All pests

Eastern chipmunk (Tamias striatus)Eastern chipmunk

Tamias striatus (Linnaeus, 1758)

Eastern chipmunk

A striped ground squirrel that burrows under patios and raids gardens.

Order
Rodentia
Family
Sciuridae
Group
Rodents
Ontario status
Established, common provincewide; burrows under patios and raids gardens

Why it matters

Burrows under patios, stairs, and foundations can undermine paving; garden and bulb raiding is the main complaint. Also a reservoir host for Lyme disease spirochetes in some regions. Beloved by most homeowners, control is rarely wanted.

Origin

Native to eastern North America's deciduous forests, a true local, at home in Ontario's ravines, woodlots, and suburban gardens.

Behavior

Diurnal and famously busy, stuffs cheek pouches with seeds and nuts, then vanishes down a burrow entrance you'd never notice. Scatter-hoards food in shallow caches. Spends winter in torpor, waking every few days to eat from its stores.

Living conditions

Woodland edges with cover and loose soil for burrowing: ravines, parks, gardens, and cottage country. Burrows have hidden entrances and separate chambers for nesting, food storage, and waste.

Signs of presence

  • Neat round burrow entrances ~50 mm wide with no excavated soil fan (it carries soil away in its pouches)
  • Half-eaten seeds and small droppings on patios and walls
  • Rapid 'chip-chip' alarm calls from cover
  • Bulb and garden raiding in spring and autumn

Weaknesses

  • Tied to its burrow and caches, rarely ranges more than 100 m from home
  • Winter torpor with periodic waking burns its cached food; a poor mast year means a hard winter
  • Diurnal and noisy, easy to watch, which makes its habits an open book
  • Small size puts it on every predator's menu: hawks, foxes, cats, snakes

Myths and facts

  • Myth Chipmunks are just small squirrels and hibernate all winter.

    Reality They're ground squirrels, but they don't truly hibernate, they sleep in torpor bouts and wake to snack from their food stores all winter.

Research notes

Morphology

Head-body 130-160 mm, tail 75-110 mm, weight 70-130 g. Five dark stripes on a reddish-brown back (the middle stripe continues onto the head); pale belly. Internal cheek pouches extend to the shoulders.

Diagnostics

Confirm by: five back stripes + internal cheek pouches + burrow entrances with no spoil heap. The thirteen-lined ground squirrel has thirteen stripes and prefers open prairie, not Ontario woodlots.

Easily confused with

  • Red squirrel, Tamiasciurus hudsonicus Red squirrel is larger, uniformly reddish with no stripes, and nests in trees, chipmunks are striped and live in burrows.
  • Thirteen-lined ground squirrel, Ictidomys tridecemlineatus Thirteen stripes (count them) vs five, and a prairie species rare in Ontario.

Life cycle

Egg
N/A, viviparous
Nymph or larva
Pups blind and hairless; emerge at ~6 weeks; independent by 8 weeks
Adult
Lifespan 2-3 years in the wild; breeds the spring after birth
Egg to adult
Gestation ~31 days
Generations per year
1-2 litters per year (spring, sometimes late summer)

Development

Viviparous; altricial young born in the burrow nest chamber.

Reproduction

3-5 pups per litter × 1-2 litters/year.

Distribution

Native range
Eastern North America, Nova Scotia to Manitoba, south to the Gulf states
Ontario
Established provincewide wherever deciduous or mixed woods meet open ground
Global
Eastern North America only

Ecology

Scatter-hoarder: buries seeds singly across its ~0.5 ha range, an important forest regenerator. Torpor bouts through winter with periodic arousals to feed from caches. Vocal: distinct 'chip' alarm and trill calls.

Resistance

N/A, not a pesticide target species.

IPM implications

Monitoring: burrow-entrance mapping (no spoil heap is diagnostic) and cache-raiding patterns locate the territory. Exclusion of garden beds and bulb plantings is by buried mesh; the animal's small range means local exclusion works. Live-trapping is regulated, FWCA licensing applies.

Chemical ecology

Scent glands on the cheeks and flanks mark burrow entrances and routes; urine marking of caches reported.

Genetics and DNA

No reference genome published as of 2026.

Taxonomy

Rodentia: Sciuridae. Tamias striatus (Linnaeus, 1758), 'tamias' is Greek for 'storer', for the cheek pouches.

Open questions

Cache pilferage rates and their effect on overwinter survival in suburban vs forest populations.

References

  • Naughton, D. (2012) The Natural History of Canadian Mammals, Univ. of Toronto Press
  • Snyder, D.P. (1982) Tamias striatus, Mammalian Species No. 168