A 'ringtail' harrier at Cley, Norfolk, from October 1957 to April 1958 was identified as a first-year Hen Harrier Circus cyaneus of the Nearctic subspecies hudsonius (previously known as Marsh Hawk in North America, but now called Northern Harrier) because, after lengthy research, it was found to resemble immatures of that subspecies seen in the USA (Brit. Birds 64: 537-542). As noted by D. I. M. Wa


Stay at the forefront of British birding by taking out a subscription to British Birds.

Subscribe Now