Mimicry in Birds 267 



both species. It may further be remarked as a wonderful 

 coincidence that, just as the plumage of the Mimeta from 

 Bourou differs from the Mimeta of Ceram or Timor Laut, 

 even so does the Philemon of each island differ in the same 

 degree, mimicking in every case the specific characters which 

 have served to separate the different insular forms of 

 Mimeta. Professor Newton thinks that the advantage lies 

 on the side of the Oriole, which is " comparatively a weak 

 bird, and must benefit by being mistaken for the strong, 

 pugnacious, and noisy Philemon, two or three of which will 

 drive away Crows and even Hawks, that venture to perch 

 on a tree they have occupied." 



The latter author likewise draws attention to a wonderful 

 case of " mimicry " in two birds from Madagascar. One is 

 a Tylas, belonging to the harmless group of Bulbuls 

 {Pycnonotidce) and is an exact copy of a Xenopirostris, 

 which is a genus of Shrikes (Laniidce). Thus Tylas eduardi 

 and Xenopirostris polleni are both alike in colour, and the 

 Bulbul doubtless benefits by being mistaken for the fiercer 

 and more energetic Shrike. Yet, as Professor Newton 

 points out, the two birds are alike " feather for feather," and 

 the difference in the colour of the under surface of 

 T. eduardi, which is sometimes buff and sometimes white 

 below, is faithfully represented in the Xenopirostris, which 

 the Bulbul " mimics." 



Then there is the case of the Black Drongo (Buchanga 

 atrd) of India, and the Black Cuckoo (Surniculus litgubris) 

 which is found in the same country. These birds are black, 

 and of the same size, have red eyes, a forked tail, and white 

 bands across the under tail-coverts. The only difference to 

 be found in their external appearance is in the long thigh- 

 feathers which are to be seen in the Cuckoo, but not in the 

 Drongo, and, of course, the Cuckoo has a zygodactyle foot, 

 with two toes in front and two behind, while the Drongo has 

 a Passerine foot, with three toes in front and one behind. 



