Rana catesbeiana, the bullfrog, is the largest frog in the United States. They are often suggested as a species to add to ponds because they eat algae. Yes, tadpoles eat algae and other plant foods for two years while they grow, but as adults, they eat anything that fits in their big mouths. They hunt by sneaking up on their prey. That means, you may notice tadpoles, frogs, fish, insects, crustaceans, snakes, bats, small birds, etc. vanishing. I would not suggest these frogs for small fish ponds. Bullfrogs can grow to 8 inches long but may range from about 4 to 8 inches. The males call is a deep “jug-a-rum. ” Bullfrogs are supposed to be nocturnal. The bullfrogs I have call most often at night, but they are also active during the day going after bugs. I didn’t put any in my pond at first, but they showed up anyway. One big male stayed for a few years. They are twice as big as the green frogs and look very fat. Who did they eat? Around 2008, I started adding a few bullfrog tadpoles to the pond every spring to help it grow. One became an adult female.
The ear drums of men are bigger than their eyes, while the drums of women are the same size or smaller than their eyes. The males ear drums touch their eyes. Also, during breeding season, the male bullfrog has a bright yellow throat unlike the females white throat. His call is described as “jug-o-rum. ” Males will wrestle for territory. They can lay up to 20,000 eggs at once in the summer. Depending on the temperature, the eggs hatch in 4 to 8 days. Bullfrog tadpoles feed on algae and whatever plant and animal materials are around. If they are starving, they will eat each other. In an aquarium setting, they can be fed most fish foods and even Cheerios. Bullfrogs take 2 to 3 years before they leave the water as adults (usually two years). At that point, it is at least a few more years before they can breed themselves. Both eggs and tadpoles taste bad to predators. People say that the bullfrog tadpole has a ridge of skin that goes from behind the eye to over the eardrum and ends at the base of the front legs. Other tadpoles do not have this ridge. Bullfrogs like warm, shallow, still, highly vegetated waters.
I had read about male bullfrogs fighting but had never seen it until 5/19/05. I stayed low around the pond and worked on weeding and mulching, so no one could hear or see me. At least 3 male bullfrogs and 2 male green frogs started calling. After a while, I heard a lot of splashing. I looked up over the hill to see two male bullfrogs fighting. They would rear up showing off their bright yellow throat pouches which they inflated. They would call each other and then charge, slamming into each other and flapping their front legs. It was quite intense and interesting to see.
People who like to eat frogs and people who like to keep ponds mean that bullfrogs sometimes get loose and go to places they don’t belong. With their large appetites, bullfrogs can eat native frogs and fish and even birds, sometimes eliminating them entirely. Never release any non-native animal into your pond that is able to leave your pond. Because there are no streams or water coming in or going out in a closed system, this would include any animal that isn’t aquatic. Of course, even non-native fish, snails, etc. could get into the wild if the pond overflowed into a natural pond or stream. Many big, expensive koi were lost to the wild after the big floods on the Mississippi in the early 2000s.
I have never tried to catch a bullfrog. I can easily catch my green frogs, sometimes even by hand, but otherwise by net. They hide most of the time and only come out at night. If I even open the door to the outside, they jump in. Other people have bullfrogs that are less shy. I would later have a female bullfrog who ignored me unless I touched her. She suggested this method that she had used to catch bullfrogs: “Use a headlamp (or get a friend with a flashlight) and listen for them at night.” When you finally find them, shine a flashlight on them and slowly put a lingerie bag over the frog. I found this is a simple way, since the light seemed to mesmerize the frogs. I could see them under the water, but mine were always on the edges of my pond. I would hold the open bag out in front of them and wiggle it on their butts. They would hop right into the bag. Hope this helps if you ever need to round any up. “.
