Modified bait stations
for control of California ground squirrels in endangered kangaroo rat habitatModified bait stations
for control of California ground squirrels in endangered kangaroo rat habitat
1. Inverted
"T" design
45 degree PVC elbows and additional pipe can be placed on each
entrance of the traditional station such that the entrance to the
station is 12 inches above ground level. Ground squirrels
generally begin visiting these bait stations at the same time as
they would visit the traditional station (between 1 and 6 days).
In the event that ground squirrels do not visit the modified
station, the extensions should be removed, and the station
pre-baited with clean (i.e., no poison) grain. Once the squirrels
begin feeding from the station, the extensions can be replaced,
poison grain added and the squirrels will continue to visit the
station.
Specifications:
i) The entrances must be at least 12 inches above the ground
ii) Vegetation should be cleared from around the entrances.
Kangaroo rats will be able to climb into the stations if dense
vegetation is present or if the stations are placed against a 1/2
inch (or finer) wire mesh fence. Keep entrances away from fence
posts and large rocks that might be used by kangaroo rats to gain
access.
iii) Rain or sprinkler irrigators will result in water collecting
in the bait stations. In locations or at times when this is
likely, it may be necessary to further modify the bait station
(e.g., by adding an additional horizontal extension; drilling a
hole in the bottom of the station to drain water, etc.). It is
important to remember that ground squirrels will not take moldy
bait.
iv) In kit fox range, the entrance to the station should be no
greater than 3-inches in diameter. This can be achieved by
fitting a 4-inch to 3-inch PVC reducer or 1/2 an endcap.
2. Platform for other
bait station types
Almost any type of bait box may be elevated on a 12-inch high
platform (Figure 3). Any material may be used for building the
platform but due to kangaroo rat behavior, it is important to
adhere to the specifications.
Ground squirrels generally begin visiting these bait stations at
the same time as they would visit the traditional station
(between 1 and 6 days). In the event that ground squirrels do not
visit the modified station, the station should be placed at
ground level and pre-baited with clean (i.e., no poison) grain.
Once the squirrels begin feeding from the station, it can be
elevated, poison grain added and the squirrels will continue to
visit the station.
Specifications:
i) The platform should be 12-inches high.
ii) The platform must not have a solid base. Kangaroo rats are
able to jump or climb to heights of up to 24 inches if
they’re presented with a solid base. Even a platform top
with a 3-inch overhang over a solid base is easily negotiated by
kangaroo rats.
iii) The legs of the platform should be inset at least 2-inches to
stop kangaroo rats from climbing into the station. Ramps or wire
mesh should not be added to improve accessibility by ground
squirrels as kangaroo rats will learn to use these to climb into
the bait station.
iv) Vegetation should be cleared from around the base of the
platforms. Kangaroo rats will be able to climb into the stations
if dense vegetation is present or if the stations are placed
against a 1/2 inch (or finer) wire mesh fence. Keep entrances
away from fence posts and large rocks that might be used by
kangaroo rats to gain access.
v) It may be necessary to add a lip to the top of the platform to
stop grain spillage. Any grain spilled from bait stations should
be picked-up daily.
vi) In rangeland areas, bait stations should be firmly secured to
the ground to avoid them being tipped over by livestock.
vii) In kit fox range, the entrance to the station should be no
greater than 3-inches in diameter.