The Tawny Eagle, or Aquila rapax, is a majestic bird of prey found mainly in sub-Saharan Africa and South Asia. This raptor is recognizable by its golden-brown plumage, broad wings, and relatively short tail. It measures between 60 and 75 cm in length with a wingspan of up to 2 meters. Preferring savannas, steppes, and semi-deserts, it primarily feeds on carrion but also hunts small mammals and birds. Its call is a piercing whistle, often heard during the breeding season. Although a solitary hunter, it can be seen in groups around carcasses.

Tengmalm's Owl is a small nocturnal raptor, easily recognized by its small size and large, piercing yellow eyes. It has gray-brown plumage with characteristic white markings on the head, wings, and back. Its ears are very inconspicuous, and its face is surrounded by a pale facial disc. This owl primarily inhabits coniferous forests, dense wooded areas, and mountains, where it hides in tree cavities or abandoned nests of other birds. Tengmalm's Owl mainly hunts small mammals, birds, and insects, which it catches at night by flying silently through the forests. It is particularly active during the breeding season, when it emits characteristic calls to attract its mate. Although it is relatively discreet and often difficult to observe, Tengmalm's Owl is protected in some areas, though its population is threatened by deforestation and habitat loss.

The Tawny Owl is one of the most common owls in Europe, easily recognized by its round face forming a facial disc and its large, piercing black eyes. Its plumage is typically brown, with irregular white spots on the belly and back. It has a stocky body, broad wings, and silent flight, which is suited to its nocturnal hunting. This nocturnal raptor primarily inhabits broadleaf and mixed forests, as well as lowland wooded areas. The Tawny Owl primarily hunts small mammals like rodents, as well as birds, insects, and worms. It uses its ability to fly silently to capture its prey, often in open areas like clearings, forest edges, or fields. It is also known for its characteristic calls, a deep, melodious "hoo-hoo." While its population remains stable in many parts of Europe, the Tawny Owl can be affected by habitat loss, light pollution, and human disturbances.

The Trumpeter Swan, Cygnus buccinator, is the largest swan in North America, renowned for its pure white plumage and long, elegant neck. It is distinguished by its black bill and dark eyes. Its powerful, resonant call, reminiscent of a trumpet, gives it its name. This majestic swan frequents lakes, marshes, and rivers, feeding primarily on aquatic plants. It is often seen in small family groups. Although its population was once threatened by hunting and habitat loss, conservation efforts have led to an increase in numbers. The Trumpeter Swan is a symbol of beauty and grace in aquatic ecosystems.

The Common Damalisque is a medium-sized antelope, recognizable by its reddish-brown or gray-brown coat, with distinctive white markings on the legs and belly. It stands about 1.10 to 1.30 meters tall at the withers and weighs between 45 and 70 kg. This mammal primarily inhabits the savannas and open grasslands of East Africa, notably in Kenya, Tanzania, and Uganda. It mainly feeds on grasses and herbaceous plants but can also consume leaves and fruits when grass resources are limited. The Common Damalisque is known for its social behaviors, typically living in groups of females and young, while adult males are often solitary or form small groups. During the breeding season, males fight to defend their territory and access females. While it is currently listed as of least concern, the Common Damalisque faces threats such as habitat loss due to agriculture and urban expansion, as well as hunting for its meat and skin.

The Tasmanian Devil is a medium-sized carnivorous marsupial, easily recognized by its black fur and white patches on its chest and hips. It measures about 50 cm in length, with a tail of 25 cm, and weighs between 5 and 10 kg. This nocturnal predator is found exclusively on the island of Tasmania, where it primarily feeds on small mammals, birds, insects, and carcasses of dead animals. The Tasmanian Devil is known for its aggressive feeding behavior, often making growling and screaming noises. It is also a solitary animal, only coming together during breeding or when it finds a large carcass. While this species plays an important scavenging role in its ecosystem, it is now threatened by a devastating infectious disease, Devil Facial Tumour Disease (DFTD), which has significantly reduced its population. Habitat loss and vehicle collisions also pose threats to its survival.

The Thorny devil is a fascinating lizard native to the deserts of Australia. Its skin is covered with sharp spines that allow it to camouflage effectively among rocks and desert vegetation. It primarily feeds on ants, which it captures using its sticky tongue. When threatened, it adopts a defensive posture, inflating its body and displaying its spines to appear larger and more threatening. While calm, it is an expert in the art of camouflage and uses its appearance to protect itself from predators.

The Tufted Duck is a medium-sized, elegant diving duck, measuring 40 to 47 cm in length. The male displays glossy black plumage with striking white flanks and a distinctive black tuft on the back of the head. The female is dark brown with paler flanks and a more modest tuft. Both sexes have a bluish-grey bill and bright yellow eyes. This species frequents lakes, ponds, reservoirs, and slow-moving rivers, often in flocks, and prefers areas rich in aquatic vegetation. It feeds mainly on mollusks, insect larvae, crustaceans, and aquatic seeds. A partial migrant, it is present year-round in temperate regions. Generally of Least Concern, though locally threatened by water pollution and wetland loss.