Bullfrogs showed up in my pond in the summer of 1998. They were scared and wouldn’t let me see them outside, but I could see them sometimes through the window inside. A male began to call loudly in 1999 but we could only catch a glimpse of him. Finally, in July of 1999, they came out of hiding. From August 1, 1999, I could see that a male and two females were ruling the pond as king and queen. The male had a dark yellow throat, large ear drums, and was bigger than the females. He swam up to them, floating on the water and skimming across lily pads. To make his “blahhhhh” sound, he blew up his throat. She did not look impressed. These bullfrogs got a large portion of their diet from butterflies. I watched one eat a tiger swallowtail and the blue capensis lily flower along with it. There were butterfly wing pieces and torn lily flowers all over the pond surface. I guessed I would have to live with it because these guys were un-catchable. The poor green frogs ruled the other small ponds. The bullfrogs probably ate the small green frogs and some minnows along with the poor butterflies. Lions rule the African savannah and eat anything small enough. In the same way, bullfrogs ruled my pond and ate everything that was there. It was the coolest and wettest summer in over 100 years in 2000, so the adults left. But some babies who had just changed into butterflies showed up. In 2002, the pond became the property of one mega-large male bullfrog whose picture is below. He came back in 2003 and spent the winter in my pump basket. At least one or two other ones came to join him.
By 2007, I had not seen any bullfrogs much in the last few years. My mother bought me a single 3. 5 inch bullfrog tadpole that I put into my 1800 gallon pond on 5/11/07. In 2008 and 2009, I added two bullfrog tadpoles each year.
I last saw the big male in 2008 or so. In 2009, a female bullfrog took up residence, and by 2010, she was the queen of the pond. I have not seen any males in 2010. I added six bullfrog tadpoles from the pond store in 2010.
In March 2011, I found my big female bullfrog hanging out under the biofilter’s lip. She held the liner down, which caused more water to leak out between the liner and the filter, but I didn’t bother her.
This is a picture from May 22, 2012, of a male American toad amplexing a female bullfrog. Sometimes, they get confused! This is a close-up of a male American toad amplexing a female bullfrog.
From May 13, 2012: Young bullfrog Young bullfrog. The green frog in this picture from the same day has lines down its body, but the bullfrog does not.
Bullfrog tadpoles – tadpoles that I got on 4/28/11; note that one is missing a tail.
From 4/20/11: Huge female bullfrog in the overflow Huge female bullfrog in the overflow, different view
Female bullfrog hiding under where the water comes out of the biofilter on 3/13/11. The hill has collapsed almost a foot under the lip of the biofilter.
Two big bullfrogs and a male green frog were sitting next to each other in the overflow of my 1800-gallon pond on March 21, 2010. They were still brownish because it was cold. Two frogs – green frog on the left, bullfrog on the right. Bullfrog – close-up from two photos before. Bullfrog.
From the 153 gallon pond cleaning on 4/1/08. Huge male bullfrog sitting in a cat litter bucket while I clean the pond. He fills up the entire bucket!.
On 5/11/07, my mother bought three orfe and a bullfrog tadpole. Three new orfe and bullfrog tadpole (view above the bag) on 5/11/07 before release. You can see the tadpole in the pictures on the left. Three new orfe and bullfrog tadpole (view above the bag) on 5/11/07 before release.
On 6/19/05, I pulled a poor male bullfrog out of my submerged plant protector. I don’t know how long he was down there, but he was sick from the lack of oxygen in the air and turned the dark colors that animals usually have when they hibernate. You can see a top view and bottom view of him as I held him. He was pretty limp and weak.
Male bullfrog hiding next to an Albata lily flower in my 153 gallon pond on 6/9/05.
Male bullfrog on my floating terrestrial plant holder under the net (to keep out the heron) on 8/9/04.
These three photos are of the same male bullfrog and taken around the same time. Bullfrog head closeup, huge male, in the shallows of 1800 gallon pond on 7/5/02. “I will eat you!” he says to you. Male bullfrog taken from a distance to show size, in 1800-gallon pond, 7/5/02. Bullfrog entire body closeup of huge male, 1800 gallon pond, 7/5/02. Yes, this is the same photo that is at the top of the page.
