WILD DUCKS 139 



from nineteen species of a total of thirty- two in his collection. 

 Most of those that breed lay their eggs under bushes and 

 sprouts in a strip of woods, and some kinds, such as pintail, 

 shoveller, and teal go back of this into a strip of open grass 

 and weeds, formerly a cultivated field, where they nest. 

 Mallards, black ducks, gadwalls, and various foreign species 

 nest in the wooded strip, among bushes, beside stumps or 

 logs, or in rotted-out hollows in stumps. Redheads lay on 

 grassy banks close to the water. Wood, mandarin, and tree 

 ducks nest in boxes or in hollow stumps. Besides the above 

 species, the following also have bred: green- winged, cinna- 

 mon, pampas and barganey teals, red -billed and fulvous 

 tree-ducks, European widgeon, Bahama duck, rosy-bill, 

 spotted-bill, and Australian duck. 



Live Food. Mr. Cook feeds his ducks some live minnows 

 in spring. Also at times he brings them watercress and 

 other pond weed which frequently are covered with water- 

 insect Hfe. Such insect Kfe he thinks is a considerable fac- 

 tor in the breeding of wild ducks. He has found that when 

 captive wild ducks are put in a new pond, where such life 

 abounds, the laying is materially increased. After a season 

 or two, unless a stream enters the pond, the insect life is 

 depleted, and egg-production decreases. He believes that 

 the breeding of wild ducks is largely a matter of having 

 proper natural food, especially animal food, which must be 

 suppHed in some form. 



Fish Diet as Stimulus. The value of a fish diet as stimu- 

 lus to reproduction is indicated by an experience of which 1 

 was informed. On a commercial duck farm, where Pekin 

 ducks were raised, it was the practice in late winter to secure 

 fish heads and other remains at the wharves where incoming 

 fishermen dressed their fish. These were freighted by the 

 barrel to the inland farm, and boiled in cauldrons until the 



