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Monday, 27 November 2017

As we all know, nature is the storehouse of wonders, and numerous events are happening around us which are astonishingly implausible. Till now, modern science thought that evolution is a process which happens in a long course of time. However, newly, scientists discovered a new species of finches in Galapagos Island which evolved into a completely new species within a very short period of time. Researchers revealed that new species can develop in as little as two generations and the findings would have left Charles Darwin excited. The arrival of 36 years ago of a peculiar bird to a remote island in the Galapagos provides direct genetic evidence of their claims.

The newcomer, who belonged to one species, mated with a member of another species on the small island of Daphne Major in the Pacific Ocean. Therefore this produced a new species, recognized as the “Big Birds” that now involves of approximately 30 birds, according to researchers from Princeton University and Uppsala University in Finland. The researchers took a blood sample and released the bird, which later bred with a resident medium ground finch of the species Geospiz fortis, starting a new lineage. The Grants and their research team followed the new “Big Bird lineage” for six generations, taking blood samples for use in genetic analysis.

The new study, published in the journal Science, followed work carried out over the last four decades on Darwin’s finches in the Galapagos Islands. Through our work on Daphne Major, we were able to observe the pairing up of two birds from different species and then follow what happened to see how speciation occurred, Rosemary Grant, senior biologist at Princeton in the US, said:  The newcomer, a male with an rare song which was larger in size than the three resident species on the island, was spotted in 1981. He was so different from the other birds that we knew he did not hatch from an egg on Daphne Major.” It is very remarkable that when we match the size and shape of the Big Bird beaks with the beak morphologies of the other three species inhabiting Daphne Major, the Big Birds occupy their own niche in the beak morphology space.

The current study, DNA collected from the parent birds and their offspring over the years. They learned that the original male parent was a large cactus finch of the species Geospiza conirostris from Española Island, more than 100km away. The distance meant the male finch could not return home to mate with a member of his own species, so chose a mate from among the three species on Daphne Major. Thus, this reproductive isolation is considered a critical step in the development of a new species when two separate species interbreed. It is believed that the amount of time these birds spent on birdfeeders has resulted in this evolution and its infrequent growth from the 1970s and is still continuing today.

The offspring were also reproductively isolated as their song, used to attract mates, was unusual and failed to attract females from the resident species. They also differed from the resident species in beak size and shape, which is a major cue for mate choice. This led the offspring to mate with members of their own lineage, strengthening the development of the new species. Researchers previously thought the formation of a new species takes a very long time. But in the Big Bird lineage, it happened in just two generations, according to observations made in the field, along with the genetic studies. The researchers say a striking aspect is that after just two generations, the new lineage behaved as any other species of Darwin’s finches would. Leif Andersson, a professor at Uppsala University in Sweden, said: “A naturalist who came to Daphne Major without knowing that this lineage arose very recently would have recognised this lineage as one of the four species on the island.

This clearly demonstrates the value of long-running field studies. We’ve no indication about the long-term survival of the Big Bird lineage, but it has the huge potential to become a success, and it offers a stunning example of one way in which speciation occurs. The scientists said it is probable that new lineages like the Big Birds have originated numerous times during the evolution of Darwin’s finches. The majority of these lineages have gone extinct but some may have led to the evolution of contemporary species, they concluded.Source: Charismatic Planet

