Wild Tiger Health Project
Created by Dr John C M Lewis

Sexual maturity for both sexes is generally between 2.5 and 3 yrs.

• First breeding normally occurs at between 3–4 yrs in females and 4–6 yrs in males, but females have been recorded giving birth as young as 2.9 years.
• Males usually breed later than females as it often takes them longer to establish a breeding territory.

Breeding occurs all year round, although in temperate areas young are more likely to be born in summer.

Oestrus and mating:

• Females scent-mark more frequently as they come into oestrus and are ready for mating.
• Oestrus occurs every ~ 25 days, although a range of figures are to be found in the literature.
• During oestrus females are receptive for 2-3 days only.
• Male tigers copulate frequently with females during their peak receptive period (< 50x daily).
• Tigers are thought to be induced ovulators, requiring a number of copulations within a limited period of time to stimulate ovulation (i.e. the release of eggs for fertilisation).
• If a litter is lost the next oestrus occurs within a few weeks.

Gestation is generally considered to be ~ 103-105 days.

• Shortly before a birth, a tigress will choose a secluded place in which to have her young – a den, a place in a thicket, shallow depressions in dense grass, rock crevices & caves etc.
• Litter size is usually 2-3 cubs, although < 5 is possible. However, tigresses in the wild are rarely accompanied by more than 2-3 cubs.

Cubs are born with their eyes closed, opening around day 10.

• Tiger cubs feed only on mother’s milk for the first 6-8 weeks.
• Young become mobile at 2 -3 months
• Weaning occurs progressively between 3-6 months, but cubs lack the ability to kill prey effectively at this age.
• Permanent canine teeth erupt between 12 & 18 months.
• At 6 months the cubs weigh < 50kgs at which stage they learn to hunt.
• At 18 months tiger cubs can hunt alone and can be considered independent

Dispersal is the stage at which young tigers leave their natal area to find a new territory. Males always disperse from their natal home range while females often take over part of or settle adjacent to their mother’s territory.

• After being independent for a while in the natal territory, dispersal can occur at between 18 and 24 months.
• Males disperse further than females, and are generally less successful in establishing a territory. As a result males often get into fights with resident males as they search.
• Prey density and female territory size are correlated, but higher prey density does not always result in more breeding females. The lower limit for female territory size appears to be about 15 – 20 km², a threshold probably limited by social intolerance rather than prey density. 

The reproductive life span:

• It has been estimated that females in Chitwan National Park have an average reproductive lifespan of ~ 6 years, that of males ~ 3yrs. However, reproduction in females is possible < 15 yrs.
• Reproductive parameters inevitably vary between the subspecies in response to different climates, habitats, prey densities and other environmental parameters.
• Inter-birth intervals can be as short as 20 months in high quality habitats, but longer where resources are poorer. The range is more likely ~ 22 – 33 months.
• If habitat and prey remain intact, tiger populations can rebound rapidly from substantial hunting losses.