The brown fish owl (Ketupa zeylonensis) is a species of owl that is part of the family known as typical owls, Strigidae, which contains most living owls. It inhabits the warm subtropical and humid tropical parts of continental Asia and some offshore islands. Of the four living species of fish owl, it is the most widely distributed, most common and best-studied. It occupies a range of over 4,300 miles from eastern China to Palestine.
This species is a large owl, ranging from 19 to 24 inches in length and in wingspan from 49 to 55 inches. Weight can vary considerably, reportedly ranging from 1.1 to 2.5 kg (2.4 to 5.5 lb). Some of the variability is attributed to the range of sizes across the subspecies and the difference in size between females and males.
It has prominent ear tufts but as in all fish owls, their tufts hang to the side of the head and have a scraggly look. The upperparts are rufous brown and heavily streaked with black or dark brown. The underparts are buffy-fulvous to whitish, with wavy dark brown streaks and finer brown barring. The throat is white and can be conspicuously puffed, while the facial disk is indistinct. The irides are golden yellow, the feet a duller yellow, and the bill is dark. Sexes do not differ in appearance except for size.
Fish owls will not submerge any part of their body while hunting, preferring only to put their feet into the water, although they will hunt on foot, wading into the shallows. Unlike most owls, the feathers of fish owls are not soft to the touch and they lack the comb and hair-like fringes to the primaries, which allow other owls to fly silently in order to ambush their prey. Due to the lack of these feather-specializations, fish owl wing beats make sounds. The brown fish owl in particular is said to have a noisy wing beat. The lack of a deep facial disc in fish owls is another indication of the unimportance of sound relative to vision in these owls, as facial disc depth (as well as inner ear size) are directly related to how important sound is to an owl's hunting behavior. Also different from most any other kind of owl, the bill is placed on the face between the eyes rather below it.
Its calls are described as a deep, trisyllabic tu-hoo-hoo, which is seemingly the territorial song emitted before breeding. Other calls recorded for the brown fish owl have included a soft, "almost human-like" huphuphuphuphuphup or a loud huhuhuhuhuhuhu. Another call is a boom-uh-boom.
Brown fish owl primarily hunt by stationing itself on a rock overhang or hanging perch over water, or by wading into shallow waters. It grabs food by gliding over the water, nearly skimming it with its feet and grabbing its prey by quickly extending its long legs. It feeds mainly on fishes, frogs and aquatic crustaceans, especially Potamon crabs. If hungry, brown fish owls will scavenge carrion, a rare behavior for owls. A case where a putrefying crocodile carcass was consumed by this species was observed.
The brown fish owl is not considered a threatened species by the IUCN. It is fairly common in many parts of India. However, being a large predatory bird, it is only rarely found at a high population density, an exception being Sri Lanka, where this particular owl's adaptability to human habitat change has been beneficial in continued high numbers. Habitat destruction will eventually cause the species to desert a region. Due to this, it seems to be extinct as a breeding bird in Israel nowadays, attributable largely to damming practices leading to drying up of many waterways. In Israel, it was decimated by the use of the rodenticide Thallium(I) sulfate, which in addition to potential direct exposure through rodents also poisons surface waters.
The Yungas screech owl Megascops hoyi, also known as Hoy's screech owl and montane forest screech-owl, is a species of owl in the family Strigidae. It is found in Argentina and Bolivia. Its natural habitat is subtropical or tropical moist montane forests.
The Yungas Screech-Owl is found over a relatively small range in the mountains of southern Bolivia to northwest Argentina, usually at elevations between 1000 and 2800 m, and is sometimes thought to be a subspecies of the Black-capped Screech-Owl.
This screech-owl is predicted to make altitudinal movements, descending to lower elevations in the austral winter, and the species seems to be reasonably numerous, at least locally. Most of its range is reasonably remote and therefore to some extent protected.
The Yungas pygmy owl (Glaucidium bolivianum), is a species of owl in the family Strigidae. It is found in Bolivia, Peru, and possibly in Argentina. Its natural habitat is subtropical or tropical moist montane forest.
The Yungas Pygmy-Owl is very similar to the Andean Pygmy-Owl (Glaucidium jardinii), indeed until very recently it was not recognized as a distinct species. The primary difference between the two species is in the pace of the song: typically three-four notes per second in Andean, but a more languid one-two notes per second in Yungas.
As is the case with Andean, the Yungas Pygmy-Owl occurs in several color morphs. A brown and a red or rufous color morph are common and widespread, but a gray morph apparently is restricted to southern Bolivia and northern Argentina.
The Yungas Pygmy-Owl is uncommon to fairly common in humid montane forest of the Andes along the east slope of the Andes, where it occurs at higher elevations than any other species of Glaucidium. As is typical of Glaucidium, this species is partially diurnal, although it may be more nocturnal in the southern part of its range.
