ACTIVITY, MOVEMENT AND HOME RANGE
 OF VIRGINIA OPOSSUM (DIDELPHIS VIRGINIANA)
 IN FLORIDA



 Jan Ryser'




 ABSTRACT


 The activity and spatial organization of the Virginia opossum (Didelphis virginiana), a solitary didelphid
marsupial, were studied in north-central Florida. Opossums were strictly nocturnal, and the activity level peaked
between 2000 h and 0200 h. Activity was influenced by temperature. Below 80C, duration of nightly activity
decreased strongly with decreasing temperature. Above 80C, activity tended to decrease with increasing
temperature. Average nightly activity did not differ among months from August to December or between males
and females. Opossums lived in well defined and at least seasonally stable home ranges with moderate to
extensive home range overlap. Females tended to more exclusive space use and greater stability of home ranges
than males. Males often shifted home ranges at the end of mating seasons. Three different measures of home
range size were presented. Average values for males and females were 141.6 ha and 64.4 ha, respectively
(corrected minimum convex polygon). Individual home range sizes of males were influenced by habitat, being
larger in presumably poorer habitats, and by body size. Average distances moved per hour were 234 m in males
and 178 m in females. Nightly movements of males and females averaged 1835 m and 1465 m, respectively
(maximums 4665 m and 3973 m). Distances traveled were associated with temperature, home range size or body
size. Very limited data from other regions suggest greater space use by opossums in the studied population.



 RESUME


 En el centro-norte de Florida, se estudi6 la actividad y organizaci6n espacial de la comadreja de Virginia
(Didelphis virginiana), el cual es un marsupial did6lfido solitario. Las comadrejas fueron estrictamente
nocturnas y el nivel de actividad Ileg6 a su maximo entire las 2000 hr y las 0200 hr. La actividad estuvo
influenciada por la temperature. Bajo los 8 C, la duraci6n de la actividad noctura disminuy6 fuertemente con
una disminuci6n de la temperature. Sobre 8 C, la actividad tendi6 a decrecer a media que la temperature
aumentaba. El promedio de actividad nocturna no difiri6 entire meses, entire agosto y diciembre, ni entire hembras
y machos. Las comadrejas habitaron Ambitos de hogar bien definidos y estables al menos estacionalmente con

SDepartment of Zoology, University of Bern, Baltzerstrasse 3,3012 Bern, Switzerland, and Florida Museum of Natural History, P. O. Box 117800,
University of Florida, Gainesville FL 32611-7800, U.SA. Present address: Dorfbergstrasse 1, 3550 Langnau, Switzerland.


RYSER, J. 1995. Activity, movement, and home range of Virginia opossums (Didelphis virginiana) in Florida.
Bull. Florida Mus. Nat. Hist. 38, Pt. II(6):177-194.