I would like to share our knowledge on the early denning behaviour and raising pups after weaning in wolves basing on the information that was gained in Belarus mostly in Naliboki Forest and Paazierre Forest.
The information is divided into three items:
- Early denning behaviour in wolves
- Raising of pups after weaning
- Some behavioral traits of wolf-stray dog pairs at denning and raising pups
Early denning behaviour in wolves
Here it is important to define that under the wolf breeders at the denning stage we mean one or several pregnant females with an adult male or sometimes several males. Additionally, it may be a non-pregnant female amongst the mentioned breeders. We definitely know that besides of breeding pair i.e. a pregnant female and its male (perhaps, the father of the coming pups) there may be other allowable individuals relative and non-relative. We definitely know that they help with foraging and protecting pups at the den. That is enough. So, when we say wolf breeders at the denning stage, it means either a breeding pair or such a larger breeding group. Usually, the breeders send the rest pack members mostly yearlings away.
An interesting question, how far from the breeders this non-breeder part of the pack stays. We will say that it is quite rare that they stay in the proximity of the actual denning site, nevertheless, such two situations were revealed in our experience. According to our information that is based on tracking, marking of pups and camera-trapping, usually, this distance between breeders at denning and yearlings varied between 3 and 8 km.
The above-mentioned behavioural switch of breeding wolves for denning happens usually about 10-15 days before parturition. The breeders start staying in a rather small area up to 20 km2, usually 8-12 km2only. In this pre-denning period, the pregnant females begin staying a lot in the denning site chosen, walking less and less with shorter and shorter radius of 0.6-2.2 km. This time i.e. 10-15 days before parturition breeders begin to dig a lot. It looks different. It may be a small pit, deepened couch, enlarged entrances of badger sett or red fox-earth, self-made burrow or just some try to create a burrow like an entrance only etc.
The pregnant female prefers to walk slowly leaving wavy track trail like a dog. It is heavy due to the pregnancy. On soft substratum (sand or peat) heavily pregnant female leaves unusually deep footprints.
The tracks of male breeders demonstrate busy. In this pre-denning period as well as during denning male breeders never walks slowly on forest roads for more than several hundred meters, usually it runs.
On the other hand, during the wolf denning period yearling wolves stay on a small area (up to about 70 km2, usually 10-20 km2 only), too. Appeared alone they got shy and walk slowly, location and trajectory of their track trails are characterized by not much sense, looks like that of loitering individuals, they carry and leave stupid things such rubber boots and plastic bottles, they collect and gnaw ungulate bones and antlers. All the above help a lot to distinguish tracks of breeding wolf pair from yearlings and other non-breeders.
Here it should be pointed out that parent wolves may carry such “stupid things” too while bringing them for their pups to play. Such a toy is bitten by small thin canines of small pups and lies about dens, while toys of yearlings are forgotten by the at roads usually. In Belarus at two-thirds of the inspected wolf denning sites there were found pup toys. About a half of them was small things of man-made origin, others were mammalian bones and antlers.
Concerning breeder marking in pre-denning and denning periods, they mark their currently occupied territory, but mostly not much. In this context under marking, we implicate the full procedure of marking with not only urinating, but also with scratching. Being at denning, the male breeder renews several marking points (1–7, mostly two or three) that are mainly situated on the terrain roads not far away, but not nearby the denning area — usually about 2 km away. Quite rare we saw parent wolf scratching close to the active denning area. The exception is the female’s scats and its urinating, when all the time it has to guard and take care of pups of few days old. The low rate of marking and hidden wolf life in the area of 1–2 km around the den lasts, at least, a month after parturition. As to yearlings that stay alone, they do not mark or only use some marking. In wolf breeding period those packs, which have no a litter, tend to continue marking intensively and mark own territory the home range wide.
Also, it is worthwhile to notice that 2–5 days before the parturition it looks like marking behaviour of the breeding wolves suddenly nearly stops. Actually, anyway the parent wolves continue some marking in a few spots.
In Naliboki Forest and Paazierre Forest in Belarus wolves use the following denning habitats: thickets with many uprooted trees, especially with spruces; thickets in logging areas with a lot of trees remains and timber left-off; abandoned peatory with peat mounds left-off; and small sand-dunes with young pines and small openings at the border with boggy habitats having dense ledum and bilberry shrubs.
