Ecology

Introduction to the species

The Iberian lynx (lynx pardinus, Temmick, 1827) is part of the evolutionary line f the great carnivores (Tigers, Lions, Jaguars and leopards) from which it separates 3 or 4 million years ago. Because of its physical appearance, in an intuitive way is usually associated to the other lines of felines, but the Iberian lynx is closer to a tiger than to a cat in the evolutionary scale.

One common ancestor for the four current species of lynx 

The scientists currently place the origin of lynxes in North-America, where approximately 3’2 million years were distinguished the first known species of the Lynx gender: the red lynx (Lynx rufus), that currently lives in North-America, and the lynx of the villafranchian (Lynx issiodorensis) that became extinct in the Pleistocene. About this last extinct species is thought that is from which other three species proceed, that migrated into Eurasia by the Bering Strait. Because of the isolation of South Europe during the Pleistocene glaciations, arises the lynx of the caves (Lynx spalea) whose remains stayed deposited in caves. This species is the direct ancestor of the Iberian lynx (Lynx pardinus) and the Boreal Lynx (Lynx lynx).This European lynx had a bigger body size than the Iberian species and smaller than the Boreal species. As in many species, the Eurasian glaciations played a very important role in the speciation of the lynxes, and so by fragmentation and isolation arise in the lower Pleistocene the Boreal Lynx (Lynx lynx) in Asia and the Canadian Lynx (Lynx Canadensis) in America. Although the other three species of lynx have wide ranges of distribution, the Iberian lynx is distributed (already in the historical epoch) in an exclusive way in the Iberian Peninsula.

It’s no wonder that these three species have some characteristics in common like short tail, ears with a tuft of hair on the top (known as paintbrush) and beards. However, the body sizes of the four of them have been the origin of the adaptations of each species to its habitat and diet, varying from the Red Lynx, the smaller one that is about 6 kg of middleweight, to the Boreal Lynx that can reach 30 kg.

Description of the physiognomy of the Iberian lynx

The Iberian lynx is a strict Carnivore of medium size. Its medium weight is around 12’5 kg. There are important differences between males and females, with deviations from the average of up to 3 kg for each gender) being the males bigger. Their average length is of about 80 cm and their height at withers of use 45 cm, give them a graceful appearance. 

Its most striking characteristics are those already described as general characteristics of the lynxes: paintbrushes, beards and short tails with an apical black footrope. To these characteristics we can add the own felines characteristics: bright frontal eyes, which give them precision in the measurement proper of hunters of short distances; big eyeballs that allow him to see in low light conditions; ruffled and triangular ears, prelude to a fine hearing, capable to detect the discreet walking of the soundproofed legs of the rabbits; disproportionately big hands, useful to apprehend with firmness their prey and with sharp nails to prevent their escape (they stay always sharp because they are retractable.) Its high rump draws attention because of its long hind legs that allow him to develop jumps which are advantageous for hunting.

Their dentition is typical of a strict Carnivore with big canine to strike the deadly blow, carnivorous back teeth to tear big meat pieces, and small incisive. 

The dental formula is 3.1.2.1/3.1.2.1.
Basic biometrics information of the adult Iberian lynx obtained in sanitary evaluations of the LIFE project (only referred to specimens of more than 3 years old).

Finally, its mottled fur, which provides them the ability of camouflage with the clear-dark tones of the bush where it moves. The varieties of its layer are usually grouped in: “thick mote”, “intermediate” and “small mote”. In fact, the tendency to define and narrow everything observed leaves without defining a varied gradation between the two extremes that steer from big spots, that go so far as to be aligned in the shape of stripes in some specimens on an orange background, going through different spot sizes, up to mottled hairs with so thin motes that they pass almost unnoticed in brown or brown – greyish layers. Although all phenotypes have historically been present in all populations, in Doñana have been copies only of thick mote since the 60s of the last century and as a result of the alleles fixation caused by a "bottleneck" in which the few specimens that survived had this phenotype. Nevertheless, the biggest genetic variability conserved in the population of Sierra Morena has allowed the current presence of individuals with all types of layer. 

In 2007 an individual from Andújar was moved to Doñana-Aljarafe to initiate the genetic reinforcement of this population, and in the spring of 2008 were able to see in the host population the first native puppies of intermediate mote, result of the genes’ mixture.

The Iberian lynx: closely connected to the Mediterranean forest and to the rabbit

This feline is known as a specialist in habitat and prey. The rabbit is the fundamental and almost exclusive piece of hunting for this carnivore. The rabbits’ biology, dependent on refuge areas and pastures that allow that when the Lagomorphs go out to eat, the lynx is able to come without being seen or heard and catch their prey. Their hunting tools and complexion provide them with a perfect design to move without being seen between the Mediterranean forest vegetation, constituted predominantly by noble mount and, in less measurement, scrubland, bordering pastures. This extreme specialization makes it very successful in places with both requirements well represented, but it has been also the cause of its decline. The disappearance of well preserved habitat and the drastic decline of rabbit’s population, joined to the direct pursuit of the human being, have placed him at the edge of extinction.

Territorial individuals 

The adult lynxes manage territories that can overlap with the opposite sex adults' contiguous ones and in less measurement with those of the same sex. The average sizes are about the 600 Ha, but there are much wider territories limited to low quality spaces. The territory acquisition takes place with the disappearance of the regent animal, by clashes between the dispersant and the regent that ends up by gaining the space, or by colonization of areas that they have improved in the previous years. Females can start reproduction from 2 years-old, although it usually happens when they are older, normally for not having achieved to be established before. The lynxes enter the zeal once a year, although some annuities some females do not get pregnant or they are not able to breed successfully the pups. It is frequent that some young sub adults (mainly females) of the litter of the previous year, to remain and collaborate in the breeding of new puppies of their mother. Sometimes mother and daughter share the same territory for years, splitting or ending up the mother leaving it when it finishes the reproductive age. The lynxes tend to defend territories of the lower surface as possible to help ensure food to survive. This way, as major quality has the environment (more rabbits and preserved Mediterranean mount present) lower is the territory, as they find the necessary resources in less surface.

