Canyon Creek Hike

This week I went for a hike on the Canyon Creek Trail that parallels part of the North Yuba River.  The sun was out and the temperatures were in the low 50's so I had high hopes for seeing some wildlife!

Common Garter Snake - Thamnophis sirtalis

I was REALLY surprised to find this young Garter Snake underneath a rock I picked up!!!  It was coiled up, but quickly uncoiled and scooted behind another rock before I got its picture!  It was about 6 inches long and pretty skinny, definitely a young snake!  It wasn't a newborn, as Fall is the time of year that Garter Snakes usually hatch.  I don't know how to tell how old it was.  I did find out that young Garter Snakes mainly eat earthworms during their first year!

Garter Snakes often congregate together for the winter, sometimes in large numbers!  Often their hibernacleum (the place where a critter hibernates) is located underground, on a south facing rocky slope.  Brumation is the term for hibernation of reptiles.  It is not a true hibernation, but rather a cold-blooded version of slowing down, and entering into a state of sluggishness.  Reptiles don't eat during winter, but they do wake up periodically and drink water, during warm spells!!

Garter Snakes will mate in March and give live birth in August.  The females are ovoviviparous, and carry their developing eggs internally.  The usual number of eggs is 20 to 50!!!   As soon as they're born, the young Garter Snakes are on their own.  They are excellent swimmers and climbers, and usually live for 2-3 years in the wild. As adults, Garter Snakes will eat small rodents, birds, lizards, frogs, tadpoles, slugs, salamanders, and fish!  

   Ladybug or Ladybird Beetles  - Hippodamia convergens    Woolly Bear Caterpillar - Pyrrharctia isabella

In a super sunny spot on the trail I came across LOTS of ladybugs, that were busy mating.  Like all cold-blooded critters, they are ectotherms, and need the sun to warm themselves up.  They generate very little heat metabolically.  After they mate, the females will lay their eggs on the underside of a leaf.  In 3-5 days the larvae emerge from the eggs.  After 2-3 weeks of eating aphids, the larvae pupate, and turn into an adult ladybug in about a week.

The Woolly Bear Caterpillar will overwinter under the bark of a tree, or forest duff.  Like other cold-blooded animals, it produces an anti-freeze or cryoprotectant in its tissues.  Once it emerges in the Spring, it will mate, eat a wide variety of plants, pupate, and turn into an Isabella Tiger Moth.  The moth will lay eggs, from which new caterpillars will emerge.

Folklore has it that if the Woolly Bear's brown stripe is thick, the winter will be mild.  

If the brown strip is thin, the winter will be severe.  Scientists, however, have 

determined that the size of the brown stripe varies with the age of the 

caterpillar and the moisture levels in the area where it developed.  

What do you think about the size of the brown stripe? 

Pacific Tree Frog - Pseudacris regilla

As luck would have it, I found two Pacific Tree Frogs right on the trail!  They come in 3 different color phases, green, brown, and gray.  I didn't see the gray phase.  They change their color to blend into the background.  The less contrast between their color, and their immediate environment, the less chance they will be spotted by predators.  The complete color change takes approximately two weeks.  

These tiny frogs are only 2" big, but they have loud voices!  The male frogs (Female frogs don't croak!) are some of the loudest croakers of the frog world!  Right now is the time that males are croaking to attract a mate.  Male frogs have a dark patch on their throat, which is their inflatable vocal sack.  They usually croak at night, in ponds, where the females will lay their gelatinous eggs after mating. The tadpoles will hatch from the eggs in 1-3 weeks.  The newly hatched tadpoles spend 7 to 12 weeks in their pond, 
maturing into an adult frog.

They spend the winter buried under forest duff.  Just like insects, fish, and plants they replace fluids in their body with a type of anti-freeze to keep their cells from freezing, in winter.  Once they emerge in Spring, they eat spiders, beetles, flies, ants and other insects.  When they sense that an insect is near, they commonly twitch a toe to attract it, then snatch it up with their tongue!

Why is the North Yuba River Green?
Are the female willow flowers blooming yet?
Have any other birds arrived for the coming Spring?
What are all the lizards doing?

Check back next week for the answers!