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!