The characteristics of the dens
In terms of structure, they are closed, provide a good refuge, have few entries andmeasuring 1m2. Most of dens were located in mixed
forests relatively with open space, allowing visibility for 10 to 20m. Spite of all expectations, the natal and maternal den were constantly exposed to disturbances by man and were placed on a ground more or less dangerous. The two types of burrows clearly differ. While cubs were better hidden in the natal dens, which in most cases not having an open structure, maternal dens were open but were surrounded by hiding places. May differ in terms of positioning, so that the dens from Jura Mountains are located at lower altitude, on flat ground, in addition they were located at a longer distance by settlements and borders of woods and close to roads, unlike the dens located in the Alps.
Dens are selected to provide good camouflage, while camouflage seems to be not so important in native den, where over two thirds of the maternal dens, the degree of camouflage was high. This may be explained by the fact that, in the maternal dens the cubs are in constant motion, providing a hiding in the natural landscape is very important. On the other hand, the color itself does not seem to be important, most of them are brown.
While the maternal dens have the same brightness inside and in front of them, the native are in most of the cases darker. However, the differences between the two types of burrows are not significant, but there are certain trends. Brightness differences were associated with forest structure, the more open forest, the more dens are dark inside.
To recognize the potential danger in advance, the mother should be based on the visibility provided by a terrace in front of the den. More than half of the dens have such a place of rest, especially the native ones, where three-quarters of them have a terrace. In high areas, both types of holes provides visibility of 5m and the visibility from the lower areas is 20m (23m in native dens and 19m in maternal dens).
The main factors that lead to a better protection against of predators are the forest structure related to visibility and slope. Slopes are between 25-45 0, the more steep is the slope, the more secure the shelter is, but the cost is the reducing of visibility.
The main distance from the natal den to another lynxes next available permanent settlement is about 560 m and in the case of a maternal den about 540 m. Native dens are generally located closer to the water sources than maternal dens, the distance between water source and native den is 385 m (at an extent of the field of 2486 m) and between the water source and the maternal den, of 628m (extent area 2640 m).
Lynxes expand their area of use during the winter and during summer it reduces (due to the abundance of food). They also avoid high altitudes, prefer medium altitudes and in the case of low altitudes, although they have not avoided during the winter, though some specimens have avoided during the summer. Female and male preferences in terms of seasonal use of altitudes was not different . Most of lynxes avoid the selection of steep slopes more than 40% , and prefers light to moderate slopes between 40-20%. The most used are those with slopes between 4-9%. But in areas like the northwest Alps bobcats can choose to place the dens on steep slopes.
The selection of settlement position differs between specimens of lynx.
Lynxes also can cross a road or a highway, this influence their behavior in selecting their area, the road is seen as a natural dominant feature, we observe that the existence of roads can influence the movement of the lynx, depending on accessibility of the road, traffic volume and probably animal sex and reproductive status. Bobcats usually choose as areas of low density areas with roads.
Linxes show variable selection for topographic attributes, which can be related to habitat conditions, human and snow. Avoiding the high altitudes and steep slopes can be caused by unsuitable habitat associations and high energy costs needed to reach in an area with favorable conditions. Even though, lynxes use higher altitudes than canines (wolves) during the winter, they can choose a lower altitude for their own area, if habitat conditions are unsuitable for lynxes. During the summer lynxes can minimize the competition with canines using higher altitudes and steep slopes. For example the open habitats associated with high altitudes contain additional prey species that are not available during the winter and snow conditions that may increase the the energy cost necessary to take trips to higher altitudes, in order to obtain the prey
The marking of the territory
Urine marking behavior of the european lynx is similar to that which is met at the tiger (Panthera tigris), guepard (Acinonyx jubatus) and domestic cat. A lynxe is able to identify through the urine left by an animal of the same species, the sex and age. It marks especially trees and roots at the surface or from toppled trees and shrubs.
