The Regulars

Because I know you are wondering this fine summer evening, here is a short introduction of some of the regular amphibious inhabitants of Oregon:

One of our outreach animals. I want to do this set over again
and really capture the color and pearly sheen they have about
them. Note the sticky toe pads for climbing!

 Pseudacris regilla (Family Hylidae-tree frogs; Pacific treefrog, Pacific chorus frog): quite numerous, these are the ones you will hear calling persistently and loudly. They are smallish (up to ~ 5 cm says Wikipedia) and are climbers, hence they sticky toe pads. I can tell you they are hard to count and transfer because they are always moving and love to trek to the highest spot. Much like goats.

This is our nice copper-tinted one! If I had a favorite...

They come in simply marvelous hues, the most flashy being a Kermit the Frog green but they can also appear in browns, golds and even, to me at least, a bit copper-ish. (They can also change colors...look that up!) A lot of the ones I have seen in the lab have a cute little Y-shaped mark on the tops of their heads between the eyes. Another feature I like about them is the dark streak that runs through the eye. Sometimes its splotchy and sometimes it is so sharp and smooth it makes me think of Cleopatra's eyeliner!
They are found in largely in the US west of the Rocky Mountains and poking into Mexico and Canada.

Rana cascadae (Family Ranidae; Cascades frog): This is a species I don't have too much familiarity with. They are a ranid species (Rana = Latin for frog) which means they are considered "true frogs," that family has a huge worldwide distribution and they are what we typically think of as frogs -  large sized, strong hind limbs for jumping, and webbed-feet for swimming. Those general characteristics make for a frog that spends much more time in and around the water.

© 1998 Harry Greene from AmphibiaWeb

The Cascades frog does not have as delicate an appearance as the treefrog. Indeed, the first time I handled Cascades frogs I was unimpressed with their bumpier skin, grayish-brown coloring, and haphazard smattering of spots. But, I have grown to admire their spots and hardy nature. Look closely at the photo, the spots are shaped much like the spots of a leopard, no?
Oh, and be careful, they are plucky individuals and quite accomplished escaped artists!
Their range overlaps with P. regilla in the Cascades Mountain range but is much more restricted. Their populations are presently in a decline for a number of usual reasons: habitat loss, non-native predators like some fish, a water mold that attaches to and kills egg masses, etc.

Rana aurora (Family Ranidae; Northern red-legged frog): Another Rana! I liked this frog even before I ever officially met one. That name. What a gloriously seductive name! Aurora, the goddess of the dawn - and here is why:

That strawberry red flush through the legs! I love it! This one might be a young one but there are photos of some with an intense red flush extending all through the legs and up the sides of the stomach creeping on to the backside! So much color!
Like other ranids they are never far from water, smooth skin, strong and long legs for jumping, webbed-feet. Their range includes the western portions of Oregon, Washington, with some populations extending into California and the west coast of Canada.
The Northern red-legged frog is not a species of concern but their close cousin, Rana draytonii, the California red-legged frog is. R. draytonii used to be a subspecies of R. aurora but has now been elevated to a separate full species status.

Wikipedia
See the circle behind its eye? That is called a
tympanum, the ear of the frog.

Lithobates catesbeianus (Family Ranidae; American bullfrog): Ah yes, the uninvited party guest. The philistine who tags along and drinks all the beer, eats all the food and picks fights with everyone! That is the reputation of the bullfrog in amphibian circles.
They occupy a variety of watery environments and can/will eat anything they can stuff into their mouths. In fact, stomach contents have been known to include birds, rodents, and snakes among crazier things! And because they are fairly large (~4-6 in) they not only compete with native frogs for food but will also eat them. 20,000 eggs per egg mass also can't hurt its persistence and spread...
Native to the midwest-to-east coast portion of North America as well as Mexico and Canada, it is now found every where else it seems: Europe, Asia, South American, Hawaii, and is spreading. Notable exceptions are Australia and Africa. They were/are carried outside their native range mainly for food purposes but also in the pet trade and by accident. You wouldn't think it, but a lot more people in the past ate frogs. Back in the late 1800s when the west was filled with hungry gold miners with a penchant for frog legs, someone had the grand idea to ship in tons of bullfrogs from back east to rear in frog farms. Well, you can kind of guess what happens next...


Anaxyrus boreas (Family Bufonidae; Western toad, Boreal toad): Bufo!!! Latin for toad, Bufo are great. After spending so much time looking at ranids and hylids, playing around with toads is a welcomed change. So what is the difference between a frog and a toad? Well, you know a bit about frogs from the species described above, especially the true frogs in the genus Rana. They tend to have:
     - smooth moist skin
     - strong hind limbs for jumping and maybe climbing
     - buggy eyes!
     - lay eggs in large clumps
     - have webbed-feet
     - remain near water

Toads meanwhile in the Bufonidae family, are a bit different for many reasons:

The second goat parallel tonight!

     - drier, thicker, wartier skin
     - stockier shaped body, not tapered at the waist like a    frog
     - short, weak limbs for walking not jumping long distances
     - can be away from water
     - poison glands (!) called parotoid glands
     - lays eggs in strings
     - really cool horizontal pupils...much like...a goat!
 

Anaxyrus boreas are found in the southeastern tip of Alaska, the western half of the US and Canada, and the Baja peninsula. Though they can be found in good numbers around Oregon, overall the species is in decline due to western populations in Colorado, Wyoming, Montana, etc.
As noted above they are quite different in appearance from frogs. I remember after handling and measuring so many ranids for a project when I moved onto A. boreas it was like encountering an alien. Similar body plan...but everything about it was weird: the stocky torso and non-waist, the thin, wiry arms that walked rather than leap, and peering out at me - a tiny, short, rounded face. After working with certain taxa for some time you get habituated to the appearance of it. It is a cool feeling to realize you have memorized its form well enough you can clearly see the morphological departures when comparing it to a similar creature. I remember it happening for all sorts of snails and birds for me in the past :)

A. boreas metamorphs also have what I like to think of as "pants." The skin of their underside changes abruptly from a light speckled color to a darker color right above the waist. Like they are wearing a pair of trousers. I shall snap a picture tomorrow. Until next time!