Mating in Eurasian lynxes

Mating in Eurasian lynxes and other questions in relation to that (such as pre-mating activity; life of kits, when their mothers go for mating; others) are quite poor investigated (e.g. Schmidt et al., 1997;  Schmidt, 1999; Jędrzejewski et al., 2002; Breitenmoser-Würsten et al., 2007; Samelius et al., 2012). The scarce information published on the question shows that these complicated mating-related actions in Eurasian lynxes are too simplified, while researchers mention about mating in lynxes. Let’s say there is evident gaps in the lynx-related literature on the species mating.

General idea in the published literature is that adult male lynxes roam a lot and far away during the mating season in search of females (from telemetry: increasing home ranges and increasing daily movement distances in mating season). Not much mentioned about behavioral specificity of adult female lynxes at mating (e.g.  their behavior during mating season and life of kits that were abandoned by their mother).

The reasons for that knowledge shortage are evident. First, the Eurasian lynx is a species with fairly hidden behavior and ecology, and study on the species demands so much presence of an experienced researcher (not beginner-assistants) in the wild in a close proximity to lynxes. To regret, in the recent and modern carnivore ecology and ethology the acting academic system forces a team-leader (such an experienced researcher) to be at a computer-screen more and more with  long-doing application for the next project, reporting for on-going projects and so time-consuming publishing scientific articles with too huge demands of journals. Otherwise, there will be no money for study and private life anymore. When they waste their time at a computer screen, the amazing life of lynxes is going on by unknown way.

The second thing is that telemetry as the prevailed method  evidently does not provide sufficient information for such a behavioral thing. Alternative approach with a lot of habitat inspection, tracking on snow cover and learning activity signs in snowless periods, smart camera-trapping need huge efforts, these research activity is time-consuming without sufficient amount of results for an acceptable project reporting. Also and crucial that with such an alternative approach, only those researchers, who know lynxes in details, can be successful. But that does not match with city life and sitting at a computer in office. So, again the same pitfall with the on-going academic system in animal zoology.

Another problem around is that specialists on carnivore ecology and behavior turn into molecular biologists more and more, because in that scientific branch there are  more possibilities of getting money to investigate carnivores, whereas study in the wild on carnivore behavior and ecology are getting more and more forgotten.

At least, during the last study period I tried to go by another way (also, it was not such hard before in the academic zone) and succeeded to organize my zoological work by another more effective way. The poorly known behavior and ecology in lynxes during mating season was one of the curious question for me. Piece by piece during a number of years and particularly during the two last fruitful years the above questions are getting more and more known, and I would like to share  in this post the knowledge what I principally learnt so far. It is not a finished study, and I feel that still there are a lot of unknown in that. It looks like after huge efforts I started realizing  what is actually going on in lynxes during mating season, but still my knowledge is far to be complete sufficiently. Here I would also like to mention that the last years I studied on the question together with Wild Naliboki, first of all, Jan Gouwy as well as with my wife Irina Rotenko.

We guess that adult male lynxes begin preparing to the next mating season far before the mating season sometime in the mid or late autumn. Within their home range they choose and guard habitat spots with a tunnel structure that is favor at mating. In Naliboki Forest (the central-western Belarus), where we mostly studied on mating in lynxes, such mating habitats are of three types: young spruce thickets with or without fallen and rotten trees; quite recent treefalls of several layers; and willow bush thickets. In such habitats with a tunnel structures, lynxes at mating feel safe against possible wolf attacks (seemingly it is a crucially important for a female lynx). In the mid or late autumn just around such outstandingly sheltered spots lynx tracks and other activity signs begin to appear in numbers (about 30-100 fold more often), whereas during summer and early autumn the places looks like abandoned by lynxes. The same results were provided by camera-trapping; the difference in lynx registrations at mating spots was 19 and more (usually 50-70) fold more frequent since the mid-autumn than during summer.
Concerning sheltered spots that adult male lynxes start protecting since the mid-autumn, also it makes sense to notice that mother lynx may leave kits there for the period of her next mating; in Belarus mother lynx only temporarily abandons kits for the period of mating, and then she picks them up after mating for a  joint life till the next parturition (see below, where it is given with more details). So, somewhere within adult male home range there should be several (3-5) such mating thickets preferably not far away from each other. Otherwise, such an  adult male lynx may appear unsuccessful in mating season.

