The cetaceans are animals belonging to the infraorder Cetacea, which consists of approximately 106 species, divided into two suborders: Mysticeti, which includes the whale subgroup, comprising four families and six genera with 14 species, and also the Odontoceti suborder, which includes porpoises, dolphins, and sperm whales, comprising 34 genera and 92 species. These animals are mammals adapted to the aquatic environment, they suckle their young and breathe through lungs, with the need to rise to the surface at intervals of seconds to minutes according to each species.
The brain of cetaceans is, in proportion to their body mass, one of the largest among mammals, and also has a high cortical complexity. Thus, these animals have sophisticated echolocation that allows the identification of predators, communication between individuals and capture of information about the environment, formation of complex societies, well-established social and maternal relationships, in addition to good spatial memory and the development of strategies to protect their offspring, which is generated during a long gestational period and remains with the mother for six to ten months.
The notion of self differentiation is already demonstrated in behavioral studies by perceiving how things work and taking strategies to manipulate them. Humpback whales perceive situations of risk to their calves and, surprisingly, also pay attention to trouble faced by other animals, taking initiative to avoid their suffering. Aggressive behaviors are observed to defend other individuals against attacks by orcas (Orcinus orca), for example, even without direct benefits to their self-preservation. There is also the adaptation of their vocalization to reduce the attention of predators while their babies are still vulnerable, which indicates a keen understanding of how to deal with risky situations, as well as cooperation with others.
From this perspective, the animals belonging to this infraorder are well known for their magnificence and beauty, as well as for the size and prominence of many of their representatives, such as the blue whale, which is the largest existing animal, reaching up to 30 meters in length and 170 tons in mass. In addition, we can include in this list the enchanting fixed song patterns of humpback whales and the intelligence of dolphins - commonly compared to the intelligence of primates. Associated with the enchantment caused by these animals, there are also the historical challenges faced by them, resulting from historic hunts and threats by human actions over the centuries - whether for meat, fat, or other culturally valued by-products, in addition to the impacts of fishing, boat accidents, and other human activities.
According to MMA Ordinance No. 148 published by the Ministry of Environment, currently four species of right whales are included in the red list of endangered species according to the International Union for Conservation of Nature and Natural Resources of endangered species (IUCN), they are: the fin whale, sei whale (Balaenoptera borealis) and fin whale (Balaenoptera physalus) in the "Endangered" category, and the blue whale (Balaenoptera musculus) as "Critically Endangered." The odontocetes also suffer from this sad reality, with the Guiana dolphin (Sotalia guianensis) and the sperm whale (Physeter macrocephalus) categorized as "Vulnerable to the threat of extinction", the Amazon river dolphin (Inia
geoffrensis) as "Endangered" and the harbor porpoise (Pontoporia blainvillei) as "Critically Endangered".
The National Action Plan for the Conservation of Marine Cetaceans Threatened with Extinction - PAN, as well as the Humpback Whale Project, Porpoise Project, among other conservation purposes, seek to mitigate this reality, but it is noticeable the urgency to minimize these impacts that collect day after day more aquatic mammals for the list of animals at risk of extinction, as well as strategies for the recovery of its ecosystem and conservation of these and other animals that live in vulnerable conditions.
REFERENCES
Benoit-Bird, K. J., Dahood, A. D., & Würsig, B. (2009). Using active acoustics to compare lunar effects on predator–prey behavior in two marine mammal species. Marine Ecology Progress Series, 395, 119-135.
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Guia de Ilustrado de Identificação de. Cetáceos e Sirênios do Brasil – ICMBio/CMA 2ª Edição-- Brasília, DF: ICMBio/CMA, 2020. 72 p. : il., color.
Nigro, J., Balda, A., & Saenz, C. (2020). COMUNICAÇÃO EMOCIONAL ENTRE O HOMEM E O ANIMAL NÃO - HUMANO. ENCICLOPEDIA BIOSFERA, 17(34).
Pérez‐Manrique, A., & Gomila, A. (2018). The comparative study of empathy: sympathetic concern and empathic perspective‐taking in non‐human animals. Biological Reviews, 93(1), 248-269.
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