Mediterranean Monk Seal

This species of seal grows from approximately 80 centimetres (2.6 ft) long at birth up to an average of 2.4 metres (7.9 ft) as adults, females slightly shorter than males. Males weigh an average of 320 kilograms (710 lb) and females weigh 300 kilograms (660 lb), with overall weight ranging from 240–400 kilograms (530–880 lb). They are thought to live up to 45 years old; the average life span is thought to be 20 to 25 years old and reproductive maturity is reached at around age four. The monk seals' pups are about 1 metre (3.3 ft) long and weigh around 15–18 kilograms (33–40 lb), their skin being covered by 1–1.5 centimeter-long, dark brown to black hair. On their bellies, there is a white stripe, which differs in color and shape between the two sexes. In females the stripe is usually rectangular in shape whereas in males it is usually butterfly shaped. This hair is replaced after six to eight weeks by the usual short hair adults carry. Adults will continue to molt annually, causing their color vibrancy to change throughout the year. Pregnant Mediterranean monk seals typically use inaccessible undersea caves while giving birth, though historical descriptions show they used open beaches until the 18th century. …

The habitat of this pinniped has changed over the years. In ancient times, and up until the 20th century, Mediterranean monk seals had been known to congregate, give birth, and seek refuge on open beaches. In more recent times, they have left their former habitat and now only use sea caves for these activities. Often these caves are inaccessible to humans. Frequently their caves have underwater entries, and many caves are positioned along remote or rugged coastlines. Scientists have confirmed this is a recent adaptation, most likely due to the rapid increase in human population, tourism, and industry, which have caused increased disturbance by humans and the destruction of the species' natural habitat. Because of these seals' shy nature and sensitivity to human disturbance, they have slowly adapted to try to avoid contact with humans completely within the last century, and, perhaps, even earlier. The coastal caves are, however, dangerous for newborns, and are causes of major mortality among pups when sea storms hit the caves.

Very little is known of this seal's reproduction. As of 2020, it is thought that there are roughly 500 pairs of monk seals remaining in the world. Scientists have suggested that they are polygynous, with males being very territorial where they mate with females. Although there is no breeding season since births take place year-round, there is a peak in September, October, and November. Although mating will take place in the water, females will give birth and care for the pups on beaches or underwater caves. The use of underwater caves may have begun in order to make predatory actions almost impossible as these caves are difficult to access. Because they will stay with the pups to nurse and protect, they use their stored fat reserves to nurse. Data analysis indicates that only 29% of pups born between September and January survive. One cause of this low survival rate is the timing of high surf around the areas of breeding, creating a threat to young pups. As well, if a female is in an unsafe environment, she may have an abortion, indirectly lowering the population. Because of smaller populations there is an increase in genetic events such as inbreeding and lack of genetic variation. …

The Mediterranean monk seal occasionally appears in Classical mythology. In Homer's The Odyssey, the sea god Proteus is shown herding monk seals for Poseidon. The mythical hero Phocus of Aegina (with phokos literally translating to seal in Greek) was the son of the nereid Psamathe, and was conceived while she was transformed into a seal. The ancient city of Phocis (and possibly Phocaea) was named after Phocus, and the city of Phocaea took on the monk seal as an emblem. This has been thought to either be due to the myth of Phocus' birth, or monk seals formerly inhabiting the area where Phocaea was established. There is only a single known surviving depiction of the monk seal from antiquity, this being on a Caeretan hydria likely created by Phocaean refugees in Etruria. Despite its mythological connections and association with certain peoples, the monk seal still seems to have generally been reviled and feared by the ancient Greeks and Romans due to its form and smell, as well as its association with the unknown nature of the ocean. Many Greek and Roman metaphors and idioms portrayed the seal in a negative light. …