In Naliboki Forest there are large meadows on drained lands that surrounded by dense forest habitats. Such a meadow may be used by wolves as a denning habitat, when the height of grass stand is about 40 cm and taller. Within grassy openings pups may be placed either nearby the opening centre or at its edge at the border with forest. Closely located terrain roads are not avoided by such families, if the grass thicket is sheltered enough. In grassy openings wolf parents evidently prefer to place pups at drainage canals, if they are present there. Sometimes, there wolf parents dig burrows preferably in canal banks or on a relatively higher plot with sand layer. The evident benefit of such a denning habitat is following: rather low abundance of mosquitoes, easy watching of surroundings, well-sheltered environments for pups and quite often for parents as well. During too rainy weather, pups may be temporarily replaced in neighbouring forest or they stay in burrows. If nobody disturbs such a wolf family, they may stay in such large meadows until mid-October.
Usually, wolves locate their den not far away from the main road in the area that they have chosen for breeding. Parent wolves need to know what people do in the area by monitoring human-related situation from the den or not far from the den. On the other hand, it is convenient for parent wolves to walk by the road, when they go for hunting and come back with food. Marking of borders of the denning area at the road seems to be also important for the parent wolves, and on such a road it can be done faster in this very busy time. Moreover, just along such a road alien wolves may come into the denning area. So, such terrain roads are very essential for wolves at breeding. Nevertheless, that does not mean that wolves like breeding at a busy road. Such a road nearby the denning area may be quite small and rarely used by people, but anyway at the same time it is forever the main road, which human uses to get to the wild area. Really big roads with intensive traffic and their adjoining areas are normally avoided by wolves (not always, 7–10 days staying of pups in the pipe under busy road was once recorded). For most of cases wolves choose not a busy terrain road (approximately up to 60 visits per day) by which people come into the area. Having a large material on wolf denning in Belarus, we learnt that in most of the cases (76%) a wolf den was situated on the distance of 0.4–1.0 km from the main road in the terrain fragment that was chosen by breeding wolves for denning. It is not seldom that the denning area is situated on the distance of only 0.4–0.7 km from the main terrain road.
There is the wild-spread belief that wolf pups should be located at a stream or another source of drinking water. Actually, it is hard to reveal such a relation in our material on the wolf denning. In Belarus and adjoining regions there are 0.4–0.7 km of watercourses per one km2 on average. Moreover, in the areas, where draining was conducted, the stream density is several fold (locally more than tenfold) higher than it used to be. Additionally, usually there are numbers of other sources of drinking water. Thus, there is so much water for wolves to drink that the mentioned feature of plausible den location is not useful, because water is actually available everywhere. The only exception is extensive sand dune areas with pine stands, where wolves breed rarely inside, but not rarely at the border. In sand dune massif breeding wolves indeed create dens not far from a stream or glacial lake, but it does not mean that such a den is situated one or two hundred meters from the water source. Parent wolves evidently avoid situating pups in the close proximity of any waterbodies, because the surrounding is usually full of wild ungulates and people frequently visit these places. Both wild ungulates and people are dangerous for pups, and parent wolves know that very well.
While analyzing the ecological situation in the denning sites, we found that wolves prefer to situate den in places, where wild ungulates are not active a lot. These animals are a real danger for small pups, and parent wolves know that very well. Usually, wolves follow this tactic quite strictly. Nevertheless, there may be exceptions. Once an open den was discovered on the root point of uprooted huge oak among swamped logging area, and there were many wild ungulates. The den was placed so high that it made it unavailable even for elks.
Despite the fact that wolves avoid places with many ungulates for denning, at the same time, places with rich prey (beavers and/or wild ungulates) supply needs to be located not far away, optimally on the distance of 1–2 km away.
Usually, while denning breeding wolves normally avoid the places, were brown bear or lynx are present frequently, at least, for the majority of cases. However, there may be some exceptions of these. For instance, once in Naliboki Forest we faced with the location of brown bear hibernation den in the same 2 km2 plot, where a couple of wolves placed their pups. This denning area was still used by brown bear family until 25th of May, at least, whereas wolf pups were placed there since the last days of April till the mid-May. The distance between the centres of the denning area of the brown bear family and wolf family was about one km only. As to lynx presence, we found this quite complicated. When wolf pups and lynx kits are of early days, and both mothers stay nearby the dens, such wolf den and lynx den may be very close. In one case we found that lynx kits were placed in former wolf burrow on island among black alder swamp, and the distance between this lynx den and wolf denning site with two litters (a case of pack double breeding) was only about 500 meters. When pups and kits are older than 10 days and mothers leave litters alone for hunting, such a proximity of lynx and wolf den is not a character.
