How wolves break the idea of the species monogamy

Co-author Irina Rotenko

In our large experience and large dataset on wolf reproduction in Belarus (e.g., Sidorovich and Rotenko, 2019), there is much evidence that the widely spread idea of monogamous wolves is mainly wrong.

We studied the wolf reproduction in Belarus (basically in Naliboki Forest and Paazierre Forest) for almost 25 years, and during this long period we gained many kinds of materials (finding of dens with pups and tracing the litters until winter by camera-traps, autopsy of wolf carcasses etc.). In particular, the gained denning material is based on finding of 86 dens with pups and further tracing the litters.

Based on our data, we would like to state that in our study areas in Belarus the minority of adult wolves breed monogamously, and adult wolves change breeding partners for different reasons not rarely, therefore, in general this idea of monogamous wolves is wrong. To support our hypothesis, we would like to refer to two kinds of our materials: First, it is the registration of multi-breeding in a wolf pack. Second, it is pairing stories of three long-living wolves from the same pack that we traced for a decade.

As for our first argument, we have already shared our findings on pack multi-breeding in one of our recent posts. Here we summarize them briefly. Till 2019, we obtained fairly detailed information about denning of 59 wolf breeding groups (i.e., a pair or a complex breeding group that consists of two breeding females and an adult male, at least) in Belarus, as well as an autopsy of all wolves from nine whole packs which were killed in March-early April, was conducted. In 17 cases we detected double-breeding (i.e., there were two breeding females in a complex breeding group), and in two cases triple-breeding was observed (Sidorovich & Rotenko, 2019). The obtained data show that till 2019 a pack multi-breeding occurred in 32% of cases (denning information) or 22% of cases (carcass information); however, we might have underestimated these values, because some of the cases of pack multi-breeding could not be detected, especially before 2015.

Since 2015 in Naliboki Forest we have studied on pack multi-breeding in wolves with high accuracy by investing a lot of efforts and knowing a lot about wolf breeding behaviour in this forested terrain. In total, during nine years (2015-2023) we traced 24 wolf breeding groups (11 pairs and 13 complex breeding groups). During these nine years, we investigated 38 breeding stories in detail; pack multi-breeding was very common, and it occurred in more than half of the studied cases, so pack multi-breeding became more common than breeding in pairs there.

Regarding pack multi-breeding, it is important to note that in the cases of breeding several females with one male, the other breeding females often were his daughters. Alternatively, they were subordinate non-related roaming females.

Now we would like to describe the pairing stories of three long-lived wolves from the same pack, whom we have traced for a decade in Naliboki Forest, central-western Belarus. We named them: Torn Ear (female), Pryhazhun (male), and Pliamistaja (female). They were easily recognizable wolves. Actually, only Torn Ear was known to us since 2013. You can see these wolves in the photos and video below.

Before describing the stories, we would like to point out that Naliboki Forest wolf packs mainly consisted of adults because of high pup mortality (Sidorovich and Rotenko, 2019). Please take this into account, and do not be surprised if a pack had double or triple breeding, the pack had no young ones during the next winter.

Since February 2013, Torn Ear has lived and reproduced in Naliboki Forest. In the spring of 2013, Torn Ear was part of a wolf breeding group that consisted of three females and one or two males. A big, dark-colored male stayed with Torn Ear alone, while either the same male or another smaller and lighter one mated with the other two females. We found their three litters at distances of about 430, 220, and 380 meters from each other. The pups in each litter were of different ages. The denning area in mid-May covered about 8-10 square kilometers. This denning area was slightly larger or smaller in other years in mid-May (hereafter referred to as the denning area).

In the breeding seasons of 2014 and 2015, wolves were bred by three adult females and two large adult males in this denning area. Two of the females were the same as before, including Torn Ear, and one was a new one that we named Pliamistaja (which means spotted). One of the males was the same dark one as before, and the other was a new one with brown-black-white fur that we named Pryhazhun (which means beautiful). Pryhazhun stayed mainly with Pliamistaja during denning.

In the spring of 2016, there was a wolf breeding group in this denning area that consisted of two females (Torn Ear and Pliamistaja) and two males (Dark one and Pryhazhun). The dark-colored male paired with Torn Ear still, while Pryhazhun mated with Pliamistaja. These pairs either stayed together or apart, but within a small distance of 1-2 km from each other. Torn Ear had pups, but we were not sure if Pliamistaja did or not.

