Field Guide for Aging Tigers

Dr. Y V Jhala & Dr. Ayan Sadhu


We have developed a new method for estimating the age of wild tigers in the field. In the past, experts have used a variety of physical characteristics, such as tooth colour and wear, body size, and nose pigmentation, to determine a tiger’s age. However, there was no established method for doing so. So, we created our own method based on our observations of wild tigers and close inspections of more than 20 captured tigers, whose ages were already known.

Gumline Recession

Nose Pigmentation

Tooth Eruption


Wear & Coloration

Body Characterisitcs

Our Approach

Our technique involves looking at the tiger's body size, body characteristics, teeth eruption, wear and coloration, gum line recession, and nose pigmentation to determine its age and place it in one of six categories: cubs (less than 12 months), juveniles (1-2 years), sub-adults (2-3 years), young-adults (3-5 years), prime-adults (5-10 years), and old-adults (over 10 years).

Tigers often yawn when in proximity to people in a non-confrontational manner, as a means to intimidate. This helps to closely observe teeth condition and gum-line recession with binoculars or telelens photographs. Teeth eruption, wear and coloration as well as gum line recession are highly correlated with the age of the tiger.

Cubs (<12 months)

Cubs were usually observed after they were about 2 months old. At this time, they rarely accompany their mother and are restricted to birth site. By 5-6 months age they reach the belly of their mothers and accompany to nearby kills. By the age of 6-8 months there is a distinct size difference between male and female cubs (fig. s1d).


Large domestic cat at 2-3 months (fig. s1a), as large as a jackal by 5-6 month age (fig. s1b, s1c).


Color of iris is blue-grey in small cubs & turns to amber by 3-4 month age.


Born toothless, develop milk dentition by 1-1.5 months. Have meat diet by 5-6 months age.

Juveniles (1 to 2 years)

Juvenile tigers accompany their mothers to larger kills and are usually not photographed alone, making size comparison easy (fig S2a, S2b). Male tigers show faster growth than females and are seen to be substantially larger.


Half the size of their mothers (about the size of a leapord, 50-120 Kg).


Face proportions are cub like, with a shorter snout and smaller face.


Partly developed dentition which begins at the age of about 9-10 months and is completed by 12-14 months (fig S2c, S2d).

Sub Adults (2 to 3 years)

At the sub-adult stage, the males are substantially larger than the females. Often sub-adult tigers move around with their siblings, but by 30 months they become more solitary. The body is almost as large as adults and can no longer be used for size comparisons as most of the camera trap images are of solitary tigers. A prominent ridgeline on the inner side of the canines and a groove on the outer edge of the canines is clearly visible (fig. s3c, s3d). Facial hair in the form of a short mane below the lower jaw/cheek is usally seen even in camera trapped photos of males.


Males can weigh as much as 200 Kg, females as much as 120 Kg by 30 months.


Face is close to that of the adult after 20-22 months, belly is flat and taut (fig. S3a, S3b), skin flap on the belly is missing. Nose is pink with no black specks or pigment (fig. s3c, s3d)


Permanent dentition is fully formed, the canines are milk white often with a pinkish tinge, tips are pointed without any wear, no signs to show a receding gum line.

Young Adults (3 to 5 years)

By 3 years most tigers are close to full adult size (fig. s4a, s4b), but continue to accumulate weight upto 4-4.5 years of age. 

Pregnant & lactating tigers : A heavily pregnant tigress (fig. s4e) can be distinguished from a fully fed tigress by the visibility of prominent teats and udders. After birth, the belly is normal with full udders where nipples show signs of intense suckling (fig. s4f). For un-bred females and early days following first births the nipples are pink in color (fig. s4g) and become pigmented, darkened grey and keratinised after cubs suckle intensely.


Adult males range from 200-260 Kg, while adult females range from 110-180 Kg, showing a pronounced sexual dimorphism in size.


Face is no longer cub like with full snout and adult skull proportions. Belly gets rounded, often with a slight sag (fig. s4a, s4b), skin fold on belly begins to show. nose pigmentation is seen.


Teeth start to turn cream color to yellowish and are no longer milky white. By 5 years of age, the yellow canines begin to get brownish stains. The canine ridge & grooves are visible, with little or no wear on teeth (fig. s4c, s4d).

Prime Adults (5 to 10 years)

Careful inspection shows a receding gum line on canines, making the canines appear larger (fig. s5d). The canine ridge is amlost indiscernible, and the grove is highly worn out (fig. s5c).


The belly is sagging and rounded, often belly fold is visible (fig. s5a, s5b).


Black spots on nose and slightly sagging lips on the lower jaw are often seen.


Teeth are bownish-yellow and begin to show wear which is visible on canines and incisors.

Old Adults (>10 years)

Body condition of tigers is usually not a good parameter to use for ageing. Often very oldtigers that have lost their canines can be in poor condition (fig. S7a) but can regain condition withjust a couple of good meals (fig. S7b).


Belly and belly skin fold are sagging.


Nose pigmentation, Jaw and lips are sagging, lips show a fold.


Canines & incisors are worn down, broken or missing with dark brown stains (fig. s6b, s6c), receded gum line.

We believe that by using the criteria described above an experienced researcher can age anadult tiger to its stage accurately with an error margin of about a year, and younger tigers(sub-adults and juvenile) to about 3-4 months. Cubs can be aged with the accuracy of about amonth by field observations.

Quiz Time