Reptiles & Amphibians - Internet Center for Wildlife Damage

32 Pages·2006·1.72 MB·English

REPTILES, AMPHIBIANS, ETC.
F-1 Alligators Allan R. Woodward and Dennis N. David
F-7 Crayfish James F. Fowler, Wendell Lorio, and Greg Lutz
F-9 Frogs and Toads Paul E. Moler
F-13 Salamanders James L. Byford
F-15 Snakes, Nonpoisonous James L. Byford
F-21 Rattlesnakes Walter E. Howard
F-27 Turtles James F. Fowler and Jimmy L. Avery
Allan R. Woodward ALLIGATORS
Alligator Research Biologist
Florida Game and Fresh Water Fish
Commission
Gainesville, Florida 32601
Dennis N. David
Alligator Management Section Leader
Florida Game and Fresh Water Fish
Commission
Gainesville, Florida 32601
Fig. 1. American alligator,
Alligator mississippiensis
Damage Prevention and Toxicants Identification
Control Methods None are registered.
The American alligator (Alligator
Exclusion Fumigants mississippiensis, Fig. 1) is the most com-
mon of two crocodilians native to the
Bulkheads along edges of lakes and None are registered.
United States and is one of 22 crocodil-
waterways.
Trapping ian species worldwide. The other
Wire mesh fences. native crocodilian is the American
Baited hooks and trip-snare traps are
crocodile (Crocodylus acutus). Caimans
Habitat Modification most effective.
(Caiman spp.), imported from Central
Minimize emergent vegetation. Shooting and South America, are occasionally
released in the United States and can
Drain ponds and borrow pits where Hunt during the day or night with
survive and reproduce in Florida. The
appropriate and permitted. rifles or crossbows.
American alligator is distinguished
Frightening Other Methods from the American crocodile and
caiman by its more rounded snout and
Prodding or other harassment can Hunt with detachable-head harpoons
black and yellow-white coloration.
increase wariness. or handheld, breakaway pole
American crocodiles and caimans are
snares.
Hunting pressure increases wariness olive-brown in color and have more
and avoidance of people. Capture with snatch hooks or tongs. pointed snouts. American alligators
and crocodiles are similar in physical
Repellents
size, whereas caimans are 40% smaller.
None are registered.
PREVENTION AND CONTROL OF WILDLIFE DAMAGE — 1994
Cooperative Extension Division
Institute of Agriculture and Natural Resources
University of Nebraska - Lincoln
United States Department of Agriculture
Animal and Plant Health Inspection Service
Animal Damage Control
F-1
Great Plains Agricultural Council
Wildlife Committee
Range fish and turtles comprise most of the her hatchlings against intruders and
diet. Recent studies in Florida and stay with them for up to 1 year, but
The American alligator is found in Louisiana indicate that cannibalism is gradually loses her affinity for them as
wetlands throughout the coastal plain common among alligators. Alligators the next breeding season approaches.
of the southeastern United States. readily take domestic dogs and cats. In
Growth rates of alligators are variable
Viable alligator populations are found rural areas, larger alligators take
and dependent on diet, temperature,
in Texas, Oklahoma, Arkansas, Louisi- calves, foals, goats, hogs, domestic
and sex. Alligators take 7 to 10 years to
ana, Mississippi, Alabama, Florida, waterfowl, and occasionally, full-
reach 6 feet (1.8 m) in Louisiana, 9 to
Georgia, South Carolina, and North grown cattle and horses.
14 years in Florida, and up to 16 years
Carolina. The northern range is limited
in North Carolina. When maintained
by low winter temperatures. Alligators General Biology,
on farms under ideal temperature and
are rarely found south of the Rio
Reproduction, and nutrition, alligators can reach a length
Grande drainage. Alligators prefer
fresh water but also inhabit brackish Behavior of 6 feet (1.8 m) in 3 years.
