Rouge Valley Conservation Centre


2014 Deer Census and Mammal Count
Rouge River Valley
Central Woodland Complex to
Steeles Avenue

By Paul Harpley

March 8, 2014

The Annual Rouge Valley Deer Census took place on March 8, 2014 beginning with the pre-census strategy meeting outside the Rouge Valley Conservation Centre. The participants included naturalists from the local Rouge area and other communities in and around the City of Toronto, York and Durham Region. Some participants were experienced recent surveyors of the census while other naturalists were new to the count. The Rouge Valley Deer Census has become well known over the years for its unique naturalist experience, consistent records and deer observations. The area of the survey is bounded in the south by Twyn Rivers Road, on the east by the Markham-Toronto-Pickering Townline, north by Steeles Avenue, and west by Meadowvale Road, Old Finch Avenue and Sewells Road. This is a large, relatively continuous wilderness-like near urban representative deer range habitat area, with rural/cultural affinities in the Rouge River watershed.

The day started out fully overcast at 9:00 a.m. with temperature -8 and moderate wind conditions. The temperature had risen to -3 degrees Celsius by midday. The sun appeared intermittently in the afternoon after 3:00 p.m. but overall the sky remained 85% cloudy for the day. Participants started the count with a walking surface of hard-packed unusually deep snow in about 100% of the walking surface, mostly in the forests and sheltered north-facing farm field and meadow areas, including drifts. Generally the snow varied from 5 inches to 15 inches thick. Uncharacteristically, almost no areas had absence of snow on the ground. Snow had accumulated from continuous winter storms from late December. The snow was relatively easy to walk on the walking trails in the morning, but became difficult with snow-pack decay from warming and sun in the afternoon. Skis and snowshoes were used in locations off trail. These field conditions were welcome for count signs and typical for this winter compared to previous years in the huge area. Optical conditions were good on count day.

As in past years, deer were surveyed by signs (and estimated as to number) and by actual observation of individual deer seen. Signs observed and recorded ranged from tracks, trails, scat (pellet groups), beds, buck rubs, browse evidence, urine spots, kills (dead deer or parts – coyote, car or railway caused), corn and other agricultural browse evidence, to pseudo winter yarding areas (not full yards like in central/northern Ontario). Final day data was reviewed by census participants and evaluated by each major geographic survey zone in the study area. A final informed estimate of overall deer numbers for the census study area was determined by those in the field that day. The past established count methodology was followed, and informed by current field knowledge of contemporary local conditions and previous seasonal other observations, and past experience of the organizers.

The census ended by 4:30 p.m. A few key management comments can be made. As in 2013 there was little evidence of deer hunting (poaching) in the area (within the boundaries of Toronto) in contrast to some past recent years. Few existing hunter/deer stands were observed. Coyote (Brush wolf) tracks were seen on survey day, and a couple of individual animals observed.  A couple of areas were noted as hot spots for coyote (sign and observed animals) at the time of the count. Consistent with historical data, much of the deer activity was observed in the north of the survey area in 2013 and 2012. Some deer browse of a few recent planting sites was noted in the survey area. Corn fields, sumac and Eastern white cedar were preferred deer browse. Up to 14 deer were observed by participants during the main count day, a few small groups of 3-4 adult deer together were seen including yearlings.

There were fewer buck rubs reported than in some past surveys, and similar to 2013. Some traditional deer areas in winter were being used by people (and dogs not on leashes), and in some of these, deer have started to move out of those areas (for example old Woodland Park, the Meadowvale east yard, and the Beare Landfill) similar to observations in 2012 and 2013. As previously reported some future refinement to human use trails in these areas may lessen future human impact on deer in the study area. Dog-walkers were perceived as the most probable cause of the movement of deer out of southern, more accessible trail areas. Concern was expressed about deer being pushed out of high use areas by continued trail development and homogenization of established trail areas over time. In general all deer observed looked to be in good health. No deer antlers were reported found by surveyors.  

In total, 70 - 80 White-tailed deer were estimated to be in the count area on the survey day (observed and inferred by signs) consistent with 2012 and 2013 numbers, and 14 individual deer were actually seen by participants (mainly adult does and yearlings) during the census. This estimate was considered relatively accurate than most past years, as the prevalence of full ground snow made overall estimates less speculative than in past years. In general the estimate was considered to be accurate based on signs. The increased human and dog track interference on trails on count day inform this consideration. The observation of the study area having fewer recently planted restoration area trees for browse was considered a possible reason for lower deer numbers than in the late 1990’s , as planting trees are maturing above easy deer browse height. Also, the harshness of the weather and consistent deep snow all winter, limiting factors for W.T. deer in Ontario, has kept deer winter numbers down. Due to the snow conditions evidence for over 200 deer night beds were documented on the count this year.

As in past recent years, other mammals were observed and documented, as were birds and other fauna. In total there were 8 mammal species observed including White-tailed deer, Coyote, Gray Squirrel, Eastern chipmunk, Cotton-tail rabbit, Raccoon, Domestic dog, Opossum evidence observed being highlights. Avian notables were rare this winter due undoubtedly to the cold, long and snowy weather, with only 9 species recorded compared with 29 last year. Various species of mice, voles and shrews were seen or identified by sign. There was a deep subnivian environment of snow pack and large drifts. There were some invertebrates observed, including flies sp., stoneflies sp., and Stiltflies sp. All species observed are listed in Appendix I.

Many thanks to those who contributed to the census.

Paul Harpley B.Sc. (Hons.) M.A. Doctoral Candidate, York University

Appendix I – Summary of all Mammal and Bird and other animal data

Mammals Observed (seen) on the Census Day (7 species)

Eastern chipmunk – 1

Gray squirrel - 2+

Raccoon - 3

Cottontail Rabbit - 3

Coyote - 3

Domestic dog – 4

Opossum – 1 dead (remains)

Significant mammal tracks and other signs: Beaver, Mink, Short-tailed shrew, Red squirrel, Weasel (not to species level), Meadow vole, Deer mouse, Raccoon, Porcupine , Domestic cat.

Birds Observed on the Census Day (9 species)

Canada Goose - 6

American Crow - 3

American Robin - 20

Black-Capped Chickadee - 12+

Downy Woodpecker - 1

Pileated Woodpecker – 3 – (estimate from fresh tree hole evidence)        

Blue Jay - 2

Red Tailed Hawk - 3

Wild Turkey – 4

Insects (4 species)

Stone fly - 6+

Stilt fly- 5+

Fly – many ?

Flies (unidentified to species)- 10

White-tailed deer in the Rouge River Valley. Photo by Bill Lewis.

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