The Mediterranean Monk Seal (Monachus monachus) is, as the name suggests, a monk seal found in the Mediterranean Sea, as well as in a couple of locations in the eastern North Atlantic. The species is classified as Endangered by the IUCN. Estimated population size = 700.
M. monachus are a fairly large true seal (males ♂ up to 2.8 m long/ 320 kg, females ♀ up to 2.2 m/ 240 kg) with very short front flippers, and long, slender hind ones. Their bodies are slightly elongated, and they have long necks, and broad, round heads with flattened crowns. Facially, they have round, thick muzzles, and large nostrils that open upwards. M. monachus have fairly dark coats with short fur, and the colour usually ranges from brown to grey to black, with lighter cream or silver on the undersides. There is occasional blotching at the sides, but they are mostly uniformly coloured. Female monk seals have 4 nipples, unlike the usual 2 in most phocids.
The varied diet of M. monachus, including over 70 different prey types,paints them as rather opportunistic feeders. They tend to forage in relatively shallow waters along the continental shelf and have been observed taking bony fish (sea bream, mullet, parrotfish, and eels), cartilaginous fish (rays), cephalopods (octopus), and crustaceans (crabs). Preferences vary across different populations although it seems that cephalopods are a particular favourite.
Sexual maturity – males ♂ 5-6 years old/ females ♀ 2-4 years old.
Mating between mature M. monachus occurs in the sea, and they are thought to be slightly polygynous, with males defending aquatic territories. Gestation lasts around a year and unusually, pupping does not have a strict season, and may occur all year round. Having said that, there is a strong peak in births around October and November. Historically, females hauled out on beaches to pup, however with increasing human presence, these shy seals have adapted their behaviour to give birth in sea caves. Multiple females and their pups will occupy a single cave, although the species is fairly solitary the rest of the time. The youngsters, sporting a dark-coloured lanugo, will make their first forays into the water in their first or second week, and the mother will leave them alone while she goes to sea to feed. There is a high mortality rate in young pups born in caves as the autumn/winter season coincides with severe storms in the Mediterranean, which can leave them washed away and separated from their mothers, or seriously injured by being knocked into the rocks. M. monachus has a long lactation period of 14-21 weeks, and the pup will lose its first coat at around 8 weeks, developing a silvery-grey replacement. The mother’s moult will take place at about 19 weeks after parturition, which sometimes occurs before weaning of the pup. By this time the youngster will be adept at swimming, diving and foraging. The usual life span of M. monachus is between 20 and 30, though they do sometimes live into their mid-forties.
M. monachus is found in scattered, isolated locations across their range, with three significant populations, one in the eastern Mediterranean, Aegean and Ionian Seas and two in the eastern Atlantic Ocean. These are on the Turkish and Greek coasts, at Cabo Blanco in the Canary Islands, and in Madeira. Substantial morphological and genetic differences between individuals from the different populations indicates the existence of identifiable subspecies, however none have been formally recognised at this time.