Iberian Lynx

The Iberian lynx (Lynx pardinus) is a wild cat species native to the Iberian Peninsula in southwestern Europe that is listed as Endangered on the IUCN Red List. It preys almost exclusively on the European rabbit. In the 20th century, the Iberian lynx population declined because of sharp declines in rabbit populations, caused by myxomatosis, rabbit haemorrhagic disease and overhunting, fragmentation of grassland and forest habitats and poaching.

By the turn of the 21st century, the Iberian lynx was on the verge of extinction, as only about 100 individuals survived in two isolated subpopulations in Andalusia. Conservation measures implemented since 2002 included improving habitat, restocking of rabbits, translocating and re-introducing Iberian lynxes, so that by 2012 the population had increased to 326 individuals. As an attempt to save this species from extinction, an EU LIFE project is underway that includes habitat preservation, lynx population monitoring, and rabbit population management.

Formerly considered a subspecies of the Eurasian lynx (Lynx lynx), the Iberian lynx is now classified as a separate species. Both species occurred together in Central Europe in the Pleistocene and evolved as distinct species in the Late Pleistocene. The Iberian lynx is thought to have evolved from Lynx issiodorensis.

Characteristics


The Iberian lynx has a bright yellowish to tawny colored spotted and short fur, a short body, long legs, a short tail, a small head with tufted ears and facial whiskers, called a ruff. Head and body length of males is 74.7 to 82 cm with a 12.5 to 16 cm long tail and a weight of 7 to 15.9 kg. Males are larger than females who have a head-to-body-length of 68.2 to 77.5 cm and weigh 9.2 to 10 kg.

The spot pattern of the fur varies from uniformly and densely distributed small spots to more elongate spots arranged in lines that decrease in size from the back towards the sides.

Distribution and habitat
The Iberian lynx was once present throughout the Iberian Peninsula and southern France. In the 1950s, the northern population extended from the Mediterranean to Galicia and parts of northern Portugal, and the southern population from central to southern Spain. Populations declined from 15 subpopulations in the 1940s to only 2 subpopulations in the early 1990s, most noticeably in Montes de Toledo and Sierra Morena. Before 1973, it was present in Sierra de Gata, Montes de Toledo, eastern Sierra Morena, Sierra de Relumbrar and Doñana coastal plains. Between the early 1960s and 2000, it has lost about 80% of its former range. It is now restricted to very limited areas in southern Spain, with breeding only confirmed in Sierra Morena and Doñana coastal plains.

A study of mitochondrial DNA from fossil remains, published in March 2015, suggests the Iberian lynx had a wider range during the Late Pleistocene and Holocene, including northern Italy and southern France.

The Iberian lynx prefers heterogeneous environments of open grassland mixed with dense shrubs such as strawberry tree, mastic, and juniper, and trees such as holm oak and cork oak. It is now largely restricted to mountainous areas.

Ecology and behaviour
The Iberian lynx preys foremost on the European rabbit (Oryctolagus cuniculus) for the bulk of its diet, supplemented by red-legged partridge, rodents and to a smaller degree also on wild ungulates. It sometimes preys on young fallow deer, roe deer, mouflon, and ducks. A male requires one rabbit per day while a female raising kittens will eat three per day. The Iberian species has low adaptability — it continued to rely heavily on rabbits (75% of its food intake) despite the latter's repeated population crashes due to two diseases: myxomatosis, which spread to Iberia after a physician intentionally introduced it in France in 1952, and rabbit haemorrhagic disease beginning in 1988. There were two major outbreaks of the latter in 2011 and 2012. Recovery has occurred in some areas — in 2013, rabbit overpopulation was reported south of Córdoba, causing damage to transport infrastructure and farms. In December 2013, however, it was reported that wildlife officials were concerned about the spread of a new strain of the hemorraghic disease, affecting mainly young rabbits. Sierra Morena's rabbit population was worst affected, falling from an average of three per hectare to less than one — below the minimum required level of 1.5 to two per hectare. Forced to travel greater distances for food, the lynx became more susceptible to death in road accidents, particularly on Autovía A-4.

It competes for prey with the red fox, the Egyptian mongoose (Herpestes ichneumon) and the wildcat. The species is solitary and hunts alone; it will stalk its prey or lie in wait for hours behind a bush or rock until the prey is sufficiently close to pounce in a few strides.

The Iberian lynx is smaller than its northern relatives, and typically hunts smaller animals, usually no larger than hares. It also differs in habitat choice, with Iberian lynx inhabiting open scrubland and Eurasian lynx inhabiting forests.

