Richard Meinertzhagen was the most dynamic ornithologist of his generation - as an observer of birds, as a researcher and as an author of books and papers for specialist journals.

He was not a trained scientist. Constant pleas to his father to send him to study Zoology were in vain.

After a brief unfulfilling stint as a clerk for the family-owned bank, he joined the Army and enjoyed an impressive career, rising to the rank of Colonel.

His travels as a soldier, and later as a diplomat, took him to many exotic locations in East Africa and Arabia.

These journeys, plus others in later life, also provided him with countless opportunities - none of which he wasted - to study every aspect of birdlife from behaviour to the environmental factors that influenced size and plumage in a range of different species.

On one of his expeditions, he discovered a new species, the Afghan snowfinch - also known as Theresa's snowfinch after his cousin and long-term companion, fellow-naturalist Theresa Clay, herself an expert on the lice found in birds' feathers.

What fascinated Meinertzhagen, above all, was the mystery of migration - he recorded his own plentiful observations, both on land and when in an aeroplane, and he pored through every book and research paper he could find on the subject.

In 1920, he collated his research which was published, in 1920, in an edition of The Auk, quarterly publication of the British Ornithologists Union of which he was a longstanding member.

Despite the passage of more than a hundred years, most of his analysis and conclusions are as relevant today as they were then.