Spotted Skunk and Weasel Populations Den and Cover Usage by Northeast Iowa

Examination of dens and territories of 118 Mustela frenata, 59 Mustela rixosa, and 65 Spilogale interrupta, in northeast Iowa indicated that tall grass, hay meadow, and brush-bramble-weed growth at field edges were the favorite habitats of the three species. Black willows were attractive to Spilogale and M. Jrenata. M. rixosa was most tolerant of sparse cover. Spilogale and M. frenata preferred burrows of Franklin ground squirrels and pocket gophers for primary den sites. M. rixosa favored mole runs and Blarina burrows for den sites. The present trend to continuous corn, reduced hay acreage, removal of permanent fences, and use of herbicides is reducing much of the cover needed by these small predators and the burrowing mammals associated with them

Vertebrate Coactions With the Franklin Ground Squirrel

Nearly 30 years of observation of Franklin ground squirrels in central and northeast Iowa indicates that they are of minor importance as prey for carnivorous birds, mammals, and reptiles. These ground squirrels are predators of some significance on eggs and young of ground-nesting birds and the helpless young of some small mammals. The Franklin squirrel burrows are of considerable importance as dens for long-tailed weasels and spotted skunks and are of seasonal value as retreats for young opossums, striped skunks, and mink during mid-summer dispersal. Amphibia use the dens as a moist daytime refuge during hot, dry weather and garter snakes sometimes use the burrows for winter hibernation. Damaged burrows are used by small rodents and insectivores and are utilized as nest sites by cottontails and ground-nesting birds

Recent Locality Records for Some Iowa Mammals

In 1953 the writer published a Checklist of Iowa Mammals with notes on new species and changes in distribution since 1937. At that time it was apparent that much information was lacking on distribution of some species. A few forms were small, retiring, and difficult to collect. A large number were conspicuous fur bearers and game species that had moved into new territory or had escaped notice of systematic mammalogists in the past. Some larger mammals for which considerable distribution data were lacking included the otter, grey fox, wildcat, woodchuck, chipmunk, red squirrel, grey squirrel, and white-tailed jack rabbit. Most of the mammals in this list would obviously be known to hunters, trappers, and naturalists who were not aware of the dearth of distribution information. The information used in this survey was obtained, in part, from published journal papers, local news stories, questionnaires relative to county bounty claims, and responses to statewide newspaper appeals for information regarding conspicuous fur bearers and game mammals. State biologists and conservation officers cooperated in providing information on skins, skulls, breeding records, local data on populations, bag checks, and purchases by fur buyers

A Check List of Mammals of Present Occurrence in Iowa with Notes on New Additions and Distribution Since 1937

There is little definite information regarding the distribution limits of mammals known to occur in Iowa and neighboring states. The purpose of this paper is to add to the rather sketchy knowledge of mammal distribution in Iowa. There is need for much more observation and collection of specimens and data before a comprehensive picture of mammal distribution is completed. A better knowledge of where certain mammalian forms do, or do not, occur is important to the students of ecology, game management, parasitology, taxonomy, and agriculture since the mammal coactions with other life forms have important relations to these fields

Some Mammal Remains from a Jackson County Cave

Excavation of a trench in the floor of a cave at Springbrook, Jackson County, Iowa, yielded bones of nine species of mammals. At a depth of 19 to 24 inches the jawbone of a porcupine and the upper right canine tooth of a black bear were found. There are no museum records of either species in Iowa. Intermingled with these remains were clam shells and ashes probably left by cave dwelling Indians. Historical literature indicates that the bear probably was extinct in Iowa before the Civil War and the porcupine before the advent of white settlers

Notes on Hibernating Bats in Dubuque County Caves

In the fall and winter of 1958 and 1959 four species of bats, Myotis lucifugus, Myotis sodalis, Eptesicus fuscus, and Pipistrellus subftavus, were found in five Dubuque County caves. M. sodalis was a new species record for Iowa. Migration of bats into the caves began when the minimum temperature dropped to 24° F. The greatest increase in cave population occurred when the daytime high temperature was below freezing and nighttime lows ranged from 13° F. to 1° F. Midwinter copulation of E. fuscus was observed, and drinking of condensed water on cave ceilings by M. lucifugus was noted. No intercave movements occurred but intracave movements did occur when cave temperature reached 43° F