Tuesday, July 24, 2018

Goldfinch - mating


AMERICAN GOLDFINCH 
            (Part Two)                
MATING & RAISING THEIR YOUNG



Although the female is a pretty finch in her own right, she is drab compared
to male in his brilliant mating plumage.
   
In early spring the American Goldfinch male undergoes one of the most dramatic color changes of all  finches, from its winter plumage of olive green with black markings to its brilliant mating feathers of yellow with black wings, 
black tail and black forehead.



It is almost impossible to to miss the male when he visits the summer garden.

For back yard bird feeders it is amazing to watch this transformation take place. The males feathers change in blotches rather than one area at a time.
The male bonds with the female in late winter and then males feathers change early in the spring.  In spite of this, Goldfinches are the last birds in our area to mate, waiting until July or August. This delay is due to the goldfinches incredible reliance on 'Thistle plants', a family of hardy native plants that bloom in midsummer. The goldfinch use the cottony fluff of the thistle plant  as the main substance in the construction of the nest and its seeds are the main food source for feeding the young.



The life cycle and mating of the American Goldfinch is linked closely to our native thistle plants.

The nest building begins in late June or July. The nest is built a few feet off the ground with soft materials and includes twigs and sticks found nearby. The nest is constructed so tightly that it can hold water and is held in place with spider webbing or other sticky substances.




When thistle and other plants such as milkweed create their fluffy seed covering
the rush is on for goldfinches to  build their nest and mate.


After the nest is constructed  the pair leave it for a week or so and return when the timing is right. When they return the female lays from two to seven eggs and incubates them for fifteen days while the male guards the nest and feeds her.


After the eggs hatch the male stays with the clutch while the female protects the
nest and feeds the family, including the male. 

Once the chicks are born the male and female change places. The male stays with the young while the females guards the nest, forages for food and returns to feed the chicks by spitting up undigested food into their mouths. Goldfinches are almost totally seed and grain eaters. This means they extract enough protein from the seeds to promote the rapid healthy growth of the young.  Almost all other birds feed their young insects for their high protein level.*
After eight days the young are more independent and can leave the nest while staying close to the parents. After fourteen days the young can fly but remain close to the parents three to four weeks to learn the skills they need for survival.



The male stays with the young until they can fend for themselves.
After the young have fledged the nest the female may abandon them and find a
new mate to have a second clutch.




 For this reason it's good to have a feeders ready with black oil seeds so the parents can teach the young how to use them. Winter bird feeders have become a major source of food, especially during severe winter snow storms.  
If all goes well the female will now leave her young with the male and seek a new mate to have a second clutch in  the same year.



*The Brown Headed Cowbird, a brown female and the male, a black bird with a brown head mate. The female lays their eggs in other birds nest for the host to feed and raise. 
Cowbird eggs laid in Goldfinch nests hatch, but without the insect diet starve to death before fledgling.



We will discuss the Brown headed cowbirds in an upcoming article.

Part one: Goldfinches- winter bird feeding was written in March 2018 
 
              
Enjoy the summer season,                                                        
 James

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