WASSMER ET AL.: SOUTH-CENTRAL FLORIDA BOBCAT ECOLOGY


following summer. A similar trend in sex ratio during a "crash" and recovery of
a California bobcat population was observed by Lembeck (1986). Thirteen
juveniles whose sex was known included 7 males and 6 females (1.17
males/female). Adult and juvenile sex ratios of the bobcats trapped were 0.86
and 1.00 male/female, respectively.

 Breeding Season.- Eight litters whose birth dates could be determined to
within a week were born in April (4), May (2), October (1), and January (1).
Births of four other litters of radio-collared cats were estimated to have
occurred in February (1), April (1), and May (2); and an unmarked female on
the periphery of the study area apparently produced a litter in April. Based on
a gestation period of about two months (McCord and Cardoza 1982), the
breeding season extended from August through March, with 10 of the 13
known or estimated mating dates occurring in February and March and 1 each
in August, November, and December.
 Variously derived estimates of the breeding season in other parts of the
 range include February to April in 11 western states (Duke 1954); January to
 July or later in Utah (Gashwiler et al. 1961); January to July or later in
 Wyoming (Crowe 1975); December to March in Arkansas (Fritts and
 Sealander 1978); February to July with peaks in March and April in Alabama
 (Miller 1980); February to mid-March in South Carolina (Griffith and Fendley
 1986); and November to July in Texas (Blankenship and Swank 1979).
 Comparison with these data suggests that there may be more fall and early
 winter breeding in southern Florida than elsewhere in the range.

 Natality.- Mean litter size of 1 unmarked and 12 radio-collared females
 was 2.6 (range = 1-5). As all litters observed were over 2 months of age and
 may have experienced some mortality, mean litter size at birth was probably
 higher. Four litters of the semi-tame female (Fl) during the study averaged 3.5
 with a range of 2-5 compared with a mean of 2.2 and range of 1-3 for 9 litters
 of other females. This suggests higher litter size at birth for F1 or better
 survival of her young, possibly as a result of the supplemental feeding she and
 her kittens received at the cottage they visited. Mean litter size in this study
 was lower, particularly if litters of the semi-tame individual are omitted from
 the sample, than values (2.8-3.5) based on observations of kittens in three
 studies in the western United States (Bailey 1972, Gashwiler et al. 1961,
 Zezulak and Schwab 1979).
 Two females (F8, F9) gave birth to litters when about 1 year old. The low
 number of young (1 and 2) in these litters suggest that young primiparous
 females produce smaller litters than older females. The first litter of the
 semi-tame female (Fl) was also smaller than the average of succeeding litters
 (Winegarner and Winegarner 1982). Breeding between the first and second
 years of life has been recorded in other bobcat populations (e.g. Crowe 1975;