The
American bullfrog
(
Rana catesbeiana
or
Lithobates catesbeianus
) is a semi-
aquatic
frog
. It belongs to the
family
Ranidae
, or 'true frogs'. Bullfrogs are
native
to most of
North America
,
Canada
and
Mexico
. The ones that live in northern America
hibernate
during
winter
. However, bullfrogs in
southern
US states
are active all the time. Bullfrogs have been seen in
South America
,
Asia
,
Western Europe
and the
Caribbean
. These bullfrogs were brought on
ships
. Many people, including pet owners, have placed bullfrogs outside of their native area. They have done this: on purpose because they no longer want them, to control the
pest
population
, or by accident by catching them in fishing nets.
Bullfrogs can
adapt
and live almost anywhere if there is water nearby. They can eat
rodents
,
insects
, small
fish
,
arachnids
, small
birds
,
crustaceas
, small
mammals
,
worms
, and other frogs. Because of this, they have been blamed for many animal extinctions. Bullfrogs live in large bodies of water such as
swamps
,
lakes
, and
ponds
. They like to stay near the edge of the water. During a
rainstorm
, they may travel on land. They travel in search of a new
habitat
.
Bullfrogs are
prey
to various birds like
herons
, and their life in the wild is much less than in captivity. One
captive
bullfrog lived almost 16 years. The name "bullfrog" was given because males
roar
when
mating
with a female. Bullfrogs can be kept as
pets
. Captive bullfrogs are given rodents, small fish,
crickets
,
worms
, and
fruit flies
as food and treats. Pet owners may add
supplements
on the frogs food for health. Bullfrogs can
host
many
viruses
,
bacteria
and
parasites
. They were blamed for an
intraerythrocytic
virus
outbreak
in Canada in 1997. Bullfrogs are the cause of the
chytrid
fungus
spreading into
Arizona
. The fungus is one of the main reasons that there are fewer amphibians.
A female bullfrog can lay up to 20,000
eggs
. Bullfrog
tadpoles
take up to a year to become a young frog. Males will stay behind and take care of the tadpoles. Males are
territorial
and will attack any animal, including their own kind, if they come near them. Bullfrogs can reduce the
mosquito
population. They do this by eating most of the mosquito's
larvae
. Bullfrogs do not move during the day, except if there is food nearby or when
threatened
.
Bullfrog legs are eaten by humans. The
International Union for the Conservation of Nature
(IUCN) rates the bullfrog as "
Least Concern
", which means that they are not an
endangered species
. However, they are dying because of
habitat loss
,
water pollution
[
broken anchor
]
,
pesticides
, and
over harvesting
.
The American bullfrog (
Rana catesbeiana
) is its
common name
.
[2]
It is one of 90
species
of the
genus
Rana
.
[3]
In
Quebec
, Canada and
Louisiana
US the bullfrog is called ouaouaron
(wa'wa'ron)
; a word originating in the
Wendat
language and borrowed in the 17th century
.
[2]
The American bullfrog is also known as
Lithobates catesbeianus
.
[1]
[5]
[6]
The parent family for
Rana
is
Ranidae
, or "true frogs".
The Ranidae is split into nine sub families.
Ceratobatrachinae
(southeast Asia),
Conrauinae
(Africa),
Dicroglossinae
,
Micrixalinae
(India),
Nyctibatrachinae
(India),
Petropedetinae
(Africa),
Ptychadeninae
(Africa),
Raninae
(Australia, South America), and
Ranixalinae
(India).
The American bullfrog's genus name comes from the
Latin
word rana, which means frog.
Bullfrogs were first described in 1802 by
George Shaw
. Shaw described the bullfrog in his book
General Zoology or Systematic Natural History
.
[8]
A bullfrogs
call
is a slow deep
g-r-r-u-u-u-u-m
. Young bullfrogs will make a high
pitch
chirp
before going in the water. Bullfrogs have
toxic
skin, though it is not
harmful
to humans. The toxins make it less likely that other animals will eat them.
[10]
The American bullfrog is the largest of the "
true frogs
" family.
[10]
Bullfrogs can reach a length of 6 to 8
inches
(15 to 20
cm
). Females are larger than males.
[11]
Bullfrogs can weigh up to 1.7
pounds
(770
g
).
