All pests

Red squirrel (Tamiasciurus hudsonicus)Red squirrel

Tamiasciurus hudsonicus (Erxleben, 1777)

Red squirrel

Small, loud, and fiercely territorial, the forest's alarm system.

Order
Rodentia
Family
Sciuridae
Group
Wildlife
Ontario status
Native, common

Why it matters

Chews into cabins, cottages, and wood-sided homes; cone middens and noise; damages conifer seed crops.

Origin

Native across Canada's boreal and mixed forests; common in GTA ravines and wooded lots.

Behavior

Diurnal, solitary, aggressively territorial, chatters and foot-stomps at intruders ten times its size.

Living conditions

Middens (cone-scale piles) at the base of conifers; larder-hoards cones in one defended cache; active year-round.

Signs of presence

  • Cone-scale middens under conifers
  • Loud chattering and rattling calls
  • Small gnawed holes at eaves
  • Stripped conifer cones

Weaknesses

  • Larder-hoarding concentrates activity at one midden, predictable
  • Small size limits entry to gaps of about 4 cm and up
  • Strictly territorial, one animal per territory, not colonies

Myths and facts

  • Myth Red squirrels are just baby gray squirrels.

    Reality A separate, smaller species, adults weigh 200-250 g and never grow into gray squirrels.

Research notes

Morphology

Body 19-23 cm, tail 13-16 cm; weight 200-250 g. Rusty-red dorsum, white venter in winter, white eye-ring.

Diagnostics

Small size + red pelage + intense territorial vocalizations.

Easily confused with

  • Gray squirrel (Sciurus carolinensis) Twice the size, gray, quieter; the red squirrel is the noisy one.

Life cycle

Egg
N/A, viviparous (placental mammal)
Nymph or larva
Pups: nest-bound about 8 weeks
Adult
Sexual maturity about 1 year; lifespan about 3 years wild
Egg to adult
Gestation about 38 days; weaning about 8 weeks
Generations per year
One litter per year (occasionally two in mast years)

Development

Altricial; weaned at about 8 weeks.

Reproduction

4-6 young × 1 litter/year.

Distribution

Native range
Canada and northern United States
Ontario
Native, common in forested and ravine habitat
Global
North America only

Ecology

Conifer specialist; larder-hoarder with a single defended midden; does not hibernate; territories about 0.5 ha.

Resistance

Unknown, not applicable.

IPM implications

Single-animal territories simplify the problem, one red squirrel, one territory. Exclude small gaps; the midden location reveals the resident. Licensed wildlife-control rules apply.

Chemical ecology

Urine and glandular scent-marking of territory boundaries; the loud 'rattle' vocalization is the primary territorial signal, acoustic, not chemical.

Genetics and DNA

No reference genome published as of 2026.

Taxonomy

Order Rodentia, family Sciuridae. Tamiasciurus hudsonicus (Erxleben, 1777).

Open questions

Mast-year population irruptions and their effect on human-wildlife conflict timing.

References

  • Animal Diversity Web, Tamiasciurus hudsonicus species account (University of Michigan)
  • Steele (1998), Tamiasciurus hudsonicus, Mammalian Species