As to denning itself, we would like to state that usually there are wolf denning sites including many dens (in our practice it was up to 79), whereas single den exists from several hours too, perhaps, several days after the giving birth. Then parents replace pups from one den to newly created one all the time, especially, when there are too many mosquitos or the weather is rainy. Moreover, parent wolves worry all the time, and plausibly this nervousness pushes parents to replace pups, too. Otherwise, it is hard to explain many replacements of the litter. Normally, a new den during such replacing of the pups ( that is motivated by the above reasons, but not because people scared the wolves), is situated fairly close to the previous den — from 3 m to 1.2 km, on average about 40 m (more often 10–20 m only). There are two basic types of wolf dens: an open couch-den and a burrow. In the case of couch-den the smaller pups are, the deeper and narrower such a den is. Such a narrow couch den for early days pups may be called as a pit-den. Deep enough pit-den of 25–40 cm in the diameter keeps the pups together saving their warmth and prevents their creeping around. Some breeding wolves do not create such a pit-den, whereas they do larger den in kind of a couch with a scratched floor (approximately 60–100 cm long by 40–70 cm wide) sometimes even in the beginning of their denning. Quite often breeding wolves create a burrow by enlarging badger sett or red fox-earth, sometimes beaver burrow. The wolf part of such an enlarged burrow extends for 0.4–5.2 m and in case of relatively long wolf burrow it ends by a chamber of 45–70 cm in diameter. Diameter of wolf burrow passage is usually 30–40 cm. From the chamber, markedly smaller initial passage goes (i.e. from former badger sett or red fox earth), where pups can hide. Fairly often in peat and sand wolves dig entirely own burrow, usually 1–3 m long with a chamber in it. All breeding wolves do open dens, but not all of them dig burrows. Some of them produce many burrows (30–50 burrows, in particular, if they stay in abandoned peatory), whereas others only dig some entrances in badger setts and burrows of red foxes. Both members of breeding couple (i.e. the male and female) create dens. Digging activity of breeding wolves begins 5–21 days before parturition, whereas in the most of the cases it happens about ten days before that. So, finding a wolf burrow does not mean that there are already pups nearby. Small open dens in kind of small pits suggest either there are already pups or they will appear in few days maximum. However, such a pit with worn down look says about the presence of pups. Fairly often parent wolves do not use the created burrows in May and the first half of June. Only later in July–August such burrows may be used a lot mostly, particularly, if it is either too rainy or too hot or there are too many mosquitoes. Sometimes in June–August, wolf litters stay in badger setts with enlarged entrances and around for many days.It is an important question, what is possible distance between neighbouring denning areas with different litters (normally there are several denning areas for the same litter of a given wolf pack). It makes sense to consider this parameter, if the neighbouring packs overlap in their home ranges. Otherwise, in the conditions of low population density in wolves, neighbouring packs may be too remote from each other, and it means merely that the wolf number is too low, i.e. markedly lower that potential level at the habitat carrying capacity. In our practice in Belarus litters of such really neighbouring packs were remote for 6–24, mean 16.7 km apart. However, it may happen that in the neighbouring pack there is not any litter. One of the reasons for that is that the dominant female is sterile. Another cause — the pregnant female was killed after the mating season, for instance, in March as it frequently happens. On the other hand, there may be two or even three litters in one pack, for instance, when a dominant male (the father) mated with daughters, too. In this situation the litters may be situated within smaller distance 0.4–4.2, mean about 1.2 km apart.
While investigating the effect of several external factors on the wolf denning behaviour, we found that the number of mosquitos, rainy weather and human presence drive the complexity of denning behaviour in wolves. Increasing in these factors leads to the higher number of dens that were used by parent wolves. Besides, the disturbance by people (mostly indirect disturbance like logging activity) leads to more used denning plots and longer distance between the denning plots.
