The temperature has been in the high 80's to low 90's and the North Yuba River is warming up! It's also slowing down, clearing up, and turning its beautiful glass-green color! I spent several days cooling off and exploring in the river this week! It was wonderful!
Stonefly nymph and Adult - Plecoptera sp.
I found quite a few different aquatic insects in the river! Biologists can gauge the health of a stream by taking a census of the aquatic insects that live in it. Because the insects I'm featuring this week cannot tolerate pollution, high sedimentation, and high amounts of algae and fungi, their presence in our stream and river is an indicator of good water quality!
Pictured above are a Stonefly nymph exoskeleton (left) and an adult Stonefly (right). Stonefly nymphs will live underwater for 1 to 4 years, depending on the species. They prefer running rivers and streams, not lakes and ponds. They feed on algae, detritus, and plant materials under water. When their nymphal stages end, the nymphs will crawl out of the water onto rocks, their exoskeletons will dry out and crack open, the adult will pull itself out of the exoskeleton, pump up its wings, dry out, and fly away! As adults they feed on nectar, as well as algae and lichens. The adults usually live for about a month, just long enough to mate and lay eggs!
Caddisfly larvae - Trichoptera sp.
Pictured above are Caddisfly larvae in their cases. These larvae can be found in streams, rivers, lakes, and ponds! The material used to make the cases varies between species. The cases I saw were a combination of wooden pieces and small stones. Inside its case, a Caddisfly larva makes a silken cocoon around its body. It will pupate in this silken cocoon before it becomes an adult. As larvae they feed on algae, as well as aquatic and terrestrial vegetation. As adults, Caddisflies feed on nectar! The larvae live for about a year, whereas the adults live for about one month! Thousands of these adults have been clinging to our window screens for the past few nights! They are attracted to light, just like moths! I'll get a photo of them tonight and post it next week!
Mayfly nymph - Water-penny
Ephemeroptera sp. - Eubrianax edwardsi
I found the Mayfly nymph pictured above (left) in the stream behind our house, they can also be found in rivers, lakes and ponds. Nymphs will live for 1 to 2 years, depending on species. They scrape and eat algae and other micro-organisms off of underwater rocks. As adults, Mayflies do not eat, and live for less than 24 hours! Just long enough to mate and lay eggs for the next generation!
I found the Water-penny Beetle larva above (right) in the North Yuba River. They prefer to live in aerated rushing rivers and streams, but are occasionally found in wave-washed lake shores. As larva they live for approximately 1 year, and survive on algae scraped from the surfaces of submerged rocks. I couldn't find information on how long the adults live other than, "they live for a short time and eat little to nothing"!!
Up in the Lakes Basin there were LOTS of dragonflies and flying insects! We also watched a dragonfly nymph (top right) crawl up out of a lake!!!
Last week I asked, "Why do you think dragonflies are commonly seen hovering over rivers, even though they are born in ponds?" Well, it turns out that dragonflies can be born and live in the slow moving sections of streams and rivers, not just ponds! I have never seen dragonfly nymphs in rivers or streams, but a watershed biologist I know has seen many of them! I apologize for posting the wrong information! So maybe dragonflies are commonly seen hovering over rivers because they were born there, and/or because there's lots of flying insects they can prey on! Probably both!
Western Yellow-bellied Racer Snake - Thamnophis elegans Southern Alligator Lizard - Elgaria multicarinata
Photos by Carl Butz ©2017
Reptiles in Combat!!!
A local resident and friend of mine, Carl Butz, took these amazing photos last week of a Western Yellow-bellied Racer Snake and a Southern Alligator Lizard locked in combat! WOW! What amazing photographs! He only had time to get a few shots before he had to leave. When he returned to the same site later, there was no sign of these reptiles! Racer snakes like to eat lizards, but it looks like this Alligator Lizard used a defense strategy that may have saved his own life! Unfortunately, we don't know who won. Who do you think walked away alive?
Leopard Lily - Lilium pardalinum
What's Blooming?
This past week I camped up in the Lakes Basin for three days! There were LOTS of flowers in bloom! There were hundreds of Leopard Lilies (above) along a path that ran through an aspen grove! Such beauty!
Death Camas - Zigadenus venenosus
In the wet meadow areas, one of the main flowers was Death Camas! This flower grows from an underground bulb. All parts of the plant are poisonous, particularly the bulb! There was an abundance of these lovely flowers in the meadows I saw!
Spreading Phlox - Phlox diffusa
I found this phlox growing on just about every rocky, sunny slope that I saw! Their fragrance is heavenly! Get down on your knees and smell them! They start out white in color and turn lavender with age!
Nesting News!
The American Robin is no longer incubating her eggs, but no chicks have hatched. Apparently she has abandoned her nest, or her eggs were eaten by a predator. I don't know what happened! However, up in the Lakes Basin their were lots of baby birds!
Common Merganser with Chicks - Mergus merganser
I saw this female Common Merganser with her chicks in Grassy Lake, in the Lakes Basin Campground. I watched them for about half an hour and even saw the chicks jump up and ride on her back!! Common Mergansers make their nests in a natural cavity or woodpecker hole in a live or dead tree, up to 100 feet off the ground and within a mile of water. The chicks are born precocial and can feed, swim, and fly within 1 or 2 days! As chicks they mainly eat aquatic invertebrates, including the aquatic insects featured in this blog! As adults they mainly eat fish, but supplement their diet with aquatic invertebrates. These Common Mergansers live in fresh water lakes and rivers. I saw three of them down on the North Yuba River just this morning!
Mountain Quail chicks - Oreortyx pictus
We came across these Mountain Quail chicks on one of our Lakes Basin hikes! Their mom really made a racket and rapidly flapped her wings to distract us from her chicks!! They were so tiny, and so well camouflaged, we could hardly see them when they "froze" in place! Mountain Quail make their nests on the ground. Their chicks are born precocial, and can readily follow their mother! We think we saw about 9 chicks altogether! WOW! Mountain Quail are uncommon so we were really lucky to see them!
What's happening up in Rock Creek?
What's happening with the fish in our rivers and streams?
What are the Hummingbirds feeding on, now that most of the flowers have dried up around here?
Check back next week for the answers to these questions and more!
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