COMMON POCHARD 159 



nothing definite seems to be known. Almost till the end of the past century it seems 

 to have steadily decreased until about 1880 or 1890 it began to be recognized as in- 

 creasing as a nesting bird, at least in Norfolk (Stevenson and Southwell, 1890). 

 Through the prohibition of netting and the enforcement of the protective laws there 

 has been an uninterrupted increase in breeding birds and a steady extension of the 

 nesting range in the British Isles. Baxter and Bintoul (1922) think the colonization 

 in Scotland has advanced from the southeast. In old times it received no considera- 

 tion at the hands of decoymen, because the enormous numbers which came into some 

 of the pools interfered with the taking of other ducks. Destructive methods of cap- 

 ture by flight -nets were brought into use and huge numbers were taken in this man- 

 ner. Its irregularity as a winter visitor in the British Isles makes it difficult to esti- 

 mate its numbers and determine whether there has been a recent change for better or 

 worse. There is, however, reason to suppose that there was a considerable decrease 

 during the past century. 



There is also some evidence of local increase in breeding birds in Germany. At 

 Potsdam, and in the vicinity, the number of nesting Pochards has grown till now they 

 outnumber even the Mallard (B linger, 1900). 



In winter "immense" flocks visit the Venetian lagoons (Arrigoni degli Oddi, 1898) 

 and in Algeria, Zedlitz (1914) says it is almost as common as the Marbled Duck 

 on Lake Fetzara during the breeding season. The native Arabs in this region are 

 said to plunder the eggs. In Palestine, Tristram (1884) considered it the most abun- 

 dant duck, perhaps exceeding in numbers all the other ducks combined. On the 

 larger jheels of India where there are open expanses of water of some depth the 

 Pochard still winters in enormous numbers (Baker, 1921). No doubt war conditions 

 and especially lack of powder in Russia may greatly favor an increase of ducks and 

 other game at the present time, but these conditions will not last. The Pochard is 

 not a far-northern nester and so comes more and more into competition with im- 

 proved agriculture, drainage and dense populations. 



Enemies. Most destructive to the eggs of Pochards and other ducks in England 

 and on the Continent are the Magpies, Hooded and Carrion or Common Crows. 

 Large pike are said to kill the ducklings in some numbers, while rats and other ground 

 vermin account for a good many. The usual birds of prey (Peregrine Falcon and 

 hawks) occasionally attack Pochards successfully if these are not near enough to the 

 water to dive; the Kite is said to prey very much on the young (Millais, 1913; Nau- 

 mann, 1896-1905). 



A number of species of parasitic insects and intestinal worms that have been 

 found on the Pochard are listed by Naumann. 



Damage. None of the diving ducks feeds on land and consequently they can 

 very seldom do damage to crops. 



