BULLETIN FLORIDA MUSEUM NATURAL HISTORY VOL 38, PT. 11(6)


Table 3. Means, standard deviations, and extremes of male and female home range sizes (ha). MCP=minimum
convex polygon, MCPcorr=MCP with unusable area subtracted, HM95=harmonic mean 95% isopleth. The data
include home range calculations based on more than 40 location points.

 Number of Tracking
 location period
 points (days) MCP MCPcorr HM95

Males (n=23)

Mean 90.0 142.6 155.9 141.6 170.6
S.D. 46.1 69.8 113.1 103.1 90.9
Range 46-217 34-275 33.7-564.1 31.1-520.4 41.7-433.3

Females (n=23)

Mean 113.9 161.8 73.1 64.4 86.0
S.D. 70.3 112.7 45.8 40.7 46.7
Range 43-285 54-400 8.1-195.2 8.1-186.6 14.6-220.5




 Male spatial structure was less stable than that of females, mainly because of
range expansion during breeding seasons, frequent shifting of home ranges at the end
of breeding seasons, and because of natal dispersal. During mating seasons, males
expanded their home range considerably (see Ryser 1992). After breeding seasons,
males retreated again to a smaller range. But only 11 of 19 males for which sufficient
data from breeding and non-breeding seasons are available, retreated to the same area
as before. Eight males established home ranges in another part of the expanded
breeding range, up to 3.8 km away from the previous home range. Among opossums
trapped in July 1987, two males were caught 2.8 and 4.6 km, respectively, away from
their original site of capture during the breeding season in April/May. One male was
apparently trapped and radio-tagged during a dispersal movement at the end of the
breeding season. He had moved 5.3 km when his collar was removed after 5 days.
Between mating seasons, male home ranges were fairly stable. Of 21 adult males
tracked for more than two months during non-breeding seasons, only two clearly
shifted or expanded their home range. Four males were lost during non-breeding
seasons (July, August) and could possibly have dispersed, although a failure of the
transmitters is more likely.
 Male young generally dispersed before or during their first breeding season (see
Wright 1989). Contrary to other males, young males that were recorded dispersing
during the breeding season did not expand home ranges prior to dispersal and thus did
not seem to participate in mate searching. Their ranges averaged only 67.5 ha (n=6,
compare with data below).