![\"\"](\"https:\/\/featheredphotography.com\/blog\/wp-content\/uploads\/2019\/08\/american-goldfinch-5374-ron-dudley.jpg\" "\\"american-goldfinch-5374-ron-dudley\\"")
<\/p>\nAnd an interesting goldfinch strategy for combating brood parasitism of the Brown-headed Cowbird.<\/p>\n
<\/p>\n
<\/p>\n
1\/6400, f\/6.3, ISO 800, Canon 7D Mark II, Canon EF 500mm f\/4L IS II USM + EF 1.4 III Extender, not baited, set up or called in<\/em><\/p>\n A little over a week ago I found this male American Goldfinch feeding on thistles in the mountains. I’ve always liked the color combinations in my photos when goldfinches in breeding plumage are foraging on the red-purple thistle flowers and in this case I think the flower cluster is particularly interesting and attractive. A different choice of aperture would have helped to get the tail sharper but I chose not to take the time to make the adjustment.<\/p>\n American Goldfinches are among the latest songbird breeders in North America, often waiting to nest until early July. Flowering thistles are an important food plant for them so it’s thought that they delay nest building until that food source will be available at the best time for feeding chicks. A single musk thistle plant can produce as many as 120,000 seeds so thistle is a source of abundant food for them.<\/p>\n American Goldfinches are almost exclusively seedeaters but unlike most other granivorous songbirds they don’t temporarily switch over to an insect diet while feeding nestlings, suggesting that they’re well adapted to fulfilling the high protein requirements of their growing chicks from a diet of seeds. This may be an adaptation meant to combat some of the negative effects of brood parasites, especially the Brown-headed Cowbirds that lay their eggs in the nests of other species.<\/p>\n Cowbird eggs laid in goldfinch nests hatch successfully but nestling growth is retarded (likely because of insufficient protein from a seed diet) and they nearly always die before they fledge.<\/p>\n Ron<\/p>\n <\/p>\n <\/p>\n","protected":false},"excerpt":{"rendered":" And an interesting goldfinch strategy for combating brood parasitism of the Brown-headed Cowbird.<\/p>\n