One of the interesting behavioural features of breeding wolves is that parents abandoned some pups to die, while replacing the litter from one den to another one. During our long-term experience of searching for wolf pups we discovered not once such abandoned pups on the former den: one abandoned pup for five times, two pups twice, and once there were four definitely abandoned pups. Mostly the abandoned pups were dead. In one case one pup was killed by one of the parents. For all these 8 cases of leaving some pups on the former den the parent wolves still had other pups alive that were tended by them. Normally such a leaving of a few pups to die happened with a large litter consisted of more than 7 pups. In our materials that was recorded in 5 out of 6 cases, and in 2 cases the number of pups was unknown. So, perhaps, such leaving of few pups to die by parent wolves having many pups (e.g. 8-12) is motivated by their feeling of inability to raise so many of them.
There is the suggestion (Mech & Boitani, 2003) that young mother may abandon litter, first of all, in particular in the case of a multiple breeding in a wolf pack. In our experience with wolf breeding in Belarus we did not face with this feature. In the above-mentioned 8 cases of abandoning of a part of pups by parents, for 7 cases we know the mother’s age approximately. Only one mother was young, two years old. Other six mothers were older than 3 years; two of them were killed by hunters later during the next winter, and we determined their ages precisely (4+ and 6+).
The above-mentioned cases of leaving pups without care to die relate to early days pups. That is more or less common phenomenon in breeding wolves. However, even older pups may be abandoned by parents. In the mid and late summer of 2013 in Naliboki Forest we faced with that, at least, for several times. The stories were as follows. During the quite long period of 1999 till the spring 2013 in Naliboki Forest wolves lived in the conditions of a high density of medium-sized and, so, not risky prey: roe deer – on average 398 inds per 100 km2; wild boars – on average 234 km2; and beavers – 847 inds per 100 km2. It looked like that they were spoiled with foraging on the abundance of these relatively easy-catching prey, and they almost did not hunt bigger and risky elks and even red deer (Sidorovich, 2016). Perhaps, at that time the local wolf population in Naliboki Forest even lost good skills to hunt this bigger prey as an elk. During February-July of 2013 the supply of wolves with the medium-sized prey declined greatly. Extremely long-lasting and abnormally snowy the end of winter in 2013 impacted dramatically the populations of the wild boar and roe deer. More than 80% of wild boars and more than 90% of roe deer died in those March and April. Then in June and July most wild boars, which survived through the harsh early spring, died from a hard disease. The summer of 2013 was rainy and beavers were not so easy available to hunt as usually. In the conditions of the much-declined efficiency of foraging parent wolves refused from their litters being already 2-4 months old. We guess that 7 out of 11 present litters were abandoned to die during that summer of 2013 in Naliboki Forest (Sidorovich, 2016).
However, precisely we could learn the stories of two such litters only. One of the litters, which in May consisted of 5 pups, was left to die in the beginning of August, when still there were 3 or 4 pups. These pups starved, but persisted 15-20 days (at least, 1-2 of them survived so long), then they died. Another wolf litter, in which initially there were 7 pups, was abandoned in the late August. Pups were already big enough to forage something small themselves, and they hunted small rodents on the large grassy opening, where they stayed. By the lucky chance, the late summer and early autumn of 2013 were characterized by an abundance of voles of genus Microtus on grassy openings, and 3 pups survived themselves for long till the beginning of October, when they were accepted by their parents again. Nevertheless, the food shortage suppressed their growing, and even in March of 2014 they were rather small compared to a normal almost yearling wolf.
On the other hand, some parent wolves tend about already dead pups (even decayed one), by carrying them from one den to another together with alive pups. Such a behaviour by parent wolves was recorded by us for three times. These three litters on the moment of their finding consisted of 5 alive pups and one dead pup, 7 alive pups and one dead pup (already bad smelling), and 3 alive pups and 4 dead pups.
