Migration in North-west Ceylon. 195 



following (and perhaps some others^ regarding which there 

 are doubts) : — 



Galliuula chloropiis. Plegadis falcinellus. 

 Erythra plioeuicura. (?) Xenorhynclius asiaticus. 



Gallicrex cinerea. Ardea ciuerea. 



Porphyrio polioceplialus. Ardea purpurea. 



Hydropliasiauus clururgus. Herodias alba. 



Podiceps fluviatilis. Herodias intermedia. 



Sarcidioriiis melauonotus. Herodias garzetta. 



Nettapus coromaiideliauus. Bubidcus coromandus. 



Deudrocygna javaiiica. Ardeola grayi. 



Platalea leucorodia. Butorides javanica. 



Tantalus leucoceplialus, Nycticorax griseus. 



Anastomus oscitans. Phalacrocorax pygmeeus. 



Ibis melanocephalus. Plotus melanogastei'. 



The first to leave is the Moorhen [GalUnula chloropus), 

 which disappears in March, the reason being not any want of 

 food or climatic change, but manifestly the absence of the 

 shelter or means of concealm'ent that it apparently considers 

 a necessity in Ceylon. Unlike the Waterhen {Erythra 

 phoenicura) , which for some time appears to feel at home in 

 the jungle closely surrounding its former haunts, even after 

 the water of the tanks has nearly evaporated, this bird com- 

 pletely abandons the district as soon as the low partly sub- 

 merged thorn-bushes and the sedges which it frequents are 

 left almost dry. The Blue Coot [Porphyrio poliocejjhulus) , the 

 Water-cock [Gallicrex cinerea) , and the Bitterns are the next 

 to follow. The other birds, being less partial to concealment, 

 remain as long as a good supply of food is obtainable at 

 no great risk ; but the majority disappear before the de- 

 parture of the true migrants. 



Such being the general facts observed, it remains to en- 

 deavour to account for them. 



In every case the birds which nidificate at Mannar at an 

 earlier date than in other parts of Ceylon find a most abun- 

 dant supply of food during their stay in the district — a supply 

 that a few months later is entirely wanting. This, and the 

 almost complete security experienced, and the suitability of 

 their haunts for breeding-purposes, appear to me to be the 

 only causes of the variation from the usual time of nesting. 