Wednesday, 22 November 2017

An eye-catching parrot “The dusky lory” (Pseudeos fuscata) is a species of parrot in the family Psittaculidae. Alternative common names are the white-rumped lory or the dusky-orange lory. This beautiful parrot is short tailed just 25cm long, and has mainly brown and whitish back and rumps. Mostly it is found in New Guinea and the offshore islands of Batanta, Yapen and Salawati. The dusky lory's native range includes New Guinea below about 2500m in both the Indonesian zones of the island. It is also native to the nearby Indonesian islands of Salawati and Yapen.
The Dusky Lory has two color phases; the band across the upper chest together with its abdomen is either yellow or orange. However, the beak is dark orange, and an area of bare orange skin at the base of its lower mandible. The irises are red and the legs are grey. As far as external appearance the both male and females are identical. Though, the juveniles are duller with a yellowish back and rump, yellowish-grey irises, and a beak that is yellow at the base and brown/black towards the tip. The Dusky Lory natural habitats are subtropical or tropical moist lowland forests, subtropical or tropical mangrove forests, and subtropical or tropical moist montane forests. Dusky Lory calls heard as harsh and grating screeches. They reach reproductive maturity when they are about 2 to 2.5 years old. Lories are typically quite easily bred; so many Lory species are readily available. The average clutch consists of 2 - 3 eggs, which are incubated for 24 - 25 days. The young fledge when they are about 10 weeks old.
The parrot wild Diet consists of flowers, fruits, seeds, nuts and insects. Lories require a higher percentage of fruit, buds, nectar and pollen in their diet. In fact, in the wild, they can feed on as many as 640 flowers in a one day. They also feed on seeds and unripe grain. Their ecology and behavior is very social, forming large, boisterous flocks. He mainly relies on availability of flowering trees for food and is therefore nomadic, and roosts communally in large groups. However, this stunning species is considered endangered within their natural range, typically due to habitat destruction; there is a high demand for these birds as pets or aviary birds, and they have been doing well in captivity and are, therefore, regionally readily available on the pet market. Maybe the most playful of the lories, excellent pets and great talkers. The only drawback is their terrible, high pitched screeching! They would never work in an apartment. It can live 28 to 32 years, and one of the major contributors of ill health and early death in pet birds is the fact that their specific dietary needs are neglected.

Tuesday, 8 August 2017

The whiskered treeswift (Hemiprocne comata) is a species of bird in the family Hemiprocnidae. It is found in Brunei, Malaysia, Singapore, Indonesia, Myanmar, Philippines, and Thailand. The adult male has dark bronze-brown body with white belly, flanks and undertail-coverts, long wings and deep blue forked tail, and tertial flight feathers are white. In addition the underwing shows blue coverts and white tertial flight feathers. The head is blue to glossy black, and slightly crested. Moreover two conspicuous white parallel stripes formed by bold supercilium from forehead to hind nape, and a second stripe from chin back to neck side. Therefore, female bird is much like same but she has deep blue-green ear-coverts. Thus, juvenile has finely barred brown, grey and white plumage. The Whiskered Treeswift feeds mainly on insects and small flying arthropods. 

These species natural habitats are subtropical or tropical moist lowland forests, subtropical or tropical mangrove forests, and subtropical or tropical moist montane forests. The Whiskered Treeswift is a forest-living bird which frequents small cover breaks such as tracks or streams. The bird follows the vegetation up around the highest emergent crowns in evergreen forest and locally in tall mangroves. This species occurs from plains up to 1000 to 1100 metres on slopes, but it is often seen below 800 metres in N Malay Peninsula. The whiskered treeswift has a very large range, and hence does not reach the thresholds for Vulnerable under the range size criterion, with a declining or fluctuating range size, habitat extent, quality, or population size and a small number of locations or severe fragmentation. In spite of the fact that the population trend appears to be declining, the decline is not believed to be adequately rapid to approach the thresholds for Vulnerable under the population trend criterion. The Whiskered Treeswift is quieter than the largest species of this family. Hence, the contact call between pair-members includes high-pitched “chew” or “kweeo”, and series of short notes “kwee kwee, kwi-kwi-kwi-kwi” or “she-she-she-SHEW-she”. The bird calls are uttered while the birds are flying or perched.

The Whiskered Treeswift feeds mainly on insects, hunts from perches where it sits in upright posture, and from where it can have a good all-round vision of the surroundings. The bird is very nimble in flight; it chases insects and small flying arthropods, even amongst the foliage but well below the canopy. The preys are habitually taken on the wing, but it also picks off the food items when perched, or by hanging from the tip of a small branch. Thus, it may perform short sallies from its perch, close to the surface of the vegetation.

The courtship displays are poorly identified, but noisy soaring has been observed at least for the largest species. The breeding season occurs between February and August. The breeding pair is territorial during the breeding season, remains in its nesting territory all year round. The Whiskered Treeswift is very alert and manoeuvrable in flight. The narrow, curved wings and the long tail streamers are very typical of fast fliers.