Lynx males apply urine on vertical objects (at a height of 15 cm), while females apply it to the horizontal surfaces. These features of his behavior make it possible to distinguish the sex of the animals tracked in the field, by taking into consideration the height of the signs left by them. The rate of urine marking at the European lynx is influenced by many factors, such a low rate of marks during the search for prey is characteristic of hungry individuals. After a successful hunt, the animals marks the objects almost 5 times more frequently than when searching prey. But during the prey tracking the situation is different: for example a lynx male pursued a rabbit, on a distance of 3.5 km, this time without leaving any trace of urine. Another male who passed a forest to another made 8.6 marks on a kilometer. The rate of urination of a lynx is of 8,1 marks with urine per day and 12.3 marks on 10 kilometers.
The urination rate varies with the type of habitat. In the central part of their area, lynxes leave their urine more frequently on this part, thereby observing that the markings are more intensively at the boundaries between fields. Into the nature the lynxes let their urine on certain guidelines, which facilitates the detection of their traveling direction by other individuals. Rate of urine marking by upright position of the males, increases substantially at the end of the ruth season in February-March, because of the need to be spotted by other lynx. Higher frequency of urination does not seem to be linked tospecific the metabolism regarding the amount of water but is related to the food. Bobcats in captivity in a cage for feeding them,have urinated once a day and those who did not receive food until1-3 days urinated after 3-6 days were.
During the winter, the smell signals left on various objects persistconsiderably longer than in summer. Man is able to detect the smell of urine coming from lynx, after a month when it was left,because the chemical components of urine are decomposed more slowly in negative temperatures.
The marking of the territory at the cubs occurs after the age of 9-12 months, when they switch the behavior from family life at independent lifestyle.
The birth and the growth of the young
The birth among large mammals is often a rare event, despite the fact that cats have a relatively large number of offspring compared to other mammals, however, only a few survive the first year of life. Lynx females reach sexual maturity at the age of 21 months. Age of the mother has no direct influence on the survival of the offsprings. The breeding occurs from March to April.
After a gestation of about 68-72 days the female gives birth to 1-4 kittens at the end of May. Kittens are born with eyes closed and have a weak locomotor and temperature regulator system. For this reason they depend on a number of environmental factors in the first instanceof maternal behavior. After two weeks, they open their eyes and begin to develop the control of thermoregulation. As they develop the senses and motor actions, puppies (which are about 26 days) begin to explore the surrounding of the den. Once the baby leaves the nest protection area is very vulnerable a position. Not being familiar with the surroundings, is in danger to stay away from the nest and get lost. Or,if the den is located in an area with high potential of danger, there is a danger that puppies to fall and get hurt. They are still relatively small and weak, so are definitely in danger of being attacked by predators.
Cubs growth involves three stages:
- - lactation period, recognized as being in terms of energy, the most expensive time of reproduction for mammals
- - period of mixed nutrition, during till juveniles begin to eat solid food but continue to drink milk during weaning, the young learn how to procure their own food and then become fully independent;
For an optimal calving, lynx requires a diversity of forestry conditions. These forest mosaics should include young forest, which are required for hunting, but it needs to include mature forests, which are used for installation of the den. Forests must be large enough to provide optimum coverage required by hunting, as well as for changing the position of the dens. A fixed field of lynxes allow their own exclusive use of already known resources (cover with trees, dens positions and sufficient prey) in order to ensure the successful birth and growth of the offspring. Despite the fact that lynxes, compared with other large mammals can give birth to a relatively large number of offspring, only a few survive the first months of life, mortality among pups is high (at the age of 3-4 months after birth). Only 50% survive after the first year of life.
Mother grow his puppies by itself. But it was observed the presence of the male around the central area of the field belonging to the mother of the offspring, to protect puppies and resources against other lynxes, but he avoided the central area so as not to endanger the success of female in the hunting. The juveniles who are in developmental stages all show a special request for soft and dry den substrates. Dens during the summer should provide a low temperature inside (because of the inability to ensure its pup thermoregulation), preferable are those placed directly on the rock. So, pups should be protected from direct exposure to sunlight and should not be exposed to rainfall and humidity.
Food and pradatorism
Prey base consists in small ungulates, lynxes use rabbits as the main food only in areas where there are no species of ungulates available in this category (the situation is met in eastern Finland). Among small ungulates, deer (Capreolus capreolus) plays a significant role in lynx diet , generally it represent 50 to 99 percent of biomass consumed. Also chamois (Rupicapra Rupicapra) is considered the favorite prey where prey density is high. In Romania, the food consists of specimens of chamois and deer.