Stealing pups by mothers from each other in a case of pack multiply breading is another pattern of unusual denning behaviour in wolves. They steal not all pups; usually only 1-3 pups are taken from another litter. Actually, in our research experience and the practice of three other wolf pup searchers (altogether about 160 wolf litters that were looked through) such a denning behaviour was registered for six times. In the respective litters there were recorded normally developed pups of definitely different ages. These mixed litters consisted of 3 and 4 pups of distinctive ages; 4 and 1; 5 and 1; 3 and 2; 7 and 1; 5 and 4. In such a case wolf litter consists of bigger and smaller pups. Sometimes, this size difference may be too much, and bigger pups suppress smaller ones. Such a suppressed small pup die somehow, finally being trampled in the den bedding materials. Twice we faced with such a case of dead pups in the mixed litters. In one of those wolf dens there were found 2 small alive, one small dead and 4 markedly bigger pups; whereas in another one – 3 small alive, 2 small dead and 4 markedly bigger pups.
One of the common behavioural pattern of denning wolves is persecution of red foxes. Particularly wolf breeders kill mother red foxes at their denning earths. Usually one of them is digging the red fox-earth, while another one ambuscade in a close proximity. Deep digging into the earth disturbs the red fox a lot, and finally it tries to escape. Another wolf in ambuscade overtakes the escaping fox and kills it. Usually carcass of such a red fox that was killed by breeding wolves remains 30-100 meters from the destroyed earth. As to the badger and raccoon dog, killing of them in denning period at their dens similarly as in the case of the red fox is not so common.
One of the specific features of the wolf denning behaviour is so fast finding of a new partner, when one of the mates died (or killed). We learnt actually many such an anecdotal story, but four of them we know more detailed and were partial evidences. These stories may be briefly told as follows.
Story 1. In early June still a bit lactating female wolf was trampled by six caws in a grassland at a homestead in Naliboki Forest; the pups survived somehow, and locals from the homestead registered presence of wolf pups on the distance of 1-2 km away during the whole warm season (pup howling, footprints etc.); in early November just in that place a wolf pack was killed; the pack consisted of three pups of the year (one of them was markedly bigger than other two pups); two big males (one of them, perhaps, was the pups’ father) and one adult female (step-mother). Perhaps, the step-mother appeared quite soon, otherwise, so small pups could not survive. We think that it was a case of multiple breeding in the wolf pack, and the step-mother was the mother of another litter, because the killed pups were much distinctive in their sizes.
Story 2. In Paazierre Forest in the mid-June a big male bringing food for its mate with pups was killed at a pathway to the denning site; the mother was slightly wounded in the hind leg, and it began crippling; in 5-7 days a new big male appeared with the crippling mother; in the early July this step-father was killed; the female was still crippling; it got the new mate within 10 days; in December all of them i.e. the pair of the mother and second step-father and 4 pups of the year were killed more or less in the same area.
Story 3. In the late May in Paazierre Forest a big male wolf and a lactating female wolf were killed; then in about 3 days several adult wolves walked there again; in the mid-August in the same place (wolf pathway) five wolves were killed; the killed wolves were an adult female and 4 normally developed pups of the year of greatly different sizes; the next night at the same pathway a big male wolf and a pup were killed again. Afterwards, in 9 days an adult female and male wolves and three pups walked in the place proximity again. We guess that it was a case of double breeding in the wolf pack with quite fast getting of a new mate, when the previous partner was killed.
Story 4. In Paazierre Forest in the early August two adult wolves with 5 pups of the year were observed; one big adult male and one pup were killed; others escaped; in 10-15 days the two adult wolves and 4 pups were seen, while walking more or less in the same area; in early December a pack of 6 wolves was eliminated there; there were 2 pups of the year, one adult female (perhaps, the mother), big male (step-father) and two more males look like yearlings.
At the end of this item, we would like to say one more the main results of the denning studies. Defining under the wolf breeders at the denning stage one or several pregnant females with an adult male or sometimes several males, our results suggest that for the most of the investigated situations during the denning period breeders send away the rest members of the pack (mostly yearlings), at least, for two months. In this case yearlings stay at the distance of 3 to 8 km from the breeders.
Denning in wolves takes place in several denning sites (up to four such a site) that are situated at the distance of 2 to 7 km from each other. In each denning site there are usually from 10 to 30 dens (mostly open couches and few burrows), between which pups are replaced by parents. Usage of each den is not long and lasts from several hours up to 3 days mostly. The choice of denning site is driven by sheltering features of habitats, presence of wild ungulates as fewer as possible, absence of aggressive lynxes, good habitats for foraging not far away and proximity of the main road in the area chosen for denning. Number of mosquitos, rainy weather and human presence drive the complexity of denning behaviour in wolves. Increasing in these factors leads to the higher number of dens that are used by parent wolves.
