Rainy Days!

North Yuba River

This week we got three days of rainy weather!  It really poured a few times, and we got a little more than 1/2" of rain in total!  It smells wonderful outside! 

Up in the Lakes Basin this week, we watched

bubbles form when raindrops landed on the surface of Summit Lake (below)!  The bubbles only lasted for a few seconds, but it was amazing to watch!  When a raindrop impacts a solid surface, a very thin film of air is entrapped under the drop and transforms into a bubble! It was beautiful to see!

Summit Lake 

(It's really more a pond than a lake!)

     Sulfur Shelf - Laetiporus conifericola      Giant Sawtooth - Neolentinus ponderosus

Fungi Season!

Cool, rainy, Fall days are when fungi start to show up!  Right now I've only seen fungi on the trunks of a few trees, and none on the forest floor yet.  Fungi, or mushrooms, are the "flower" or "fruiting body" of the fungi.  Instead of seeds, the fungi produce spores.  Fungi found on the trunk of a tree usually indicates that the tree isn't healthy.  Fungal spores are born on the wind, or a carried inside a tree on the feet of wood-boring insects. Once inside a tree, fungi begins to break down the wood.  

unknown fungi on oak trunk                          Wolf Lichen - Letharia vulpina

Although they are both found on trees, the fungi (left) and lichen (right) have totally different relationships with their host plants.  Most fungi, but not all, can be destructive to their host plants. Lichen, however, doesn't affect its host plant at all.  When found above ground in a living tree, most fungi can cause the tree's death and decay.  Whereas lichen found in trees, grows on the outside surface of the bark and doesn't tap into any of the trees nutrients.  Lichen produces its own food, with the help of a photosynthetic green algae that lives inside it!  In the cool damp days of Fall, lichen can become soft and pliable.  In the summer, lichens become brittle, dry and dormant!  In contrast, mushrooms will decay over the winter and be absent in Summer.

Lesser Goldfinches  - Carduelis psaltria    Pine Siskin - Carduelis pinus

Spotted Towhee (out-of focus in the background) - Pipilo maculatus

Garden Update!

On Wednesday, when the rain stopped around 5:00 pm, the seed eaters were back in our garden big time!  More Lesser Goldfinches, Pine Siskins, and Spotted Towhees showed up in our garden during that time, than I'd seen all week!  They spent several hours busily gleaning seeds from the Sunflower heads!  It was delightful to watch them and to listen them chattering away!

Anna's Hummingbird (male) - Calypte anna

Hummers

Only two hummers are in our garden these days!  Since the flowers are past their prime, we recently put up a hummingbird feeder in our garden.  Now the hummer (above) is ceaselessly defending the feeder!  I started thinking that maybe we shouldn't have put it up, because it might make the the hummer stay on too long and not migrate!  I looked it up on the Cornell website www.allaboutbirds.org, and here's what they had to say!  

"Keeping your feeders up has no influence on whether a bird will start its journey south. A number of factors trigger the urge for birds to migrate, and the most significant one is day length. As days grow shorter in late summer, birds get restless and start to head south, taking advantage of abundant natural food, and feeders where available, to fuel their flight.  Hummingbirds are no different from others and will migrate regardless of whether feeders are kept up. However, we encourage people to keep feeders up for several weeks after the last hummingbird leaves the area, just in case a straggler shows up in need of additional energy before completing the long journey south."

So I'll keep it up for a while longer!  Yahoo!  I love watching the hummers!

Steller's Jays - Cyanocitta stelleri

Steller's Jays

Steller's Jays are year-round residents in our neighborhood.  Right now they are busy eating the sunflower seeds in our garden.  Lately we've seen and heard them imitating the call of the Lesser Goldfinches!  They are opportunistic feeders and will eat seeds, fruit, insects, small mammals, and even carrion!  Their beautiful blue feathers are not blue because of pigment.  The color comes from the structure of the cells in the feathers that cancel out the red and yellow wavelengths, but reflect the blue wavelengths of light!  Here's a quote from an article written by the Park Ranger/Resources Management & Science Liaison of Yosemite National Park!

"Feathers are made of keratin, the same stuff your fingernails are made of.  As a feather that will become blue grows, keratin molecules grow inside each cell, creating a pattern. When the cell dies, a structure of keratin interspersed with air pockets remains. As sunlight strikes one of these feathers, the keratin pattern causes red and yellow wavelengths to cancel each other out. The blue wavelengths reflect back, giving the feather its color. Different shapes and sizes of air pockets and keratin make different shades of blue. This is what scientists call a structural color (as opposed to pigmented color.)"