water and occasionally venture into Alligators are not normally aggressive
Alligators are ectothermic — they rely
salt water. American crocodiles are toward humans, but aberrant behavior
on external sources of heat to maintain
scarce and, in the United States, are occasionally occurs. Alligators can and
body temperature. They are most
only found in the warmer coastal will attack humans and cause serious
active at warmer temperatures and
waters of Florida, south of Tampa and injury or death. Most attacks are char-
prefer 82o to 92o F (28o to 33o C). They
Miami. Caimans rarely survive win- acterized by a single bite and release
stop feeding when ambient tempera-
ters north of central Florida and repro- with resulting puncture wounds.
ture drops below 70o F (21o C) and
duce only in southernmost Florida. Single bites are usually made by
become dormant below 55o F (13o C).
smaller alligators (less than 8 feet [2.4
Habitat
Alligators are among the largest ani- m]) and result in an immediate release,
mals in North America. Males can possibly because they were unsure of
Alligators can be found in almost any
attain a size of more than 14 feet (4.3 their intended prey. One-third of the
type of fresh water, but population
m) and 1,000 pounds (473 kg). Females attacks, however, involve repeated
densities are greatest in wetlands with
can exceed 10 feet (3.1 m) and 250 bites, major injury, and sometimes
an abundant food supply and adjacent
pounds (116 kg). Alligators of both death. Serious and repeated attacks are
marsh habitat for nesting. In Texas,
sexes become sexually mature when normally made by alligators greater
Louisiana, and South Carolina, the
they attain a length of 6 to 7 feet (1.8 to than 8 feet in length and are most
highest densities are found in highly
2.1 m), but their full reproductive likely the result of chase and feeding
productive coastal impoundments. In
capacity is not realized until females behavior. Unprovoked attacks by alli-
Florida, highest densities occur in
and males are at least 7 feet (2.1 m) gators smaller than 5 feet (1.5 m) in
nutrient-enriched lakes and marshes.
and 8 feet (2.4 m) long, respectively. length are rare.
Coastal and inland marshes maintain
the highest alligator densities in Geor- Alligators begin courtship in April Contrary to popular belief, few attacks
gia, Alabama, and Mississippi. Alliga- throughout most of their range and can be attributed to wounded or terri-
tors commonly inhabit urban wetlands breed in late May and early June. torial alligators or females defending
(canals, lagoons, ponds, impound- Females lay a single clutch of 30 to 50 their nests or young. Necropsies of alli-
ments, and streams) throughout their eggs in a mound of vegetation from gators that have attacked humans have
range. early June to mid-July. Nests average shown that most are healthy and well-
about 2 feet (0.6 m) in height and 5 feet nourished. It is unlikely that alligator
Food Habits
(1.5 m) in diameter. Nests are con- attacks are related to territorial
structed of the predominant surround- defense. When defending a territory,
Alligators are exclusively carnivorous
ing vegetation, which is commonly alligators display, vocalize, and nor-
and prey upon whatever creatures are
cordgrass (Spartina spp.), sawgrass mally approach on the surface of the
most available. Juvenile alligators (less
(Cladium jamaicense), cattail (Typha water where they can be more intimi-
than 4 feet [1.2 m]) eat crustaceans,
spp.), giant reed (Phragmytes spp.), dating. In most serious alligator
snails, and small fish; subadults (4 to 6
other marsh grasses, peat, pine attacks, victims were unaware of the
feet [1.2 to 1.8 m]) eat mostly fish, crus-
needles, and/or soil. Females tend alligator prior to the attack. Female
taceans, small mammals, and birds;
their nests and sometimes defend alligators frequently defend their nest
and adults (greater than 6 feet [1.8 m])
them against intruders, including and young, but there have been no
eat fish, mammals, turtles, birds, and
humans. Eggs normally take 65 days confirmed reports of humans being
other alligators. Diets are range-depen-
to complete incubation. In late August bitten by protective females. Brooding
dent; in Louisiana coastal marshes,
to early September, 9 to 10-inch (23 to females typically try to intimidate
adult alligators feed primarily on
25-cm) hatchlings are liberated from intruders by displaying and hissing
nutria (Myocastor coypus), whereas in
the nest by the female. She may defend before attacking.