[12]
[13]
Bullfrogs are either brown or green. They also have darker spots on their back.
[10]
[11]
Bullfrogs have
webbed feet
for swimming.
They can
leap
up to 6 feet (1.8 m).
[15]
Male bullfrogs can be heard
roaring
when
mating
with a female. Males also have bigger
tympanic membranes
which cover their ears.
[10]
Bullfrogs have brown or gold eyes. They also have
broad
flat heads and bodies.
[10]
The mouth of a bullfrog are small and have tiny teeth inside.
Bullfrogs can live up to 4?5 years.
[15]
There was one captive bullfrog that had lived up to 18years.
Males are
territorial
and will attack any animal, including their own kind, if they come near them.
[17]
They will jump,
wrestle
, and even chase any animal away.
[15]
Bullfrogs are good at hearing.
[15]
A group of bullfrogs are called an "army".
[12]
Bullfrogs are known to have many
viruses
and
bacteria
. However, only a few of them are important to nature.
Bullfrogs were blamed for an
intraerythrocytic
virus
outbreak
in Canada in 1997. They were also blamed for a
chytrid
fungus
that spread into Arizona in 2000. The chytrid fungus is believed to be one of the major causes of the decline in amphibian populations.
Many bullfrogs can have
parasites
including
helminths
,
trematodes
,
nematodes
,
protozoans
and
leeches
.
In a 1913 study, it was found that bullfrogs will eat any animal it can
overpower
and stuff down its
throat
.
[13]
[15]
Bullfrog
stomachs
have been found to have rodents, baby
muskrats
, small
turtles
, snakes, frogs (including bullfrogs), birds, and a bat, as well as the many
invertebrates
, such as insects.
[13]
[20]
These studies show the bullfrog's diet is
unique
among North American
Rana
.
[20]
Bullfrogs are also known to eat
ducklings
and tadpoles. Bullfrogs have
teeth
on the top of their mouths. Their
tongues
are capable of flipping their food into their mouths.
[15]
Bullfrogs will eat at night.
[17]
In
captivity
, pet bullfrogs are given
crickets
,
worms
, small fish,
rodents
, and
fruit flies
.
In the wild they like to eat
crayfish
,
water beetles
,
snails
, and
dragon fly
larvae.
[12]
Bullfrogs may
eat each other
, this makes up of 80% of their diet.
In a 1935 study, it was found that smaller bullfrogs eat mostly insects. However, larger bullfrogs eat crayfish, frogs and mice.
In an Arizona study in 1988, it was found that bullfrogs there eat invertebrates such as snails and insects. While two other studies, one in 1977 (in
New Mexico
) and the other in 1993 (in
New York
), found that bullfrogs in New York eat mostly
Ranidae
frogs. The study from New Mexico, found that bullfrogs there eat mostly
toads
.
Adults can help
decrease
the
mosquito
population
by eating most of their
larvae
.
Bullfrog tadpoles can reach 6 inches in length.
Bullfrogs will become
sexually active
after 2?4 years of becoming a frog.
[15]
Females are attracted to males who have territories that provide the most food.
[15]
Bullfrogs mate between early spring to early summer.
A male bullfrog grabs the female and begins roaring. A female bullfrog makes an
aggressive
call.
[15]
The female lays her eggs in
shallow
waters.
[25]
The male releases
sperm
on the eggs as
fertilizer
. A female can lay up to 20,000 eggs.
[10]
[15]
The eggs of the bullfrogs are laid on the surface of water. They are then exposed to harmful
UV-B
radiation
. Because of this, many bullfrogs may have
abnormal
(not normal) development.
The eggs hatches after four days.
[15]
They are called "
tadpoles
" and live in the water eating
algae
.
[25]
Bullfrog tadpoles are larger in length than other tadpoles by other frogs.
They become frogs in more than a year.
[15]
In captivity, they can become frogs in twelve weeks. If a bullfrog tadpole remains as a tadpole for more than a year, it will become larger when it is an adult. Because of this, they will have a better chance at survival in the wild.
[15]
There are many
predators
such as larger fish,
crustaceans
, and some birds that eat some of the eggs and tadpoles.
[17]
[25]
Because bullfrog tadpoles are not very active, they are less likely to be eaten by any animal.
