Featured Research

from universities, journals, and other organizations

What do American bullfrogs eat when they're away from home? Practically everything

Date:
March 14, 2013
Source:
Pensoft Publishers
Summary:
A control program on southern Vancouver Island provided the carcasses of over 5,000 adult and juvenile invasive alien American bullfrogs. Examination of their stomach contents confirms that bullfrogs eat virtually any organism that can fit into their large mouths, whether it be under water, at the surface, on land, even when it can defend itself with stingers, spines, or claws. So native ecosystems beware!

This picture shows a bullfrog and songbird removed from its stomach.
Credit: Stan A. Orchard/CC-BY 3.0

American bullfrogs are native to eastern North America but have been transported by people to many other parts of the globe, and other parts of North America, where they have readily established populations and become an invasive alien menace to native ecosystems. In the largest study of its kind to date, the stomach contents of over 5,000 invasive alien American bullfrogs from 60 lakes and ponds on southern Vancouver Island were examined to identify the native and exotic animals that they had preyed upon.

The study was published in the open access journal NeoBiota.

Over 15 classes of animals were reported from a total of 18,814 identifiable prey remains, including terrestrial and aquatic insects, spiders, crayfish, fish, frogs, salamanders, newts, snakes, lizards, turtles, birds, and small mammals. The study examined the stomach contents of adults and juveniles of all size-classes, but excluded tadpoles. These results show that bullfrogs will attack and consume virtually any organism that is within reach and can be swallowed, including their own species.

Previous studies on bullfrog diet have examined relatively small numbers of stomachs from a comparatively small number of lakes and ponds. Our results reinforce the general consensus that there is good reason for concern about the ecological harm that uncontrolled populations of American bullfrogs might have, or are having, on populations of native species.

For decades, bullfrogs have been transported and released around the world by prospective frog-farmers, pet owners, game managers, recreational fishermen, biological supply houses; and even by entrants in frog jumping contests. They adapt readily to a variety of habitats from the tropics to temperate zones and once established, their numbers grow fast with each adult female producing about 20,000 or more eggs per year. For these reasons, American bullfrogs are internationally recognized as one of the 100 worst invasive alien species in the world.


Story Source:

The above story is based on materials provided by Pensoft Publishers. The original story is licensed under a Creative Commons License. Note: Materials may be edited for content and length.


Journal Reference:

  1. Kevin Jancowski, Stan Orchard. Stomach contents from invasive American bullfrogs Rana catesbeiana (= Lithobates catesbeianus) on southern Vancouver Island, British Columbia, Canada. NeoBiota, 2013; 16 (0): 17 DOI: 10.3897/neobiota.16.3806

Cite This Page:

Pensoft Publishers. "What do American bullfrogs eat when they're away from home? Practically everything." ScienceDaily. ScienceDaily, 14 March 2013. <www.sciencedaily.com/releases/2013/03/130314111644.htm>.
Pensoft Publishers. (2013, March 14). What do American bullfrogs eat when they're away from home? Practically everything. ScienceDaily. Retrieved October 1, 2014 from www.sciencedaily.com/releases/2013/03/130314111644.htm
Pensoft Publishers. "What do American bullfrogs eat when they're away from home? Practically everything." ScienceDaily. www.sciencedaily.com/releases/2013/03/130314111644.htm (accessed October 1, 2014).

Share This



More Earth & Climate News

Wednesday, October 1, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Raw: 12 More Bodies Found on Japan Volcano

Raw: 12 More Bodies Found on Japan Volcano

AP (Oct. 1, 2014) — A dozen more bodies were found Wednesday as Japanese rescuers resumed efforts to find survivors and retrieve bodies of those trapped by Mount Ontake's eruption. (Oct. 1) Video provided by AP
Powered by NewsLook.com
Cultural Learning In Wild Chimps Observed For The First Time

Cultural Learning In Wild Chimps Observed For The First Time

Newsy (Oct. 1, 2014) — Cultural transmission — the passing of knowledge from one animal to another — has been caught on camera with chimps teaching other chimps. Video provided by Newsy
Powered by NewsLook.com
Raw: Trapped Scientist Rescued from Cave in Peru

Raw: Trapped Scientist Rescued from Cave in Peru

AP (Oct. 1, 2014) — A Spanish scientist, who spent 12 days trapped about 1300 feet underground in a cave in Peru's remote Amazon region, was rescued on Tuesday. (Oct. 1) Video provided by AP
Powered by NewsLook.com
Media, Industry Groups React To Calif. Plastic Bag Ban

Media, Industry Groups React To Calif. Plastic Bag Ban

Newsy (Sep. 30, 2014) — California is the first state in the country to ban single-use plastic bags in grocery, liquor and convenience stores. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
 
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:  

Breaking News:

Strange & Offbeat Stories

 

Plants & Animals

Earth & Climate

Fossils & Ruins

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:  

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile iPhone Android Web
Follow Facebook Twitter Google+
Subscribe RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins