
Crooked
Photo: Thomas Olander
Mole Management
Habitat Modification
Soil conditions: Dry packed clay
Type of ground cover or turf
Reduction of food supply: Earth worms, not grubs
Mole Management
Habitat Modification
Install rocks, gravel, packed clay barriers: 24" deep
Install fences or metal barriers: 24" into grade
Natural predators: Coyotes/dogs, cats, and bull snakes
Photo: University of Nebraska
Mole Management
Repellents
Two types: Smell or Tactile
Odorous repellents such as castor oil must be applied often and watered in properly
Vibration devices must be very strong and only cover a small area.
Limitations: Both these types of repellents have very limited results on deterring moles
Photo: University of Nebraska
Trapping Safety
Wear appropriate safety equipment, such as gloves when handling traps and animals
Avoid setting traps in areas with high human/pet traffic
Check traps daily. Don't set them if you can't check them the next day
Mole Management
Traps
Many types of lethal mole traps
Use on surface runs that are active and reappear
Walk over all runs
Place traps on runs the mole has reopened
"Test fire" harpoon traps in non-sandy soils
Trapping can be very labor intensive
Extreme care must be taken when using traps
Mole Control: Lethal
Trapping: All the traps work
Trapping is extremely effective
Pesticide free
Drawing: University of Nebraska
Mole Control Trapping Principles
Use more than one trap
Surface tunnels
Set the long straight tunnels
Set the new tunnels
Boils
Dig to the tunnel
Set the new boils
Photo: University of Nebraska
Mole Trapping: Surface Runs
Harpoon
Find the run
Make sure trap legs don't invade the tunnel
Depress only enough tunnel for the trigger
Pre-form the time holes
Set trap so tines are NOT above the soil
Cover with 5 gal. bucket
Drawing: University of Nebraska
Mole Control Trapping Boils
Scissor trap
Dig to the travel tunnel
Place jaws to straddle the tunnel
Create barrier or install woody
"Test fire" trap
Reset and back fill trap
Drawings: Tom Schmidt
Mole Control: Toxicants
Follow Label Instructions
THE LABEL IS THE LAW!
Mole Control: Toxicants
Toxicants: Fumigants
Two types:
Smoke or sulphur "bombs"
Lethal gases
Smoke "bombs" usually do not work as mole's tunnel system is very extensive and moles need very little oxygen
Photo: University of Nebraska
Mole Control: Toxicants
Toxicants: Fumigants
Two types:
Smoke or sulphur "bombs"
Lethal gases
Lethal gases are extremely dangerous and explosive! They are only to be used by specially certified applicators
Photo: Do It Yourself Pest Control, Inc
Mole Control: Toxicants
Toxicants: Baits
Remember, moles feed on LIVE earthworms, so grain based baits will NOT work!
The bait must smell and feel like an earthworm to the mole
Photos: Do It Yourself Pest Control, Inc
Mole Control: Toxicants
Toxicants: Baits
The bait must have a poison that effects the moles' different blood composition
Most common rodent poisons will not be as lethal to moles
Photos: Do It Yourself Pest Control, Inc
Mole Control: Toxicants
Toxicants: Baits
Baits must be placed in the active surface burrows
The burrows must be closed after the bait is introduced
Always read and follow all label directions
Photos: Bell Laboratories, Inc.
Mole Management "Wannabes"
Many products have been tested by Universities and found to be non-effective in controlling moles; better to use proven methods
Miscellaneous home remedies
Pinwheels/windmills
Animal scat
Birth control pills
Chewing gum
Used cat litter
Kerosene
Ultrasonics
Resources/Information
Internet Center for Wildlife Damage Management
http://icwdm.org
Prevention and Control of Wildlife Damage
http://icwdm.org/handbook/index.htm#om
Local Cooperative Extension/Pesticide Education Office
Learn more about becoming a Licensed Pesticide Applicator. Only necessary for Restricted Use Pesticides (Wildlife Damage Control Category 14)
Credits
Content Specialists
Dennis Ferraro, Douglas-Sarpy County Cooperative Extension
Stephen Vantassel, UNL Cooperative Extension
Dallas Virchow, UNL Cooperative Extension
Content Editor
Erin Bauer, UNL Cooperative Extension
Photos
Dennis Ferraro, Douglas-Sarpy County Cooperative Extension
Stephen Vantassel, UNL Cooperative Extension
Credits
Photos cont.
Dallas Virchow, Wildlife Services, USDA-APHIS
J.K. Clark, University of California Statewide IPM Program (http://www.ipm.ucdavis.edu)
Steve Hahus, All Wild About Kentucky's Environment
Laurie Smith/USDA-APHIS
(www.volecontrol.com) ©2004 Vole Control, Inc.
M.E. Tobin. New York State Integrated Pest Management Program, Cornell University
W.P. Gorenzel, University of California Statewide IPM Program (http://www.ipm.ucdavis.edu)
Credits
Photos cont.
Larry L. Strand, University of California Statewide IPM Program (http://www.ipm.ucdavis.edu)
Thomas Olander
Edward D. Kellems
OSHA
Do It Yourself Pest Control, Inc (http://www.doyourownpestcontrol.com)
Bell Laboratories, Inc.
Artwork/Graphics
UNL Cooperative Extension
University of California Davis (http://www.ipm.ucdavis.edu)
Tom Schmidt