The species nest is naturally situated between 8 and 40 metres above the ground, on the upper surface of thin branch, and looks like a part of this branch. Both male and female build the nest, small half-saucer. The rim is made with saliva into which feathers are embedded, and few twigs too. So, supplies can be added during the incubation. The bird usually builds very small nest, shallow structure letting only a single egg, standing right as in an egg-cup. The thin papery walls are unable to support an adult or a large chick. That causes incubating adult squats on the branch in its place on the nest itself.
Only the belly touches the egg. The female lays a single white egg, and both adults incubate and rear the chick. The incubation lasts about three weeks, but the chick leaves the nest very soon, within one week after hatching. The chick is fed by regurgitation from adult’s throat into the open mouth, but later, the young takes the food from the parent’s mouth. The juvenile plumage is cryptic for better camouflage, required most likely 50 days for complete development.

Friday, 4 August 2017

The colorful orange-breasted bunting “Passerina leclancherii” is a species of bunting belongs to family Cardinalidae. The orange breasted bunting endemic to Mexico, where its natural habitats are subtropical or tropical dry forests and subtropical or tropical dry shrubland. The Orange-breasted Bunting ranges along the Pacific slope from extreme southern Nayarit south to western Chiapas, and inland to western Puebla. It is more abundant in second growth than in undisturbed forest. It is found from sea level up to about 1200 m in arid habitats, including thorn forest, open woodland, and the edges of roadsides and agricultural clearings.

The species was introduced to Oahu in 1941 but did not persist, and was extirpated by 1952. This species has a very large range, and hence does not approach the thresholds for Vulnerable under the range size criterion. The bird’s population trend appears to be stable, and hence the species is evaluated as Least Concern. This species has a sweet, lilting song that you might enjoy. Not surprisingly, they are popular in the cage bird trade is a bit smaller length 12.5 cm and shorter-billed than Rose-bellied Bunting (Passerina rositae), with which it may occur, and both sexes of Orange-breasted are yellow below.

Orange-breasted bunting is also known as the orange-bellied bunting or as Leclancher's bunting, seemingly glow-in-the-dark passerine resides in dry forests and shrubland in the tropics and subtropics. The adult birds are blue above with a mossy green crown and mantle, and are yellow below with an orange wash across the breast. Hence, Females birds are immatures and entirely green above, with yellow lores, throat, and underparts are yellow, shaded with gray along the sides and chest. The birds feed on seeds in the winter and insects in the summer, and have correspondingly smaller bills than most cardinalids. The cardinalids are also known for being dimorphic, and the males often have dramatic, brilliant coloring although the females are very beautiful as well. This is migratory bird, breeding in North America and wintering in Central and South America.

Tuesday, 1 August 2017

The green-and-black fruiteater is also called “Pipreola riefferii” is a species of bird in the family Cotingidae. Cotingas have broad bills with hooked tips, rounded wings, and strong legs. The green & black fruiteater can found in Colombia, Ecuador, Peru, and Venezuela. The bird species is native to the lower and mid-level mountain forests on the eastern side of the Andes in South America. Its range extends from southern Venezuela to northern Peru and its altitudinal range is between 1,500 and 2,700 m above sea level. This species is more often seen in small flocks than some other fruiteater. As suggested by this species' name, these birds mostly eat fruit or insects. They usually construct cup shape nests, while males will mate with several females. Hence, the females alone care for the eggs and young one.

The green-and-black fruiteater is a plump, stocky bird with a length of about 18 cm only. The adult male bird has a black head, throat and chest glossed with green and mid-green upper parts, with pale tips to the tertial feathers of the wings. There is a yellow rim to the dark chest and the underparts are otherwise yellowish, usually mottled or streaked with green. However, female bird is alike to the male apart from the replacement of the black areas by green, and the absence of the yellow necklace. In both sexes, the iris of the eye is reddish-brown, and the legs and bill are orangish-red. The bird song is a high-pitched "ts-s-s-s-s-s-s" lasting only few seconds, slowing and sometimes fading as it winds down. However, somewhat rare the Green-and-black Fruiteater has a very wide range. The bird range and population size this species is not classified as vulnerable. The bird population size has not been quantified but seems stable and the International Union for Conservation of Nature has assessed the conservation status of the bird as being of "least concern".