Raising of pups after weaning
After the busy period of denning, when early days pups eat the mother milk mostly, there is a markedly different situation in the wolf family. The pups need milk less and less, begin to consume a solid food, mostly meat brought by parents in their stomachs. The pups become more and more mobile and that increases the mobility of the parents.
At this situation, an interesting questions need to be raised. At which age of pups does the lactation start declining? At which age do pups begin eating a solid food? At which age of pups does the weaning happen? We did not find any substantial publication related to the questions for wild-living wolves in the European forest zone.
Of course, there are so much published on the questions in relation to wolves in captivity, but that was not in the wild and may only suggest something. So, it does not mean that it will be the same with wolves in the wild.
Of course, there are so much investigated on the questions in the North America (Mech & Boitani, 2003 and references therein), ok, but the American and European wolves are so greatly different. They are like different species in many of their characters, particularly behavioural traits. Again, it may suggest something, first of all, to establish hypotheses to study the questions.
Telemetry? We did radiotracking (both VHF and GPS GSM) on twelve predator species and know very well, what the method can and can not. We disagree, when researchers read too much from the telemetry signal sequences with some inspection in the wild.
Thus, we would like to conclude that these quite important questions of the wolf reproduction are still poorly known in the European forest zone. We gathered not much materials on the questions, too, and it is mostly sporadic one. Anyway, this something is worthwhile to describe.
We used two kinds of materials. First, for seven times in the period of the mid-May-June we faced with situations, when pups of known age (they were found by us at dens before) ate a solid food, mostly meat brought by parents in their stomachs. Another kind of materials were carcasses of wolf mothers (n=6) and pups (n=89), which were killed by hunters in the period of May till the mid-July. In a half of these cases we knew somehow more or less the age of pups (e.g. before the pups were killed by a hunter we found the den with the pups of early days) .
These our irregular materials suggest that duration and importance of lactation depend on the food base. While comparing a few cases in the conditions of very rich and poor prey supply, the duration of lactation in wolf mothers was almost double different: for pups of about 40 days old the mother’s milk was already not so important in the conditions of rich food base and the mother secreted milk a little bit; but, when prey was scarce, pups of almost 70 days old were nursed and the mother was still milk-secreted a lot. The killed pups had meat in the stomach since the age of 20-25 days old, and stomach of pups of 40-60 days old is rarely contained milk and was filled with meat.
With finishing of lactation, a wolf family starts replacing markedly more i.e. more often and on the longer distance each time. While adverting to this period in wolf families, researches frequently use the term of a rendezvous site and differed that with a resting site (e.g. Theuerkauf et al., 2003). The authors defined rendezvous sites as places, where young wolves stayed for several days and to which the adults returned regularly, and resting sites as places, where wolves rested once for an hour or longer. We evaluate these different definitions too sophisticated and avoid to use them. In our quite large material (44 wolf families were more or less followed during summer) we faced with the following. Sometimes, wolf parent left pups in a particular place shortly, came back and pick the pups up. It is something negligible, and it does not mean that it should be named somehow with a particular term. Indeed, nobody terms a random place, where a wolf defecated once. We think that such a short stay of pups in a particular place means that something was wrong with the choice or the family was on the too long replacing. Other places, where parents leave pups, were used longer and in such a place parents spend much time (hours) every day. Fairly often parents rest few hundred meters away from the pup locations, by controlling situation around the litter and avoiding disturbance from too active pups. Well trampled resting couches of parents indicated such their habits enough. So, that is both rendezvous and resting sites altogether, and we assume that it is quite reasonable. We call such a place as wolf family homesite or just homesite.
In July-September we found the wolf family homesites (n=135) in the following habitats or microhabitats:
(1) High grass stands with some bushes or without any bush usually on abandoned drained lands (mainly at drainage canals with wolf burrows in canal banks) – 18 (15) times, 13(11)%;
(2) Willow bush thickets – 7 times, 5%;
(3) Large treefalls – 15 times, 11%;
(4) Some treefalls in old spruce forests – 24 times, 18%;
(5) Fern stands in young forests – 9 times, 7%;
(6) Wolf burrow sites, i.e. where several wolf burrows are situated in a small area up to 10 ha, it includes former badger setts with enlarged entrances; usually such wolf burrows were created in sheltered biotopes (quite often that was in abandoned peatories) – 19 (11) times, 14(8)%;
(7) Logging areas with a lot of tree remains and early reforestation – 23 times, 17%;
(8) Rye fields – 2 times, 1%;
(9) Big haystacks (in that single case the big about 30 meters long and 7 meters wide haystack from the last year that was situated at the forest edge) – one time, 1%;
(10) Thickets of grass and dead tree material in abandoned beaver settlements; there were many beaver burrows in such places – 17 times, 13%.