In the spring of 2017, there was a wolf breeding group in this denning area that included three females (Torn Ear, Pliamistaja and possibly Torn Ear’s daughter) and two males (Dark one and Pryhazhun). All three females had pups, and the dens were about 0.92, 0.72, and 0.95 km apart. The dark male cared for two females, Torn Ear and her daughter, while Pryhazhun looked after Pliamistaja. Torn Ear also visited the dens of the other females.

In the spring of 2018, a wolf breeding group bred in this denning area. There were two litters, and each litter was cared for by all four breeders. 

In the spring of 2019, Torn Ear, Pliamistaja and Pryhazhun bred again in this denning area. Pryhazhun mated with both females, who had their pups about 3 km apart from each other. Then in mid-May, both females and their litters moved to the same locality within an area of 2 square km. However, since September, Pryhazhun stayed with Pliamistaja only, while Torn Ear paired with another smaller male. Both pairs lived peacefully in the same home range, but they did not interact with each other.

This behavior continued until the following winter, when a pack of six adult wolves appeared, including Torn Ear, Pliamistaja and Pryhazhun. During the denning period in 2020, these six wolves formed three semi-independent breeding pairs. From May to July, the pups of the three families stayed close to each other, within the area of 3 km in a diameter and usually only 0.3-1.8 km apart. We observed all the adult males near each of the three litters. Also, Torn Ear and another female with visible nipples were seen near each litters for several times. Interestingly, Torn Ear’s male partner, whom she stayed with during the previous autumn and winter, disappeared. While denning, she was supported by another male, who joined the wolf group by mid-winter. The second pair was Pliamistaja and Pryhazhun, and the third pair was formed by a new male and female.

We recorded how two females and their male partners alternately or together dug a burrow-den by expanding a former red fox den; then they inspected the burrow-den repeatedly for several days; then one pair brought about five large pups to the den. At a distance of about one km, within another homesite of about 20 hectares, we clearly observed the two pairs and their pups staying together with another adult female (new one). She probably acted as a pup-sitter (because later she was seen near the pups more often). In the fourth homesite, all three subfamilies of Torn Ear’s pack joined together. Their pups stayed there mainly in an area of 2-3 km2 until the end of October. During that period, the six parent wolves and one subordinate adult female (possible pup-sitter) hunted together in the surrounding habitats (up to 6 km away).

In the spring of 2021, two couples bred in this denning area: Pryhazhun and Pliamistaja, and Torn Ear and a new large male. During the denning period, they were seen together outside their dens and nearby pups.

In early winter, Torn Ear disappeared. Before that, another adult female joined the pack. In late January 2022, Torn Ear’s large male partner left the pack or was killed, and Pryhazhun mated with both females. These three wolves (Pryhazhun and his two mates) stayed together afterward. In late March 2022, one of the females had pups in a burrow-den. On April 20th, there were at least three pups with her. Another recognizable female (whom we called Pliamistaja) had pups in late April, about 1.8 km away from the first female’s den, and in mid-May, Pliamistaja had four pups of about three weeks old in her burrow-den. Pryhazhun cared for both females. Pliamistaja visited the denning area and dens of the other female. All three wolves (Pryhazhun and his two mates) walked together in April and May.

In the spring of 2023, in this denning area, we observed triple-breeding. Pryhazhun mated with three females during denning: Pliamistaja, her daughter with a similar spot on her back, and a new female. The distance between their dens varied up to 2 km. The initial dens of Pliamistaja and her daughter were about 420 meters apart.

In the above story, we showed that wolf mating partners in Belarus are very flexible and changeable, and this can happen even if both partners are alive. Moreover, the former partners may still coexist peacefully nearby. Male wolves can have multiple mates, which is common in Belarus. So, the idea of monogamous wolves does not apply in most cases.

We have many more examples of irregular wolf breeding, but even from these above-presented two types of data, wolf breeding seems like a chaotic process. However, in this chaos, there is one consistent pattern that is vital for their survival: They produce as many offspring as possible, even by inbreeding, at any cost. This chaotic breeding is driven by the intense human persecution of wolves, which results in the only trend of increasing their numbers.

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