Florida and northern Louisiana, rough
F-2
Alligators quickly become conditioned larity of appearance” to other alligator attacks in Florida, despite in-
to humans, especially when food is in- endangered and threatened crocodil- creasing human and alligator popula-
volved. Feeding-habituated alligators ians. This provides federal protection tions. The historically low attack rate
lose their fear of humans and can be for alligators but allows state- in Louisiana is attributed to a history
dangerous to unsuspecting humans, approved management and control of intense hunting.
especially children. Many aggressive programs. Alligators can be legally
Repellents
or “fearless” alligators have to be re- taken only by individuals with proper
moved each year following feeding by licenses or permits. Florida, Louisiana, None are registered.
humans. Ponds and waterways at golf Georgia, South Carolina, and Texas
Toxicants
courses and high-density housing cre- have problem or nuisance alligator
ate a similar problem when alligators control programs that allow permitted None are registered.
become accustomed to living near hunters to kill or facilitate the removal
Trapping
people. of nuisance alligators. Other states
use state wildlife officials to remove Alligators can be readily trapped be-
Damage and Damage
problem animals. cause they are attracted to baits. A
Identification baited hook is the simplest method
Damage Prevention and and is used in Louisiana as a general
Damage by alligators is usually limited harvest method and in Florida to
Control Methods
to injuries or death to humans or remove nuisance alligators. Hooks are
domestic animals. Most alligator bites rigged by embedding a large fish hook
Exclusion
occur in Florida, which has document- (12/0 forged) in bait (nutria, fish, beef
ed approximately 140 unprovoked Alligators are most dangerous in water lungs, and chicken are popular) and
attacks from 1972 to 1991, or about 7 or at the water’s edge. They occasion- suspended from a tree limb or pole
per year. Since 1972, 5 deaths have ally make overland forays in search of about 2 feet (0.6 m) above the surface
been positively attributed to alligators. new habitat, mates, or prey. Concrete of the water. The bait should be set
Historically, nonfatal attacks have also or wooden bulkheads that are a mini- closer to the water to catch smaller alli-
been documented in South Carolina mum of 3 feet (1 m) above the high gators. To increase success, baited
(8), Louisiana (2), Texas (1), Georgia water mark will repel alligators along hooks should be set in the evening and
(1), and Alabama (1). waterways and lakes. Alligators have left overnight during the primary feed-
been documented to climb 5-foot (1.5- ing time of alligators. Once swallowed,
Alligators inflict damage with their
m) chain-link fences to get at dogs. the hook lodges in the alligator’s stom-
sharp, cone-shaped teeth and powerful
Fences at least 5 feet high with 4-inch ach and the alligator is retrieved with
jaws. Bites are characterized by punc-
(10-cm) mesh will effectively exclude the attached rope. This method can kill
ture wounds and/or torn flesh. Alliga-
larger alligators if the top of the fence or otherwise injure alligators and is not
tors, like other crocodilians that take
is angled outward. suitable for alligators that are to be
large prey, prefer to seize an append-
age and twist it off by spinning. Many Habitat Modification translocated. Hooked alligators are
most effectively killed by a shot to the
serious injuries have involved badly
Elimination of wetlands will eradicate
brain with a small caliber (.22) rifle.
damaged and broken arms on humans
alligators because they depend on
Powerheads (“bangsticks”) can also be
and legs on animals. Sometimes alliga-
water for cover, food, and temperature
used to kill alligators, but should only
tors bite or eat previously drowned
regulation. Most modifications of wet-
be used with the barrel under water
persons. Coroners can usually deter-
lands, however, are unlawful and
and according to manufacturer recom-
mine whether a person drowned
would adversely affect other wildlife.
mendations.
before or after being bitten. Stories of
Elimination of emergent vegetation
alligators breaking the legs of full- can reduce alligator densities by Trip-snare traps (Fig. 2) are more com-
grown men with their tails are reducing cover. Check with appropri- plicated and somewhat less effective
unfounded. ate conservation authorities before than are set hooks but do not injure or
Alligators sometimes excavate exten- modifying any wetlands. kill alligators. An alligator is attracted
to the bait and, because of the place-
sive burrows or dens for refuges from
Frightening
ment of the guide boards, is forced to
cold temperatures, drought, and
predators (other alligators and hu- Aversive conditioning using sticks to enter from the end of the trap with the
mans). Burrowing by alligators can prod “tame” alligators and rough han- snare. The alligator puts its head
damage dikes in impoundments. dling of captured alligators have been through the self-locking snare (No. 3,
attempted in several areas with limited 72-inch [1.84-m]; see Supplies and
Legal Status success. Hunting pressure appears to Materials), seizes the bait, and releases
be the most effective means of increas- the trigger mechanism as it pulls the
The American alligator is federally ing alligator wariness and may be re- bait. The surgical tubing contracts and
classified as “threatened due to simi- sponsible for limiting the incidence of locks the snare on the alligator. These
F-3
traps can be modified as floating sets.
