Beaches of Guayota

Prior to the 19th century, the North Atlantic coasts were inhabited by two distinct species, namely, the Mediterranean monk seal (Monachus monachus) and the great auk (Pinguinus impennis). The Mediterranean monk seal belonged to an ancient group of seals that thrived in warm waters. Contrary to its designation, the Mediterranean monk seal was not limited solely to the Mediterranean but was also commonly found in the North Atlantic, albeit its population significantly dwindled, ultimately becoming restricted to the islands of Madeira and Mauritania in the early 21st century, with dwindling and endangered populations. The primary causative factor behind this population decline was habitat degradation and contamination, issues that have plagued numerous species worldwide.

On the other hand, Pinguinus impennis, known as the great auk, was a non-flying seabird belonging to the family Alcidae. Despite its adaptation to the cold waters of the Atlantic, fossil evidence indicates its presence as far south as Morocco. However, its distribution was drastically reduced due to human hunting, culminating in its extinction in 1844. The interaction between human populations and this species resulted in its severe population decline.

With the extinction of these two species and the improvement in environmental conditions during the late Anthropocene, other species have occupied their ecological niches. Particularly, along the coasts of Guayota, two noteworthy successors have emerged: the Southern Seal (Phoca vitulina spss. meridiensis ) and the Flightless Atlantic Cormorant (Phalacrocorax apterus). 

Although these species also faced challenges due to conflicts with humans, in general, the Southern Seal is not in danger, and it has coexisted harmoniously with humans. The adaptation of this species to warmer environments, such as the Canary Islands, is partly due to the availability of beaches for rest and reproduction, as well as the abundance of fish in the surrounding waters, motivating the species to move further south. Biological evolution tends to fill ecological voids, and the Southern Seal has proven to be the most suitable species to take the place of the extinct Mediterranean monk seal. 

In the late Anthropocene, this subspecies differs very little from its ancestor, with the primary distinction being its size, as the southern subspecies has nearly doubled in size, reaching weights of up to 300 kilograms in the largest individuals. These seals have an affinity for fish but also consume benthic organisms such as crabs and octopuses. While they are solitary for most of the year, they come together on beaches for reproduction once a year, conducting courtship and reproduction underwater while harmoniously coexisting with the non-flying Atlantic cormorants.

The Flightless Atlantic Cormorants, descendants of common cormorants (Phalacrocorax carbo) a very common species during the human era, with great adaptabiliy for fishing both in the ocean and in bodies of fresh water and with a great capacity for tolerance towards humans. These birds have lost this ability throughout their evolution on this island with no natural predators and abundant fishing in the waters near the coast. Despite their large size, weighing up to 10 kilograms, their wingspan has decreased as they no longer require it for flight.

The reduction in the keel, the structure where flight-related muscles attach, is attributed to the loss of flight. Cormorants spend a considerable amount of time out of the water, drying their feathers since, like other cormorants, they produce a limited amount of oil in their uropygial gland for preening and waterproofing effect. Their diet primarily consists of fish, which they hunt with remarkable agility, although they occasionally consume crustaceans and mollusks closer to the shore. 

The stable temperatures in Guayota enable them to nest throughout the year. The construction of nests using seaweed and materials washed ashore is a hallmark of their reproduction, and pairs tend to stay together for life, although infidelity and parallel families in other colonies are not uncommon. It is not unusual for both males and females to have another pair and another nest on different beach. The exchange of gifts, such as shiny shells, stones, or undegraded plastics, is a common practice among these birds. Chicks are vulnerable to predatory birds, but they benefit from the protection provided by their parents' sharp beaks. Geckos (Tarentola mauritanica), which seem to have recently arrived from nearby islands by rafting, represent another threat to the chicks. When they reach maturity, cormorants are vulnerable while fishing in the sea and are a sought-after delicacy for Crying Whales, a fate they share with their fellow beach residents, the seals.