3.2 Matchedash Bay–Gray Marsh
Similar to Pelee, we found relatively low numbers of muskrat houses at
Matchedash in each of our five recent survey years from 2014-2018 when
compared to the historic survey period from 1979-1986 (Fig. 3). The mean
(SE) number of muskrat houses found at Matchedash between 1979 and 1986
was 650 (81.9). The 95% confidence interval for house counts averaged
across these years was 450 to 850. In contrast, we observed a mean (SE)
house count of 57 (9.1) during 2014-2018. The 95% confidence interval
for the house counts averaged across these latter years was 32 to 82.
Our contemporary surveys of Matchedash represent a 91% decline in mean
muskrat abundance from historic levels 30-40 years prior (Fig. 4).