Now that you’ve read this far, you won’t believe this picture! Susan sent it to me in the summer of 2003 and it shows her bullfrog. The frog has a songbird in its mouth. It is a bit gory so it is a clickable link. Bullfrogs do eat birds!.
Ray sent this link to a picture he took of a fat bullfrog that was an odd shade of yellow on June 12, 2006: Male yellow bullfrog
I took these pictures at the zoo on June 7, 2006, of a lot of big bullfrog tadpoles in a pond that wasn’t moving. Bullfrog tadpoles Bullfrog tadpoles.
Laurie sent this photo of a bullfrog with a goldfish in its mouth on 6/13/06. She said he eventually spit it out since it was too big. I am not sure why the date on the photo says 1/15/03. Bullfrog eating a goldfish.
This link has a photo of another bullfrog eating a fish (shubunkin?): Bullfrog Eating Fish Photo
A bullfrog was seen eating a shubunkin goldfish (or maybe a calico fantail) in David’s pond on July 12, 2008. He sent these pictures. Bullfrog eating a goldfish Bullfrog eating a goldfish Bullfrog eating a goldfish.
On 9/28/08, Carol sent this photo of a proud bullfrog consuming a poor bird. The bullfrogs name is Budweiser. Bullfrog eating a bird.
On 5/11/09, the same Phillip sent a photo of his frog. It looks to be a female bullfrog. Female Bullfrog.
Marianne sent these two photos of a bullfrog named Carl eating a sparrow (bird) on 9/1/09. “He attacked the sparrow, then dove to the bottom of the pond and drowned it. He resurfaced and then took almost two hours to swallow the bird. ” Bullfrog eating a sparrow Bullfrog eating a sparrow.
Angie sent this photo on 5/25/10 of a female bullfrog with interesting jet black eyes. Bullfrog with black eyes.
Bullfrog at a pond at the Baltimore Zoo on 6/19/12. The pond is covered in duckweed. Bullfrog – close-up of the last photo.
Carol (the same one as above) sent me these photos of a bullfrog eating songbirds on 1/23/12. The photos were taken years ago. Bullfrog eating a cedar waxwing Bullfrog eating a robin.
Go to this frog site to see a picture of a bullfrog, hear its call, and learn more about it.
To see another photo, hear a call, and get info, go to the Toronto Zoo site.
The Herps of Texas web site has a photo, call, and information on the bullfrog as well.
Bullfrogs are large, aggressive frogs that can be found throughout much of the United States. Their big appetites and ability to eat a wide variety of prey has led many pond owners to wonder – do bullfrogs eat fish?
The short answer is yes, bullfrogs do sometimes eat fish. However, fish make up a relatively small portion of a bullfrog’s diet compared to other prey like insects, crayfish and smaller frogs. While bullfrogs are certainly capable of eating fish, they do not rely on them as a primary food source.
In this article, we’ll take an in-depth look at bullfrog feeding habits, examine scientific studies on their fish consumption, and provide tips for coexisting with these voracious amphibians.
Bullfrogs, scientifically known as Lithobates catesbeianus or Rana catesbeiana, are the largest frog species native to North America. They can grow up to 8 inches long and weigh over 1 pound.
Native to the eastern United States, bullfrogs have been introduced to habitats across the country, including the west coast. They thrive in permanent sources of water like lakes, ponds, marshes and slow streams.
Bullfrogs are carnivorous and will eat just about any animal they can fit in their mouths. They are sit-and-wait predators that lie still among aquatic vegetation, remaining motionless until prey comes near. When an unsuspecting animal gets too close, the bullfrog strikes with its sticky tongue, pulling the prey into its mouth.
This technique allows them to consume a wide variety of aquatic life including insects, crayfish, tadpoles, and small vertebrates. Their diverse diet and opportunistic feeding habits contribute to their reputation as voracious predators that can wreak havoc on native ecosystems
Do Bullfrogs Really Eat Fish?
Many pond owners are concerned that bullfrogs will devour their prized fish, especially young juvenile fish that are small and vulnerable. But do bullfrogs actively hunt and feed on fish as part of their normal behavior? Or is fish consumption more opportunistic and situational?
