Sus scrofa

Sus scrofa

The wild boar (Sus scrofa Linnaeus, 1758) is a mammal belonging to the Suidae family.

Systematics –
From a systematic point of view, it belongs to the Eukaryota Domain, Animalia Kingdom, Subgenus Eumetazoa, Superphylum Deuterostomia, Phylum Chordata, Subphylum Vertebrata, Superclass Gnathostomata, Mammalia Class, Artiodactyla Order, Suborder Suiformes, Suidae Family and then to the Genus Sus and the S. scrofa Species .
In Europe there are three subspecies and more precisely:
– the Maremmano wild boar (Sus scrofa majori);
– the Sardinian wild boar (Sus scrofa meridionalis);
– the Central European wild boar (Sus scrofa scrofa) which represents the nominal subspecies.

Geographical Distribution and Habitat –
The wild boar is a mammal originating from a vast area between Eurasia and North Africa.
Due to the strong hunting pressure to which it has been subjected since ancient times, the wild boar disappeared from the British Isles probably during the course of the 13th century, only to be reintroduced several times between 1610 (by King James I) and 1700 .
Despite this, the attempts always failed because the hunting pressure on the introduced populations was always greater than the reproductive rhythm of the latter.
After the discovery of the new world the wild boar was exported to North America by the Spanish where this animal became naturalized in large areas of the United States. The expansion of wild boar in South America is more recent. Originally the presence of wild boar was limited to Argentina and Uruguay, a country of few inhabitants, about 3.5 million, and extensive forests. The wild boar began to move from Uruguay to southern Brazil, due to the absence of natural predators. Currently, after having passed through Paraná, a southern Brazilian state, it is widespread in Santa Caterina and Rio Grande del Sud; it is also sighted in the state of Sao Paulo.
In 1900, the wild boar disappeared from Denmark, Tunisia and Sudan, while it was on the brink of extinction in Germany, Austria and Russia. The French population of wild boar, on the other hand, remained stable.
We must arrive in 1950 to witness a new expansion of wild boar distribution areas up to the northern areas of Europe such as Denmark and Sweden.
The causes of the population increase in the wild boar, which in some cases has become invasive (so much so that the wild boar has been included in the list of one hundred very harmful invasive species, drawn up on a planetary level), are due to various factors, all however between correlated to them and which are linked to the change of agricultural systems, the depopulation of rural areas, the decrease or disappearance of its antagonists, especially the wolf.
In Italy the species is distributed, albeit with a discontinuous distribution area, from the Aosta Valley to Calabria, as well as in Sardinia, Sicily, the island of Elba and other small islands, where it was introduced by man.
The typical habitat of the wild boar is represented by the well-mature woods and in particular the oaks, while the African and Asian subspecies seem to prefer open and marshy areas but this animal manages to colonize practically every type of environment available provided that there is sufficient availability of water.
Wild boars tolerate the cold very well, resisting temperatures of tens of degrees below zero, while they adapt less to excessively hot climates, where they give signs of suffering: the humidity of the environment interests them relatively little, thanks to the hair highly insulating.

Description –
The Sus scrofa is an ungulate with a squat shape with powerful but short limbs and claws equipped with hoofs with an even number of fingers, two of which are frontal and two are shorter which sink into the ground only if soft. The weight of the males fluctuates between 75 and 100 Kg, that of the females between 60 and 80.
This animal has a black burnt hair with two annual wetsuits: presenting a darker winter coat with thicker bristles and a lighter summer coat with sparser bristles. On his forehead and shoulders he carries a sort of mane that rises when the animal is scared so as to increase his body volume.
Characteristic of the wild boar is also the snout with the snout (griffin) cartilaginous that it uses to turn the ground in search of roots.
It has a decidedly developed sense of smell as well as the lower canine teeth, or tusks, which protrude into the male, show up sharply upwards and have continuous growth up to 30 cm.
The eyes are small and lateral and the ears are small and erect.
The puppies have the characteristic striated mantle called “pajamas” which they lose after 6 months. This hair is brownish or reddish in color, with yellowish hair tips, which help to make it look lighter than it actually is: on the back and sides there are 4-5 horizontal streaks of a color ranging from white to beige, which give a strong cryptic effect on the undergrowth and on the cover of dead leaves of the soil. Further streaks are present on the shoulder and on the back, while spots of the same color may be present on the puppy’s snout: the arrangement of the strips varies from individual to individual, so that it is possible to recognize the small boars individually.
The average age of these animals is 10 years.

