BRIGHT FOR BREEDING Aggressively defending a territory is more important than you might think. Males will do whatever they can to defend their resources against a rival male, sometimes fighting to the death. The stakes are so high that even slight differences, imperceptible to people, can make the difference between breeding or not. A male Yellow-headed Blackbird, for example, actively defends its territory by flashing the bright yellow feathers on its head and chest. Combined with body postures and loud raspy calls, the bold feathers play a major role in the male’s success or failure to attract a female and breed.
Studies have shown that male bluebirds with the brightest blue feathers are more successful at claiming and maintaining nesting cavities and territories than males with duller feathers. We may not be able to see the difference, but birds can. Not only do male bluebirds use their vibrant blue feathers to attract females, but color intensity also helps to establish the dominance hierarchy with nearby males.
In more studies, when researchers altered the color of a male by dulling or brightening it, the change dramatically increased the bird’s territorial challenges. When he was made duller, the number of territory disputes rose. When he was made brighter, the male neighbors regarded him as more dominant and fought more often and more aggressively with him for his territory.
MARKING DISTINCTIONS Male and female Northern Flickers are identical except for facial marks, called malar marks. Depending on the locality, these are black or red in males and absent in females. In a study during breeding season, a female was captured and black marks were glued to her face. When she was put back with her mate, he chased her aggressively, trying to make her leave. After her marks were removed, his behavior returned to normal. The male had been unable to recognize his mate with the simple change of malars. This demonstrates the importance of markings and feather coloring in the bird world.
Nearly all of the world’s 200 woodpecker species show some feather coloration that differentiates males from females. This difference between the sexes is called sexual dichromatism. Usually it just consists of a red mark on the back of the male’s head, such as in Downy and Hairy Woodpeckers. In male Red-bellied Woodpeckers, the crown is red, while in females it is gray. It appears that these small color differences are extremely important in sexual identity.
The color and condition of feathers play a major role in sexual maturity in many birds. Most smaller songbirds obtain their full adult plumage at 1 year of age. However, 1-year-old male American Redstarts resemble the dull adult females, not the flashy adult males. They won’t get their bold black and orange colors until they reach 2 years. Red-headed Woodpecker young have gray heads that turn red after 1 year of age, indicating they are sexually mature.
Appreciate the Adornment of Birds
Feathers―possibly the most amazing body covering in the entire animal kingdom. No other covering does all that feathers do. From the delicate down feathers that keep birds warm to the sturdy flight feathers that allow birds to soar, these marvelous structures are something to admire. This coffee table book is filled with stunning, incomparable photos, and it promises to delight as it walks you through the world of feathers.
Book Features:
Everyone who celebrates nature will appreciate this beautiful, detailed look at feathers.
Stunningly beautiful throughout, "Feathers: A Beautiful Look at a Bird's Most Unique Feature" is a 'must' for all ornithologists, as well as very highly recommended for the non-specialist general reader with a passing interest in the feathered beauty of birds. Replete with all manner of facts about feathers, "Feathers: A Beautiful Look at a Bird's Most Unique Feature" will prove to be an enduringly popular addition to personal, community, and academic library collections. It should be noted that "Feathers: A Beautiful Look at a Bird's Most Unique Feature" is also available in a Kindle edition.--Carl Logan"Reviewer's Bookwatch" (01/01/2015)
Naturalist, wildlife photographer and writer Stan Tekiela is the originator of the popular state-specific field guide series. Stan has authored more than 190 educational books, including field guides, quick guides, nature books, children’s books, playing cards and more, presenting many species of animals and plants. With a Bachelor of Science degree in Natural History from the University of Minnesota and as an active professional naturalist for more than 30 years, Stan studies and photographs wildlife throughout the United States and Canada. He has received various national and regional awards for his books and photographs. Also a well-known columnist and radio personality, his syndicated column appears in more than 25 newspapers, and his wildlife programs are broadcast on a number of Midwest radio stations. Stan can be followed on Facebook and Twitter.
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