The American bullfrog is a royal pain-in-the-tail-end in Oregon. It doesn't belong here, and it eats anything it can stuff into its gaping maw - our native amphibians, small birds, ducklings, and other unsuspecting victims.
Bullfrogs are native to the East, and it would be a lot better for everyone - especially our native wildlife - if they had been left there. But somebody from the East who probably loved to eat frog legs just had to have them for supper when they moved to Portland, and brought the bullfrog with them.
Then someone from Medford came to visit Uncle Frank in Portland, got hooked on frog's legs and the next thing you knew, bullfrogs were taking over the ponds in southwest Oregon.
For some reason, people keep tampering with the nature of things. The hares transported from England that are now running all over Australia is one example; the non-native fish sportsman have dumped in our lakes and streams and now eating Oregon native fish are another. Then there's cheat grass and knapweed and list goes on and on.
The bullfrog is the largest frog in North America. It can reach over six inches in length, and males can weigh in at over a pound, and will eat just about anything they can get into their mouth.
The large gaping maw of a bullfrog can - and does often - swallow mallard ducklings whole. Amphibian adults, such as the native Pacific tree frog and spotted frogs, are gulped down by bullfrogs like dessert, while tree frog tadpoles are just hors d'oeuvres.
Unlike our native frogs and toads - that are only amphibious when mating, laying eggs, and growing to adults then leaving the water for a terrestrial life - bullfrogs live in water year-round, catching and devouring their prey there as well.
Worse, native fish don't like bullfrog tadpoles; apparently because they don't taste good. (And don't ask me how a fish can taste a tadpole; I have no idea how that happens.) Sure, an otter can eat bullfrog tadpoles and adults, and as you can see by the photo, so can great blue herons.
We humans have used bullfrogs for meat and as lab animals for a long time, and if we had let it go at that and left the blasted things in the East where they belong everything would be just fine. But Man-being the glutton he is, and non-thinking when it comes to introducing animals to places they don't belong- brought bullfrogs to live with us.
The American bullfrog, often known as just plain bullfrog, is an amphibious frog, a member of the family of "true frogs." Adults have an olive green back and sides blotched with brownish markings, and whitish belly spotted with yellow or grey.
As you can see below, they have a BIG mouth, the upper lip is often bright green, and adult males have yellow throats. They are usually found along the edge of large, permanent water bodies, such as ponds, lakes and swamps.
The male bullfrog belligerently defends a territory during the breeding season. His call is reminiscent of the roar of a bull - which gives the frog its common name. As stated, they are native to southern and eastern parts of the United States and Canada, but - unfortunately - have been widely introduced across other parts of North, Central and South America, Western Europe, and parts of Asia, and in most areas regarded as an invasive species.
So, PLEASE Dear Readers, leave them where you find them, and tell an ODFW wildlife biologist where you found them. Perhaps some day someone will find some ecologically safe method of ridding them from Oregon, before they kill off all our native amphibians.
In this part of Oregon, they have a prolonged breeding season, with the males continuously bellowing to protect their territory, and engaging in sexual activity all night long, clear into June and July. Males hang around breeding ponds for longer periods than females during the entire season, increasing their chances of multiple matings resulting in more frogs. With climate change upon us, their breeding season may be a lot longer.
Male bullfrogs get together into groups called choruses. To establish social dominance within choruses, bullfrogs get into various forms of aggression, especially through visual displays. Posture is a key factor in establishing social position and threatening challengers; males climb out of the water and display inflated postures, but non-territorial males remain in the water with only their heads showing.
I'm making a stink about bullfrogs because they're so hard on our native frogs, and we have a beautiful selection: northern Pacific tree frog; northern red-legged frog; Oregon spotted and Columbia spotted frogs, Cascades frog, foothill yellow-legged frog, and northern leopard frog - and who knows how many baby shorebirds, waterfowl and aquatic animals they also gobble up, upsetting native wildlife ecosystems.
If you hear a deep bull-like call coming from a pond near you, please, call ODFW at 541-388-6363 and inform them about what sounds like bullfrogs in the vicinity.
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