. The Canadian field-naturalist. 150 The Canadian Field-Naturalist Vol. 102. Figure 3. Collection records ofA^orro/»/5/)/jo/oge«/5 in Ontario: A National Museums of Canada; â Royal Ontario Museum; ^ Ontario Ministry of Natural Resources; ⢠Beak (Parker and McKee 1980); A Baldwin (1983); n Wilfred Laurier University Museum; ^ Grand River Conservation Authority. no specimens. I also found variation in numbers among samples, and captured young-of-the-year more frequently than adults (Baldwin 1983). However, Figures 4 and 5 indicate that on a larger scale the species occurs almost continuously
. The Canadian field-naturalist. 150 The Canadian Field-Naturalist Vol. 102. Figure 3. Collection records ofA^orro/»/5/)/jo/oge«/5 in Ontario: A National Museums of Canada; â Royal Ontario Museum; ^ Ontario Ministry of Natural Resources; ⢠Beak (Parker and McKee 1980); A Baldwin (1983); n Wilfred Laurier University Museum; ^ Grand River Conservation Authority. no specimens. I also found variation in numbers among samples, and captured young-of-the-year more frequently than adults (Baldwin 1983). However, Figures 4 and 5 indicate that on a larger scale the species occurs almost continuously throughout each river section within its range. Silver Shiners were rare in, or absent from, smaller tributary streams and slow-flowing sections of the main rivers. The increase in captures of the species since 1971 suggest an increase in numbers prior to or during the 1970s or early 1980s. The new locations for Silver Shiners found in Ontario since 1971 are not simply the result of surveys of new areas. The Ontario Ministry of Natural Resources, the Grand River Conservation Authority, Parker and McKee (1980), and 1 (Baldwin 1983) sampled extensively within the Grand and Thames River watersheds; the results included new captures at previously surveyed locations. There are no data to evaluate population levels or trends in Bronte Creek. Former low population levels (along with misidentification) may at least partially account for the fact that Silver Shiners were not detected in Ontario until recently (Gruchy et al. 1973). Population fluctuations have occurred elsewhere. Gruchy et al. (1973) noted that Silver Shiners were not taken in Michigan between 1942 and 1952, but appeared again in surveys after 1952. The Silver Shiner decreased considerably in numbers in many Ohio localities between 1920 and 1950 (Trautman 1981). It is generally uncommon to rare in Lake Erie tributaries (Gilbert 1980) and was apparently decreasing in numbers in those tributaries in 1970 (Van Meter
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