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In the below I will describe the revealed common pattern of territorial and hunting behavior of an adult male lynx  since the late autumn and till the mating season. This behavioral pattern was gradually found out through a lot of snowtracking in Paazierre Forest and Naliboki Forest with the pooled snowtracking length more than two thousands km.  The character of snowtracking information, distinctive information sources  (snowtracking, camera-trapping and habitat inspections) as well as the specificity of the question (it is hard to realize, which useful parameter may be calculated) make hard to calculate something statistically in relation to the pre-mating behavior of adult male lynxes. Therefore, I only can to describe the evident behavioral pattern that was noticed from the plenty amount of the mentioned information. At the same time  some estimates that were used in the description were based on the information analysis to assess the minimum, maximum and mean of the parameters I need.

Such chosen  mating spots are guarded by male lynxes by their frequent presence and scent marking in the slightly larger area of several kilometers in diameter. Within a male home range there may be several areas with presence of such mating spots. I call them as winter housing areas of male lynxes. More than a half of the well-known for us winter housing areas of adult male lynxes (14 out of 24 in Naliboki Forest and 9 out of 13 in Paazierre Forest)  are characterized by relatively poor supply with prey in relation to other possible ones.  This argument also suggests that winter housing areas of adult male lynxes are most likely chosen for other reasons, i.e. mating. Suitability of the area for sheltered mating evidently play a determinant role. Also, it is worthwhile to notice  that the majority of the winter housing areas of adult males are rarely visited by the males during summer.

Guarding the winter housing areas with mating spots, adult male lynxes survive with spotted ambush hunting, i.e. watching and waiting for prey from ambuscades in more or less relevant places in the proximity of the chosen mating spots. In this mostly snowy period they more often use hidden sites under dense low branches of a single growing spruce or at the edge of treefall or other thicket. In such an ambuscade, hunt-watching by male lynx may continue for a relatively long time up to several twenty-four hours. When it kills a prey, such a male lynx continues to stay there, by consuming the kill and continue hunting there with the same manner. In effect, it may be killed several consequent prey by the male lynx and he will stay rather long (for 5-20 days) in a proximity of the chosen mating spots. These days the male lynx usually walks in a small area of 1-3 km in diameter only. Some of these days of the relatively long stay in the house area this male lynx may go faraway for territorial marking mainly and then he comes back afterwards. Usually it takes 1-3 days. Intensity of territorial scent marking varies from 4 to 13 marks per one km of walking. During such a walk male lynx may hunt, but not much. In the case of a kill, it may stay at the kill few days by consuming it. However, walking-marking days of male lynxes are mostly without a successful hunting, because they follow another aim, i.e. territorial marking and messaging to females that there is such adult male not far away.

Male lynx during markig walk
Male lynx during marking walk

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Ten to twenty days before mating season adult male lynxes begin to undertake such marking walk a lot ( in a day or in two days,) but all the time they come back to the house areas with mating spots (mainly the same house area in their home range) and they mark there a lot too. At the mating spots male lynxes choose elevated positions and do mating calls from there. Often it may be just a tall tree, and male lynx  surprisingly  climbs on a height of 20 and more meters (26 meters as the registered maximum). Often they use such a tree on an open hill within an elevated glade or clearcut. Male lynxes call at night, perhaps, every night, if they still do not get a female for mating. Since the late February or early March staying of male lynxes at mating spots with their mating calls is getting more stable, and they undertake long marking walks less often (about one such a walk per 5-8 days).  Mainly they stay in a proximity of mating spots, by marking the surroundings and calling once and again especially at night.

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During mating season just adult female lynxes in heat seem to search actively for sexually active males, which have got relevant house areas  containing several relevant mating spots.  Presence of several such well-sheltered spots in a housing area also allow to the mother lynx to leave her kits safely in one of these spots, when perhaps she goes for mating to another spot not far away. This way the kits are protected against wolf attacks as well. Not once we learnt, while snowtracking (there were 7 registrations), that the passing wolves did not react on the lynx kits being in the thicket without their mother.