Taking into account possible factors and wolf demands for a family homesite, we noticed that all of them were well sheltered by one way or another. When mosquitos were plenty, the homesites of 1, 6, 8, 9 and 10 were mainly used by wolf families. During rainy weather, the homesites of 3, 4, 6 and 10 were used more frequently. In the pup raising period after weaning the distance from the wolf family homesite to the nearest road and the frequency of wild ungulate presence in the homesite were not important compared to the denning period. As to presence of people (e.g. collectors of mushrooms or berries), we noticed that, perhaps, it was the family-related, because we found so different patterns of homesite location in relation to human disturbance. One parents immediately reacted on our visiting of their homesite by escaping with pups during the first night, whereas the others sticky stayed in the same well-sheltered homesite despite the repeated visits of us and mushroom collectors. Actually, the first pattern of such a response was usual, while the second one was registered for three times only. In two situations there were young spruce thickets with some fallen trees and several wolf burrows, and in one case it was extended treefall.
Interestingly, how long a wolf family may stay in a given homesite. Checking that with howling, we made sure that it may be quite long. In one case wolf family stayed in a few hectares plot within tall grass stand at drainage canal for two months, at least. Another similar case, but in the mosaic of grass stand and willow bush thicket at drainage canal, wolf family stayed about 40 days. One more long stay of wolf family was detected in extended treefall (neighbouring treefalls in the area about 40 hectares), where the family lived from the denning in the late April till the end of September, i.e. five months. However, usually (more than for a half of the cases) wolf families used homesites for 5-10 days only.
We analyzed pup diet compared to their parent diet in the period from the mid-July till the mid-September. We could not to collect scats of pups earlier that the mid-July, even when we knew the particular place of their stay. In June and quite often till the mid-July the majority, (sometimes all) scats of pups are collected by their mother, perhaps, by both parents. Parents carry the pup scats in their stomachs (like in a bag) away, where they drop all of them by vomiting. We occasionally learnt that in Paazierre Forest in the late June of 2003 in the case, when a mother wolf was killed by a hunter from a hide in the den proximity. There were evident pup’s excrements in its stomach. We immediately realized, why we could find only some scats at the wolf homesite with pups. Later in Naliboki Forest twice we discovered wolf vomiting with many scats of pups, and we easily recognized what is that.
Such comparative dietary studies were carried out for 13 litters and their parents in 2004-2012 in Naliboki Forest. It should be noticed that those years food base for wolves in Naliboki Forest was very rich. Looking at the data, the most distinctive feature of the pup diet is markedly higher portion of beavers compared to that in the parent diet – in 1.2-2.9, mean 1.9 fold. Also, pups ate quite many small rodents catching them themselves. Therefore, the small rodent portion in the pup diet was essential for 6 out of 13 litters studied.
Approximately, in the beginning of October pups start walking with parents most of the time, however, still may be left for some time in a sheltered place. Since the late October or early November pups follow parent all the time.
Some behavioral traits of wolf-stray dog pairs at denning and raising pups
In Naliboki Forest we had possibility to trace breeding behavior and raising pups by two wolf-stray dog pairs. These unusual stories are worthwhile to tell.