Biology –
In the wild boar the females reach sexual maturity around the year and a half of life, while the males are more late and do not complete the development before the second year of age: however, they rarely manage to mate before their fifth birthday, due to of competition with other older and stronger males.
During the mating season, the males of the wild boar abandon the solitary life to join the groups of females, often even covering great distances in the wake of the fragrant slopes and not feeding or resting to reach one as soon as possible: once they reach the group, for First, the male wishes to keep away the young males that may still be found together with the female.
Moreover the males, in the period of the loves, develop a sort of armor for the fighting of supremacy, accompanied by rituals of threats, shedding of urine and buffing in the ground. The winning male courts the female with sounds similar to an “internal combustion engine” and repeated massages on the sides. They too have a wide range of verses including cries and roars.
Mating lasts about five minutes and takes place numerous times and with numerous females (up to eight for the strongest and most vigorous males), until the end of the female’s inspiration: at this point, the male abandons the group and returns to his solitary life, at least until the next mating season.
Depending on the climate and the availability of food, the wild boar females can go into oestrus from one to three times a year, with three-day inspiration on three-week cycles.
In Italy, births are concentrated in spring and late summer. Females tend to synchronize their estrous cycle, so as to breed pups of similar age, maximizing the chances of survival of the offspring.
The boar’s pregnancy lasts from 112 to 115 days.
Arriving at the moment of birth, the female isolates herself from the rest of the group to build a den in the thick of the vegetation, similar to the beds she used to use for the night. This den often has an opening facing south, so it can be better heated by the sun’s rays. The cubs, which vary in number from three to twelve for each litter, are born in this den. At birth, the young have their eyes open and are scrambling in search of one of the twelve maternal nipples, arranged in two rows along the belly of the female: in case of particularly abundant litters, the weakest boar are therefore destined to die of starvation .
During the first week after the birth, the female very rarely abandons the den with the puppies, and if it does it takes care to hide the litter covering it with branches and leaves during its absence.
During the breeding of the offspring, the females become particularly aggressive.
If a child is taken from them, the females chase the kidnapper at a gallop for several kilometers.
After a week of life, the puppies are able to follow the mother in her movements, returning to the den only during the night. At two weeks of age, the young begin to root in the ground and to taste solid food, but they continue to suck the mother’s milk at least up to three months of life.
Complete weaning will take place only after the fourth month, and it is only after this moment that the female and the cubs (who lose their youthful hair color around the fourth month) return to their herd of origin.
The independence of the young boars occurs around the seventh month of life but these tend to remain with the mother even up to a year old, when they are driven out by adult males eager to mate with the female.
The life expectancy of wild boars in the wild is around ten years, while in captivity they can even reach the thirtieth year of age.

Ecological Role –
The wild boar is a usually crepuscular and nocturnal animal but sometimes it is possible to see it during the day but it usually goes to rest in holes of leaves in the ground. Young males live in small groups as well as females with cubs while older males are solitary.
They are animals well known for their aggressiveness if they are harassed, especially the males that load with their heads down so as to use the big fangs upwards, while the female sticks with open mouth biting frontally and is particularly aggressive, as mentioned, during the breeding of offspring.
A habit in common with the deer is “the insoglio” that is to make real mud baths to get rid of pests and dirt and to cool off in the warmer months and then remove the mud by crawling on large boulders and oak trunks and spruce trees. Furthermore, the specimens of the same group often practice grooming, that is the mutual cleaning typical of primates such as chimpanzees, smoothing each other’s dorsal hair with tongue and snout.
An unmistakable sign of their passage is the plowed land they cause with their “rooting”.
As for its eating habits, the wild boar is a typically omnivorous animal, with a diet that can be very varied (roots, tubers, fruits, invertebrates, small mammals, animal carcasses and even larger-sized wounded mammals and therefore easy to preying in a group).
Over the millennia this animal has been decimated and reintroduced into large portions of its range and also into new environments, where it has also become so well rooted, thanks to its extraordinary qualities of resistance and adaptability, which is considered one of the more widespread species of mammals and it is difficult to trace a precise taxonomic profile, since the various populations, originally also pure, have undergone the contribution of alien specimens or feral pigs over time.
The wild boar has always been considered a coveted prey for its meat and a fierce adversary for its tenacity in combat, only in the course of the 20th century it ceased to be a source of food of primary importance for man, supplanted in this from his domestic descendant, the pig. Due to the close relationship with man, the wild boar appears frequently, and often with leading roles, in the mythology of many peoples.
From a taxonomic point of view it must be said that in Italy it is now very rare to find animals that have not been mixed with pigs. This is due to management errors and the release (voluntary and otherwise) of domestic swine on the territory.
In addition to Europe, in addition to the three aforementioned subspecies, given the large distribution area occupied by the species, there are other subspecies such as in North Africa and Eastern Europe.

Guido Bissanti

Sources
– Wikipedia, the free encyclopedia.
– Gordon Corbet, Denys Ovenden, 2012. Guide to European mammals. Franco Muzzio Publisher.
– John Woodward, Kim Dennis-Bryan, 2018. The great encyclopedia of animals. Gribaudo Publisher.




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