Scientific research provides some insight into how often bullfrogs actually eat fish in the wild. A study conducted in British Columbia examined the stomach contents of over 5,000 bullfrogs. Fish were present in only 2.5% of the stomachs examined. Another study in Kansas found fish in the stomachs of 14 out of 30 bullfrogs collected from a fish hatchery.
These studies indicate that while bullfrogs do eat fish on occasion, they do not rely on them as a primary food source. Fish consumption appears to be largely opportunistic rather than a preferred prey item. Factors like availability of small, slow fish and habitat conditions likely influence feeding patterns.
Anecdotal reports from pondowners provide further evidence that fish eating is situational. Many observe bullfrogs living in their ponds for months with no issues, only to see missing fish after specific events like:
- Spawning events when young fish are abundant
- Hot weather drives fish into shallow water
- Adding structures near the surface allowing bullfrogs to ambush fish
- Disturbances making fish swim in panic
Impact of Bullfrog Predation on Fish
Just because fish are not a major component of their diet does not mean bullfrogs can’t impact fish populations in certain scenarios. When ideal conditions align, bullfrogs can inflict serious damage, especially on vulnerable juvenile fish.
For example, if a pond owner adds young koi or goldfish that are 1-3 inches long, they would be easy prey during bullfrog feeding frenzies. Spawning events that result in high densities of fry can also lead to heavy predation.
Bullfrogs may not fully depend on fish as a food source, but they are certainly adept at taking advantage of easy feeding opportunities. Once they learn reliable food sources, bullfrogs will return to them.
Pond owners report repeatedly catching the same large bullfrog after removing it and relocating it far away. The territorial nature of bullfrogs motivates them to return to familiar resources.
So if easy feeding opportunities exist, a few large bullfrogs can potentially have an outsized impact on young fish despite not hunting them exclusively.
Coexisting With Bullfrogs
For pond owners who want to protect their fish, completely excluding bullfrogs is extremely difficult. Instead, the best approach is to make conditions less favorable for bullfrog predation. Here are some tips:
- Remove any bullfrogs over 4 inches long – they can eat larger fish
- Eliminate shallow areas and structures where bullfrogs can ambush fish
- Introduce only larger juvenile fish that exceed the gape size of bullfrogs
- Use a pond netting enclosure for newly introduced or spawning fish
- Maintain clear water so fish can better evade strikes and are less stressed
With some diligence and habitat adjustments, pond owners can find an acceptable balance. Bullfrogs can serve an important role in controlling pests like mosquitos without fully eliminating fish populations.
Rather than fighting a losing battle to completely exclude bullfrogs, work with nature by reducing favorable ambush spots and introduce only large juvenile fish. With some prudent adjustments, your fish and frogs can coexist!
Bullfrogs Eat Everything | National Geographic
Do bullfrogs eat goldfish?
The bullfrog would most likely eat the goldfish, since larger creatures like fish or small reptiles are their primary food source, unlike smaller frogs who feed on insects. Frogs also like higher temperatures than your average fish does. This means that most frog species are out as potential tank-mates with a fish
Do bullfrogs eat fish?
The American bullfrog, for example, is known to eat not just large fish but also other types of animals, mammals, and reptiles that are close to the size of a larger fish. This type of frog along with others uses its hands to eat its prey and not its tongue.
Do bullfrogs capture submerged prey?
The comparative ability of bullfrogs to capture submerged prey, compared to that of the green frog, leopard frog, and wood frog ( L. clamitans, L. pipiens, and L. sylvaticus, respectively) was also demonstrated in laboratory experiments. The bullfrog breeding season typically lasts two to three months.
Do frogs eat fish?
Although they are carnivores, if they don’t have anything other to feed themselves with (think about their normal diet of insects), frogs will eat fish. Tadpoles will even eat their brothers and sisters when it comes to it (more on this in the article). So, when frogs “starve” they may resort to eating fish.