Fauna of Neocene Islands

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Fauna of Neocene Islands

JOrnitho: I return with another topic! This time to discuss the islands that still need species. I had some ideas for animals of the Andaman and Nicobar islands, most of them are descendants of introduced species. One being a descendant of the spotted deer. Also, would the Archipelago of Fernando de Noronha in the coast of Brazil exist in the Neocene?

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Биолог: JOrnitho Thanks for the topic! This time to discuss the islands that still need species. There are many, in all oceans. would the Archipelago of Fernando de Noronha in the coast of Brazil exist in the Neocene? Why not? And by neocene, continental species from South America can enter there.

JOrnitho: Биолог пишет: There are many, in all oceans. That is true, maybe we can have this topic for the ones in the Atlantic. Биолог пишет: And by neocene, continental species from South America can enter there. Yes! There is also the exotic species that the humans left here. Here is the Wikipedia page about Fernando de Noronha: https://en.m.wikipedia.org/wiki/Fernando_de_Noronha The largest herbivore of the island could be a descendant of the introduced Rock cavy (Kerodon rupestris). They could look like the continental deermara, but with 50 cm at the shoulder.

Биолог: JOrnitho a descendant of the introduced Rock cavy (Kerodon rupestris) Good idea!

JOrnitho: Another ideas that I had for Fernando de Noronha are two species of descendants of the tegu, one living in forests, while the other lives in the coast searching for food at the sea. About predators, I was thinking that the apex predator could be a bird of prey that reached the island from the continent. It would hunt the cavies, tegus and the sea birds that nest in the rock islets around it. Another possibility is it being a sea bird that developed raptorial behavior.

Биолог: JOrnitho Great ideas!

JOrnitho: I made the description of the descendant of the rock cavy. Koriko pexerumen (Koriko insularis) During the Holocene, humans had caused several impacts on the environment. Among their actions was the introduction of exotic species and the places that most suffered with it were the islands. With the disappearance of the human species, these animals remained and some evolved in new species during the Neocene. One of these cases was the koriko pexerumen, the descendant of the population of rock cavy (Kerodon rupestris) that was introduced in the main island of Archipelago of Fernando de Noronha, close to the coast of Eastern South America. Koriko pexerumen is the name in the Xukuru language of Pernambuco for the rock cavy. The koriko pexerumen is endemic to the largest island of the Archipelago of Fernando de Noronha, inhabiting its forests and rocky areas. The body length of the koriko pexerumen is 95 cm, with a shoulder height of 30 cm. The fur is auburn and pale grey at the underbelly. Its legs are longer than that of their ancestors, giving them the appearance of a small and primitive ungulate. However, it has no hooves, but instead several small nails that remind rooflets. Their feet are adapted to allow them to move through rocky surfaces. The ears are short and the tail is nonexistent. They developed strong incisors, which is used to break hard fruits and shells. These animals eat fallen fruit, leaves and roots. When feeding, they will stay near each other as a protection from predators. Sometimes they can eat eggs and even shellfish on the seashore. These animals are diurnal and polygamous, with a male and two females mating and staying together for the rest of their lives. They form groups composed by the male, his females and their offspring. The female gives birth to a litter of 2 to 4 young after a gestation of 4 months. There is no defined mating season, with births occurring many times during the year. The birth usually occurs hidden in bushes and dense vegetation. The young are born well developed and are capable to follow the parents shortly after the birth. The old offspring will help the parents to take care of the young siblings. Both females will help each other to take care of the offspring. They are weaned with 16 weeks and reach sexual maturity with 2 years. Within 4 years, koriko pexerumen leaves the family to form their own. The lifespan of this species is of 19 years.

Биолог: JOrnitho Good species!

