Foothill Yellow-legged Frog
Foothill Yellow-legged Frog Tracks
Natural History of Foothill Yellow-legged Frogs
|Foothill yellow-legged frogs are found near
streams and rivers. They will come out on the banks to sun themselves, but dive to the
bottom if a predator or a threat approaches. They stay still along the river bottom and
their color helps camouflage them there. The underside of the hind legs and the abdomen
are usually yellow. The younger frogs don't have the distinctive yellow coloring right
away, but acquire it as they grow older. The frog in this photo had very faint yellow
coloring on its legs. The skin is usually granular in appearance. These frogs breed between
mid-March and early June. They range from the Cascade Mountains of Oregon all the way
south to the San Gabriel River near Los Angeles.
This species is a California Species of Special Concern. These frogs are losing habitat all over the state. There are many threats to the continued survival of the species in many places across their range.
|This is the left hind track of a yellow-legged frog. The tips of the toes are not globular or bulbous like those of the Pacific treefrog. (Pacific treefrogs have toe pads on the tips.) Yellow-legged frogs have toes that are more pointed than those of the Pacific treefrog. This track was found in fine river silt along the Eel River near Redway, California. Penny for scale is 3/4 inch across.|
|I found a place in the river where there were many egg masses deposited. I counted 9 the first day. I returned the next day and found a total of 14.|
|A small egg mass underwater in the Eel River|
|This egg mass was deposited on the downstream side of a rock, which helps protect the developing eggs from the current.|
|Close up showing one of the 14 egg masses|
Each frog egg is encased in an envelope of jelly, which protects the growing embryo.
|Each one of these eggs will hatch into a tiny tadpole. It takes between 5 and 31 days for them to hatch.|
|The eggs will hatch faster in warmer water. The river current helps provide oxygen to the developing eggs.|
|Predators can eat the eggs and there are many predators! This photo shows a creeping water bug (Ambrysus mormon) trying to eat some eggs.|
|The eggs may become covered in silt, but this helps to camouflage them.|
|Two egg masses were attached to this large rock.|
|A couple of yellow-legged frogs in amplexus.|
Personal Notes on Foothill Yellow-legged Frogs
|These frogs are fairly common where I live in California. When walking along creeks with gravel or cobble banks, it is sometimes startling when one of these frogs leaps into the water and dives to the bottom. They are hard to see amongst the rocks and their sudden appearance and disappearance is marked only by the distinct 'plop' as they hit the water. Unless you are looking right at the frog, all you hear is the sound. I occasionally find the egg masses left by these frogs. The tiny eggs are visible in their individual globs of jelly. It doesn't take long before the eggs begin to take on the shape of a tadpole. They sometimes wriggle when they are still inside the jelly envelope. Note the shape of the toes in this photo. Compare them to those of the Pacific treefrog on the treefrog page.|
|A young yellow-legged frog at the edge of the Eel River.|
|Yellow-legged frog egg masses attached to rocks in the Eel River|
|The left hind foot of a yellow-legged frog. Frog was released unharmed after posing for these photos.|
|This frog was missing part of one front toe. Possibly due to an attack by a predator. Right front foot palmar surface.|
|The palmar surface of the right
hind foot. Notice the small bumps, called tubercles. These show up only in
very fine tracks.
The frog was released unharmed after these photos were taken.
|Yellow-legged frog on the river's shore. There were many frogs along the edge of the water on this late summer day.|
|A small yellow-legged frog on my thumb.|
A foothill yellow-legged frog enjoying the sun on a warm summer day along the river.
Find frog posters, greeting cards, t-shirts, hats, and more in my new store.
Visit Beartracker's Nature Store online store at:
What else can you find in the nature store? Beartracker's animal tracks coloring book, T-shirts, sweatshirts, journals, book bags, toddler and infant apparel, mouse pads, posters, postcards, coffee mugs, travel mugs, clocks, Frisbees, bumper stickers, hats, stickers, and many more items. All with tracks or paw prints, or nature scenes. Custom products are available. If you don't see the track you want on the product you want, email me and I can probably create it. Proceeds from all sales go to pay the monthly fees for this web site. You can help support this site as well as get great tracking products! Thank you!
|Find other tracking products: www.zazzle.com/tracker8459*|
|Also visit these fine
stores for more products of interest:
NDN Pride shop - For Indian Pride items for all tribes. Custom items available on request.
ASL Signs of Love - For anyone who uses or is learning ASL, American Sign Language. Custom name items and more are available here.
Get Every Child Outdoors (Get E.C.O.) - My shop dedicated to nature and getting kids interested in nature and the outdoors.
Sales from all stores give commissions to Beartracker's Animal Tracks Den, which helps keep this site online as a free service. We are celebrating ten years online this year!
If you wish to help keep this site online, donations are
accepted through PayPal.
Got a frog story? E-mail me and tell me about it.
Copyright © 1997, 2016. Text and photos by Kim A. Cabrera
Copyright © 1997, 2009, 2016. Kim A. Cabrera - Desert Moon Design
Page updated: Tuesday, January 26, 2016.