The Thomson's Gazelle is a small, elegant gazelle known for its speed and grace. It stands about 60 cm at the withers, with a body length of 90 cm, and weighs between 20 and 30 kg. Its coat is mainly beige, with distinct white markings on its belly and a black stripe running along each side of its body. The adult male has curved lyre-shaped horns, while females generally lack them. The Thomson's Gazelle primarily inhabits the savannas and grasslands of East Africa, particularly in Tanzania and Kenya. It is herbivorous, feeding mainly on grasses, young shoots, and leaves. Very fast, the Thomson's Gazelle can reach speeds of 80 to 90 km/h, allowing it to escape many predators. Although it is currently relatively common, the Thomson's Gazelle faces threats related to habitat loss and human activities, including hunting and competition with livestock.

The Tokay gecko is a large lizard native to the tropical forests of Southeast Asia. This gecko is particularly known for its vibrant colors, with a gray or bluish body speckled with orange or red spots, making it easily recognizable. The Tokay gecko is nocturnal and arboreal, living in forested habitats, often near human dwellings. It is also famous for its distinctive call, resembling its name, tokay," which it uses to defend its territory or attract a mate. This gecko is a carnivorous predator, feeding mainly on insects and small vertebrates."

Ameerega trivittata is a colorful and toxic frog native to the humid tropical forests of South America. It is distinguished by its longitudinal yellow or green stripes on a black background, serving as a warning to potential predators. This species is diurnal and primarily feeds on small insects. It is often observed on the forest floor, using its bright colors to deter predators. The three-striped poison frog plays a crucial role in the ecosystem by regulating insect populations. Although its skin is toxic, it is not dangerous to humans unless handled directly.

The Tomato Frog is a striking amphibian species native to Madagascar, easily recognizable by its bright red color and large skin glands that secrete a toxic mucus when threatened. These frogs grow to about 10 cm and are primarily terrestrial, living in the dry tropical forests and savannas of Madagascar. Their bright coloration serves as a warning signal to predators. They are nocturnal and spend the day hiding under leaves or in burrows to avoid heat and predators. During the breeding season, they gather near water sources where they lay their eggs.

The treecreeper is a small woodland bird found primarily in mixed forests, hedgerows, and gardens across Europe and Asia. It is easily recognized by its streaked brown plumage, light belly, and its distinctive movement as it climbs tree trunks and branches in a spiraling fashion. It primarily feeds on insects found in the cracks of tree bark.

The Kiang is a large wild equid, closely related to the horse, primarily found in the high plateaus and mountains of the Himalayas and Tibet. It stands about 1.3 to 1.5 meters at the shoulder and weighs between 300 and 400 kg. Its coat is typically brownish-red or gray-brown with lighter shades on the belly and around the legs, and it has a short and sparse mane. The Kiang has a broad head and a bushy tail, similar to that of a horse. It primarily inhabits arid regions and high-altitude grasslands, feeding on grasses and woody plants. Highly social, the Kiang lives in large groups that move together in search of food. Unlike other wild equids, it is more tolerant of cold conditions and can survive at extremely high altitudes, up to 5,000 meters. While the species is relatively abundant in its range, it can be threatened by habitat loss due to climate change and human pressure, particularly from grazing and hunting.

The Tapanuli orangutan is a recently discovered primate species, considered one of the rarest and most endangered in the world. It measures about 1.2 meters in height and weighs between 30 and 60 kg. This ape has a shiny reddish coat, with long arms adapted to its life in the trees. Native to the mountains of the Tapanuli region in northern Sumatra, Indonesia, this orangutan primarily inhabits montane tropical forests. It feeds mainly on fruits, leaves, and bark. The Tapanuli orangutan is a solitary and secretive animal and is considered critically endangered due to deforestation, mining, human conflict, and forest fires.

The tree pangolin, or Manis tricuspis, is a medium-sized, nocturnal insectivorous mammal found in the tropical forests of Central and West Africa. It is easily recognizable by its protective scales made of keratin, the same substance as human nails. This pangolin is an agile climber, using its prehensile tail to navigate trees in search of ants and termites, its primary food source. Unfortunately, it is threatened by poaching for its meat and scales, which are highly valued in traditional medicine. Conservation efforts are crucial to maintaining the ecological balance of its natural habitat.

The Great Spotted Woodpecker is an iconic bird of forests in Europe, Asia, and North Africa. It measures about 25 to 30 cm in length, with a wingspan of 40 to 45 cm, and weighs between 70 and 100 g. It is easily recognizable by its black and white plumage, with a red head in males and a red patch on the nape in females. The Great Spotted Woodpecker is an excellent climber, using its strong beak to tap on tree trunks in search of insects, primarily insect larvae and ants, which it extracts with its long, sticky tongue. It is often seen hammering wood in search of food or to mark its territory. The Great Spotted Woodpecker is found in a variety of forests, from broadleaf to mixed forests, and although its population remains stable, it is sometimes affected by habitat loss.