Large ungulates are rarely used as prey, but because of the quantity of food that represent, they are found in the biomass consumed by lynxes. Compared with the deer for which it seems to not make a selection according to age or sex, for large ungulates (the stag) prefer to hunt bobcats and female juvenile specimens. In each case the deer felled by lynxes, is almost always young and female specimen, being generally ill or injured. Similarly, elk and wild boars hunted by lynx were juvenile or weak. However in 1993 were reported that a lynx hunted mature boar, being observed cases of felling of specimens of stag. The third class of prey for European lynx is represented by lagomorphs: the hare (Lepus europaeus), especially in northern regions where the importance of ungulates decreases, reaching 81 percent in the winter diet.
Among other prey species include the various species of birds: wild cock (Tetraourogallus) and capercaillie (Lyrus tetrix, Tetrastes bonasia) which are an important class of food in mountain regions and those with boreal forest, but their role in lynx diet appears to be insignificant given their scarcity in other regions. Waste of rodents and insectivores are commonly found in feces from lynxes, but their contribution in the biomass consumption is reduced as a result of their low body mass. Small predators like foxes (Vulpes vulpes), raccoon (Nyctereutes procyonoides), badger (Meles meles) and marten (Martes martes) are hunted occasionally by lynx. And domestic animals like sheep, pigs, dogs and cats were rarely hunted, excluding any possibility of any appearance of a conflict between man and lynx.
Laughter preference for small ungulates is visible in many areas of its distribution, being provided some explanation in this way:
- The small size of the lynx and the solitary style to hunt;
- Avoid competition with other predators;
- Avoid pressure from the carcasess hunters;
Relatively small size of the lynx (range 12-37 kg) makes the small ungulates optimal prey. Moreover, wolves, with a double weight compared with lynxes, hunting in packs are able to break down large animals up to 600 kg. Instead of solitary hunting strategy of the lynx reduce his chances of having a successful attack on a large prey. It is therefore doubtfull of his success in hunting large animals such as stags. But successful attacks on a large prey were observed.
Lynx dependence of small ungulates is not as strict as it seems. Prey-predator relationships are more complex not only because of the body size of the lynx defines the size of the prey but also the prey size defines the influence in weight of the lynx. Search for food among large ungulates lead to weight gain due to predator evolutionary process to adapt to the type of food, as well as acquiring of better physical conditions. This can be exemplified by comparing the size and the diet composition in different regions of Europe.
Competition with wolves may be a significant factor that influences the position of the lynx in the food chain, since their hunting areas have begun to overlap extensively. Also significant is the competition for food between the lynx and fox. Hence, to avoid competition on the one hand with the wolves, which feed mainly on large ungulates and on the other hand, the foxes, whose basic food is represented by rodents and rabbits, optimal feeding strategy of the lynxes was. to choose smaller ungulates. Underlying the assumption that lynxes choose small ungulates, as a result of competition with wolves is in part supported by the finding that lynxes tend to kill large ungulates often in Austria and Norway where there is no established populations of wolves. But, for example in the Czech Republic, where there are reintroduced populations of lynxes specimens, they tend to maintain the type of food that they have consumed in their original habitat.
The pressure of the carcasess eaters, for example ravens (Corvus corax), fox, wild boaror bear, should be considered as a significant reason for the lynx’s preference in terms of small ungulates, because lynx is unable to effectively use their prey . As long as the average consumption of a lynx is 2 kg meat / day and maximum consumption of fresh meat can be only 3 - 3.5 kg, even if a group of four lynxes (adult female with three cubs), most of the prey can be eaten by the carcasess eaters. For this reason felling of a prey of 100 kg (stag) instead of a 20 kg (deer) does not represent a great benefit for the lynx, considering the request of a much higherenergy consumption.
Despite the clear preference of the lynx for small ungulates, its importance is sometimes overestimated. Lynxes does not necessarily select small ungulate species available, as some authors suggest, but rather, deers are preferred,as similarly large ungulates like stag are preferred. The preference of the lynx for most common prey species can be a classic effect of the conditions imposed by prey which are most commonly found.