IUCN Otter Specialist Group . . . leading global otter conservation Last Update: Tuesday January 3, 2012
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Does anyone know of a protocol to take body measurements on river otters? We have a project in which we are going to trap some for DNA and hormone studies in rivers of Sonora, México and we need to have this to do things according to a protocol to report measurements. Any help will be very much appreciated

Juan Pablo Gallo Reynoso, 28 January 2009

Response from Terry Webb

There are standards for measurement guidelines published for mammals.

  1. Scientific name and common name
  2. Sex
  3. Specimen identifying number
  4. Date
  5. Reproductive condition if known (lactating, pregnant)
  6. All units should be metric.
  7. Precision varies, but nearest 10th of a unit is recommended.
  1. Total length (TL) lay animal on back against a ruler, nose should extend forward and body and tail should lie flat against the ruler, but do not stretch the animal. Hair that extends past tail tip should not be included. If animal is alive and difficult to restrain, measure mid-dorsally from tip of nose to tip of tail following curves of the body.
  2. Tail length (T) lay animal on stomach and hold tail up at a 90 degree angle, measure the dorsal (upper) surface of the tail from junction of the body (base) to the tip excluding hairs that extend beyond the tip. If the base is difficult to identify, measure from the middle of the anus to the tip and label “TM/A”.
  3. Hind foot length (HF) press the sole of the foot gently against the flat side of a ruler so that toes are straight, measure from the calcaneum (heel) to the end of the claw on the longest toe. Indicate cum unguis (c.u.) for with claw or sine unguis (s.u.) without claw.
  4. Ear length (E) use calipers, dividers, or a ruler, measure from the base of the notch below the ear opening to the most distant point on the margin of the pinna (external ear) excluding any hair that extends beyond this point.
  5. Weight (wt)

Teeth are not considered standard but are include at time.

  1. Alveolar length of maxillary tooth row- use calipers, dividers, measure on one side of upper tooth row from the anterior surface of the canine near its junction with the jaw bone to the posterior surface of the last molar near its junction with the jawbone.
  2. Alveolar length of molar tooth row- same as above but does not include canine. The first reference point is the first premolar or first molar if there are no premolars.

Response provided 31 January 2009