JOrnitho: I made more two species for the Archipelago of Fernando de Noronha, both small mammals descendants of animals left by the humans here. I'll make two bird species later. Noronha rat (Rattus noronhensis) While humans purposefully introduced some species in new habitats, others were inadvertently introduced. The black rat (Rattus rattus) followed the humans to several places, benefiting from their presence. When they were extinct, some of these rodents were able to survive and continue their evolution. In the Archipelago of Fernando de Noronha, the populations of the black rat that survived evolved into an endemic species, the Noronha rat. The Noronha rat has 12 cm of body length, with a tail of 9 cm. They have strong forelimbs that are used to excavate the ground to make tunnels to be used as their dens. It has light brown fur with a white underside. This species is an omnivore and eats a wide range of foods, including seeds, fruit, stems, leaves, fungi, and a variety of invertebrates. Some individuals will also occasionally eat eggs and newborn chicks of seabirds that are left unprotected. However, they need to be careful when approaching the colonies. The adults that nidify in the Archipelago had learned the danger of the rodents, being aggressive with them. The large species of bird can even consider them as a good snack. Differently from their ancestor, the Noronha rat is monogamous and highly territorial. The limited resources left in the Archipelago after the disappearance of the humans forced these rodents to fight against each other for what they could find. This way, only the mated pair forage together and they defend their dens fiercely against intruders. Their greatest predator is the gatito, which is capable to invade their dens and to kill them while inside it. However, these rodents don’t fall without a fight. Their fights against the feline could be considered titanic for animals of such small proportion, but even then the gatito ends winning most of the time. The Noronha rat can breed throughout the year if conditions are suitable, with a female producing up to five litters a year. The gestation period is only 21 days, and litters are formed by 7 to 14. The competition among the young is fierce, with weak siblings of large litters perishing due to it. In these cases, the parents will eat the dead. They reach sexual maturity in about five weeks, which is when they are expelled from the den by their parents. When there is enough food, the female becomes fertile again three weeks after giving birth. The maximum life span is three years, although most barely manage to one. Unlike their ancestors, they aren’t an invasive species in the Archipelago anymore. The local fauna have evolved together with them and know that they can be a good food source. Beyond the gatito, local herons will also exploit them as such. Gatito (Nanofelis musteloides) During the Holocene, humans had caused several impacts on the environment. Among their actions was the introduction of exotic species and the places that most suffered with it were the islands. With the disappearance of the human species, these animals remained and some evolved in new species during the Neocene. One of these cases was the gatito, a descendant of the domestic cats that were left in Fernando de Noronha after the disappearance of the humans. The word gatito means kitten in Spanish and can also be used informally in Portuguese to name the same thing. This species is the only representative of the Genus Nanofelis and is endemic to the largest island of the Archipelago. The gatito is one of the smallest felines of the Neocene, with the males having a body length of 30 cm, while females have 26 cm. The tail is 8 cm short in males, while in females it's 6 cm. They have a slim and flexible body with short limbs, which gives them the appearance of a weasel. Their fur is reddish-brown and entirely covered with black spots, while their tail is black with faint brown-colored rings. This species eats insects, lizards and small birds. However, their main prey is the Noronha rat. The gatito developed such a slim body exactly to hunt this rodent. Using their flexibility, these small felines are capable of invading the dens made by the rats, killing them while they are resting. Such dens are occupied and enlarged by the felines, which turn them on their home. While they can be active at any hour of the day, gatitos prefer to hunt during the night. This occurs not only because the Noronha rat is mostly a nocturnal animal, but also because they want to avoid predation by the long-legged hawk and raptorial gulls. The gatito is solitary, with males and females meeting only when mating, which can occur at any time of the year. The female have a 37 day gestation period. During this period she prepares her den to give birth by feeling it with grass and leaves. She raises its kittens without help from the male. The newborn are born pink, naked, blind and deaf, but gain a brownish coat of downy fur at the age of 4 days. At 10 days, the fur starts to become reddish-brown and the spots start to appear. The milk teeth erupt at 2 to 3 weeks of age, at which point the young start to eat solid food, though lactation can last 12 weeks. The eyes and ears open at 3 to 4 weeks of age, and by 8 weeks, killing behaviour is developed. The family breaks up after 9 to 12 weeks. They reach sexual maturity with 4 months and can live for 8 years.

Биолог: JOrnitho Wow, good ones!