However, if spotted, bullfrog tadpoles will be eaten by
salamanders
and invertebrates.
When they become adult frogs, the predators become food for the bullfrogs.
Males will stay with their tadpoles and protect them.
[12]
Males will even take their tadpoles, by digging through mud, to other large bodies of water. They do this if the water is drying up.
The tadpoles of a bullfrog are not a favorite food source for fish. This is because of their awful taste.
[29]
This gives bullfrog tadpoles a better chance in surviving than tadpoles of other frogs. Bullfrog tadpoles spend most of their time not swimming. This makes them less
noticeable
. Tadpoles of a bullfrog have also raised concerns. Their favorite food is algae and while growing up, they consume large amounts of it. They can also live anywhere where a human house is, if there is water nearby.
[29]
Froglets will begin hopping out of the water and onto land.
Once the tadpoles become "froglets", they begin hopping out of the water and into land.
They loose their tails once they are at this
stage
.
The froglets will stop using their
gills
and use them as
lungs
.
They begin eating small insects. The froglets will
remain
near the water where they were laid. If there is a
drought
, they will search for a new habitat.
At the time, froglets become easy prey to larger frogs, reptiles,
raccoons
,
foxes
, and birds.
Froglets become adult bullfrogs after four months they began hopping on land.
During the day time, bullfrogs may swim around. Some bullfrogs will stay near plants.
Bullfrogs in southern
US states
are
active
all the time. Bullfrogs in northern US states hibernate during the winter time.
Mating season begins in spring and ends in early summer.
In northern US states, bullfrogs will begin coming out of hibernation.
They will begin eating and swimming. During the summer, bullfrogs will spend most of their time in the water. They will feed on mosquito larvae. During the fall, northern US states bullfrogs will begin hibernating. Southern US states bullfrogs will become semi-aquatic. During the winter time, they will continue to be semi-aquatic.
If the weather outside is cold, they will hibernate for a few days. Bullfrogs are active at night.
They can be seen hopping around gardens and streets. During the day, they will be near the edge of the water. During the daytime, they become
motionless
(not moving). They will begin moving if food is nearby, or if they feel threatened.
The
International Union for the Conservation of Nature
(IUCN) rates the bullfrog as "
Least Concern
".
[1]
This is because they are found almost in every
continent
.
"Least Concern" means that the bullfrog is not an
endangered species
. There are more bullfrogs in southern United States than there is in the north. However, bullfrogs populations are
decreasing
because of
habitat loss
,
water pollution
[
broken anchor
]
,
pesticide
and
over harvesting
.
In 2012, Mark W. Stone
chairman
of the Santa Cruz County Board of Supervisors, is currently trying to
ban
the import, sale, and the keeping of bullfrogs in
Santa Cruz, California
. If the board signs the bill, Santa Cruz will be the first county in the United States to ban bullfrogs.
[41]
Stone is trying ban bullfrogs because of the bullfrogs appetite. They have been blamed for making many animals become an endangered species in that state.
[41]
Bullfrogs are an
invasive species
in
Puerto Rico
.
[1]
Bullfrogs were accidentally introduced starting in the 1900s in
Colorado
and California.
[29]
Fishermen
went out
fishing
and took their catchings back home, some had bullfrogs in their nets still alive. They have been introduced by pet owners who no longer wanted them. Some pet owners bought bullfrogs to control
pests
near their homes.
[42]
The impact of bullfrogs being introduced has negative
outcomes
. Because of their diet, they can decrease populations of other frogs.
[29]
Bullfrogs have been blamed for making the
California Red-legged Frog
a
near-threatened species
. They have also been blamed for many other
amphibian
extinctions
in California.
Bullfrogs compete with other frogs for food, and can even kill their own kind if food is no where to be found.
[29]
Bullfrogs are considered one of the worst alien invasive species (AIS). The AIS are animals who are able to decrease other species and even make them extinct worldwide.
[44]
Bullfrogs are responsible for the decline of
garter snakes
in Mexico.
In a laboratory experiment by Alford in 1989, bullfrogs decreased the population of
Cope's gray treefrog
.
The study introduced the bullfrogs with Cope's gray treefrog in a
controlled environment
.