You can easily see the effect of this structural coloration when watching a Steller's Jay move from sunlight into shadow!  Check it out!

White-Crowned Sparrow (immature-left & adult-right) - Zonotrichia leucophrys 

New Visitors!

These two birds are the same species!  The one on the left is in its first year.  The one on the right is an older adult.  They look so different!  These birds spent the summer at higher elevations in the Sierra, and are now migrating through our neighborhood.  They will spend the winter down in the foothills and Central Valley of California.  Their pinkish-orange bills are distinctive, and made them easy to identify!

We're so lucky that we have field guides that are the result of years and years of scientific research and study!  The internet is also an amazing source of information, that's right at our fingertips for free!  We are so spoiled!  If you would like to contribute to data that is used for the study of birds, consider joining the Cornell Lab - Project FeederWatch (www.feederwatch.org) that begins this coming November 11th!  Here's the info from their website!  

"Project FeederWatch is a winter-long survey of birds that visit feeders at backyards, nature centers, community areas, and other locales in North America. FeederWatchers periodically count the birds they see at their feeders from November through early April and send their counts to Project FeederWatch.  FeederWatch data help scientists track broadscale movements of winter bird populations and long-term trends in bird distribution and abundance."

  Think about joining Project FeederWatch.  I have!  I'll keep you posted on my FeederWatch observations this winter!

Deer (females) - Odocoileus hemionus sp.

Mule Deer species?

I finally got a deer photograph!  These three females were just off the main road, early one morning!  The more I look at them, the more questions I have!  Supposedly the main deer in our area are Columbian Black-tailed Deer.  Could there also be Mule Deer?  Are the two adults separate species?  They look different!  If I had gotten a photo of their tails, it would be simple to determine the species, but I didn't!  Black-tailed Deer have black tails.  Mule Deer have white tails with black tips.  

Is one older than the other?  Look how the adult on the left  has much smaller ears!  Does ear size vary within one species?  What could have caused the big scar on the middle top side of the left one?  Sheesh!  I'll post my photo on www.inaturalist.org and see what responses I get back!  

If you guessed that the bird in last weeks' photo was a Black Phoebe, you're right! I'll talk more about them next week!

If you guessed that the mammal tail in the last weeks' photo belonged to a Chickaree/Douglas Squirrel, you're right!

The year-round resident birds will be featured next week.  Can  you guess what species they might be?

I haven't found any fish fry or fingerlings in the river lately.  Either they've matured and moved to deeper water, or they've been eaten! I'll check again this week!

Whose track is this?

Will more mushrooms pop up?

Check back for the answers to these questions and more!

Your comments & questions are greatly appreciated! 

Please email me at northyubanaturalist@gmail.com! 

or

Click on "no comments" below, to post a comment!

Thanks!

The End of Summer!

  

This week, clouds and heavy thundershowers brought rain and hail to my neighborhood!  It poured rain for a solid hour last Tuesday and drenched everything, diminishing the ever-present threat of fire!  Yahoo!!

  It also really cooled off this week!  The daytime temps dropped from the high 90's to the mid 70's!  The nighttime temps dropped from the high 60's to the low 50's!  The crickets have stopped chirping at night and we're sleeping better!  

In just a few days, Sept. 22, Summer will officially end! 

Fall is definitely beginning!  It all happens so quickly!  

Western Gray Squirrel - Sciurus griseus

There are about 3 Western Gray Squirrels living close to our home, that have been busy burying Black Walnuts from our neighbors' tree.  They are called "scatter hoarders"  because they store small caches of  food in many different places, rather than one main location.  These caches are not what the squirrels solely subsist on in winter.  They actively search for food in winter, foraging for pine nuts, acorns, tree buds, and mushrooms.  

  Their nests are called "dreys" and are made of twigs, leaves, sticks, moss, lichen and shredded bark.  They prefer to make their nest in the top third of a tree, but will also nest in hollow tree branches or trunks.  During the winter, and in the nesting season, their dreys are covered on top.  In the summer they may also construct and open-air sleeping platform!

Like some birds, these squirrels molt twice a year!  The molt goes from head to tail in the Spring.  In the Fall, the molt goes from back to the front (excluding the tail)!    The tail only molts once, in the Spring, and the molted tail hairs are used to line the nests!  Pretty ingenious!  I wonder if they use their Fall molted hairs to line their nests for winter!  What do you think?

