1942: Zoology

Reports on Mammals.

The finding of two muskrats with fur of a peculiar wavy type has been reported by Dr. H. L. Dozier of the U. S. Fur Animal Field Station. He reports this as a rare occurrence and suggests that this condition may be hereditary. However, E. A. McIlhenny, a naturalist, later reports that numerous permanently waved specimens are found each year on his muskrat farm. This worker considers the wavy condition due to the rats having been scorched by fire. This problem might easily be settled by experimentally determining whether heredity or external environmental factors such as heat were the determining causes.

As a part of the program to further investigate reproduction in the muskrat, Dr. T. R. Forbes of the Fish and Wildlife Service, U. S. Department of the Interior, Swarthmore, Pa., has determined by histological study that the male muskrat in Maryland begins spermatogenesis in the middle of December and the female starts ovulation in the middle of February with seasonal gonadal activity terminating in both sexes approximately during the latter part of October.

David B. Cook, of the New York State Conservation Department, reported on the food habits of the beaver. It is generally recognized that beaver relish the bark on trees. However, it is also recognized now that these animals also feed on grass, roots, tubers, seed heads, and flowers.

The Forest Service reported that the Rocky Mountain goats, found only in the United States, and heretofore only in Washington, Idaho, and Montana, are now existing in the Black Hills of South Dakota. A few of these animals escaped while on exhibition in South Dakota and have adjusted themselves so well to this environment that the herd has now increased to twenty-five through the natural process of reproduction.

The Newfoundland Department of Natural Resources has completed a survey of the island with the thought of introducing either the American white-tail or the English red deer. At the present time only the black bear and the woodland caribou are native to Newfoundland and the moose has been the only large game animal which has been introduced and become established with any degree of success up to this time.

Prof. A. R. Shadle and W. R. Ploss of the University of Buffalo report what is believed to be only the second case on record of the birth of a porcupine in captivity. The young animal had its incisor teeth well developed and was able to exhibit regular porcupine defense reactions. The infant continued nursing until it was three and one-half months old. This is another instance in which zoologists are better able to obtain life history studies of animals when little of this sort has been reported heretofore.

British Columbia authorities report that experiments are now being conducted on the feeding of fur-bearing animals with sea-lions. The latter have heretofore been considered a major nuisance by West Coast fishermen because of the number of fish they consume. However, the problem of how to obtain these sea-lions in sufficient amounts for food at a low cost has not been worked out satisfactorily as yet.

Reports on Birds.

R. E. Danforth of Noank, Conn., reports that black-capped chickadees make a substantial part of their winter diet on 'jumping plant-lice' along the Connecticut shore. The plant-lice of two species, Calophya flavida and C. nigripennis were found upon sumacs in this region and the birds were observed eating, not only the fruit clusters, but also the lice from the stems.

Dr. W. S. Bullough of the University of Leeds reports that the starling may be a responsible carrier of hoof-and-mouth disease. Heretofore, authorities have succeeded in stamping out each outbreak of the disease soon after its discovery, but the origin of the disease has remained undiscovered. The migrating starling, as a carrier of the virus, now is considered a possibility and further studies will no doubt prove whether this is the case or not.

Drs. P. D. Dalke, W. K. Clark, Jr., and L. J. Korschgen of the Missouri Cooperative Wildlife Unit have shown that wild turkeys are great destroyers of harmful beetles. They have shown that turkeys in the Ozark region of Missouri feed on grasshoppers, stinkbugs, beetles, and ants for about 25 per cent of their diet while the other 75 per cent is made up of grass seeds, acorns, etc.

Aquatic Life.

C. N. Feast, director of the Colorado Game and Fish Commission, has discovered that trout raised in a hatchery can be distinguished from those that are hatched and grown in their native habitat by an examination of their dorsal fins. Mr. Feast states that trout grown to legal size in a hatchery have dorsal fins somewhat degenerated through crowding. When these fish are released in streams the fins develop, but malformations of various sorts are the usual case. Hence, this serves as a mark of identification which is generally sufficiently accurate to allow for observations on percentages in stream surveys.

C. E. Porter of Santiago, Chile, and W. L. Schmitt of Washington, D. C., report the identification of a free-living fresh water jellyfish from South America. Mr. Fick, an engineer, collected the specimen near Quilqué, a Province of Valparaíso, in March and sent it to the above authors for identification. This record is the first for the free-living fresh water medusae, Craspedacusta somerbii (Lankester), from South America.

Dr. Harvey Bassler of the American Museum of Natural History, New York, reports an account of an attack of a sting-ray on man. Authentic personal records of such occurrences are rare with none heretofore authentically reported from the Amazon Basin. From the brief account reported by the above author, it appears that the sting-ray's sting is definitely poisonous to man. While not fatal, evidently the sting is accompanied with almost unendurable pain.

Dr. Clarence R. Shoemaker of the U. S. National Museum Scientific staff has recently described a small crustacean animal and named it in honor of President Roosevelt. This new species known as Neomeganphopus roosevelti, is an important item in the diet of fish in Magdalena Bay on the coast of Lower California. It was collected on the 1938 Presidential cruise, by Dr. W. L. Schmitt of the Museum staff.

Extinct Fauna.

Another large mammal has recently been added to the extinct pre-tundra fauna known from Alaska. This mammal, a ground sloth known technically as representing a species of the Megalonyx, was found during extensive explorations of the Childs Frick Expedition in cooperation with the University of Alaska. The site of discovery, as reported by Chester Stock of the California Institute of Technology, occurs on Cripple Creek, approximately fifteen miles Southwest of Fairbanks. Heretofore, this genus has been associated with the Pleistocene forest faunas of the more southerly regions of North America. The occurrence in Alaska, therefore, extends the geographic range considerably to the north of its previously known distribution.

Fossils, mainly ancient relatives of crabs and crayfish known as trilobites, have been found in a series of limestone strata long thought to be barren of such evidences.

The strata, known as the Maryville formation and of the mid-Cambrian age occurs in many regions in the chain of Eastern Mountains. These fossils are related to similar forms found in the Rocky Mountains and present further evidence that life existed half a billion years ago in a region where the Appalachian Mountains are now located.