INSERT
A variation of the trip-snare trap can
Smooth Top
be set on alligator trails and rigged to
Notch
trip by the weight of the alligator (see
Mazzotti and Brandt 1988).
Wire box traps have been used effec- See insert
tively to trap alligators. Heavy nets
3/16" x 3" wooden 6"
have been used with limited success to dowel with eyelet
capture alligators and crocodiles at inserted into surgi- 32" surgical
cal tubing
basking sites. tubing stretched
to 80" when snare
8 P common nail
is set
driven through 1" x 2"
Translocation
upright and excess
trimmed to 3/4"
Translocation of problem alligators
was practiced extensively during the
1970s with limited success. Alligators,
especially larger ones, tended to return
to their original capture sites after
being moved. These alligators not only
caused problems during their return
trip but frequently required subse-
quent capture and translocation.
Translocation is not recommended
unless areas with depleted alligator
8"
populations are available for release of
problem animals.
WATER
Shooting
EDGE
Next to baited hooks, shooting is prob-
Surgical
ably the most effective means of Kleflock
Tubing
Fragile No. 2 Snare
removing alligators. Alligators can be
Twig
shot during the day or at night, and
20"
should be shot in the brain case with a WATER
sufficiently powerful rifle (.243 caliber LINE
and larger) for an efficient and
humane kill. Firearms, however, pre-
sent public safety problems in most
nuisance alligator settings. Further-
more, alligators sink almost immedi- Fig. 2. Alligator trip-snare trap.
ately after dying and may be difficult
to recover (by gaffs or snatch hooks) in the alligator and, after the tip pene- size of the alligator; small alligators
areas with currents or dense submer- trates the skin, withdrawn, leaving the can be caught with standard light fish-
gent plants. This method may make tip embedded under the alligator’s ing gear while large alligators require
confirmation of a kill difficult and may skin (Fig. 3b). As tension is placed on 10/0 hooks, a 100-pound test line, and
compromise the commercial value of the retrieval line, the off-center attach- a heavy-duty fishing rod. Heavy hooks
the alligator. Crossbows with lines ment location of the cable causes the with nylon line can be hand-cast for
attached to barbed bolts work fairly tip to rotate into a position parallel to larger alligators. After the hook pen-
well at short distances but should only the skin of the alligator, providing a etrates the alligator’s skin, the line
be used to kill alligators. secure attachment to the alligator. Har- must be kept tight to prevent the hook
poons are less effective than firearms, from falling out. Alligators frequently
Other Methods but the attached line helps to ensure roll after being snagged and become
the recovery of the alligator. entangled in the line. This entangle-
Detachable-head harpoons (Fig. 3a, b)
ment permits a more effective recov-
with attached lines have been used ef- Snatch hooks are weighted multitine
ery. Snatch hooks work well during
fectively to harvest nuisance alligators. hooks on fishing line that can be cast
the day and at night, provided that
A harpoon assembly (Fig. 3a) is at- over an alligator’s back and embedded
vegetation is minimal.
tached to a 10- to 12-foot (3- to 3.5-m) in its skin. The size of hooks and the
wooden pole. The harpoon is thrust at line strength should be suited to the Handheld poles with self-locking
F-4
a Base snares (sizes No. 2 and 3; Fig. 4) can be
Peg (aluminum) Tube used effectively to capture unwary
Tip (stainless steel) (copper) alligators at night. For smaller (less
(stainless steel) than 6 feet [1.8 m]) alligators, snares
can be affixed to a pole with a hose
clamp. For adult alligators, snares
should be rigged to “break away”
from the pole by attaching the snare to
the pole with thin (1/2-inch [1-cm]
wide) duct tape (Fig. 4). The tape or
Cable clamps allow the snare to be maneu-
(stainless steel)
vered and are designed to release after
the snare is locked. Carefully place the
snare around the alligator’s neck, then
Skin jerk the pole and/or retrieval line to
b set the locking snare. A nylon retrieval
rope should always be fastened to the
snare and the rope secured to a boat or
other heavy object.
