Southern flying squirrel (Glaucomys volans) COSEWIC assessment and status report: chapter 9
Population Sizes and Trends: Great Lakes Population
Very little systematic trapping for southern flying squirrels has occurred in the Great Lakes Plains Population. Population data are available for Point Pelee National Park (Bednarczuk and Stephens 2004; Bednarczuk 2003; Adams 1997) and Algonquin Provincial Park (G. Holloway unpubl. data). From 2002 through 2004, J. Bowman, P.J. Wilson, G.L. Holloway and J.R. Malcolm (unpubl. data.) completed 42 971 trap nights at 26 different sites throughout south and central Ontario (see Table 5) capturing 500 southern flying squirrel individuals 748 times. Their annual catch per unit effort was 1.36 captures per 100 trap nights in 2002 (8 542 trap nights), 3.57 captures per 100 trap nights in 2003 (16 597 trap nights), and 0.22 captures per 100 trap nights in 2004 (17 832 trap nights). Catch per unit effort data derived from other locations in Ontario are reported in Table 6.
Site | 2002 | 2003 | 2004 | New Record |
|||
---|---|---|---|---|---|---|---|
G. volans detected |
Trap Nights | G. volans detected |
Trap Nights | G. volans detected |
Trap Nights | ||
Clear Creek Forest | yes | 1 500 | yes | 120 | |||
Krug Forest (FON Tract) | no | 128 | No | ||||
Sites in Grey County | no | <50 | |||||
Sites in Bruce County | no | 130 | |||||
Ganaraska Forest | no | 266 | yes | 400 | Yes | ||
Henderson Line Woodlot (Peterborough) | yes | 75 | Yes | ||||
Keene Road Woodlot (Peterborough) | no | 75 | No | ||||
Mark S. Burnham Provincial Park | no | 75 | No | ||||
Oliver Property (Trent Research Station, Pigeon Lake) | yes | 68 | yes | 87 | yes | 84 | |
Kawartha Highlands Signature Site | yes | 183 | yes | 120 | yes | 60 | Yes |
Leslie M. Frost Centre | yes | 154 | yes | 440 | yes | 400 | Yes |
Crown land adjacent to Killbear Provincial Park | yes | 30 | Yes | ||||
Haliburton Forest & Wildlife Reserve | yes | 2 685 | yes | ||||
Crown land adjacent to Killbear Provincial Park | yes | 30 | yes | ||||
Algonquin Provincial Park - Hwy 60 | yes | 5 043 | yes | 9 499 | no | 11 295 | yes |
Algonquin Provincial Park - Achray | yes | 3 094 | yes | 2 286 | no | 900 | yes |
Algonquin Provincial Park - Kiosk | yes | 930 | no | 128 | yes | ||
Killarney Provincial Park | yes | 367 | no | 180 | yes | ||
Nipissing Crown Game Preserve | no | 140 | |||||
North of Mattawa (Olrig and Antoine Townships) | yes | 315 | no | 400 | yes | ||
Emerald Lake (Afton Township) | yes | 345 | yes | ||||
Highway 11 corridor between Temagami North and Latchford | no | 420 |
Source for all data: J. Bowman, P.J. Wilson, G.L. Holloway and J.R. Malcolm (unpubl. data.), except Clear Creek Forest: Pasma and Dobbyn (2003).
