Monday, December 23, 2019

Northern Harrier

Northern Harriers from Nisqually National Wildlife Refuge, the first on 13 December 2019, the second two days later. With its long wings and tail, harriers fly and glide low over marshes and meadows as the hawks search for their main prey, small mice and birds. The number of breeding birds is strongly correlated with spring vole numbers.

During their first year, the sexes are similar. The second bird is probably a young male, because of its yellow eyes and relatively small size. First year females have brown eyes. Older females’ eyes change to yellow after several years, and older males sport gray plumage. Thus the first bird may be an older female. Both sexes and all ages have white rumps, not visible in either of these images. These hawks are almost owl-like, with their binocular vision. Their facial disks work as parabolic reflectors. Northern Harriers can locate their prey by sound and by sight.

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