Mediterranean monk seals are found in the Aegean Sea, along the Mediterranean coast of Morocco, along the Algerian coast of Tunisia and in the eastern Mediterranean Sea. In June 1997, the first birth on Maui was recorded. The thickness of monk seal blubber is comparable to that of seals living in frigid climates. Monk seals keep cool on hot, windless days by lying on damp sand with light ventral pelage exposed at the water's edge and by making wallows into cool sand layers. Monk seals normally don't stay on dry, hot, upper beach levels except during cool, windy or cloudy weather.
Seals are also very inactive when ashore.
Their respiration includes long periods of breath-holding, and the heart ratio that accompanies holding their breath is low. These behaviors result in low levels of metabolic heat production and are excellent natural adaptations to heat exposure. The three species of monk seal are part of the family Phocidae. Monachus is the genus, and it contains the most primitive of all seals. Monk seal ancestors originated in the North Atlantic Ocean at a very early date.