Muscle
For alligators less than 6 feet (1.8 m)
long, commercially available catch
poles (Fig. 5; see Supplies and
Materials) can be used. Snake tongs
(Fig. 6, see Supplies and Materials)
are effective for catching alligators less
Fig. 3. (a) Detachable-head harpoon; (b) Rotation of harpoon tip after penetration. than 2 feet (0.6 m) long.
Avoidance
Measures can be taken to avoid con-
frontations with alligators and sub-
stantially reduce the probability of
attacks. Avoid swimming or partici-
pating in water activities in areas with
Duct tape
(1/2") large alligators. Avoid water activities
at dusk and at night during the
warmer months when alligators are
most active. Alligators can quickly
surge at least 5 feet (1.5 m) onto the
shore to seize prey, so care should be
taken when at the water’s edge. Do
not feed alligators. Avoid approaching
nests and capturing young (<2 feet
[0.6 m]) alligators.
Economics of Damage and
Nylon
Locking snare (No. 3)
rope Control
Alligators can cause injuries and death
to humans, livestock, and pets. All alli-
gator bites require medical treatment
and serious bites may require hospital-
ization. Infections can result from alli-
gator bites, particularly from the
Aeromonas spp. bacteria.
Fig. 4. Break-away snare.
Lawsuits that arise from findings of
negligence on the part of a private
F-5
Acknowledgments
We thank William Brownlee, Texas Parks and
Wildlife Department; Ted Joanen, Louisiana
Department of Wildlife and Fisheries; Steve
Fig. 5. Commercial catch pole. Ruckel, Georgia Department of Natural
Resources; Thomas Swayngham, South Carolina
Department of Wildlife and Marine Resources;
and Paul Moler and Michael Jennings, Florida
Game and Fresh Water Fish Commission for
providing information on their respective states
and for reviewing this chapter. We also thank
Thomas Murphy and Philip Wilkinson, South
Carolina Department of Wildlife and Marine
Resources, for providing diagrams of the trip-
snare trap.
Fig. 6. Snake tongs. For Additional
Information
Delany, M. F., A. R. Woodward, and I. H.
Kochel. 1988. Nuisance alligator food habits
in Florida. Florida Field Nat. 16:90-96.
Hines, T. C., and K. D. Keenlyne. 1976. Alligator
attacks on humans in Florida. Proc. Ann.
Conf. Southeast. Assoc. Fish Wildl. Agencies
30:358-361.
Hines, T. C., and A. R. Woodward. 1980.
Nuisance alligator control in Florida. Wildl.
Soc. Bull. 8:234-241.
Jennings, M. L., A. R. Woodward, and D. N.
David. 1989. Florida’s nuisance alligator
control program. Proc. Eastern Wildl.
Damage Control Conf. 4:29-36.
Joanen, T., and L. McNease. 1987. The
management of alligators in Louisiana,
U.S.A. Pages 33-42 in G. J. W. Webb, S. C.
Manolis, and P. J. Whitehead, eds. Wildlife
owner or governmental agency of $390 (at $30 per foot for skins and $5 management: crocodiles and alligators.
responsible for an attack site can lead per pound for meat). Other products Surrey Beatty and Sons Pty. Ltd., Chipping
to significant economic liability. such as skulls, teeth, fat, and organs Norton, NSW, Australia.
can be sold, but account for less than Mazzotti, F. J., and L. A. Brandt. 1988. A method
In Florida, approximately 15% of the
10% of the value of an alligator. Nui- of live-trapping wary crocodiles. Herpetol.
alligator complaints are due to fear of Rev. 19:40-41.
sance alligator control programs in
pet losses and, to a lesser extent, live-
several states use the sale of alligator Murphy, T., P. Wilkinson, J. Coker, and M.
stock losses. Losses of livestock other
skins to offset costs of removal and Hudson. 1983. The alligator trip snare: a live
than domestic waterfowl, however, capture method. South Carolina Wildl. and
administration.
are uncommon and difficult to verify. Marine Resour. Dep., Columbia. (unpub.
brochure).