The first story is as follows. During late autumn at the boundary of Naliboki Forest in the surroundings of cattle farm and village we detected a pair of stray dogs. They mostly hunted small rodents and scavenged around the cattle farm and in the village rubbish dump. Mainly they avoided to meet people, were active at night mostly, and it was hard to observe them. Quite often they rested in forest on the distance up to one km from the village. The dogs marked three terrain roads coming from the village to the forest. The stray dogs lived there between the cattle farm and village rubbish dump till the end of January, when the male dog was killed by a wolf or a pack of wolves. One of the workers of the cattle farm looked through the spot of the kill. There were remains of the male dog only, whereas the female dog had disappeared. In April few locals from the village observed a strange pair of a big wolf and medium-sized dog on road not far away from the cattle farm. In early June we noticed that there is like a wolf and dog pathway coming from abandoned peatory to road. Searching for a den of the possible wolf-dog pair, we discovered the den in few hours. The den was a burrow with several entrances (enlarged former red fox earth), which was situated in a big peat mound that was densely overgrown with raspberry and blackberry bushes. On the distance about seven meters from the den we were horribly attacked by the mother dog. It was the same female dog as that lived with the killed male dog. The mother dog chased us for about 200 meters, and we were not wounded defensing by axe and big enough stick. There were three repeated attacks for these 200 meters that we were gradually retreating. At the den we only noticed one not a small pup (about 2 kg) and there were a lot of feathers from poultry (mainly from chicken and goose) around. Later we learnt that in the village chicken and goose disappeared one by one; perhaps, the mother dog visited easily the village and killed poultry. Here it is worthwhile to notice that in Belarus it is common that in villages dogs that are walking on streets are common; nobody knows all the dogs in a village and nobody chase them. In August-September the wolf-dog pair began to attack cattle in daytime, mainly young horses and adult caws to get an udder. Hunters tried to kill the wolf-dog pair, but only three other domestic dogs were randomly killed in the village surroundings. In December, while censusing wolves, we faced with a pack trail consisted of one trail of a big wolf and four dog trails. It was on the distance of 4 km from the cattle farm. There was no doubt that the trails belong to the hybrid family. They stayed there till February on the area about 220 km2. They marked the area a lot, may be even more that an average wolf pack. Just before mating season in wolves they had disappeared. We heard something about that hunters killed some dogs in forest in that area, but we are not sure that it happened indeed. Even if that was really, we are not sure that just individuals from the hybrid pack were actually killed. That is all we know about the wolf-dog couple. The only we would like to add that the food base for wolves was rich and the wolf density was rather high – 2.3 inds per 100 km2.
Another story of wolf and stray dog pair took place in the center of Naliboki Forest. Prey supply for wolves was moderate, and the wolf population density was 1.4 inds per 100 km2 (so, wolves were not rare). In a hamlet only one house was occupied by a man, who was ill on alcoholism. The man has a female dog looks like a Siberian lajka. The dog was ranging free in the hamlet proximity for most of the time. It was smart to hunt something, and according to the owner’s words sometimes it brought roe deer, beaver or hare on the yard. Once this dog killed our domestic red fox and ate it entirely; merely the fox tail and radiocollar were left on the spot of the kill in the hamlet surroundings. Nevertheless, fairly often the dog was keeping on the chain leash at its cabin. Once in the late autumn the man started drinking alcohol too much and continuously. The female dog was not fed anymore for long. The man was so kind that released the dog from the leash before he went on the hard booze. In a month, the man was taken in a hospital. The female dog survived and even succeeded to support with food its two male pups of the year, which mostly continued to stay on the abandoned yard. In the mid-January the female dog was registered living with a big male wolf; in the hamlet surroundings we found many wolf and dog paired trails and the pair was observed for several times. They mainly hunted roe deer and beavers and lived together till May. The pair visited the hamlet and brought some food for the two dog pups. They looked not starved. The female dog gave the next birth somewhere in forest in the mid-April and on 22nd of April it replaced the new pups on the owner yard. There it dug a deep and broad burrow under the shed base close to its cabin. Also, the pups were placed in several open couches at the shed. The male wolf regularly visited the abandoned hamlet at night and fed the mother. For that time the yearling dogs were chased from the hamlet, and they ranged in the neighboring village on the distance of 13 km apart. Suddenly the owner came back to the house; he accepted pups and they were taken by other locals. The female dog still walked free, and not seldom we registered their paired trails of the male wolf and female dog on sand roads in the hamlet proximity. Till the March of the next year the female dog ranged with the male wolf. They produced a lot of territorial marking and regularly visited the former owner yard. At that time, the man sold the house and replaced in the neighboring village. In the late March the man captured the female dog on the yard and replaced it to the village. Being on the chain leash, it gave birth again in the new cabin of the new house of the owner. The male wolf seemingly disappeared. We did not follow the story anymore.