JOrnitho: I finished the description of the birds. Pernilongo hawk (Neogeranospiza dolichoscelis) The human actions during the Holocene caused the decline of many species. However some species survived and in the Neocene they gave rise to new species. One of these new species is the pernilongo hawk, a descendant of the crane hawk (Geranospiza caerulescens). The word pernilongo means long-legged in portuguese. This species inhabits the open areas of South America, from the savannas to the restingas in the eastern coast of the continent. A population had reached the Archipelago of Fernando de Noronha, where it became the apex predator of the islands. The pernilongo hawk has 55 cm of length and 110 cm of height, with 120 cm of wingspan. The males are smaller than the females. They have grey upperparts with a white rump. The central tail feathers are black tipped with white and the outer tail feathers are white. The head and upper breast are dark grey while the rest of the underparts are finely barred in dark grey and white. The bill is bright red at the base and dark grey at the tip. The facial skin and the characteristic long and strong legs are also bright red. This species developed a curved, sickle-like claw in each foot in a similar fashion to the extinct dromaeosaurid dinosaurs. This species' main prey are small vertebrates, especially rodents, bats, lizards, snakes, and small birds, but they have also been known to eat larger insects and other arthropods and snails. These hawks often forage by scanning from a perch or on the wing and swooping down to grab prey, killing it with stomps and using their sickle-like claws. However, they are capable of running after prey. Due to their long legs, they are fast on the ground. While doing it, they held off their claws from the ground. The population that inhabits Fernando de Noronha hunts mostly chasing after the koriko pexerumen, their main prey on the Archipelago. They will try to subdue the rodent with hits of their claws and by breaking their bones with stomps. The pernilongo hawk is a monogamous bird, with the pairs living together even outside the breeding season. They will also hunt large prey together in the ground, with the male guiding it toward the hidden female, who will make the kill. They nest in small trees, with nests made of sticks, plant roots, and stems, which are often lined with leaves, moss, bark and plant roots. They are built mainly by females. She lays two to four bluish white eggs with brown speckling. The female does most of the incubation. The eggs hatch in 31 to 36 days. The young begin to explore outside the nest at 38 days, and fledge, 50 days. In a year, the female can nest two times. Young birds stay with their parents for 7 months. During this period, large prey becomes a common source of food. They reach sexual maturity with three years and have a lifespan of 20 years. Papa-ratos (Ardeola rattophaga) The birds were always one of the most mobile animals. With their ability to fly, they were capable of going beyond their normal territory, this way colonizing new areas. During the Neocene, the squacco heron (Ardeola ralloides) had reached the Archipelago of Fernando de Noronha and the coast of Northeastern Brazil coming from Africa and Europe. In the Neocene, a population of this species remained here and gave origin to the papa-ratos. This name was used for their ancestor in Portugal and means rat eater. The papa-ratos inhabit the Archipelago of Fernando de Noronha and the coastal areas of Northeastern and Northern South America. The papa-ratos have 47 cm of length with a wingspan of 92 cm. When adult, its coloration is a mixture of dark brown and orange on the back and flanks, abdomen, lower back, wings and white tail, which becomes surprisingly apparent during flight. It has a nuchal crest with elongated reddish-brown feathers and black streaks that hang down the back of the neck. In the breeding season, the plumage is more vivid, with an orange-colored crown, golden feathers on the lower part of the neck and back, reddish-golden wing and chest-coverts, reddish-brown back, with long golden plumes, and the rest being white plumage. The bare parts become bright during courtship, the legs turn reddish with soon fading to pink and back to dull yellowish-green, bright blue bill with dark tip that is pale greenish-yellow with black tip and jaw in non-breeding season, blue face and yellow eyes. Juveniles are less colorful, having bars on the head and neck and darker brownish back than adults, no crest or back feathers, dark-tipped bill, gray underparts instead of white and brown flight feathers. It feeds on almost anything that moves, such as fish, frogs and their tadpoles, snakes and small reptiles, small mammals and birds, molluscs, insects and their larvae. However, they developed a preference for rodents, being capable to actively chase these animals through the ground. Their ability in hunting rodents was what gave them the name papa-ratos. The population of Fernando de Noronha learned that if they stay near the colonies of sea birds, they will be able to catch Noronha rats that came here to feed in the eggs and unattended chicks. Of course, they will also eat chicks if the opportunity arises, but the sea birds mostly tolerate their presence because of them hunting the nuisance that are the rats. The papa-ratos are active during most hours of the day, but those of Fernando de Noronha are more nocturnal due to this being the time that their main prey, the Noronha rat, is mostly active. It nests in large colonies, sometimes interspecific. The nest is a platform of branches or reeds, well constructed, made in trees, near or on the water. The nest is built by both sexes, and the material is collected by the male. They usually lay 3 to 4 blue-colored eggs green, with an incubation period of 24 days, with the incubation being made mainly by the female. The chicks are fledged after 35 days. Sexual maturity occurs around 2 years of age and they have a lifespan of 12 years.

