Coauthor Irina Rotenko
Concerning the wolf Canis lupus breeding in Europe and wider in Eurasia there is a widely spread belief that the species is strictly monogamous with a certain way of breeding and pack formation in family pattern (e.g. Bibikov D.I., 1985 and references therein; Jędrzejewska & Jędrzejewski, 1998).
Those beliefs suggested the three following theses: first, during breeding season, a wolf pack has merely one litter or there are no pups; second, usually a wolf pack consists of parent wolves and their pups of the current and previous biological years as a normal maximum; additionally, such a pack may subordinate some non-relative wolves; and third, usually offspring disperse from their maternal pack around mating season, in the second year of their life, when they are 20-22 months old.
Actually, in our study in Belarus since the late 1990s we have found so many abnormalities, that we start thinking about what actually prevails in the wolf reproduction: the “rules” or “exceptions”. Such “abnormalities” occurring often is a very interesting phenomenon.
This post is entirely addressed this batch of questions on the wolf reproduction by basing on the example of one model wolf pack in Naliboki Forest, the central-western Belarus. This pack was leaded (still leading) by female, which is called by us as Torn Ear. This wolf female has been easily recognized by the tear in her right ear since February 2017, when we began to call her Torn Ear. Before that we recognized her by whitish stripes in the lower part of her head and black marks at the eyes.
In Naliboki Forest since February 2013 Torn Ear has been registered living and reproducing in the wolf group of three breeding females and one or two adult males altogether. The whole this quite long period of 8 years just Torn Ear leaded and still leading her pack. Her leading of the wolf pack was evidenced by numerous photos taken by camera-traps.
On 11th May 2013 we discovered three wolf litters in the dens within the small spot of spruce-black alder forest somewhere between the localities of Drazdy and Rabachova. The wolf dens that belonged to the three breeding female wolves were situated at the distance of about 430 meters, 220 meters and 380 meters between each other. The pups in one litter were about 40 days old, the second litter was about 15-18 days old, and the third one consisted of small blind pups. The first and second litters were mixed as: 2 pups of 40 days old and 2 pups of 15-18 days old; and as 2 and 3 such different age pups, respectively. It happened like that because the mothers stole pups from the dens of each other. None of the pups including the litter of Torn Ear survived by the winter 2013-2014.
During the breeding seasons of 2014 and 2015 we did not collect enough precise information about the reproduction in this wolf group. At least, we knew that they bred and had pups till the late summer or autumn, but during the coming winter there were again five adults only without any pups i.e. three adult females and two adult quite big males. Sometimes, one of the males walked separately, but within the same territory of the other wolves of the pack. Again, sometimes we registered that Torn Ear walked separately with one of the males, while other two females stayed with another male within entirely the same territory.
In April-May 2016 one or more females from the wolf breeding group that included Torn Ear gave birth in the Rabachova locality; there was registered minimum one litter. But all the pups disappeared by the end of May.
In February 2017 Torn Ear (when she was with a normal right ear) and other four members of the wolf pack were taken in a fladry enclosure in the localities of Kurhany and Symonava by the local hunters. That day, by driving there, we saw a number of vehicles and more than thirty hunters, who did the hunt-drive to kill the wolf pack. The hunter tried to do their bloody work during the whole day. Nevertheless, Torn Ear and other wolves escaped more or less safely from the fladry enclosure. One shot of hunter wounded the right ear of the female (since that time the female have got the torn ear). Also one male wolf from the pack was wounded to the right hind leg, but he survived.
In the late April 2017 all three females of the wolf pack gave birth definitely. The distances between their initial dens were 0.92, 0.72 and 0.95 km from each other. One male mostly looked after two breeding females including Torn Ear, whereas the other male took care about the third breeding female. Torn Ear was registered visiting not only own den, but also the den of another breeding female, to which the same male served. Interestingly that at one of the dens all these five wolves were registered altogether on 1st May. We documented that two litters were killed by adult male lynx that we called Jury. It happened in the end of April and the first days of May, whereas the third litter disappeared in the mid-June. In 10-15 days afterwards all the five wolves started walking widely within the previous winter home range and marking a lot.
After the clear documentation that the two wolf dens were extirpated by the adult lynx male we started thinking that all previous breeding failures of the wolf pack happened due to the same lynx male aggressivity to breeding in the wolves.
