Friday, 29 June 2018
Thursday, 28 June 2018
25-3-2018 TABLE MOUNTAIN AVIARY, CAPE TOWN - SOUTHERN GROUND HORNBILL (Bucorvus leadbeateri)
The Southern Ground Hornbill (Bucorvus leadbeateri), formerly known as Bucorvus cafer, is a remarkable bird, the largest in the hornbill order and found exclusively within Africa. This majestic creature, with a length ranging from 90 to 129 cm and a wingspan of 1.2 to 1.8 meters, is a sight to behold. The males, larger than the females, can weigh between 3.5 to 6.2 kilograms, while females range from 2.2 to 4.6 kilograms. They are predominantly black with striking red patches of bare skin on the face and throat, which serve to keep dust from their eyes while foraging. In flight, the white tips of their wings are distinctly visible. The beak is robust, black, and slightly curved, with a casque more pronounced in males. Females are identified by their violet-blue throat skin, while juveniles have a paler, greyish patch instead of the vibrant red.
To identify the Southern Ground Hornbill, look for its large size, black plumage, and the vivid red or violet-blue skin on the throat. The male's throat is a pure red, while the female's is deep violet-blue. Juveniles can be recognized by their duller grey throat patch. In flight, the white primary feathers are a key distinguishing feature.
The Southern Ground Hornbill is found in woodlands and savannas, requiring a habitat with large trees for nesting and short grass for foraging.
This species ranges from Kenya to South Africa, with its presence also noted in northern Namibia and Angola to southern Zimbabwe and Burundi.
Living in groups of 5 to 10, these birds are apex predators and play a crucial ecological role. They forage on the ground, hunting a variety of prey from insects to small mammals. They are known for their loud, chorus-like calls that can be heard over great distances, serving as a means of maintaining their territory.
The Southern Ground Hornbill's calls are a distinctive aspect of their behavior, used for communication and territorial purposes. These calls can be heard up to 3 kilometers away.
Breeding pairs are assisted by at least two other birds, and experience as helpers is essential for successful rearing of young. They reach sexual maturity around 4-6 years of age and start breeding at about 10 years. Nesting typically occurs in high tree cavities or cliff face rock holes. They lay one to three eggs, but only one chick is usually reared to fledging.
The Abyssinian Ground Hornbill (B. abyssinicus) is similar but can be distinguished by its size and range.
Southern Ground Hornbills are carnivorous, feeding on reptiles, frogs, snails, insects, and mammals up to the size of hares. They forage on the ground and rarely drink water.
The IUCN lists the Southern Ground Hornbill as Vulnerable globally, with an Endangered status in South Africa, Lesotho, Namibia, and Eswatini. Their numbers are declining due to habitat destruction, persecution, and other factors. Conservation efforts include habitat preservation and captive breeding programs.
16-4-2021 MANDINA LODGE, GAMBIA - VIOLET TURACO (Musophaga violacea)
The violet turaco, also known as the violaceous plantain eater (Musophaga violacea), is a large turaco, a group of African otidimorphae.
These are unmistakable birds, but shy and often inconspicuous in the treetops. They are approximately 48 cm (19 in) long, including a long tail and a 4 cm (1.6 in) bill. They boast a winglength of 21 cm (8.3 in) and weigh approximately 360 g. The plumage is glossy violet, except for the yellow forehead, chestnut crown and white ear coverts; the bill is thick and red. In flight, the violet turaco's crimson primary flight feathers contrast with the violet plumage. The red colour in the wings is typical of turacos.
28-6-2018 CAMI LES FONTS OLIVA, VALENCIA - SPOTTED FLYCATCHER (Muscicapa striata)
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The spotted flycatcher (Muscicapa striata ) is a small passerine bird in the Old World flycatcher family. It breeds in most of Europe and in the Palearctic to Siberia, and is migratory, wintering in Africa and south western Asia. It is declining in parts of its range.
This is an undistinguished looking bird with long wings and tail. The adults have grey-brown upperparts and whitish underparts, with a streaked crown and breast, giving rise to the bird's common name. The legs are short and black, and the bill is black and has the broad but pointed shape typical of aerial insectivores. Juveniles are browner than adults and have spots on the upperparts.
The spotted flycatcher (Muscicapa striata ) is a small passerine bird in the Old World flycatcher family. It breeds in most of Europe and in the Palearctic to Siberia, and is migratory, wintering in Africa and south western Asia. It is declining in parts of its range.
This is an undistinguished looking bird with long wings and tail. The adults have grey-brown upperparts and whitish underparts, with a streaked crown and breast, giving rise to the bird's common name. The legs are short and black, and the bill is black and has the broad but pointed shape typical of aerial insectivores. Juveniles are browner than adults and have spots on the upperparts.