Levees damaged by alligator burrows Florida has the most pressing nuisance
or dens may require repair. alligator problem and currently har- Thompson, B. C., L. A. Johnson, D. S. Lobpries,
vests about 4,000 alligators per year. and K. L. Brown. 1986. Capabilities of
Alligators are valuable for their skin hunters to shoot and retrieve free-swimming
Nuisance alligator harvests also occur
and meat. An average-sized nuisance alligators. Proc. Ann. Conf. Southeast. Assoc.
in Louisiana (600), Georgia (400), Fish Wildl. Agencies 40:342-348.
alligator typically yields 8 feet (2.4 m)
South Carolina (250), and Texas (50).
of skin and 30 pounds (13.5 kg) of
boneless meat with a wholesale value
Editors
Scott E. Hygnstrom
Robert M. Timm
Gary E. Larson
F-6
James F. Fowler CRAYFISH
Wildlife Specialist
Louisiana Cooperative
Extension Service
Louisiana State University
Agricultural Center
Baton Rouge, Louisiana 70803
Wendell Lorio
Aquaculture Specialist
Louisiana Cooperative
Extension Service
Louisiana State University
Agricultural Center
Baton Rouge, LA 70803
Greg Lutz
Aquaculture Specialist
Louisiana Cooperative
Extension Service
Louisiana State University
Agricultural Center
Baton Rouge, LA 70803
Fig. 1. Crayfish
Damage Prevention and Toxicants Identification, Range, and
Control Methods None are registered. Check individual Biology
state regulations for Special Local
Exclusion Needs registrations 24(c). Crayfish, also called crawfish,
crawcrab, crab, stonecrab, crawdad,
Not practical. Approved turf insecticides used for
creekcrab, and other local names, are
insect pest control will also control
Cultural Methods native to fresh waters on all continents
crayfish in lawn and turf areas.
except Africa, where they have been
Deep tillage destroys burrows and
Fumigants widely introduced. There are over 400
generally results in lower
species in the family Astacidae world-
populations. None are registered. Check state
wide, and approximately 300 species
regulations for Special Local Needs
Drainage of rice irrigation systems and in the United States. In size, shape, and
registrations 24(c).
fields during fall and winter months color, the variation is extremely wide
reduces populations. Trapping among species. The detailed life histo-
ries and habits of all species of crayfish
Repellents Not effective in eliminating
are beyond the scope of this handbook.
populations. May be used in
None are registered.
capturing crayfish for bait or food.
PREVENTION AND CONTROL OF WILDLIFE DAMAGE — 1994
Cooperative Extension Division
Institute of Agriculture and Natural Resources
University of Nebraska - Lincoln
United States Department of Agriculture
Animal and Plant Health Inspection Service
Animal Damage Control F-7
Great Plains Agricultural Council
Wildlife Committee
Crayfish are economically important in Damage Prevention and Trapping
a number of states for use as fish bait Control Methods Wire cage traps, baited with fish,
and for human consumption. In Loui-
chicken, or other meat can be used to
siana, the crayfish is a major economic
Cultural Methods capture crayfish, but they are not cost-
crop and comprises the second largest
effective in damage control situations.
aquaculture industry in North
Deep cultivation helps reduce burrow-
America. Over 130,000 acres (56,000
ing crayfish populations in rice fields
ha) are devoted solely to crayfish Acknowledgments
and other grain crops. Drainage of rice
culture.
irrigation canals and fallow fields dur-
Figure 1 by Emily Oseas Routman.
ing fall and winter is also helpful in
Damage reducing crayfish populations in these
areas. For Additional
Most damage associated with crayfish Information
High populations of crayfish are
is the result of crayfish burrowing in
generally associated with years of high
home lawns. Burrows created by rainfall. Unseasonably dry weather Hobbs, H. H., Jr. 1972. Crayfishes (Astacidae) of
burrowing species of crayfish are dam- conditions usually reduce crayfish North and middle America. Identification
aging to turf areas and may be hazard- Manual No. 9, Biota of Freshwater
numbers.
