. The Canadian field-naturalist. 432 The Canadian Field-Naturalist Vol. 104 JlJ Wf Juveniles and fennales mn n Males SNOUT-VENT LENGTH (mm) Figure 3. Snout-vent lengths of 84 juvenile and adult female Fowler's Toads (white bars) and adult male Fowler's Toads (black bars) captured and marked at Long Point, Ontario, in May 1988. Most of the females and juveniles were captured along a one kilometer stretch of beach at Thoroughfare Point on 23 May. I , ^ 10' ,f. |Moy 28 Figure 4. Maps of the respective calling sites of five individual male Fowler's Toads (indicated by field number as in Table 1) o
. The Canadian field-naturalist. 432 The Canadian Field-Naturalist Vol. 104 JlJ Wf Juveniles and fennales mn n Males SNOUT-VENT LENGTH (mm) Figure 3. Snout-vent lengths of 84 juvenile and adult female Fowler's Toads (white bars) and adult male Fowler's Toads (black bars) captured and marked at Long Point, Ontario, in May 1988. Most of the females and juveniles were captured along a one kilometer stretch of beach at Thoroughfare Point on 23 May. I , ^ 10' ,f. |Moy 28 Figure 4. Maps of the respective calling sites of five individual male Fowler's Toads (indicated by field number as in Table 1) on active nights at Crown Marsh. Inter-individual distances estimates are indicated in feet. Male Fowler's Toads usually alternated calling with each other, especially with close neighbors (less than 15 ft). When overlap in calls was observed, it was mostly on very active nights when calling frequency was highest (8-10 calls/min). Within a chorus, any given toad typically called 1 to 2 sec after the end of a neighbor's call. In contrast with Sullivan's (1982) study of B. w. woodhousii, calling rate correlated positively with body temperature (r = , p = ; Figure 5). Toads with the highest recorded body tempera- tures (°C and °C) exhibited the highest calling rate (8 to 10 calls/min) while toads with the lowest range of body temperatures (14 to 16°C) either called at a much slower rate (less than 4 calls/min) or were silent. Discussion There are many similarities between this northern population of B. at Long Point and that studied by Breden (1982; 1988) in northern Indiana. Clarke (1975) and Breden (1988) showed that females grow faster than males, are thus larger at an equivalent age, and reach a larger size. This accounts for the distribution of size classes among the toads we examined at Long Point. Breden (1988) found that only two age classes could be distinguished in Indiana: adults two years old or more and yearling juveniles. Although Brede
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