
THE JUVEHAL PLUMAGE OF THE ATIGRICAN WOCDCCCK 
Allen J. Duvell 
Ue S. Fish and Wildlife Service, Laurel, Maryland 
In a study of the possible variation in populations of the Am. 
Woodcock (Philohela minor) from various Seen wer its breeding renge, 
one of the primary requisites has been to be able to cifferentiate 
ima ture from adult birds. Use of various measurements such as wing 
and bill lengths are dependent vpon proper ageing or sexing of the 
samples. It is known that in certain species such as the Redwing 
(Agelaius phoeniceus) first year birds have decidedly shorter wings 
than adults (Howell anc van Rossem, 1928). Any comparison of measure- 
ments, therefore, should consider the age factor when it is possible 
to determine this. It is especially importent when comparisons are 
made of fall specimens when immature birds would be present in most 
samples. The present study was made with specimens in the National 
collections in Washington, suvplemented by material borrowed from 
many museums and universities. The writer is especially indebted to 
William Shelcon, Howard Mendall, Bruce Wright, Vincent Reid, and 
Leslie Glasgow, who had specimens collected for the study. 
In attempting to separate juvenal from adult woodcock specimens 
no difficulty was experienced in separating juvenal birds which were 
obviously not full grown. At first, however, many birds taken in June, 
July and August could not be satisfactorily classified as to age, even 
though bill measurements were as large as 70-73 millimeters which is 
about the average for adult females. Jt may be noted in passing that 
the collectors have had the same difficulty as indicated by a number 
of summer specimens in the collection being labeled "adult" and which 
proved later to be actually in juvenal plumage. A perusal of the 
literature of the more important American bird publications offered 
little help since most stated that the juvenal plumage was similar to 
the adult, but softer and looser in textures, We now know that this 
difference, if discernible at all, is not the most obvious difference. 
Even at this writing there is no certainty as to the actual sequence of 
moult from the juvenal to adult or nuptial plumage. Ridgway, (1919:156) 
even omitted description of the juvenal plumage. The best account of 
this plumage, although incomplete, is that by Pettingill (1936:19) in 
which he gave the clue needed to positively classify birds as juveniles 
before the completion of the post-juvenal moult. This author states 
that in the juvenal plumage the black-centered feathers of the back, 
scapulars and some of the secondaries [tertials] have a conspicuous and 
even terminal border of "Light pinkish cinnamon," and that in the adult 
plumage these terminal borders are not pronounced and in the majority 
of cases do not occur, Although adequately illustrating the feather 
pattern of certain juvenal feathers, the manner in which these were 
compared with corresponding adult feathers does not clearly indicate 
the marked difference. 
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