Domestic Mouse--Unusual Color _Mus musculus_. Phases Japanese Waltzing Mouse _Mus musculus_. Black Rat _Mus rattus_. Black-and-White Rat _Mus norwegicus_. Gray-and-White Rat _Mus norwegicus_. Porcupine Mouse _Acomys cahirinus_. Egyptian Gerbille _Gerbillus pyramidum_. Muskrat _Fiber zibethicus_. Cotton Rat _Sigmodon hispidus_.
Coypu Rat _Myocastor coypu_. Hutia: Cuban Tree Rat _Capromys pilorides_. Short-Tailed Hutia _Capromys browni_.
Canada Porcupine _Erethizon dorsatus_. Brazilian Porcupine _Sphingurus prehensilis_. African Porcupine _Hystrix cristata_.
VISCACHAS AND CHINCHILLAS (_Chinchillidae_)
Golden Agouti _Dasyprocta agouti_. Gray Agouti _Dasyprocta prymnolopha_.
Domestic Cavy _Cavia porcellus_. Capybara _Hydrochaerus capybara_. Patagonian Cavy _Dolichotis patagonica_.
[Illustration: MUTE AND TRUMPETER SWANS.]
There are no birds which take more kindly to captivity, or which better repay their keep and their keepers, than the ducks, geese, swans and pelicans. The only drawback to the maintenance of large collections of these birds in this latitude is the annual struggle with our arctic winter. On account of the fierce winter storms to which we must pay tribute, many species of swimming birds require to be taken out of their aviary, and housed in sheltered buildings, with moderate warmth. For this reason the pelicans, tree-ducks of all species, and all species from the tropics, must necessarily be absent in winter from their summer quarters.
For the accommodation of a large, systematic collection of wild geese, an aviary two hundred and fifty feet long by one hundred and forty-three feet in width has been constructed in the north end of Bird Valley. To secure as much space as possible, the entire width of the open valley has been taken into the enclosure.
The Goose Aviary consists of a pond containing three islands, two of which are subdivided by low fences of wire netting into twelve separate enclosures. The collection of geese has become so large and important the original Duck Aviary has been taken for it, and the Ducks will hereafter be found on the Wild-Fowl Pond and in the Flying Cage.
The Geese.--The collection of wild geese, in the Goose Aviary, is unusually large, there being generally about twenty out of the thirty-five known species. Among these one of the best known is the Common Wild, or Canada Goose, (_Branta canadensis_). Once common throughout many parts of the United States, continual persecution by sportsmen and market hunters has so generally reduced its numbers that now it is of comparatively rare occurrence.