 

Douglas Squirrel or Chickaree - Tamiasciurus douglasii

There are 2 Chickarees that live right near our home!  They too have been busy storing seeds and nuts!  Unlike the Western Gray Squirrel, they will store lots of green cones for the winter in only one or two main areas.  During winter they will dig down through the snow to these caches, or "middens", and feast on the seeds in the cones!  They will also forage for food such as nuts, acorns, berries, tree buds, fungi, and insects!

In winter they mainly nest in hollow trees or abandoned woodpecker cavities.  They may also build a ball or cup-shaped nest 15'-20' up a tree, from twigs, moss, lichen and shredded bark.  In colder northern areas they may even dig a burrow underground, right under one of their food caches!

In summer their fur is reddish brown in color, in winter it is grayish brown. Like the Western Gray Squirrel, they molt or shed their fur twice a year, except for the tail!  The tail only molts once a year in the summer!   I'll bet they use it to line their nests, like the Gray Squirrels!

 Long-eared Chipmunk - Neotamias quadrimaculatus

Two of my biologist friends confirmed that the photo of a chipmunk I posted two weeks ago, is a Long-eared Chipmunk!  This is a new species for me!  Apparently it's pretty hard to identify chipmunk species, as they are so similar in appearance.  Knowing what elevation and habitat they are found in narrows down the choices.  I saw this one up at approximately 6500' in elevation, in a mixed conifer forest.

It was busy eating the seeds from green fir cones (above right)!  Unlike Western Gray Squirrels and Chickarees, Long-eared Chipmunks hibernate in an underground den during the winter!

Gray Foxes - Urocyon cinereoargentus

Gray Fox Update!

The foxes surprised me this week! There were three of them instead of two, and maybe even four!  I think I see another pair of ears just above the middle of the blurred green area!!!  Can you see them?  Wow!  The younger ones didn't stick around at all, and split as soon as they saw me!  The mom remained cool and calm as I slowly slipped away!  How exciting!!!  I sure hope to see them again!

River Update!

The river has dropped quite a bit and cooled off a lot!  My time IN the river has definitely shortened.  Brrr!  The good thing is that the algae on the underwater rocks is diminishing, so it isn't so slippery when you walk on them!

 

Water Strider Nymphs (?) - Gerridae sp.         Flame Skimmer - Libellula saturata 

In the shallows, the Water Strider Nymphs (above left) are still swimming around in groups!  They don't look much bigger than they were a few months ago!  It takes 60 to 70 days for the nymphs to mature to adults.  I first noticed them in late July, so they should be maturing soon!  One of my biologist friends thought that maybe these aren't nymphs, but rather the adults of a different Water Strider species!  I'll have to research that more and let you know what I find!

Right now, above and along the length of the river there are hundreds of big dragonflies zooming around!  They are probably catching and eating insects, as well as mating and laying eggs.  These adults will die off before winter, but their eggs will overwinter and hatch in the spring.  It is so beautiful to watch the metallic glint and gleam of their wings above the river in the late afternoon sun!

American Dipper - Cinclus mexicanus

This week I came across an American Dipper foraging for insects 

in the shallow rapids of the river!  

Instead of totally submerging itself, it was standing on the submerged rocks 

and only sticking part of its body underwater!  It was obviously finding 

insects to eat in the aerated rapids!  Wow!  

American Dippers are year-round residents, and will continue feeding in the river 

throughout this coming winter!

Garden Update!

The daylight hours are definitely getting shorter.  The sun leaves our garden by 
4:30 pm now, as compared to 7:00 pm in the middle of Summer!  I got the photo (above) of corn tassel shadows on corn stalks one late afternoon this week! 

Just last night a bear feasted in our garden!  This morning 2/3 of the cornstalks were broken down and all the cobs had been eaten!  The bear also broke up two squashes and ate all the seeds!  Luckily I had picked most of the squash yesterday afternoon!  The bear has also eaten most of the apples off our 3 trees, as well as some of the chicken manure we had in a bag!  I'm going out right now to pick the plums off our tree before it's too late!  That bear has an amazing appetite!

  

Lots of the dried Sunflower heads in our garden still have seeds, but the birds are leaving!  There's only a few Lesser Goldfinches still feeding in the morning!  The Bee Balm and most of the other flowers are past their prime and wilting.  We're down to 2 hummers, and we only see them infrequently now!  New birds are passing through!  I got the above photos of an unidentified Sparrow (left), a Yellow Warbler (center), and a possible immature American Goldfinch (right) one morning down in our garden!  I wonder how long it will be before the hummers are all gone!

What kind of bird is this?

If you guessed that last weeks photos were 

a Western Gray Squirrel's tail, 

and a Gray Fox's ears 

you're right!

Unless I happen to get a photo of a bat (highly unlikely!),

I probably can't figure out what kind of bats live here! 