Ecosystems, US Environ. Prot. Agency.
ous to mowing machinery. Newly
Washington, DC. 173 pp.
planted rice fields may be damaged by Rapid drainage of baitfish ponds dur-
foraging crayfish where local popula- ing early spring helps eliminate cray- Momot, W. T., G. Howing, and P. D. Jones. 1978.
tions are high. fish by exposing them to predators The dynamics of crayfish and their role in
ecosystems. Am. Midl. Nat. 99:10-35.
before burrowing activities begin.
Crayfish populations in commercial Principal predators include snakes, Pennak, R. W. 1978. Freshwater invertebrates of
baitfish ponds can reduce reproduc- the United States, 2d ed. John Wiley and
racoons, mink, otter, skunks, bass,
Sons, New York. 803 pp.
tion by feeding on the eggs of the
catfish, ibis, and herons.
baitfish as they are deposited on Pflieger, W. L. 1987. An introduction to the
spawning mats. During pond harvest, Toxicants crayfish of Missouri. Missouri Dep. Conserv.
Jefferson City. 16 pp.
crayfish caught in the nets injure and
destroy baitfish as they are being har- There are no General Use Pesticides Williams, A. B., and A. B. Leonard. 1952. The
crayfishes of Kansas. Univ. Kansas, Sci. Bull.
vested for market. registered for crayfish control. In some
34:961-1012.
states, however, Special Local Needs
Unwanted populations of crayfish
registration under section 24(c) of
have been established in the wild
FIFRA have been established for cer-
because of the release of bait crayfish.
tain insecticides for burrow treatment.
Some populations have reached Editors
extremely high levels. Crayfish can Toxicants, where legal, may be used at Scott E. Hygnstrom
Robert M. Timm
reduce game fish populations by prey- any time of the year when crayfish are
Gary E. Larson
ing on eggs and fry. They also can active, but best results are obtained in
degrade habitat by destroying aquatic early fall when adults are in their bur-
vegetation. rows. To be effective, applications of
toxic chemicals must reach the water
in the burrows. Additional treatments
Legal Status
may be necessary where burrows in
dikes or dams open at the bottom into
Crayfish may be protected by law in
a pond or stream.
some states. Harvest of crayfish may
also be regulated by state wildlife con-
Fumigants
servation agencies. In areas where
damage occurs, control measures are
None are federally registered for cray-
generally unrestricted. Check with
fish control. Check with your local
your local agricultural or wildlife
wildlife or agricultural agency for
authorities before initiating control.
Special Local Needs registrations.
Unwanted populations of crayfish
have resulted in regulations against
the use of crayfish as bait in some
northern lakes.
F-8
Paul E. Moler FROGS AND TOADS
Wildlife Biologist
Florida Game and Fresh Water Fish
Commission
Wildlife Research Laboratory
Gainesville, Florida 32601
Fig. 1. Great Plains toad, Bufo cognatus
Damage Prevention and Habitat Modification Trapping
Control Methods Around hatchery ponds, keep vegeta- Funnel traps.
tion closely mown and remove
Capture
Exclusion emergent vegetation and other
types of cover. Capture by hand or gig at night.
Seal all openings 3/16 inch (0.5 cm) or
larger to exclude frogs. Frightening Egg masses may be removed with a
fine-meshed net.
A frogproof fence can be used for Not applicable.
nonclimbing species, but will be in- Shooting
Repellents
effective against treefrogs and a few
Allowed in some states, but often not
related species. None are registered.
safe in areas requiring control.
On fish farms, mesh tenting over Toxicants Some states permit shooting only
ponds will serve to exclude frogs as during daylight hours.
None are registered.
well as birds and other predators.
Fumigants
None are registered.
PREVENTION AND CONTROL OF WILDLIFE DAMAGE — 1994
Cooperative Extension Division
Institute of Agriculture and Natural Resources
University of Nebraska - Lincoln
United States Department of Agriculture
Animal and Plant Health Inspection Service
Animal Damage Control
F-9
Great Plains Agricultural Council
Wildlife Committee