48 
ANAS WYVILLIANA 
supraocular and transocular stripes in Hawaiian Ducks are very indefinite. They are barely per- 
ceptible in the female and absent in the male. A careful comparison of the type of Anas aberti with 
the four other undoubted female specimens in the Museum of Comparative Zoology and the U.S. 
National Museum, shows no essential difference in color, pattern or size, hence it appears that in the 
absence of any further material from Mexico Anas aberti must be considered as a female Hawaiian 
Duck, accidentally occurring in Mexico and no longer deserving specific distinction (Phillips, lOPJa). 
GENERAL HABITS 
Haunts. This duck is without doubt closely related to the Mallard and is perhaps, 
as R. C. L. Perkins (1903) suggests, a dwarfed island form of the latter. It may be 
comparable to Coues’s Gadwall of the Fanning Island group. It is a fresh -water duck, 
but by no means absent from the coast, and according to Henshaw (1902) loves to fol- 
low the windings of the little mountain streams as they thread their way through the 
tangled woods, here and there forming little pools of standing water. Perkins 
found it equally at home on the hottest coasts, where suitable ponds are found, or 
in the mountains, up to 7000 or 8000 feet. Not infrequently he met with it in the 
boggy parts of the forest, and in localities quite heavily timbered, frequenting tiny 
pools of water in hollows. Even in the precipitous mountains, many scattered pairs 
visit small pools that form at the foot of waterfalls, temporary or otherwise, leaving 
these haunts at nightfall to visit the rice and taro patches of the valleys below. 
w ARINESS. On the mountain streams it is usually tame, rising slowly from the 
water and affording an easy mark (R. C. L. Perkins, 1903). Henshaw found the 
Hawaiian Duck tame and unsuspicious in localities where it was not harassed. 
Flight. Nothing has been noted that is characteristic of the flight. The birds 
are usually seen in pairs, or very small companies. Bryan and Seale (1901) speak of 
meeting wdth a flock of fourteen, and Rothschild (1900) states that after the breed- 
ing season they stay in flocks, for his collector. Palmer, observed aggregations on 
Niihau numbering at times not less than one hundred. 
Association with other Species. R. C. L. Perkins (1903) occasionally saw 
members of this species in company with Domestic Ducks, but it is doubtful if it 
ever hybridizes with them, for it is too small, and furthermore the size is uniform, 
while hybrids would be very much larger. In the winter season it undoubtedly 
associates with the Pintails and Shovellers, and with other northern ducks that 
visit the islands. 
Voice. The note is similar to that of the Mallard, but less powerful. The females 
quack loudly as they rise from the water, just as female Mallards do (R. C. L. 
Perkins, 1903). 
Food. The stomachs of a pair shot in October, 1899, on the coast of Kauai were 