 My apologies!

I've found out that Crayfish retreat into underwater burrows and enter a state of torpor in winter.  It's not winter yet, but maybe the colder water temperatures have affected them and that's why I'm not seeing them.

Where are the deer?

What birds are going to stay through the winter?

Did the fish fry mature?

Whose tail is this?

Check back next week for the answers 

to these questions and more!

Your comments & questions are greatly appreciated!  

Please email me at northyubanaturalist@gmail.com! 

or

Click on "no comments" below, to post a comment!

  Thanks!

Lightning Strikes!

Lightning strike near Lincoln Valley, Tahoe National Forest

This week we finally got some rain!  The newly dampened earth smelled heavenly!  Everything was so fresh and beautiful!  Unfortunately, we also got lots of lightning!  On Tuesday, Sept. 6th, there were 289 lightning strikes in the Tahoe National Forest, where I live!!!  Luckily, most of the lightning strikes were quite a distance away, mainly southeast of us.  Initially the lightning started 6 small fires, which the TNF Fire Crew immediately attacked.  So far no big fires have occurred!  We have more thundershowers in the forecast for next week.  Hopefully, the showers will be heavy.  I'm keeping my fingers crossed!

 Antlion larva - Myrmeleontidae  & two antlion pits

Antlions!

I've been noticing lots of small, 2"- 3" conical pits (above right) on the forest floor.  These pits are made by the larvae of Antlions (above left)!  The recent rain obliterated the pits I had photographed, but I noticed today that a lot of them are showing up again!  The larvae are tiny, only about 1.2 cm long!  That's the tip of my thumbnail in the photo!

Antlion larvae are pretty amazing little insects!  They hatch from an egg laid by and adult.  Then they begin making a pit in which they will ambush insects!  The pit construction is pretty amazing!   The larva will begin by walking backwards to form a circle, which is the outermost edge of the pit.  Working from the outside in, they begin removing the soil to form the pit.  They use their abdomen to shovel up the soil, as they continue to walk backwards!  Using their legs, they place a small pile of the shoveled soil on top of their head.  With a jerking motion of their head, they flip this soil out of the pit!  This process continues until they have made a conical pit about 2" deep and 3" wide!  The walls of the pit are steeply angled.  The angle is precise.  The larva maintain a critical "angle of repose" in their construction!  This angle is the steepest angle the soil can maintain without collapsing!  

Once the pit has been constructed the larva will bury itself at the bottom of the pit, with only it's mandibles showing.  The larva can sense the approach of an insect, through vibrations in the soil!  If an insect slips into the pit, the larva will grab it with its mandibles.  If the insect tries to climb out of the pit, the larva will throw soil at it to bring it back down.  When a larva catches an insect, it injects it with venom and enzymes through its mandibles.  Within a few minutes, the larva will then start sucking out the juices of the dead insect.  The empty carcass of the dead insect will be flipped out of the pit by the larva, when its used up!  Wow!  What an ingenious insect! 

Antlion larva have a very low metabolic rate and can go without eating for several months!  In winter they will dig down deeper in the soil and become dormant.  At some point in their life cycle, which can take several years, the larva will form a round ball-like chrysalis and pupate.  A month later an adult antlion will emerge from the chrysalis.  The adults are bigger than the larva, measuring 4 cm in length.  As soon as they emerge, adults go in search of a mate.  After mating, the females will lay their eggs in the soil.  The adults are rather feeble flyers, and "flutter" about at night!   The adults usually live for approximately 25 days, feeding on pollen and nectar.  Some adult species also eat small arthropods!

A friend of mine, Jerry Tecklin, has been studying and photographing antlions for years!  He kindly supplied the photos (below) of an antlion larva and adult.  The larva is covered in white sugar, because that's the "soil" Jerry keeps them in!

  Antlion larva & Antlion Adult - Myrmeleontidae

Photos by Jerry Tecklin ©2017

Mylitta Crescent - Phyciodes mylitta    Cabbage White - Pieris rapae    West Coast Lady - Vanessa anabella

Garden Update!

Lots of butterflies are still flitting around the garden feeding off the blooming flowers! They will lay eggs before the temperature gets a lot colder, and they won't be able to move.  These eggs will over-winter and hatch in the spring.

Long-horned Bees - Melissodes sp.

Native Bees!

This morning when I went down to our garden, there were lots of Long-horned Bees (above) that were still "sleeping" on the flowers!  Apparently it was too cold for them to move!  I was able to get super close to them because they were immobile!  There were also some new insects (below) that weren't moving as well!  I don't know what they are, but will try to identify them this week.  What a fun morning!

