Sunday, November 18, 2018

Bare Branches

Bullock's Oriole Nest

It's been windy off and on this week, and most of the leaves have been blown off the trees.  To my delight, the lack of leaves has exposed many empty bird nests!  Bullock's Orioles love to nest in our neighborhood.  Usually only the females will build the nests, but males have been known to assist.  They weave pouch-like, hanging nests out of grasses, string, twine, horse hair, fishing line, shreds of leaves, strips of bark, plastic tarp strips, carpet wool, and basically whatever is available.  They line the inside of the nest with cottonwood or willow cotton and feathers!  They will not re-occupy an old nest, but will re-use the old materials to build a new one.  It can take up to 15 days for the nest to be completed!  So far I've seen 9 of their nests in my neighborhood!  

Bullock's Oriole and Brewer's Blackbird Nests

The tree on the left has 3 Bullock's Oriole nests!  The bottom one was made and occupied two springs ago.  The middle one was made and abandoned this spring, probably because the fishing line was brittle and broke off.  The top one was made and occupied this past spring.  I'm almost positive that the same female Bullock's Oriole built all these nests, because they are in the same tree!  To me it is absolutely amazing that a bird can fly approximately 3,000+ miles from Costa Rica, to nest in the exact same spot in our neighborhood, 2 years in a row. WOW!!!

I've also seen 3 Brewer's Blackbird nests in the bare lilac bushes down by our garden.  The nests are made by the females with no help from the males.  The outer cup is a bulky structure of twigs and weed stems.  The inner cup material is usually rootlets and grass cemented by mud. The cup is then lined with grasses and sometimes feathers and horse hair! 

Oriole nests sometimes hang around for years!  I'm not sure if the Blackbird nests will last through the winter.  I'll just have to wait and see! 


Red-breasted Nuthatch - Ruby-crowned Kinglet
Sitta canadensis - Regulus calendula

In the leafless branches of the bushes I've been seeing lots of little birds!  Most of them have been Ruby-crowned Kinglets (above right).  These tiny birds (4.25" long) breed and nest up to 9,000' in elevation!  They come down to our neighborhood during the colder months and forage for tiny insects.  Being so small they can glean insects from the tips of branches.  They have a fluffy thick plumage that keeps them warm, but they will migrate down to the foothills for the winter. 

Not as commonly seen, but frequently heard are the tiny (4.25" long) Red-breasted Nuthatches.  They spend most of their life in the higher elevations, but can be found at almost any elevation after the breeding season.  I've seen them foraging for insects and seeds, face-first down the trunks of conifers, as well as on the ground.  They will also cache seeds and insects for the cold winter months!  I love their nasal, beeping calls!

Persimmon - Cedar Waxwing - Orchard Apples
Bombycilla cedrorum

Fruit Eaters!

There have been LOTS of American Robins in our neighborhood lately.  They have been busily eating the dried-up blackberries. During the fall and winter Robins mainly eat fruit, as most invertebrates are scarce!  They might stay here year-round if they can find enough to eat, but will probably migrate down to lower elevations for the winter.  While I was watching the Robins eat the blackberries one late afternoon, a small flock of Cedar Waxwings landed in a nearby Black Locust tree!  I was so surprised to see them again!  They too are fruit eaters!  I have since found two possible Cedar Waxwing feeding sites.  A persimmon tree and an apple tree up by the cemetery have definite signs of being eaten by birds!  I went back several times this week to see if any birds were feeding on the fruits.  I didn't have any luck, but I'll keep looking!

American Robin on Blackberry vines - Turdus migratorius

Sugar Maple and Grizzly Peak

The Nature of Leaves

Here is one of my favorite quotes about trees and leaves, 
organisms that we often take for granted!

“Concerning trees and leaves... there's a real power here. It is amazing that trees can turn gravel and bitter salts into these soft-lipped lobes, as if I were to bite down on a granite slab and start to swell, bud and flower. Every year a given tree creates absolutely from scratch ninety-nine percent of its living parts. Water lifting up tree trunks can climb one hundred and fifty feet an hour; in full summer a tree can, and does, heave a ton of water every day. A big elm in a single season might make as many as six million leaves, wholly intricate, without budging an inch; I couldn't make one."
                                                       from Pilgrim at Tinker Creek by Annie Dillard


Leaves are amazing!  They are the food factories of plants!  During the process of photosynthesis light is absorbed by the chlorophyll pigments and carbon dioxide is absorbed through the stomatal pores. This sunlight, plus carbon dioxide, plus water, combine to form carbohydrates/food for the tree.  In most leaves, the top surface is where photosynthesis occurs, and the underside is where transpiration occurs.  Quaking Aspens, however, can photosynthesize on both sides of their leaves!  In order to absorb the most amount of sunlight for photosynthesis some leaves, and even entire plants, change their orientation to the sun during the course of a day!  This process is called phototropism.  What actually happens is that the plant cells furthest from the sun elongate.  This causes the plant to "curve" or move towards the sun! 
Green plants are the only living organisms on the planet that can manufacture their own food! 

A by-product of photosynthesis is oxygen, which is released into the environment. Through photosynthesis, green plants contribute to the oxygen we breathe. 70% of the oxygen on the earth is produced by phytoplankton (microscopic plants) in the ocean, 28% is produced by rain forest plants, and 2% by other trees. The maintaining of healthy oceans and forests is critical for our survival.  If you can, support organizations that actively campaign for the preservation of our wild places!  It's critical!

As the hours of daylight decrease and temperatures drop, the chlorophyll in leaves breaks down, photosynthesis stops, and the anthocyanins and carotenoids that have been masked by the chlorophylls become visible.  This is what causes the beautiful fall colors in our trees!  These seasonal changes also cause the leaves to eventually fall off the trees.  If the leaves of our local deciduous trees stayed on through the winter, the water in their cells would freeze and destroy the plant tissues.  Evergreen trees, like conifers and live oaks, can keep their leaves during winter because they concentrate chemicals in their cell fluids that work like anti-freeze! 

Five-finger Fern - Mountain Dogwood
Adiantum aleuticum - Cornus nuttalli

 North Yuba River - 11/11/18 and 11/15/18

Smoky and Cold!

The smoke from the tragic "Camp" Fire reached us this week.  A few days were REALLY smoky.  I am just so relieved that we don't have any fires in our area.  It has also been really cold, 30's at night 60's during the day.  However, as of this morning the weather watchers are forecasting rain on this coming Wed.-Thurs.-Fri.-Sat!!!!  Yahoo!!!  I'm keeping my fingers crossed!  Hopefully it will put the "Camp" fire out, and drench our forest!  Wouldn't that be fabulous?!!!

Is that Magpie still hanging around?

Where are the foxes and deer?

Will it rain a lot?  Is it going to snow?

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

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