Биолог: JOrnitho Good ones! I've added them to our catalogue.

JOrnitho: I made another description. This time for a reptile. Marine tegu (Talassosalvator piscator) During the Holocene, humans had caused several impacts on the environment. Among their actions was the introduction of exotic species and the places that most suffered with it were the islands. With the disappearance of the human species, these animals remained and some evolved in new species during the Neocene. The marine tegu was one of these cases. It’s a descendant of the Argentine black and white tegu (Salvator merianae) that was introduced in the Archipelago of Fernando de Noronha. This species first evolved in these islands before reaching the coastal areas of South America. They are semi-aquatic marine reptiles that inhabit the tropical coast of Northern and Northeastern South America, including their ancestor land of the Archipelago of Fernando de Noronha. Some vagrants can be seen in the Southeastern coast of the continent. The marine tegu are sexually dysmorphic, with males being larger than the females. While the male can reach 200 cm of length, the females rarely surpass 150 cm. While the young are born an emerald green color with black markings, the adults are completely black, with only small and faint green spots in their backs and tail. Their dark color helps them get warmer faster under the sun. These lizards have a flattened, paddle-like tail and webbed feet, both adaptations that help them swim. Their bodies are also more flexible than that of their ancestors, giving them more maneuverability underwater. This species had become so adapted to live in the water that they became slow when walking on land. This species is omnivorous, feeding on fishes, algae, molluscs and crustaceans. They use their strong jaws to crush shellfish. When hunting fish, these animals patrol rocks after fish that are hiding there. When foraging, they don't go into open sea, remaining in areas near the coast. The marine tegu is capable of hunting schools of fish, usually in small groups, in a similar way to how the sea lions used to do in the Holocene. The marine tegus spend most of their time under the sun in rocks or in the sand. When they are warm enough, the reptiles go to the sea after food. They form large congregations while basking in the sun. These groups have a hierarchy, with large and dominant males only tolerating females near them. Other males will be expelled aggressively. The breeding season starts at the end of the winter. The males will fight against each other for the right of having access to the females. Bites and hits of their tails are used during these fights. After they are fecunded, the females will move inland to dig holes where they will lay eggs. While doing it they become susceptible to being attacked by predators. They lay 18 to 25 eggs. The young are born after 64 days and instinctively they will move to the water, usually estuaries and mangroves. For the first two years, they avoid the sea. They can be eaten by birds, large fishes and even adult marine tegus. The sexual maturity is reached with 8 years and their lifespan is of 47 years.

Биолог: JOrnitho Good tegu!

JOrnitho: I was wondering if the Genus Thalassocrator could have other species beyond the Nomad albatross of the chapter Lord of the Sky. Would it be possible?

Биолог: JOrnitho Why not? But only in other regions, where the niche is not already occupied.

JOrnitho: Биолог пишет: But only in other regions, where the niche is not already occupied. Yes! I was thinking that these species would be smaller and inhabit or the tropical areas of the Atlantic or in the South Pacific.

Биолог: JOrnitho Yes, why not!

