AVIFAUNA OF LAYSAJV, ETC. 



265 



69. NYCTICORAX NYCTICORAX N^VIUS [Bodd\ 



AUKU KOHILT, AUKU. 



Ardea navia, Boddaert, Tabl. PI. Enl. p. 56 (1783). 



Ardea exilis (non Gmelin !), Dole, Proc. Boston Soc. N. H. 1869, p. 303; Peale, U.S. ExpL Exp. p. 216 

 (1848). 



Nycticorax nycticorax ncevius, Stejneger, Proc. U.S. Nat. Mus. x. p. 8t (1887), xi. p. 102 (1888). 

 Nycticorax griseus, Wilson, Aves Hawaiienses, pt. vii. (June 1899). 

 Nycticorax nycticorax (partim), Sharpe, Cat. B. Brit. Mus. xxvi. p. 146 (1898). 



I prefer to keep the American form of the Night-Heron subspecifically distinct, because in 

 nearly every case the bill and wings are decidedly larger than in the Old World form. The 

 Hawaiian birds certainly belong to the American form, their beaks especially being of very 

 large size. Palmer describes the bill as black, shaded with green, the tarsi as brownish and 

 pale yellow, the iris as pale red. 



Palmer procured ten adult birds, six young, and two nestlings on the islands of Oahu, 

 Kauai, Molokai. Wilson and Knudsen obtained it on Kauai, while Perkins reports it to be 

 commonly breeding all over the islands. On March 20th, 1893, Palmer found a breeding- 

 place on Oahu. The nests were built of small dead sticks, and varied much in size, some 

 being almost as big as a crow's nest, others being so small that they hardly appeared to hold 

 the eggs, which could easily be seen from below. The nests were either placed in forks on 

 dead branches of trees or on the top of the green « Lankala " or " screw-pine " bushes. The 

 majority of the nests contained two eggs, but one had three, and one only a single hard-set 

 egg, while several had already small young ones. Most of the eggs were more or less hard- 

 set. The young are, needless to say, not white, as described by Dole. They have, according 

 to Palmer, the " iris yellow ; tarsi greenish with a yellow tinge, soles yellow ; upper mandible 

 blackish brown, with a light grey ridge; lower mandible yellowish at tip, dark brown 

 at base." 



The eggs sent from Kaalualu, Oahu, measure : 51 by 39 5, 505 by 38'8, 51 by 37, 52 6 

 by 39-1, 50 7 by 375, 50'6 by 37, 50 by 35, 52-5 by 35, 49 by 36'5 mm. 



A number of eggs of the European Nycticorax nycticorax, taken by Hartert on the 

 Hansag in Hungary in May 1891, measure : 49 by 35, 49 5 by 33'5, 51 by 36, 51 by 325, 

 48 by 36, 50 by 375, 49'5 by 352, 485 by 36, 50 by 36-5, 48'6 by 35 mm. 



It would thus appear that the eggs of the American and Hawaiian forms are, on an 

 average, slightly more bulky. 