                      Unknown Bee (?)                      Urban Anthophora and a small unknown bee

Male                                        Juvenile                           Female

Lesser Goldfinches - Carduelis psaltria

Lesser Goldfinches!

I finally got a photo of the male Lesser Goldfinch, with his distinct black forehead and crown!!  He's been showing up in the early evenings in our garden.  I also got a photo of a fledgling with fluffy downy feathers!!  Lesser Goldfinches can have 1 to 3 broods in a season.  This must have been a fledgling from their last brood.  There are actually about 6 Lesser Goldfinch fledglings in our garden!  One of them flutters his wings to get his parents to feed him!  The rest of them forage on their own!  As the days get shorter and temperatures drop, these lovely colorful birds will migrate down to lower elevations in California for the winter.  Right now it is pure pleasure to watch them probe the Sunflower heads for seeds!

Spotted Towhees - Pipilo maculatus 

adult male & fledgling

Spotted Towhees!

I also finally got a photo of an adult male (above left) Spotted Towhee!  The adults blast out of our garden as soon as they see me approaching!  I've repeatedly watched 6 or 7 of them leave all at once!  The fledgling, however, doesn't seem as wary of me, and is a lot easier to photograph!  I caught the photo (above right) of him all puffed up, on a recent cold morning! 

Both the adults and the fledglings have red eyes.  The color apparently comes from red oil droplets in the cones of the retina.  These red droplets increase contrast and sharpen distance vision, especially when hazy!   Maybe that's why the can see me coming from a long ways away! 

The coloration of birds' eyes varies greatly!  Some eyes change color as the birds age.  Some change color during the breeding season!  In some species, the males and females have totally different eye color!  Both the male and female adult Towhees have red eyes.  The fledglings' eyes are initially brown in color, and change to red as they mature.  

The birds in the photos below are both Green-tailed Towhees, but the one on the right has red eyes and the one on the left has brown eyes.  The one on the right was taken in the Spring, the one on the left was taken this week.  Do you think their eyes change color during breeding? 

    

Anna's Hummingbird (male) - Calypte anna

Hummers!

This little male Anna's Hummingbird is still defending his territory in our garden!  This week he took a break to preen his feathers!  First he puffed them way out, and then he poked and prodded around in them with his beak!!  When he was finished preening, all his feathers flattened back into position and some of his metallic feathers caught the light!  Wow!  What a difference in his appearance! 

        Rufous Hummingbird (male) - Selasphorus rufus          Anna's Hummingbird (juvenile) - Calypte anna

This male Rufous Hummingbird (above left) and the juvenile Anna's Hummingbird (above right) are some of the hummingbirds that are getting driven off by the male Anna's Humming bird! They feed off of other flowers in our garden, and sit and wait for a chance at the Bee Balm!

Right now this Rufous Hummingbird is just stopping by for a week or two, on his 3,900 mile migration from Alaska to Mexico! The Anna's Hummingbird will also migrate but not as far as the Rufous Hummingbird. It may just migrate to a lower elevation in California, or the southwest, or maybe the northern end of Mexico! That's such a long way for these tiny birds to fly! It's amazing!

Gray Fox - Urocyon cinereoargenteus 

Gray Fox Update!

I lucked out again photographing the Gray Fox near our garden!  This time he saw me and barked!  It looks like he's howling, but he is only barking his hoarse cough-like bark!  I only peeked from the bushes for a few seconds, but he still saw me!  I'll be more cautious next time.  I don't want to disturb them!!

Gray Fox - Urocyon cinereoargenteus 

There's another Gray Fox in our neighborhood!  I've seen him several times, but he's always been far away!  When I first saw him, about a month ago, he looked pretty scrawny and sickly.  Yesterday, my neighbor and I saw him quite close as we walked back from the river!!!  He looked a lot better!  His fur doesn't have the same coloration as the ones near our garden, but he's getting some of the red coloration on his belly and his throat now!  He doesn't look as skinny as he was a month ago and that's encouraging!  I sure hope he continues to improve in health and appearance in the months to come.  I think he is just beautiful!

Who's tail is this (above)?

Bears and Crayfish have been eluding me! 

Hopefully, I will investigate them this coming week!

The bear poop from last week was mainly filled with the skins of grapes and apples that grow all over my neighborhood!

What's happening down at the river?

What about those bats?

Where are the deer?

Whose ears are these (below)?

Check back next week for the answers 

to these questions and more!

Your comments & questions are greatly appreciated!  
Please email me at northyubanaturalist@gmail.com! 
  Thanks!