JOrnitho: I finished the description of another species in the genus Thalassocratror that lives in North and Central Atlantic. Lesser nomad albatross (Thalassocrator minor) The human actions during the Holocene caused the decline of many species. However some species survived and in the Neocene they gave rise to new species. One of these new species is the lesser nomad albatross, a close relative of the nomad albatross. This species wanders the skies over the North and Central Atlantic, returning to land only to nest. The lesser nomad albatross is a large seabird, having 150 to 180 cm of length and a wingspan up to 400 cm. It makes it one the largest birds of the Neocene, being only behind the nomad albatross and the acatou. Their plumage is similar to that of their large cousin. Beyond the size, the main differences between the two species are the bright yellow beak with a dark gray tip and a yellow-stained nape and crown that are present in the lesser nomad albatross. Their feet and legs are red, with a partial web between the fingers. Like their relatives, they also have a long beak, with the bottom jaw having a "comb" which juts out downwards and the tip of the top jaw is hooked. This species travels vast distances and tends to feed further out in the open sea than other members of the Genus Thalassocrator. They will also forage in tropical areas, on rare occasions approaching the coast of South America and Africa. They feed on cephalopods, small fish, and crustaceans and on animal refuse that floats on the sea. They aren’t capable of diving, needing to catch food that is located on the surface. The lesser nomad albatross is a monogamous bird, living together for the rest of their lives. The pairs are formed at the sea, with an aerial courtship and vocalization of both the male and the female. The male will start to fly in circles, while vocalising to the female. If she is receptive, she will mimic him. After the pair is established, they will forage together. At breeding time they occupy loose colonies on isolated island groups. The nests are a large bowl built of grassy vegetation and soil peat. The female lays one large and white egg, which is incubated by both parents for 37 weeks. During the early stages of the chick's development, the parents take turns sitting on the nest while the other searches for food. During this period they can be very aggressive to any animal that approaches the nest. Later, both adults search for food and visit the chick at irregular intervals. The chicks fledge after 310 days. The adolescents return to the colony within six years; however they will not start breeding until 11 to 15 years. They have a lifespan of 76 years, but a good number of chicks will not survive until adulthood.

Биолог: JOrnitho Thalassocratror The letter shown in red seems unnecessary, if I got it right: the meaning is "one who rules the sea", from Greek "thalassos" for "sea" and "crator" for "one who rules", right? Good species!

JOrnitho: Биолог пишет: The letter shown in red seems unnecessary, if I got it right: the meaning is "one who rules the sea", from Greek "thalassos" for "sea" and "crator" for "one who rules", right? Ops, my bad! I'll correct it.

Биолог: JOrnitho It's OK, thanks.

JOrnitho: I made another description for Archipelago of Fernando de Noronha. This time is a dove. Pin-tailed dove (Zenaida apicauda) The human actions during the Holocene caused the decline of many species. However some species survived and in the Neocene they gave rise to new species. One of these new species is the pin-tailed dove, a descendant of the eared dove (Zenaida auriculata). This species inhabits the forests of the Archipelago of Fernando de Noronha, but small populations inhabits the coastal areas of the continent that are close to the Archipelago. The males of pin-tailed doves are larger than the females. They have 28 cm of length, while the females have 24 cm. Their size increases with the main characteristic of the species, a 15 cm elongated central feather on their wedge-shaped tail. They have a mainly chestnut upperpart plumage, with black spots on the wings. The head has a grey crown, black line behind the eye, and an iridescent path is found on the side of the neck. The underparts are dark brown, and the tail is tipped with cinnamon. Female and juvenile coloration is slightly duller, lacking the iridescence in their neck. The bill is black and the legs dark red. These birds feed mainly on seeds, but they can also eat insects and small fruits. They forage in the ground, forming small flocks of three to six individuals. The pin-tailed dove is monogamous, with the male and female forming pairs that last until one of them dies. When it happens, the surviving individual will seek a new partner. It builds a solid but sparsely lined cup-shaped stick nest in a tree and lays two white eggs. Incubation is 13 days with another 14 days to fledging. There is no fixed breeding and provided with plentiful food, birds breed almost continuously. Chick mortality through predation and falls from the nest is high. They reach sexual maturity with one year and have a lifespan of 13 years.

Биолог: JOrnitho Good dove!