The tree pipit is a small passerine about 15 cm long with streaked brown upperparts and a pale breast. It inhabits woodland edges, open woodlands and hedgerows, feeding mainly on insects and seeds. During breeding, males sing in flight and from low perches to attract mates and defend territory.

The tawny pipit is a small passerine of 16–17 cm with finely streaked sandy plumage and a pale breast. It inhabits open steppe, dry fallow land and garrigue, feeding mainly on insects and seeds picked from the ground. During breeding, males perform singing flights and sing from low perches to attract females and defend their territory.

The Tibetan Fox is a small carnivore endemic to the mountainous regions of Tibet, Nepal, and northern India. It measures about 45 to 60 cm in length, with a tail of 30 to 40 cm, and weighs between 2 and 3 kg. Its fur is typically light gray to brown, with darker shades on the back and lighter underparts. It has large pointed ears and a long bushy tail. The Tibetan Fox is an opportunist, feeding on small mammals, birds, fruits, and berries. It primarily lives in dry and mountainous regions, where it digs burrows to protect itself from the cold. Although its population remains relatively stable, the Tibetan Fox is vulnerable to habitat loss and hunting.

The tiger salamander is a robust terrestrial amphibian of 15–25 cm (sans la queue), with an olive to brown body marked by yellow blotches and a pale throat. A nocturnal and crepuscular species inhabiting woodlands, damp meadows and pond margins, it feeds on insects, worms and molluscs. During breeding, males produce low underwater calls to attract females to egg-laying sites.

The Takin is a large herbivore found primarily in the mountainous regions of the Himalayas and China. It typically stands between 1.2 and 1.5 meters at the shoulder, with a body length of 1.5 to 2 meters, and weighs between 250 and 350 kg. Its fur is dense and ranges from golden to light brown, with longer hair around the throat and shoulders, giving it a robust appearance. The Takin is an excellent climber and primarily feeds on woody vegetation, leaves, young shoots, and fruits. It lives in social groups and is mainly active at dawn and dusk. While its population remains relatively stable in certain areas, this species is threatened by deforestation and human activities, including hunting and encroachment on its natural habitat.

The Tarsier is a small nocturnal primate found primarily in the tropical forests of Southeast Asia, notably in the Philippines, Indonesia, and Borneo. It typically measures about 10 to 15 cm in length, with a tail of 20 to 25 cm, and weighs between 100 and 150 g. The Tarsier is known for its remarkably large eyes, which account for about one-third of its head size, allowing it to see in low-light conditions. It also has long legs and large hands, which enable it to move agilely through the trees, where it primarily hunts insects, spiders, and occasionally small vertebrates. While its population remains relatively stable in some areas, the Tarsier is threatened by deforestation and habitat loss.

The tayra is a carnivorous mammal native to the forests of Central and South America. It resembles a large marten, with dark fur and a long bushy tail. It is known for its great agility and ability to climb trees, where it hunts small mammals, birds, and fruits. It is a territorial and solitary animal, preferring forested habitats. Although its population is stable, it faces threats from deforestation and hunting.

The Tiger is a large cat primarily found in the forests, savannas, and grasslands of Asia, notably in India, China, Indonesia, and Russia. It typically measures between 2.5 and 3.5 meters in length, including the tail, and can weigh between 100 and 300 kg, depending on the subspecies. The Tiger is easily recognizable by its striped coat, which varies from yellow-orange to white, with distinctive black bands. It is a solitary and territorial predator, primarily feeding on large herbivores such as deer, wild boars, and buffalo. While it is at the top of the food chain, the Tiger is threatened by habitat loss, poaching for its fur and bones, and conflicts with human populations. Some subspecies, such as the Sumatran Tiger and the Siberian Tiger, are particularly endangered.

The thylacine, or Tasmanian tiger, was a large nocturnal carnivorous marsupial up to 1.8 m long (including tail) and weighing 15–30 kg, with pale yellow fur marked by dark dorsal stripes. Endemic to Tasmania, it inhabited rainforests, scrublands, and grasslands, preying mainly on wallabies and birds at dusk and night. Solitary and shy, it sheltered in natural dens or rock crevices.

The toco toucan is the largest toucan species (55–65 cm long), with black plumage and a white throat topped by a large bright orange bill. It inhabits tropical humid forests and woodland savannas in South America, feeding on fruits, insects, and small vertebrates. During the breeding season (February to June), it nests in tree cavities and pairs perform aerial display flights.

The Sphenodon punctatus, commonly known as the tuatara, is a reptile endemic to New Zealand. Often considered a living fossil, it belongs to an order of reptiles that thrived around 200 million years ago. The tuatara is nocturnal, primarily active at night, and feeds on insects, spiders, small birds, and eggs. It is recognizable by its spiny crest along the back, more pronounced in males. Tuataras have an exceptional lifespan, with some living over 100 years. They are oviparous, and females lay eggs that take between 12 and 15 months to hatch. Although protected, tuataras are threatened by habitat loss and introduced predators.