A lynx, especially with younger animals, will roam widely, with ranges reaching more than 100 km. Its territory (≈10 to 20 km2) is also dependent on how much food is available. Adult Iberian lynx tend to require a minimum amount of space of 5 to 20 km2, and a population of 50 breeding females requires about 500 km2 of habitat area. Nonetheless, once established, ranges tend to be stable in size over many years, the boundaries often being along man-made roads and trails. The Iberian lynx marks its territory with its urine, droppings left in existing tracks through the vegetation, and scratch marks on the barks of trees.

Reproduction
During the mating season the female leaves her territory in search of a male. The typical gestation period is about two months; the kittens are born between March and September, with a peak of births in March and April. A litter consists of two or three (rarely one, four or five) kittens weighing between 200 and 250 g.

The kittens become independent at 7 to 10 months old, but remain with the mother until around 20 months old. Survival of the young depends heavily on the availability of prey species. In the wild, both males and females reach sexual maturity at the age of one year, though in practice they rarely breed until a territory becomes vacant; one female was known not to breed until five years old when its mother died. The maximum longevity in the wild is 13 years.

Siblings become violent towards one another between 30 and 60 days, peaking at 45 days. A kitten will frequently kill its littermate in a brutal fight. It is unknown why these episodes of aggression occur, though many scientists believe it is related to a change in hormones when a kitten switches from its mother's milk to meat. Others believe it is related to hierarchy, and "survival of the fittest."

Difficulty in finding mates has led to more inbreeding, which results in fewer kittens and a greater rate of non-traumatic death. Inbreeding leads to lower semen quality and greater rates of infertility in males, hindering efforts to increase the species' fitness.

Conservation
The Iberian lynx has been downlisted from the critically endangered species to the endangered species thanks to reintroduction and other conservation actions. If the Iberian lynx were to become extinct, it would be the first big cat species to do so since Smilodon populator 10,000 years ago. Its small population makes the cat especially vulnerable to extinction from sudden random events such as a natural disaster or disease. Conservation measures include restoring its native habitat, maintaining the wild rabbit population, reducing unnatural causes of death, and captive breeding for release. The Spanish National Commission for the Protection of Nature endorsed the Iberian Lynx Ex Situ Conservation Breeding Program to serve as a "safety net" by managing the captive population and also to "help establish new Iberian lynx free-ranging populations through reintroduction programmes." Before release of captive-bred cats, their natural habit may be simulated to prepare them for life in the wild. A 2006 study used a non-intrusive monitoring system involving cameras to monitor the demographics of both lynxes and rabbits residing in Sierra Morena. Supplemental food sources could be provided if wild rabbits suffered a decline.

The Iberian lynx and its habitat are fully protected, and they are no longer legally hunted. Threats include habitat loss, vehicle strikes, poisoning, feral dogs, illegal poaching, and occasional outbreaks of feline leukemia. Chronic renal illness affects some captive animals. Habitat loss is due mainly to infrastructure improvement, urban and resort development and tree monocultivation, which fragments the lynx's distribution. In the 20th century, rabbit diseases such as myxomatosis and hemorrhagic disease resulted in a dramatic decline of its main prey; outbreaks have been reported into the 2010s. Accidental vehicle strikes are the leading cause of unnatural death; The death toll on Spanish roads was 14 in 2013, and 21 in 2014. Illegal traps set for rabbits and foxes are other leading causes for lynx fatality.

In 2013, it was reported that the Iberian lynx possesses antibiotic resistant bacteria within its digestive tract, which may lead to more dangerous and difficult-to-treat infections and decrease the cat's fitness. A 2013 study suggests climate change may threaten the Iberian lynx species due to their inability to adapt well to new climates or it may lead them to relocate to areas that have a more suitable climate but fewer rabbits, increasing mortality.

Management efforts are being developed to conserve and restore the animal's native range. Officials intending to release captive-bred lynx look for areas of appropriate habitat, rabbit abundance, and acceptance by the local human population. About 90 million euros was spent on various conservation measures between 1994 and 2013. The European Union contributes up to 61% of funding.



Wild population and re-introductions


The Iberian lynx species has declined by about 80% in the last 20 years. The cat was estimated to number 3,000 in 1960, about 400 in 2000, less than 200 in 2002, and possibly as few as 100 in March 2005. Doñana National Park and the Sierra de Andújar, Jaén had the only known breeding populations until the 2007 discovery of a previously unknown population of around 15 individuals in Castile-La Mancha (central Spain). In 2008, the Doñana population was assessed at 24 to 33, while the Sierra Morena group was believed to number 67 to 190 adults. The total population was estimated to be 99 to 158 adults, including the La Mancha population. The Iberian lynx was thus listed as Critically Endangered under C2a(i) on the IUCN Redlist.