25-3-2018 TABLE MOUNTAIN AVIARY, CAPE TOWN - AFRICAN GREY PARROT (Psittacus erithacus)
The grey parrot is native to equatorial Africa, including Angola, Cameroon, the Congo, Gabon, Ivory Coast, Ghana, Kenya, and Uganda. The species is found inside a range from Kenya to the eastern part of the Ivory Coast. Current estimates for the global population are uncertain and range from 630,000 to 13 million birds. Populations are decreasing worldwide. The species seems to favor dense forests, but can also be found at forest edges and in more open vegetation types, such as gallery and savanna forests.
A population study published in 2015 found that the species had been "virtually eliminated" from Ghana with numbers declining 90 to 99% since 1992. They were found in only 10 of 42 forested areas, and three roosts that once held 700–1200 birds each, now had only 18 in total. Local people mainly blamed the pet trade and the felling of timber for the decline. Populations are thought to be stable in Cameroon. In the Congo, an estimated 15,000 are taken every year for the pet trade, from the eastern part of the country, although the annual quota is stated to be 5,000.
Wednesday, 27 June 2018
25-3-2018 TABLE MOUNTAIN AVIARY, CAPE TOWN - SCARLET IBIS (Eudocimus ruber)
The Scarlet Ibis (Eudocimus ruber), sometimes referred to as the red ibis, is a strikingly colored member of the ibis family, Threskiornithidae. Its brilliant scarlet plumage sets it apart from other species, making it an unmistakable sight in its native habitats. This bird is one of the two national birds of Trinidad and Tobago and is celebrated in the region's culture and folklore.
Adult Scarlet Ibises are predominantly scarlet, with the intensity of color varying slightly across their feathers. The tips of their wings are the only exception, displaying a rich inky black or dark blue on the longest primaries. The bill and feet are generally red, though the bill may darken towards the end. Juveniles start out grey, brown, and white, gradually acquiring the adult's scarlet hue as they mature. Adults measure 55–63 centimeters in length, with a wingspan of approximately 54 centimeters.
Scarlet Ibises favor wetlands and marshy environments, including mudflats, shorelines, and rainforests. They are often found in areas with abundant water sources, such as swamps, where they can forage for food.
This species has a broad range across South America and the Caribbean. It is native to Brazil, Colombia, French Guiana, Guyana, Suriname, Venezuela, and several Caribbean islands. The Scarlet Ibis is also known to inhabit the coastal regions of various Brazilian states.
Scarlet Ibises are strong fliers, migrating in flocks that adopt the classic V formation. They are sociable birds, living in groups and nesting in close proximity to one another. These birds are also known for their aggressive behavior when foraging, often dominating over other species to secure food.
The Scarlet Ibis is relatively quiet, with its vocalizations typically consisting of low-pitched honking sounds.
Mating pairs construct simple stick nests in trees, often above water for protection. They lay clutches of three to five eggs, which incubate for about 19–23 days. Both parents share in the care of the young.
The American White Ibis (Eudocimus albus) is the closest relative and is sometimes considered conspecific. However, the Scarlet Ibis is distinguished by its vibrant red coloration.
The diet of the Scarlet Ibis is varied, including insects, crustaceans, and other small prey. They use their long, curved bills to probe for food in mud and under plants. Their red coloration is due to a diet rich in red crustaceans, which contain the carotenoid astaxanthin.
The Scarlet Ibis is classified as Least Concern by the IUCN. While some local populations are declining, the species as a whole is not currently considered threatened.
The Scarlet Ibis holds significant cultural importance in Trinidad and Tobago, where it is a national bird and features on the country's coat of arms. It is also a focal species for conservation efforts in the region, particularly within the Caroni Swamp wildlife sanctuary.
27-6-2018 POTRIES, VALENCIA - EPAULET SKIMMER DRAGONFLY (FEMALE) (Orthetrum chrysostigma)
Orthetrum chrysostigma, the epaulet skimmer, is a species of dragonfly in the family Libellulidae. It is found in Algeria, Angola, Benin, Botswana, Burkina Faso, Cameroon, Central African Republic, Chad, the Democratic Republic of the Congo, Ivory Coast, Egypt, Equatorial Guinea, Ethiopia, Gambia, Ghana, Guinea, Kenya, Liberia, Libya, Malawi, Mali, Mauritania, Morocco, Mozambique, Namibia, Niger, Nigeria, Senegal, Sierra Leone, Somalia, South Africa, Sudan, Tanzania, Togo, Uganda, Zambia, Zimbabwe, and possibly Burundi as well as Canary Islands, Israel, and Portugal. It was recorded in the Maltese Islands in 2010. One was also spotted in Tel Aviv, Israel in August 2022.