JOrnitho: I made the description of other two birds for Fernando de Noronha. Insular racket-tailed tyrant (Tyrannoelegans insularis) The human actions during the Holocene caused the decline of many species. However the species that were resilient enough survived, with their descendants now living in the Neocene. The genus Tyrannoelegans is part of the Tyrannidae Family. These birds originated in the savannas of South America, but some species have adapted to different biomes. One of the members of this genus is the insular racket-tailed tyrant, an endemic species of the Archipelago of Fernando de Noronha. The insular racket-tailed tyrant has 18 cm of length and a wingspan of 38 cm. This species is sexually dimorphic, with the males having bright reddish-orange underparts, while the rest of the plumage is dark brown. Their head is black with a strong white supercilium and a concealed yellow crown stripe. The females are drab and have a peach-colored belly with a dark gray upperside. Their head is pale brown. The main characteristic of the genus are the conspicuous elongated outer feathers on its tail which have long streamers ending in paddle-shaped tips. Both sexes have this characteristic but the length is different. In the males it's 10 cm, while in females the length is 8 cm. These birds are mostly insectivorous, but will occasionally eat small berries. When hunting insects, they perch openly in trees, several meters above ground. From such perches they will sally out for considerable distances to catch insects in flight, to which purpose they utilize a range of aerobatic maneuvers. They also regularly hover and glean for prey. Such predatory behavior is shared with other members of the genus. The insular racket-tailed tyrant is a monogamous bird, with the pairs defending a territory against members of the same species. These birds are aggressive around predators, mobbing them and alerting nearby prey with their aggressiveness. This species breed during the spring and summer. Both sexes build a large domed nest that has a side entrance. It's chiefly composed of grasses and small twigs. The nest is placed in a wide range of sites, often in an exposed position high up in a tree, but occasionally the nest is placed in a cavity. The clutch is 3 to 4 eggs. These are moderately glossy, light yellowish cream in colour with purplish black and purplish brown spots. Only the female incubates the eggs; the male guards the nest while she leaves the nest to feed. The eggs hatch after 16–17 days. The chicks are fed by both parents and fledge after 17–18 days. They reach sexual maturity with 11 months and have a lifespan of 9 years. The insular racket-tailed tyrant closest relative is the scarlet racket-tailed tyrant (Tyrannoelegans rubroventer), a inhabitant of the Atlantic forests of Southeastern and Northeastern South America. They have 22 cm of length and 40 cm of wingspan. The males are similar to that of the insular species, with the exception of the vivid and bright red underparts that are present in the continental species. The plumage of the female of this species is also similar to that of the other. Another species of the genus is the Amazon racket-tailed tyrant (Tyrannoelegans amazonicus). This species inhabits the rainforests of the Amazon basin. They have 20 cm of length and 38 cm of wingspan. The males of this species have bright orange underparts. Noronha cardinal (Paroaria noronhensis) During the Holocene, the man introduced many species to other continents. The Archipelago of Fernando de Noronha received many exotic species, not only through the humans but also that arrived there by themselves. The red-cowled cardinal (Paroaria dominicana) was introduced in the Archipelago where they found good conditions to their survival. Due to that, they survived and gave origin to the Noronha cardinal in the Neocene. This species is endemic to the Archipelago, with most of the population being found in the largest island. The Noronha cardinal has 14 cm of length and 31 cm of wingspan. Both sexes have similar plumage, with a bright scarlet head and throat, with black ear-coverts that give the appearance of masks. They have a short crest that is raised by the birds when excited. Belly, breast and undertail are white, with a gray back, wings, and tail. Wing coverts are gray, but the primaries, secondaries, and rectrices show a darker gray. Juveniles are similar to the adults, but they show a dull brownish orange head and bib. The beak and legs are pale gray. This species feeds mainly on seeds, fruits, insects and other small arthropods. They generally search for food in the ground, forming pairs or small groups. The Noronha cardinal is a monogamous bird, with the pairs staying together while they are in flock. During the breeding season they live strictly in pairs, being extremely faithful to a territory, defended by the male. Each brood usually has between 2 and 3 eggs, with 2 to 4 broods per season. The chicks are born after 13 days and are fed by both parents. They fledge with 21 day and reaches sexual maturity at 10 months. The lifespan of the nomad cardinal is 4 years.

Биолог: JOrnitho Good ones!

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