Stinkpot (Sternotherus odoratus) COSEWIC assessment and status report: chapter 7

Population Sizes and Trends

There are not enough data to estimate the overall size of the Canadian population of stinkpots. The population appears to be broken up into scattered localities across south-central Ontario. Twenty-seven Ontario districts have documented reports of the stinkpot between the years 1881 and 1997 (NHIC unpubl. data) (Table 1). Some locations have relatively high populations. For example, at Twelve Mile Bay, 575 individuals were marked between 1991 and 1997 (Edmonds 1998); and in Big Clear Lake, 69 individuals were recorded from casual sampling between 1983 and 1990 (NHIC unpubl. data; R. Saumure pers. comm.). Populations in some other districts were based on a single sighting. In Quebec, stinkpots have been found in only two counties -- Hull and Pontiac (Chabot and St. Hilaire 1991). In both counties, only a few individuals were found.

Of the 27 Ontario districts that have records of stinkpots, 11 (41%) have had no confirmed sightings after 1984 (Table 1). It is possible that populations in many of these districts have been extirpated (M. Oldham pers. comm.). Most of these 12 districts are in the southwestern end of Ontario, a region experiencing intense agricultural activity and increasing urban development. Although stinkpots behave cryptically and are not normally observed unless one deliberately searches for them (Bendall 1959; Lamond 1994), it is striking that they have apparently disappeared in the most heavily developed areas, where there are more potential observers (e.g. Hamilton-Wentworth, Lamond 1994). Nevertheless, it would be prudent to search areas with old stinkpot sightings to confirm or refute local extirpation.

Table 1. A list of Ontariodistricts for which there are records of the presence of Sternotherus odoratus. The first and last years in which the species was recorded are listed (NHIC, unpubl. data)
District First sighting Last sighting
Peel (RMFootnotea)
1969
1969
Sudbury (RM)
1970
1970
Durham (RM)
1974
1975
Hastings
1977
1977
Halton (RM)
1977
1977
Hamilton Wentworth
1932
1978 Footnoteb
Kent
1970
1978
Nipissing
1978
1978
Niagara (RM)
1979
1979
Brant
1979
1980
Simcoe
1961
1984
Haldimand Norfolk (RM)
1978
1985
Ottawa Carleton (RM)
1958
1987
Northumberland
1973
1987
Lennox and Addington
1988
1988
York
1858
1988
Essex
1881
1989
Frontenac
1931
1989
Lanark
1926
1989
Prince Edward
1941
1990
Lambton
1957
1990
Renfrew
1992
1992
Peterborough
1958
1992
Victoria
1993
1993
Leeds and Grenville
1936
1994
Muskoka
1925
1995
Parry Sound
1973
1997

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