THIRD ANNUAL REPORT. 43 



SPECIAL IMPROVEMENTS BY THE DIRECTOR. 



A number of installations for animals are being constructed, 

 partly by day labor and partly by contract, under the personal 

 supervision of the Director. These are the Ducks' Aviary, the 

 Beaver Pond, the Prairie Dogs' Knoll, the Burrowing Rodents' 

 Quarters, the Mountain Sheep's Hill, Pheasants' Aviary, Croco- 

 dile Pool, Aquatic Rodents' Pond, and Otters' Pool. A brief 

 memorandum regarding each of these improvements may be of 

 some interest. 



The Ducks' Aviary is designed to accommodate about thirty 

 species of wild ducks and geese, separately installed, and also one 

 mixed flock of large and showy species. Between the site of the 

 Flying Cage and Cope Lake about three acres of level, swampy 

 ground have been converted into ponds containing three islands, 

 the surfaces of which are high and dry. Two of these islands have 

 been laid out to form fifteen separate enclosures, each one of 

 which, when fully completed, will contain an area of running 

 water, with sandy banks, grass, shrubbery, a sanded runway, and 

 a room in a low and inconspicuous shelter-house. Every yard is 

 thoroughly under-drained. The outer boundary fence will be a 

 barrier to rats and weasels, and all the fences will be low and in- 

 conspicuous. This aviary will be completed about May 15. 



The Beaver Pond is situated in the wildest and most secluded 

 spot in the Zoological Park, in a narrow valley between two tim- 

 bered ridges of granite rock which rise quite steeply to a height 

 of about seventy feet. Heretofore the valley has been an impass- 

 able bog, choked with weeds, but sufficiently free from forest trees 

 that a pond area of about two acres has been secured. In order 

 to obtain a good depth of water, and prevent too great an accumu- 

 lation of back water, about two feet of earth was excavated and 

 deposited in suitable places on the banks. About a dozen small 

 maple trees, now standing on tiny islets in the pond area, will be 

 given to the beavers to cut down for use as food wood and ma- 

 terials for their dams. The large and valuable trees within the 

 enclosure will, of course, be protected from all injury. An iron 

 fence three feet in height is now being constructed to enclose the 

 area to be devoted to the beaver colony. Beyond question, the 

 work of the beavers in dam-building, tree-cutting, and house- 

 making in this ideal situation will prove of general interest. 