Natural mortality of the species 

Mortality in the first stages of development- Perinatal mortality

The entire wild animals have perinatal mortality; this is, during pregnancy and in the first days after the delivery. In the case of the Iberian lynx, is difficult to determine the real causes of the perinatal deaths. Is also difficult to know how many pregnant females lose their puppies before or during delivery, or even during the first weeks of life. The ex-situ conservation programme begins to give us information in this sense, but it has to be noted that the physical conditions of the females in the wild state (condition) are different from those of captivity.

In the multiple litters of three and four pups that have been controlled in the last decades, has been observed that in a high percentage, it ended up by surviving only two, appearing the first mortality peak concerning the first month of life and a second one concerning around 3-4 months. Predictive models developed by scientists of the EBD measured the effect of extracting pups of the litters of more than two pups like tool of beginning of the baby's program in captivity, and the low impact described, made the decision to move some puppies found in these circumstances. Nevertheless, very few are the contributions that they could have realized of newborn babies, since it is complicated to gain access without disturbing the lairs of the females, a completely opposite circumstance of the work realized in all these years.

The survival of pups was found that it is related to the abundance of food of the native territory.

Pre-dispersal mortality – siblings fights

Before the start of the breeding in captivity, it was confirmed by the scientists of the EBD and subsequently by the conservation equipment of the lynx of the CMA, that there existed a second peak of mortality around the three months of age. When there are obtained the first litters of the ex-situ conservation program, it is observed that concerning these dates the pups develop an extreme aggressiveness in the games with its brothers, that can become mortal. Mothers play a decisive role in the moment of separation of their puppies. In captivity, the mother is always very close to the puppies, while in wild life it is assumed that it can be different.

It is very probable that the absence of the mother in search of hunting has facilitated that some brothers have finished with others because of excessively aggressive games for training hunting. It has been aware of any case, as is the "Chrome", found with signs of fight coinciding with the age of aggressiveness of the puppies and subsequently incorporated into the captive breeding program.

Conspecific fight by territories

Sometimes the confrontation of the lynxes opposite to the resident adults is the only way or the way chosen by some dispersants to obtain a proper territory. It is in the zeal season when the fights usually get exasperated leading sometimes to the death of one of the opponents in a struggle for monopolizing the maximum number of adjacent females to several males' territories in reproductive epoch. It is not the habitual thing, since they stay usually informed about the occupation of a territory through the marking with urine and droppings that the Regents made throughout its foraging area or meetings in which threats are enough to stay calm. However the few holes in suitable habitat, can lead to situations of extreme aggression.

Senile dispersions and death by old age

In recent years, and thanks to the high percentage of radio-equipped Lynx within the framework of the project Life-Lynx of the CMA it was possible to be present at the dispersion of several specimens of advanced age (around 9 years), that remain after all its reproductive stage in the same territory, are displaced and moved to suboptimal areas, carrying out sometimes for it, big dispersion movements. This disappearance of the territory, when the animal was not radio-equipped, was deemed to have due to the natural death of the same, but there are already several cases of specimens that have been found thanks to the radio, in Doñana (Roja, Teo, Mata, Viciosa), and Sierra Morena (Nuria, Flaca, Casandra), that realize dispersions of long distance, remaining alive several months or years in other territories. It maintains a strict control of these individuals to observe possible deliveries in this senile stage and
to understand better the value that can be represented in the founding of new territories and mounting of other individuals in your environment. The deaths for old age, in wild fauna usually happen for wear of the organism, with some pathology associated with casualty capacity of answer of the immune system or for degenerative illnesses. In the case of the Iberian lynx, few deaths that have been found with certainty of this type, since it is difficult to find the corpses that are not radio-equipped. However, good news is that we are trying more and more for individuals to arrive at ages like 8-10 years, as it suggests a decline in mortality of the population in general and of the adult serving in particular, capital player on the reproduction of the species.

Signs of presence of the Iberian lynx

Iberian lynx’s latrine		Iberian lynx’s track

Apart from these indirect signs of the presence of lynx, the Iberian lynxes are one of the most observable carnivores in the natural environment. They have enough day activity if the weather is not very warm and also its nobility makes them not be too distrustful. When a lynx is placed in an area, in addition to abundant tracks and latrines are, it usually generates remarks on the part of the local population with enough regularity.

The specimens in dispersion (both juvenile and senile) can go more unnoticed, so in its trip (that can be of around 25 daily km) they do not use the shape of latrines or other specific marking systems. The sporadic appearance of isolated droppings corresponds more to the dispersion specimens than to the real presence of placed individuals.

The presence of the Iberian lynx in an area is easy to detect. In its territoriality, the Iberian lynxes use marking systems based primarily on the marking with urine and droppings, some of which are quite showy. Although urine marks are not detectable, the Iberian lynx has multitude of signalling latrines in their territories that serve as notice with the co specifics of the same property. These latrines are easily detectable for its plenty. The size of the latrines is variable, but it seems to be increasing in areas of overlap of territories of several individuals. The latrines are abundantly found although only one lynx is seated in an area. In addition to this, the footsteps of lynx, features of feline, are easily identifiable in suitable substrates.