Feathers!

Bird feathers are beautiful, complex structures. They serve a wide variety of purposes including flight, insulation, and ornamentation.  All birds have lots of feathers, up to 25,000 per bird!

Feathers are not living structures and cannot be repaired by a bird.  The process of getting rid of old, worn feathers and growing new ones is called "molting."  Birds usually molt once a year.  Most often molting begins after the reproduction cycle has finished, and before migration begins.  The molting process can take up to a month to be completed.  The feathers are lost gradually, in a symmetrical pattern across the body.

Right now is one of the premium times for birds to molt.  That's why I've been finding lots of individual feathers on the ground lately!

"Pterylosis" is the scientific name for the arrangement of feathers on a bird.  Each feather has a very specific place and use!  The downy feather (above left) is probably from a young bird, and was used for insulation.  The contour feather (above right) is probably from a large adult bird such as a Canada Goose, and was used for flight.  The beautiful breast feathers (below) are from a Sharp-shinned Hawk, and were probably for insulation and ornamentation!  I think they are all incredibly beautiful!

Sharp-shinned Hawk (breast feathers) - Acipiter striatus

Bullock's Oriole - Icterus bullockii

Preening & Parasites

the Maintenance of Feathers 

Whenever I'm watching birds, like the Bullock's Orioles above, they are often scratching or digging into their feathers with their bills and feet.  Apparently what they are doing is removing parasites, dust, and dirt from their feathers!  They are also using oil from their preen gland, located just above the base of the tail, to help waterproof and keep feathers flexible.  Additionally, they are aligning each feather in its optimum position!  

Birds have to deal with a lot of parasites!  Bird Lice eat their feathers and skin.  Feather Mites feed on feathers or skin.  Feather flies are blood sucking parasites!  To deal with these parasites, birds sun themselves, take dust baths, bathe in water, place ants that exude formic acid on their feathers, and even occasionally apply plant juices to get rid of them!

Common Merganser female & ducklings - Mergus merganser

River Bird Update!

I watched the Common Merganser female (above) and her four ducklings on the river this morning!  I was surprised to see these downy ducklings, this late in the season!    They can feed themselves within one or two days after they're born, but remain with their mother for 60 to 75 days.  Winter migration will begin in October.  Hopefully these ducklings will mature by then! 

Great Blue Heron - Ardea herodias

Four mornings in a row, a Great Blue Heron has honked as he flew past me along the river this week!  These large birds are the only species of heron living above the foothills of the Sierra!  They are 4' tall and have a wingspan of 7'!  They are usually solitary, except when nesting colonially.  Fish, frogs, crayfish, reptiles, other birds, and aquatic insects are their main prey.  Maybe this is the critter that leaves all those Crayfish shells behind! 

Gray Fox - Urocyon cinereoargentus

Gray Fox!!

Just this morning when I was walking my dog, Buster, this Gray Fox barked at us from farther up the road!!!  When we got close to where we thought the fox had been, I saw him watching us from the bushes!  WOW!  I just got this one photo before he dashed off!  How exciting!  I've seen foxes in the evening, but it has always been too dark to photograph them!  Earlier this Summer, my neighbor saw an adult fox playing with its offspring in the same area!  I hope I get some more photos to post soon!

Lizard Hatchlings!

I've seen several lizard hatchlings in my garden this week!  The eggs must have just hatched, after being buried underground for several months!  They are so tiny, only about 3" long!  I think these are Northwestern Fence Lizards.  I didn't pick any of them up, but apparently their bellies are blue!  The neutral colored pattern on the rest of their body really camouflages them!  These lizards don't have any vocal chords, so they communicate solely with body language!

Western Fence Lizards' blood carries a special protein that kills the Lyme Disease bacterium, Borrelia!  This bacteria is carried in the guts of ticks.  If an infected tick bites a Western Fence Lizard, the Borrelia is completely killed off!  Wow!

       Monarch Butterfly - Danaus plexippus  & Western Tiger Swallowtail Butterfly - Papilio rutilus rutilus

Butterflies!

There are still lots of Butterflies flitting around our neighborhood!  Since it's not bird nesting season, they don't seem to be prey for lots of birds right now!  I love how their wing patterns are also found on their bodies!  Very fancy!

Monarch butterflies migrate south to spend the winter as adults.  Most Swallowtail Butterflies do not migrate for winter.  They pupate and overwinter locally, in a chrysalis.  

 The only guess I got back from my readers, about what they thought the Black Bear had been eating, was from my sister!  She guessed he was eating Grape Nuts Cereal!  Nope!  If you guessed that the Black Bear had been eating Blackberries you guessed right!  It's all the tiny berry seeds that showed up in his poop! 

OK, so next week I'll talk about Crayfish and where they live!  I have some friends coming to visit, that I'm sure will catch a couple of them for me!  

Will the Merganser ducklings survive?

What else is busy pollinating the flowers besides Butterflies?

Are the Yellow Jacket Wasps emerging soon?

Check back next week for the answers to these questions and more!