BULLETIN FLORIDA STATE MUSEUM VOL. 33(4)


 3) Scat marking: Deposition of scats which are left exposed.
 Exposed scat deposition sites were counted along a 10-km route of primitive roads, firelanes,
 and footpaths through various habitats in the core study area during February, March, July, and
 August 1979 (Guenther 1980), and more intensive censuses of scrapes and scats were conducted
 from October 1979 through April 1981 (Wassmer 1982). Foot trails and railroad tracks were
 walked and primitive roads or firelanes were surveyed from a vehicle at a speed of 1-5 km/hr. All
 scats were collected, and scrapes were usually marked with a toothpick to prevent their being
 recounted in a subsequent census. In the October 1979-April 1981 period, regular censuses were
 made along 37 km of routes, which included the 10-km route used by Guenther (1980). Most
 routes were censused once or twice a month; a few regularly-driven roads were inspected more
 frequently; and some trails that were infrequently marked were searched every 1 to 3 months.
 Other parts of the study area were searched irregularly. As it was not possible to census all
 routes on the first day of each month, several types of evidence were used to estimate the age of a
 mark so that it could be assigned to a particular month. These included time since the route was
 last searched, whether or not the mark was made before or after a recent rain, amount of vehicle
 tracks or other disturbance in the vicinity of the site, and the condition of the scat or scrape.
 Totals of 2220 exposed scats and 5291 scrapes (including scrapes containing scats) were recorded.
 Of these, 1461 (66%) scats and 3326 (63%) scrapes were located along the regular census routes.
 A total of 349 sightings of bobcats were made by us or reported by others during the study.
 Sixteen of the collared cats and 10 unmarked but recognizable (e.g. kittens accompanying a
 collared female) individuals were observed. In addition, unidentified bobcats were seen on 30
 occasions.
 Information on food habits was obtained from analysis of 146 scats; 69 were collected in the
 core study area on a random basis from 1967 to 1978, and 77 were collected from January to
 September 1979. Each scat was soaked in detergent for 3 or 4 days, then rinsed in a sieve with
 fine wire mesh until all fine debris was removed and the remaining material oven dried for
 examination. The minimum number of individuals of a given prey species represented in a scat
 was based on the number of the most frequent element occurring singly in a skeleton (e.g., left
 third upper molar). Weights of mammals and other vertebrate species used to convert prey
 frequency of occurrence to biomass values were obtained from specimens collected in or near the
 study area.


 Data Analysis


 Density estimates were based on the cluster of individuals centered on the core area that was
most intensively and continuously monitored. Estimates were computed for 12 unequal time
intervals during the period from April 1979 through August 1981 for which the most complete
data on the number and sexes of individuals and sizes of home ranges were available. Five of the
intervals were delimited by known deaths or disappearance of individuals. Break-points for the
remaining intervals were more subjective, involving times of collar failures which prevented
further detailed monitoring of individuals or prolonged (about 1 month) gaps in radiotracking.
For each period, the area used for calculating density was that of the minimum convex polygon
formed by the outermost boundaries of the cluster of contiguous or overlapping home ranges of
the individuals present during that interval. Individuals known or assumed to be present on the
study area during a given interval on the basis of tracks or other evidence, but for which there
was no, or insufficient, data on home range, were treated in 1 of 2 ways. If they were located on
the periphery of the cluster of known home ranges, they were excluded from the calculations. If
they were within the cluster and data on their home range from a prior or subsequent time
period indicated that the range was most likely included within the cluster during the current
period, they were included in the density estimate. Estimates of juvenile density were based on
the total number of juveniles known or believed to be present within female ranges. As number
of young in a litter usually could not be determined until the young were approximately 2 months
or older and moving with the mother, juvenile density estimates apply to mobile young prior to
dispersal.