Its natural habitats are subtropical or tropical moist lowland forests, dry savanna, moist savanna, subtropical or tropical dry shrubland, subtropical or tropical moist shrubland, rivers, intermittent rivers, shrub-dominated wetlands, swamps, freshwater lakes, intermittent freshwater lakes, freshwater marshes, intermittent freshwater marshes, and freshwater springs. The adults prey on various flying insects. The bodies of adult males are blue, and those of young and females are yellow and brown.
Very widespread and occurs virtually throughout Africa, including North Africa. It also occurs in parts of Southern Europe and the Middle East. In South Africa it occurs virtually throughout, but is scarce in the dry central regions.
The Epaulet Skimmer is a southern European and African dragonfly. A little similar to the Keeled Skimmer of the UK, it has a narrow elongated body with central raised "keel". Above is the attractive pale blue male with turquoise eyes, but the "epaulet" marking on the thorax that gives it its name is not often clear and darkens with age.
18-4-2018 OKAVANGO DELTA, BOTSWANA - YELLOW BILLED DUCK (Anas undulata)
The yellow-billed duck (Anas undulata) is a 51–58 cm long dabbling duck which is an abundant resident breeder in southern and eastern Africa. This duck is not migratory, but wanders in the dry season to find suitable waters. It is highly gregarious outside the breeding season and forms large flocks.
These are mallard-sized mainly grey ducks with a darker head and bright yellow bill. The wings are whitish below, and from above show a white-bordered green speculum. Sexes are similar, and juveniles are slightly duller than adults. The north-eastern race is darker and has a brighter bill and blue speculum.
It is a bird of freshwater habitats in fairly open country and feeds by dabbling for plant food mainly in the evening or at night. It nests on the ground in dense vegetation near water. Rarely, it is found in suburban areas, in close proximity to golf courses, parks and lakes or dams. The clutch numbers between six and twelve eggs.
The male has a teal-like whistle, whereas the female has a mallard-like quack.
There are two subspecies of the yellow-billed duck: A. undulata rueppelli (northern yellow-billed duck) and A. undulata undulata (southern yellow-billed duck). The yellow-billed duck is one of the species to which the Agreement on the Conservation of African-Eurasian Migratory Waterbirds (AEWA) applies. The southern nominate subspecies is declining due to competition and hybridization with feral mallards (Rhymer 2006)
Male and female yellow-billed ducks have a statistically significant difference in life spans. Male ducks live for 4 years and 4 months on average while female ducks only live for just over 3 years. As such the difference in survival rate is statistically significant as well. 79% of males survive any given year while only 72% of females do. While the juvenile survival rate is highly variable year to year, on average 67% of juveniles survive. Highest mortality for the yellow-billed duck occurs in the summer months with December typically having the highest death rate out of any month of the year closely followed by January.
The male yellow-billed duck performs multiple displays of courtship, similar to many other African ducks. The number of courtship displays the yellow-billed ducks perform is greater than many other African ducks. Ornithologists have noted seven major displays of courtship similar African ducks perform; most species do not perform all seven, however, the yellow-billed duck will engage in all seven forms of courtship. The lack of sexual dichotomy and generally bland plumage may be the driving factor for the elaborate displays of courtship.
In the mid-20th century, mallards were introduced to Africa and as the invasive population size has grown, concerns over possible hybridization with the yellow-billed duck have occurred. This fear is fueled by other examples of invasive mallards causing localized extinction of other native ducks around the world because of hybridization.
The fear of possible hybridization between mallards and yellow-billed ducks has been exacerbated by casual observations that suggest possible hybridization of the yellow-billed duck with other native ducks is occurring, however, no genetic tests have been done to shine additional light on these morphological observations to confirm if these individuals are truly hybrids.
Even when genetics have been used, it is still difficult to understand if hybridization is occurring. If hybridization between mallards and yellow-billed ducks is occurring is still debated. Two recent (2019 and 2020) DNA sequencing studies reached opposite conclusions on if hybridization between mallards and yellow-billed ducks is happening. Nevertheless, scientists agree that changes to the gene pool of yellow-billed ducks from possible hybridization, even in the long term, is likely to be negligible. This is because even if mallard and yellow-billed duck hybridization is occurring, introgression is mainly occurring to the mallards’ gene pool, keeping the yellow-billed ducks genetics fairly intact.
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