Concerning to natal dispersal of lynx kits, it should be paid a special attention to this mating-related question. Schmidt et al. (1997) stated that in Bielaviezha Forest, the Polish part lynx family breakup coincides with the lynx mating season in February-March, and lynx kits dispersal may be provoked by adult intolerance. The timing of lynx dispersal in Bielaviezha Forest was similar, but not entirely the same to that of reintroduced lynx populations in Switzerland (Haller and Breitenmoser, 1986; Breitenmoser et al., 1993): age at independence ranged from 8.1 to 10.7 months and did not differ between populations or sex; independence began from January to the beginning of May with a peak in April; after kits got independence they stayed a few days in the maternal home range. As to dispersal timing of lynx kits in Belarus (mainly Naliboki Forest and Paazierre Forest), we will not say that we obtained much precise data on the question. Nevertheless, those registrations that we have got on the question strongly suggest that in Belarus mother lynxes only temporarily abandoned kits for the days of mother mating and then she recollected them for most of the cases. While snowtracking lynxes, we followed correctly enough two situations, when 2 and 4 kits joined with the mother after about 4-5 and 7-10 days of their lonely stay; perhaps, when the mother was at mating.  Moreover, in Belarus it is really not rare to see tracks mother lynxes with kits in March and early April,  even sometimes in the second half of April, when still there is snow cover or it appeared for a few days. We feel hard to produce an exact estimate on the question, but we may say that during about 30 years of presence in the lynx habitats in April mother lynxes with kits were registered approximately more than 40 times; the latest one  was on 22nd April. Also, camera trapping of lynxes in Naliboki Forest suggest principally the same; lynx family groups with kits of the year were registered several times in the mid-March and in early April, twice in the mid-April.  Also, lynx mother with one kit was observed on 18th of April; and several similar observations were reported by nature-related respondents.

It is not always easy for a mother lynx, which is going for mating to leave kits somewhere. Sometimes, they may tend following the mother anyway. Such a situation happened less often  (3 out of 37 situations studied). The kits, while  following their mother in this situation, take a risk to be killed by an adult male lynx in heat. Once in Naliboki Forest, being snowtracking red fox we discovered carcasses of two lynx kits, which were evidently killed by mating male lynx (character bites, stay of mating lynx pair not faraway).

Lynx kits in treefall that were left by their mother which went for mating
Lynx kits in treefall that were left by their mother which went for mating

Sometimes, especially at the end of mating in lynxes, some of adult male lynxes in heat may range a lot searching for more sexually active  females  and they may go far away out of their home ranges. Facing with other adult males, they may struggle and that may result in a death of one of them. Once in Naliboki Forest such a died male lynx was found by us. It was a lot wounded, and nearby of the carcass there were fresh tracks and tree scratching mark of another male lynx.

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The earliest mating in lynxes was registered in the period of  20-26th of February and the latest in the mid-April. Most of mating in lynxes in Belarus (24 out of 37 cases checked) were registered in the period of 1-20th March. One male may mate with up to three females in the same or different mating spots. In one situation male stayed in the same house areas with different females in the late February, mid-March and early April.

Generally, basing on the registrations of lynx tracks on forest roads the lynx activity  during the cold season including the mating time looks like following.  There were registered three following peaks: late autumn-early winter – on average about 4.8 lynx track trails per 10 km daily (establishing of a home range with marking before overwintering); second half of February – about 5.7 lynx track trails per 10 km daily (mainly demonstrating by males in heat that they are present and wait for females to mate); and the late March-mid April – about 4.1 lynx track trails per 10 km daily (re-establishing of home ranges with marking after mating). Remarkably, that registrations of lynx activity during main mating in lynxes during 1-20th March were relatively rare – about 1.2 lynx track trails per 10 km daily.

A mating pair stays together about 4-12 days. We registered three situations, when two different males were present at one mating female, and that may suggest that such female may mate with both of them in a turn. In one of the case there were evidently bigger and smaller males, and the female in heat stayed several days with bigger male, at first (3-5 days, on the snow cover it looked like that they copulated), than the bigger male went away, and the female stayed at least 8 days with the smaller male, and they definitely copulated for many times (several evident copulation spots  were found).