Beginning in 2009, the Iberian lynx was reintroduced into Guadalmellato, resulting in a population of 23 in 2013. Since 2010, the species has also been released in Guarrizas. Discussions were held with the Ministry of Environment on plans for releases in the Campanarios de Azaba area near Salamanca. In April 2013, it was reported that Andalusia's total wild population—only 94 in 2002—had tripled to 309 individuals. In July 2013, environmental groups confirmed the presence of a wild-born litter in the Province of Cáceres (Extremadura). A study published in July 2013 in Nature Climate Change advised that reintroduction programs take place in northern Iberia, suggesting that climate change would threaten rabbits in the south.

On 26 November 2014, 8 Iberian lynxes were released into Toledo, Spain, one of them traveled near Madrid, the first time in 40 years.

The presence of Iberian lynxes in Portugal, particularly in the south has been verified. In 2014, the Institute for Nature Conservation and Forests signed contracts securing 2,000 hectares of land for Portugal's reintroduction project. On 16 December 2014, a pair of Iberian lynx was released into Guadiana Valley Natural Park near Mértola, Portugal. On 7 February 2015, another pair was released into the park, but the female was later found dead on 12 March 2015 after being poisoned in Mertola. The last pair of captive-bred Iberian lynxes were released into Guadiana Valley Nature Reserve on 12 May 2015. By the end of 2015 there were 400 lynx on the Iberian peninsula, the vast majority in Andalusia, in southern Spain, but with smaller new populations in the hills near Toledo, in Extremadura (south-western Spain) and in southern Portugal.

The reintroduction of iberian lynx in Portugal has been a success, from 17 animals that were reintroduced, 12 have already established territories.

Since a 2007 outbreak of feline leukemia virus (FeLV), wild lynxes are tested periodically for possible disease. September–December 2013 samples were negative for FeLV but one male became the first of his species to test positive for feline immunodeficiency virus (FIV) and was placed into quarantine.

Captive breeding
In 2002, the Jerez Zoo confirmed it had three females and was developing a plan for a captive breeding program. One of those females was Saliega, captured as a kitten in April 2002. She became the first Iberian lynx to breed in captivity, giving birth to three healthy kittens on 29 March 2005 at the El Acebuche Breeding Center, in the Doñana Nature Park in Huelva, Spain. Over the following years, the number of births grew and additional breeding centers were opened. In March 2009, it was reported that 27 kittens had been born since the beginning of the program. In 2009, the Spanish government planned to build a €5.5 million breeding center in Zarza de Granadilla. Portugal established a breeding center in Silves.

There were 14 surviving kittens in 2008 and 15 in 2009. In 2010, intense rain and health issues resulted in lower reproductive success—14 born, 8 surviving —but the next year, breeding centers recorded 45 births with 26 surviving kittens. In 2012, breeding centers in Portugal and Spain reported a total of 44 survivors from 59 births, while 2013 saw a total of 44 survivors out of 53 born.

In March 2013, it was reported that Iberian lynx embryos and oocytes had been collected and preserved for the first time. They were collected from Saliega and another female—both sterilized and retired from the breeding program—by Berlin's Leibniz Institute for Zoo and Wildlife Research and stored in liquid nitrogen at the Museo Nacional de Ciencias Naturales de Madrid for possible future breeding. In July 2014, the MNCN-CSIC announced they had produced sperm cells from the testicular tissue of sexually immature lynx.

Iberian lynx can be observed in captivity only at the Jerez Zoo, since December 2014 at the Lisbon Zoo, and since July 2016 at the Madrid Zoo. The Jerez animals integrate the breeding program, the two Lisbon lynxes were formerly in the Portuguese breeding center but are no longer suited for the program (the female had multiple failed pregnancies and the male has a form of epilepsy), and the two Madrid lynxes were equally retired from the breeding program for not being suited for reproduction.

Genetic studies
In August 2012, researchers announced that the genome of the Iberian lynx had been sequenced. They also plan genetic testing of the remains of long-deceased lynx to quantify loss of genetic diversity and improve conservation programs. In December 2012, it was reported that researchers had located remains of 466 Iberian lynx in private and museum collections. However, it is estimated that 40% of specimens were lost over the preceding 20 years.

Genetic diversity in the Iberian lynx is lower than in any other felids known to be genetically impoverished, including the cheetah (Acinonyx jubatus), Ngorongoro crater lions, and Scandinavia's Eurasian lynx. Researchers believe this may be a consequence of decreasing population sizes and isolation. A study published in 2013 indicated strong genetic differentiation between the Doñana and Andujar populations, due to both allelic frequencies and allelic composition. Doñana lynxes have differentiated more from the ancestral population as a result of their longer isolation and lower population size. The researchers suggested bringing the two groups together in order to lessen the degree of inbreeding.