The Secret Love Lives of Wild Snow Leopards

When are snow leopards old enough to breed?

Based on data available from the wild, it appears that female snow leopards are ready to have their own cubs by age 3 or 4.

Male snow leopards are likely sexually mature by age 2 or 3 but are not big or experienced enough to defend a territory until they are around 4 years old. Therefore they likely don’t participate in mating until this age. 

How do snow leopards find each other in such vast and remote habitat?

Female home ranges are generally centered on the border between two or more males, providing them with a choice as to which of the overlapping males to mate with.

Scent marking is likely important before mating season as the cats need to show where they are, who they are, etc. These also serve as territorial markings so they are needed year-round. Vocalizations occur in mating season, but we don’t know how common they are. It is windy in the mountains and the cats can probably not hear sounds from too far a distance. Though to find a cat within, say 500 m – 1 km, they are likely useful.

Video: snow leopard scent marking

When do snow leopards typically mate?

Mating season for wild snow leopards is between January and March. During this time, a male and a female will travel together for a few days and copulate.

We have four instances when GPS-collared males and females traveled together during the mating season. These lasted between 1 and 8 days. Most likely, the 1-day occasion is an underestimate. It could be that one of the collars did not take locations as programmed or that another, unmarked, cat came in and pushed one of the collared cats away, as it seems rather short. But we don’t know for sure. 

In one of those instances, the mating pair of snow leopards were together for four days in early March. Most of the time, they were not more than 10 meters away from each other. Three months after that, the female started to decrease her home range size and two weeks later, we found her den site where she had a small cub. 

Interestingly, one February, while following GPS signals from collared female F12, Gustaf noticed signs of two cats walking on the same track for quite a while. “It was F12 and male M15. Then I came across what I think were signs in the snow of two cats mating. I can’t be sure, but the timing and the situation make it likely.”

Do snow leopards hunt cooperatively when they are together for mating?

The average interval between snow leopard kills is 8 days though it is not uncommon for cats not to kill anything for 14 days. It would not be unusual if they didn’t hunt during the time they are together for mating. Though, if an opportunity presented itself, I wouldn’t be surprised if they tried to make a kill. 

What is the gestation period for female snow leopards?

The female is typically pregnant for 90-105 (mean 96) days before retiring to a sheltered den site and giving birth to her cubs between April and July (the mean date for the litters we have studied is June 3). The mother raises her offspring alone, providing food and shelter for her cubs. The cubs open their eyes when they are around seven days old. Between one and three cubs are usually born in each litter.

Do male snow leopards pose a threat to young snow leopard cubs?

In many other large carnivore species, it has been shown that females mate with several males. It is suggested that this is a way to reduce the risk of infanticide (males killing offspring). We do not think that infanticide is common in snow leopards because they have a fixed mating season, and males and females are very similarly sized, implying that females could protect their cubs with aggression. We suspect that in the event that a male killed the cubs, the female would not come into oestrus again (until the next mating season). Though again, we do not know this for sure. 

How long do cubs stay with their mothers?

Cubs typically remain with their mother until their second winter (20–22 months of age), when they start moving away and leave their mother for a few days at a time. This initiation of independence appears to coincide with their mother mating again. In our research, two female cubs remained in their mothers’ territory for several months after the initial separation, whereas the male cub quickly dispersed. When examined across 11 Felid species in relation to their body size, it was clear that snow leopard cubs stay with their mothers longer than any other medium-to-large-sized cat. This may be related to their mating behavior and the difficulty juvenile snow leopards might face hunting their prey in steep terrain.

For example, the mountainous habitat, low density and large size of the prey relative to their own body size could imply that snow leopard mothers may have fewer opportunities to release large prey for their cubs to practice successful hunting. This could be one of the factors contributing to young snow leopards becoming independent at an older age. 

How does this research benefit snow leopard conservation?

Reproductive data including breeding ages, mate selection, birth rates, sex ratios, litter sizes, dispersal ages, etc., are all critical to our work to protect snow leopards. These variables are largely unknown for wild snow leopards but essential for developing conservation actions to ensure this endangered cat’s future. 

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Photo credit: Lionel Falcao