Location | Year | n (indiv) |
Catch per Unit Effort |
Source |
---|---|---|---|---|
Point Pelee National Park | 2001 | 155 | 44%* | Bednarczuk 2003 |
2003 | 68 | 22%* | Bednarzcuk and Stephens 2004 | |
Clear Creek Forest | 2003 | 38 | 6.0%* | Pasma and Dobbyn 2003 |
Norfolk Township | 1993/94 | 114 | 0.84% | Adams 1995 |
2000 | 396 | 45.8% | Bednarczuk 2003 | |
Hamilton | 1999 – 2001 | 200+ | 20-50% | Bednarczuk and Judge 2002 |
Minden | 2001 | 21 | 21.6% | Bednarczuk 2003 |
Trent University Research Station | 2001 | 25 | 5% | L. Bridges pers. comm. 2004 |
2002 | 4 | 6% | P. Wilson pers. comm. 2004 | |
OMNR provincial study (Table 5) | 2002 | 8 542 TN* | 1.36% | Bowman et al. unpubl. data |
2003 | 16 597 TN* | 3.57% | ||
2004 | 17 832 TN* | 0.22% |
* denotes number of Trap Nights
There is no abundance estimate for the Great Lakes Plains Population. Multiplying even a conservative density estimate by the area of Extent of Occurrence would provide a vast over-estimate of population size because the Area of Occupancy (unknown) is a small fraction of the Extent of Occurrence.
Estimates of population size for southern flying squirrels are constrained by low capture rates and unequal capture of individuals. G. volans also exhibits wide annual variation, rendering any point-in-time estimate unreliable. Published densities vary widely (Table 7). Raised trap height can increase trapping success (Risch and Brady 1996), but catch per unit effort is usually quite low (Table 6).
The total number of individuals of all ages in the Great Lakes Plains population may number in the several thousands to tens of thousands, the majority of which are mature individuals capable of reproducing. Roughly half of the marked population at Point Pelee National Park was composed of mature individuals in 2001, and 75% of captured individuals in 2003 were mature (Bednarczuk and Stephens, 2004). During trapping in Hamilton in 2001, 2.5 times more adults than juveniles were captured (Bednarczuk and Judge 2002).
Location | Density (per ha) | Forest type | Source |
---|---|---|---|
Point Pelee National Park, Ontario | 1.7 – 2.3 (2001) |
hackberry, maple, oak | Bednarczuk and Stephens, 2004 |
0.3 – 0.4 (2003) | |||
Algonquin Prov. Park, Ontario | 2.9 (2003) | beech – maple | G. Holloway unpubl. data |
2.6 (2003) | sugar maple | ||
0.6 (2003) | mixed maple - conifer | ||
no captures in 2004 | |||
Nova Scotia | 0.9 – 8.4* | mixedwood | Lavers 2004 |
Michigan | 2.82 | oak – hickory | Jordan 1948 |
5 | Baker 1983 (in Stabb 1988) | ||
Maryland | 6.2 | hardwood - conifer | Gilmore and Gates 1985 |
Virginia | 34.0 – 38.0 | hardwood – pine | Sawyer and Rose 1985 |
3.7 – 13.8 | oak – hickory - beech | Sonenshine et al. 1979 | |
Arkansas | 0.2 – 0.9 | pine – hardwood | Taulman 1999 |
Alabama | 1.8 – 3.5 | pine – oak | Hatten 1992 |
* Lavers (pers comm 2004) advised caution when using these population data as they are based on few captures.
There are few data on population fluctuations for the Great Lakes Plains population, due to a lack of long-term monitoring studies and no historical data. However, results from northern and central Ontario and Point Pelee National Park suggest that southern flying squirrels undergo wide population fluctuations throughout the Great Lakes range.
Given widespread habitat loss throughout southern Ontario (see Habitat Trends: Great Lakes), a decline from historical levels has probably occurred. Observed range extensions in central Ontario appear subject to fluctuation and may not offset declines in the southern part of G. volans’ Great Lakes Plains population range.
There is limited possible rescue effect for the Great Lakes Plains population. Immigration to Ontario is restricted by the Great Lakes and their associated rivers. Flying squirrels are poor swimmers because the patagium restricts leg movement. They therefore can cross water bodies no wider than “one glide”; maximum 50 m.
The only land border between the United States and Canada is in southwestern Québec. There is little known about southern flying squirrel distribution in this area of Québec or adjacent states New York, Vermont and New Hampshire.
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