Tag Archives: Zonotrichia leucophrys

Immature White-crowned Sparrow

Leonard and I always think of white-crowned sparrows (Zonotrichia leucophrys) as “winter birds”.  White-crowned sparrows breed in Alaska and Arctic Canada and winter throughout much of the Lower United States. A couple populations remain along the Pacific Coast and in … Continue reading

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ZW Gender Determination

Sex determination in mammals and most other animals is via the XY chromosome system. Simply put, the X and Y chromosomes determine the sex of the offspring. A female has two X chromosomes, one from the father and one from … Continue reading

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Winter Resident

For Leonard and I, a sure sign that winter is approaching is the return of white-crowned sparrows (Zonotrichia leucophrys). These distinctive sparrows with their black and white heads and pink or yellowish beaks summer in higher latitudes and winter throughout … Continue reading

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