Bullfrogs being sold alive at a supermarket in China.
Bullfrogs are a source of food for
Southern United States
and the
Midwestern United States
.
[45]
People hunt bullfrogs at night near rivers. The bullfrogs' legs are cooked, while their backs are
fried
.
In China, bullfrogs are sold alive for eating. They are then killed and cooked with
vegetables
. In the state of
California
, people must have a license to catch bullfrogs for food.
In schools, bullfrogs are
dissected
in
biology
classes. Usually, this is done in
middle school
.
The dissecting is a
method
for teaching students the
anatomy
of a bullfrog.
Bullfrogs are also kept as pets.
They are kept in
aquariums
or a terrarium.
A terrarium is a tank that is
decorated
with plants and
soil
on one side. On the other side, there is water.
A bullfrog would need one place for land and another for water.
- ↑
1.0
1.1
1.2
1.3
"Lithobates catesbeianus"
. International Union for Conservation of Nature and Natural Resources. Archived from
the original
on 5 June 2011
. Retrieved
18 June
2012
.
- ↑
2.0
2.1
"G. Sagard, Le Grand voyage du pays des Hurons, Paris, 325 ds G. Massignon, Les Parlers fr. d'Arcadie, Paris, t.1, p.279"
.
Centre Nationale de Ressources Textuelles et Lexicales
. 1632
. Retrieved
23 October
2018
.
- ↑
Pauly, Gregory (2009).
"Taxonomic Freedom and the Role of Official Lists of Species Names"
.
Herpetologica
.
65
(2): 128.
doi
:
10.1655/08-031R1.1
.
S2CID
283839
.
- ↑
Crowley, Joe.
"American Bullfrog (
Lithobates catesbeianus
)"
.
Ontario Nature
. Ontario Nature Inc
. Retrieved
May 27,
2012
.
[
permanent dead link
]
- ↑
"Lithobates catesbeianus"
.
United States Department of Agriculture
. 4 April 2012. Archived from
the original
on 12 May 2012
. Retrieved
May 24,
2012
.
- ↑
"Rana catesbeiana Shaw"
.
wcsu.edu
. Archived from
the original
on 14 August 2011
. Retrieved
11 July
2012
.
- ↑
10.0
10.1
10.2
10.3
10.4
10.5
"American Bull Frogs"
.
Essortment
. Archived from
the original
on 28 August 2012
. Retrieved
27 May
2012
.
- ↑
11.0
11.1
Elizabeth, R. (29 November 2010).
"Species Spotlight: North American Bullfrog"
. BrightHub
. Retrieved
May 27,
2012
.
- ↑
12.0
12.1
12.2
12.3
"American Bullfrog Facts"
.
Washington NatureMapping
. Retrieved
11 July
2012
.
- ↑
13.0
13.1
13.2
"American Bullfrog"
.
National Geographic
.
National Geographic Society
. 10 October 2010
. Retrieved
24 May
2012
.
- ↑
15.00
15.01
15.02
15.03
15.04
15.05
15.06
15.07
15.08
15.09
15.10
15.11
15.12
"Animal Profile: North American Bullfrog"
.
Seaworld.org
. Archived from
the original
on 30 July 2013
. Retrieved
16 July
2012
.
- ↑
17.0
17.1
17.2
Hughes, Catherine D.
"American Bullfrog Facts and Pictures"
.
National Geographic Kids
.
National Geographic Society
. Archived from
the original
on 18 June 2012
. Retrieved
16 July
2012
.
- ↑
20.0
20.1
Cardini F. 1974. Specializations of the feeding response of the bullfrog,
Rana catesbeiana
, for the capture of prey submerged in water. M.S. Thesis, U. of Massachusetts, Amherst, MA
- ↑
25.0
25.1
25.2
Harding, Jim.
"Bullfrog (
Rana catesbeiana
)"
.
FCPs.edu
. Island Creekes
. Retrieved
19 June
2012
.
[
permanent dead link
]
- ↑
29.0
29.1
29.2
29.3
29.4
Murphy, Martin (17 February 2003).
"Invasive Species Summary: Bullfrogs"
.
Colombia.edu
. Retrieved
11 July
2012
.
- ↑
41.0
41.1
Platt, John (13 December 2011).