In the late April 2018 the wolf breeding group consisting of Torn Ear, two more breeding females and still two adult males began preparing denning in the same Rabachova locality again. They prepared minimum 5 dens before any parturition. Everywhere in the places they stayed there were registered lynxes in the close proximity. Then suddenly before any giving birth the wolf breeding group disappeared and they were not found in the whole Naliboki Forest during the summer. We hypothesized that they emigrated from Naliboki Forest to breed in the surrounding more rural area where there were not so many lynxes around because of the dramatic experience of the previous May, when Jury the lynx had killed all their pups.
After a long absence, Torn Ear with one of the males and one of the females was found to come back to their former territory in early March 2019. They were with another unknown third female, which could be a young adult (i.e. the one survived pup of the year). The area was already occupied by other three wolves. These wolves were gradually sent away by the former owners including Torn Ear.
In late April 2019 Torn Ear and at least one more female of this wolf group gave birth. Torn Ear’s den was placed in the Asovyja locality, while another female denned in the Rabachova locality. Their single male served for both mothers, which together with their pups were situated at the distance about 3 km apart. Then since the mid May both mothers with their litters were registered on stay in the Asovyja locality. Another female’s litter was situated in a badger outlier, where the pups were killed by a male lynx. We registered the tracks of the lynx entering the burrow-den and two pup remains about 40 and 120 meters away of the den. The litter of Torn Ear was saved and in July it consisted of 6 pups you may see in the photos below. Both females and their male took care about the pups.
Till December of 2019 only Torn Ear, another adult female, their adult male and 6 pups composed the pack. In the mid of December another bigger adult male joined the pack. Afterwards Torn Ear became more related to the first male, while another breeding female seemingly paired with the arrived adult male. Anyway these four adults (two breeding females and two males) walked mainly altogether till the mid-April 2020. Moreover, in the mid-January this pack subordinated three more wolves. In the late February the whole large pack already of 13 wolves were taken in fladry by local hunters. In the effect of that hunting 6 wolves were killed, while 7 of them including the mentioned two pairs of adults succeeded to escape. In the mid-April in the core area of the pack home range we found the two couples including Torn Ear with her male. Till the late May both couples stayed on the area about 30 square km maximally in the localities of Rabachova, Drazdy, Kazialiets and Patashnja.
The second breeding female gave birth around 3rd May (on 13th May we found her den with 9 pups about 10 days old), and the new adult male served for her.
Moreover, on 18th of May we photographed one more heavily pregnant female (not Torn Ear) at the distance of about 800 meters from the discovered den (see the photo below). That still pregnant female was plausibly one of the three wolves, which seemingly disappeared in the early April. May be they still stayed not faraway, but we did not know. So, anyway, in May 2020 in the Torn Ear pack there were at least two breeding mothers with their litters. This pregnant female plausibly gave birth on 19th or 20th of May, because on 21st May we found all the features of presence of one more den with pups there.
The breeding story of the old female Torn Ear is still unclear. On the video taken in the late April Torn Ear looked like heavy and possibly was pregnant. On the other hand, in the mid-March we took photo of the rear part of Torn Ear body, and the look under her tail evidenced plausible recent abortion. Anyway in May Torn Ear and her male built dens, but still we did not find any pups in the prepared dens. The Torn Ear denning area was situated on the opposite side of the Biarezina medium-sized river on the distance of 1-2 km from the dens of the other couple. Possibly Torn Ear and her male had pups in another den that was not found. It will be learn anyway in the next month and we will tell you about.
In the conclusion, we would like to say that the presented multiannual example of out-rule packing and breeding in wolves suggests that the given story is not something abnormal, exceptional or extraordinary. The phenomenon of multi-breeding and presence of several big males that are playing a founding role in the pack breeding was repeated across this story from year to year with changing composition of the pack. Therefore it is quite opposite, the revealed phenomenon looks like something usual, common and routine.
Also, here it is worthwhile mentioning one our hypothesis on multi-breeding in a wolf pack relating presence of either merely one or several founding males in the pack. Our (still insufficient) data suggest that in case a leading individual in a wolf pack is a female, there can be not only one but two or even three founding males if double or triple breeding happens in the pack. Two founding males looks like a norm more or less in such a case. When a male leads a pack, a founding male is mainly one even in a case of multi-breeding.