Something outstanding about breeding in lynxes

Co-author Irina Rotenko

Over two decades ago, for the first time, I encountered a lynx family’s tracks showing that the mother had very small kittens in mid-December. The kittens’ footprints were almost half the size of a typical kitten’s at this time of year. A few years later, I observed this phenomenon again.

Once later during a meeting with lynx experts, I brought up instances where exceptionally small lynx kitten tracks were recorded at the beginning of winter (suggesting unusually small kittens). I proposed this could be due to females giving birth very late in their second or third years (their first breeding). Interestingly, we have observed a similar pattern in wolves (marked by finger clipping), where first-time breeding females gave birth about a month later than older females. It seemed that my colleagues perceived these accounts as potential errors on my part.

Recently, I encountered remarkably small footprints of lynx kittens in the early winter again at least twice more. I had nearly forgotten about these observations. However, we managed to capture footage of an exceptionally small lynx kitten on November 4th. It was roughly the size of a large domestic cat, which is typical for lynx kittens around the first half of August at the latest. Therefore, it’s likely that the lynx kitten shown in our photo was born in August. The breeding site was located in a dense area of treefall spanning several hectares.

The entire breeding story is quite fascinating. From the spot pattern on the coat, we know that the mother lynx of the registered small kitten was born in the same treefall in May 2023. It was raised by the known female lynx, Mikhalina. In May 2024, Mikhalina bred there once more. Typically, Mikhalina used the treefall as her year-round home, visiting it quite often. Although Mikhalina gave birth there last May and remained through June and July, in the treefall we observed an adult male lynx regularly and occasionally last year’s kitten, which was the mother of this outstandingly small kitten. Then, in mid-August, Mikhalina left the treefall with her kittens and never returned still. This was peculiar until we discovered that her daughter from the previous year had given birth in the same den. The photo below shows a single, small three-month-old kitten, born and nurtured by Mikhalina’s slightly over one-year-old daughter. The photo was captured on November 4th.

It is noteworthy that all five instances of yearling lynxes giving birth considerably later (approximately 2-4 months) were observed under conditions of relatively low population density. This may indicate a form of reproductive regulation within low-density lynx populations. Essentially, female lynx kittens are not sexually mature during the species’ mating season yet, but they reach sexual maturity and experience estrus a few months later. Consequently, they may mate with adult males who are still undergoing active spermatogenesis.