Mammal field guide · Mustelids

Photographing the Long-tailed Weasel

How to photograph the Long-tailed Weasel (Neogale frenata): the right lens for its size, shutter speeds for perched and moving animals, and when it's most often seen (May, June and July).

20–130 cm1/2000 s
Long-tailed Weasel (Neogale frenata)
Photo: © benjchristensen, some rights reserved (CC BY) via iNaturalist
20–130 cm
Typical length (family range)
1/800 s
Shutter: perched / still
1/2000 s
Shutter: action / flight
f/5.6–f/8
Aperture
5,784
Research-grade sightings in N. America
ModeManual + Auto ISOLock shutter & aperture, let ISO float
Shutter (still)1/800 s
Shutter (action)1/2000 s
Aperturef/5.6–f/8
FocusAF-C + subject/eye detectionGet down to eye level; a long lens with close focus (or an extension tube) helps with small subjects.
DriveHigh-speed burst
Lens100–400 mmFull-frame equivalent

Focal length needed to frame it#

For a subject about 75 cm long filling a third or half of the frame width horizontally.

Distance⅓ of frame (FF)½ of frame (FF)⅓ of frame (APS-C)⅓ of frame (MFT)
5 m (16 ft)78 mm117 mm52 mm39 mm
10 m (33 ft)156 mm234 mm104 mm78 mm
15 m (49 ft)234 mm352 mm156 mm117 mm
20 m (66 ft)312 mm469 mm208 mm156 mm
30 m (98 ft)468 mm703 mm312 mm234 mm
50 m (164 ft)780 mm1,172 mm520 mm390 mm

When to find it#

Jan: 4% Jan Feb: 4% Feb Mar: 5% Mar Apr: 8% Apr May: 13% May Jun: 15% Jun Jul: 18% Jul Aug: 13% Aug Sep: 8% Sep Oct: 5% Oct Nov: 4% Nov Dec: 4% Dec
Share of iNaturalist observations by month across North America. Peak months: May, June and July.

About the Long-tailed Weasel#

The long-tailed weasel (Neogale frenata), also known as the bridled weasel or big stoat, is a species of mustelid distributed from southern Canada throughout all the United States and Mexico, southward through all of Central America and into northern South America. It is distinct from the short-tailed weasel (Mustela erminea), also known as a "stoat", a close relation in the genus Mustela that originated in Eurasia and crossed into North America some half million years ago.

Summary adapted from Wikipedia via iNaturalist (CC BY-SA 4.0).

Field-craft tips#

  • River otters play at the same haul-out spots daily.
  • Get down to eye level; a long lens with close focus (or an extension tube) helps with small subjects.
  • Sightings peak in May, June and July, which is when you'll have the most chances.

Ethics#

  • The welfare of the animal comes first: if it changes its behaviour because of you, you are too close.
  • Stay on trails, respect closures around nests, leks, dens and haul-outs.
  • Avoid playback and baiting in sensitive seasons; never bait predators.
  • Don't share precise locations of rare, nesting or roosting animals publicly.

More Mustelids#

North American River Otter North American River OtterLontra canadensis American Mink American MinkNeogale vison Sea Otter Sea OtterEnhydra lutris American BadgerTaxidea taxus FisherPekania pennanti American Ermine American ErmineMustela richardsonii American Marten American MartenMartes americana

Frequently asked questions#

What lens do I need to photograph a Long-tailed Weasel?

At about 75 cm long, a long-tailed weasel fills a third of a full-frame image at 10 m with roughly 156 mm, or at 20 m with 312 mm.

What shutter speed should I use for a Long-tailed Weasel?

1/800 s when it's still; 1/2000 s for action.

When is the best time to photograph a Long-tailed Weasel?

Observations in North America peak in May, June and July. Early morning and late afternoon give the best light and activity.

Sources & licences#

Last updated October 03, 2026 · How we calculate · Sources