"Should California Ban American Bullfrogs?"
.
Scientific American
. Retrieved
19 June
2012
.
- ↑
"Invasive Species Profiles: Bullfrog"
.
Invasive Species Profile.gov
.
United States Department of Agriculture
. Archived from
the original
on 12 May 2012
. Retrieved
11 July
2012
.
- ↑
Francesco Ficetola, Gentile; Thuiller, Wilfried & Miaud, Claude.
"Prediction and validation of the potential global distribution of a problematic alien invasive species ? the American bullfrog"
(PDF)
.
Biodiversity Research
. Diversity Distribution
. Retrieved
11 July
2012
.
{{
cite web
}}
: CS1 maint: multiple names: authors list (
link
)
- ↑
Reference, Mobile (2008),
The Illustrated Encyclopedia of North American Reptiles and Amphibians: An Essential Guide To Reptiles and Amphibians Of USA, Canada, and Mexico
, MobileReference,
ISBN
978-1-60501-459-3
- Beltz, Ellin (2006),
Scientific and Common Names of the Reptiles and Amphibians of North America - Explained
, Houghton Mifflin Company,
ISBN
0-395-98272-3
- Stebbins, Robert (2003),
A Field Guide to Western Reptiles and Amphibians, Third Edition
, Houghton Mifflin Company,
ISBN
0-395-98272-3
- Haney, Johannah (2009),
Great Pets: Frogs
, Marshall Cavendish,
ISBN
978-0-7614-4151-9
- Storer, Malcolm (2004),
Experimental Approaches to Conservation Biology
, University of California Press,
ISBN
978-0-520-24024-7
- Murphy, Adelaide (1984),
A Field Guide to the Familiar: Learning to Observe the Natural World
, UPNE,
ISBN
978-0-87451-865-8
- Lawrence, William; Moncuit, Teddy (2003),
Amphibians: Animal Life Encyclopedia
, Gale Group,
ISBN
978-0-7876-5782-6
- Starosta, Paul; Moncuit, Teddy (2006),
Frogs: And Other Amphibians
, ACC Distribution,
ISBN
978-1-905377-05-3
- Dickerson, Mary Cynthia (2009),
The Frog Book: North American Toads And Frogs, With A Study Of The Habits And Life Histories Of Those Of The Northeastern States
, Nabu Press,
ISBN
978-1-173-11240-0
- Harding, James (1997),
Amphibians and Reptiles of the Great Lakes Region
, University of Michigan Press,
ISBN
978-0-472-06628-5
- Lannoo, Michael (2005),
Amphibian Declines: The Conservation Status Of United States Species
, University of California Press,
ISBN
978-0-520-23592-2
- Glotzhaber, Robert (2000),
Biology Laboratory Set Student Manual
, Hayden Mcneil Publisher,
ISBN
978-0-520-24096-4
- Wechsler, Dough (2002),
Bullfrogs (Really Wild Life of Frogs)
, Powerkids Press,
ISBN
978-0-8239-5855-9
- Purser, Phillip (2006),
Tadpole Care
, TFH Publications,
ISBN
978-0-7938-1035-2
- Gray, Susan (2009),
Bullfrog (Animal Invaders)
, Cherry Lake Publications,
ISBN
978-1-60279-327-9
- Murphy, Patricia (2003),
A Frog's Life: Learning Sequential Order Using a Timeline
, University Of Chicago Press,
ISBN
978-0-8239-8905-8
- Glotzhaber, Robert (1973),
The Life Cycle of a Bullfrog
, Children Press,
ISBN
978-0-87191-233-6
- Davidson, Charles Elliott & Lang; Gerhardt, Carl (2009),
The Frog Book: North American Frogs and Toads
, Houghton Mifflin Harcourt,
ISBN
978-0-618-66399-6
{{
citation
}}
: CS1 maint: multiple names: authors list (
link
)
- Wells, Kentwood (2007),
The Ecology and Behavior of Amphibians
, Rosen Publishing Group,
ISBN
978-0-226-89334-1
- Storer, Tracy Usinger, &Lukas, David (2005),
Sierra Nevada Natural History
, University of California Press,
ISBN
978-0-520-24096-4
{{
citation
}}
: CS1 maint: multiple names: authors list (
link
)