236 
JOURNAL OF MAMMALOGY 
Venice, California, where they were exhibited in a tank of water for a year or 
two. The tank was on a pier extending out into the ocean. 
A year or two ago a heavy storm demolished that portion of the pier where the 
seals were exhibited and they escaped into the ocean. It is quite probable that 
these animals, or some of them at lea^t, are still living in the waters off south- 
western California. No elephant seals have been heard of in this vicinity for 
many years. The nearest rookery is Guadalupe Island and it seems more natural 
to believe that the specimens recently reported are escaped animals rather than 
ones that have left the herd at Guadalupe and wandered north. — John Rowlet, 
Los Angeles Museum, Los Angeles, California. 
MUSKRATS IN CENTRAL EUROPE 
In 1906 Princess Colloredo-Mannsfeld imported four pairs of muskrats {Fiber 
zihethicus) from America and turned them loose in Dobrisch, an estate south- 
west of Prague, Bohemia. These animals subsequently increased in such num- 
bers that at present they have spread all over Bohemia, into Upper and Lower 
Austria and Moravia and also into Bavaria and Saxony, following the water- 
courses. 
The muskrats have shown themselves to be very injurious, as they construct 
their burrows in the dams and embankments of the rivers and ponds, and thus, 
by undermining the banks they endanger the whole system of waterways, sub- 
jecting the surrounding fields to the danger of floods. 
Very strict regulations have been issued, therefore, in all the countries invaded 
by the muskrat’ to curtail its further spread, and it is generally forbidden under 
heavy fines to maintain the animals, breed them, or turn them loose. All persons, 
directly or indirectly interested, are required to report every appearance of 
muskrats to the authorities. Owing to his secretive habits of life, the muskrat 
often succeeds in remaining unnoticed for a considerable period in his new haunts. 
The muskrat is inclined to be nocturnal, but in districts where he feels him- 
self unnoticed he is to be seen during the day also. In general it has been ob- 
served that during overcast weather and dark nights the rats do not appear for 
days at a time, and rarely swim about when it is windy. The muskrat builds 
his summer-dwelling in the high banks or dams of water courses and poDds. This 
consists of a burrow from which a carefully concealed exit leads to the bank, 
often 10 to 15 feet away; other runways lead under the water level and to the 
bottom of the water. Piles of earth which have been removed from the ponds 
are also used. 
The animals established in Europe breed twice or three times a year and 
produce 6 or 8 young at a time. Thus an annual family of 18 to 24 young may 
be expected which suflSciently explains the phenomenal spreading of the species. 
In winter the muskrats often abandon their burrows and build so called 
“winter-castles” in shallow places in the ponds. These consist of heaps of bitten 
off reeds, rushes or sedges, more or less mixed with mud. They have a diameter 
of 3 to 6 feet, project 2 to 3 feet above water level, and have no visible exits. 
These quarters contain a dry sleeping-place above water level and, connected 
with it, a burrow extending into the water. 