The Yungas Pygmy-Owl hunts for invertebrates and small vertebrates from perches in the canopy, and frequently is mobbed by the small passerines that it hunts.
Xenoglaux loweryi, the long-whiskered owlet, is a tiny owl that is endemic to a small area in the Andean mountains in Amazonas and San Martín in northern Peru. It is restricted to cloud forests with dense undergrowth and epiphytes at about 6,200–7,220 ft above sea level. The name of its monotypic genus Xenoglaux means "strange owl" and—among others—refers to these long facial feathers.
The long-whiskered owlet is mainly brown with a whitish belly and eyebrow. The large eyes are orange-brown. Although it has no ear tufts, this small owl's facial feathers extend out past its head, making it appear to have long tufts. With a total length of 5.1–5.5 inches and a weight of about 47.5 g, it is among the smallest owls in the world. It probably feeds on insects.
Very little is known about this species. It has been captured in 1976 in mist nets on three separate occasions in San Martín. It had never been observed under normal circumstances until early 2007 when rangers and researchers working in the Area de Conservación Privada de Abra Patricia-Alto Nieva encountered it three times during daylight hours and recorded its calls during the night. In addition to later records from the same general area, the long-whiskered owlet has been observed several times at La Esperanza in the Amazonas Department, where first discovered in January 2010.
Due to its rarity, restricted habitat, and ongoing deforestation within its tiny range, it is currently considered endangered by BirdLife International. It is estimated that the total population is between 250 and 1000 individuals. The recently established Area de Conservación Privada Abra Patricia-Alto Nieva and the Area de Conservación Privada Copallín (ACP-Copallín) protect important sites for the owlet and other species restricted to this region. In La Esperanza, the creation of a community run conservation area, supported by community based tourism is intended to ensure the survival of this and other endemic species.
The white-throated screech owl (Megascops albogularis) is a widely distributed and rather distinctively plumaged bird of the Andes, where it is found from northern Colombia south to central Bolivia. It is the largest species of the genus Megascops, at 10 inches and 185 grams (6.5 oz).
The obvious white throat patch, from which the species derives its name, make this screech-owl easily identifiable; it is also comparatively large-headed, long-tailed, and generally dark-plumaged, except for the posterior underparts. The ear-tufts are usually practically invisible.
Males produce a somewhat gruff-sounding series of barking notes that may be uttered for as long as one minute, but also give evenly spaced hoots that gradually fall in pitch, which the higher-pitched female may respond to in duet.
It is generally uncommon, but is locally fairly common. The ICUN considers the population to be stable and lists the white-throated screech owl as a species of “least concern.”
The white-fronted scops owl (Otus sagittatus) is a small Asian owl in the family Strigidae. The White-fronted Scops Owl feeds on insects, mostly moths. It has a small and declining population about which little is known, and is dependent on lowland and foothill forests which are rapidly being destroyed.
The White-fronted Scops Owl is relatively large for a scops owl, and has a relatively long tail and rounded wings. Average length is 9.8 to 11 inches and weight ranges from 109-130g. It has a prominent white forehead which extends into the large ear-tufts.
The facial disc is pale rufous, with a broad ring of deep rufous-chestnut feathers around the eyes, and bordered by black-tipped feathers. The forehead and superciliary stripe extend to the ear-tufts, and are white with a pinkish tinge, obscurely vermiculated with fuscous. Eyes are deep brown to dark honey-brown with pink eyelids. The bill is bluish-white, and cere pale-bluish-green. The bristles around the base of the bill are whitish with black tips. A patch of close-set, pinkish-white, black-tipped feathers form a partial ruff extending from the chin to above the gape line.
Upperparts are rufous-chestnut, with the mantle and back having small, triangular, buffish-white spots with a black lower margin. The inner scapulars have similar but larger spots, and the outer scapulars are yellowish-white to rufous on the outer webs, with 3-4 moderately sized black spots on the shafts. The wings are rounded, with the ground colour similar to the back, with some darker and paler brown bars. The tail is chestnut-rufous with about ten transverse blackish bars that are more distinct on the outer feathers and towards the base.
Underparts are pale rufous, finely vermiculated with brown on the breast and throat, and each feather having a pale or whitish centre broken by a roundish black shaft-spot, the largest being on the centre of the belly.
Tarsi are feathered rufous. Toes are flesh-pink and claws bluish-white.
The white-fronted scops owl has two camouflage modes. The first is that it can puff up its feathers to triple its body size. The second is that it can stretch its body upwards and turn its head at an angle in the direction of a predator from which it is hiding, reducing its profile and hence visibility.
Verreaux's eagle-owl, also commonly known as the milky eagle owl or giant eagle owl, (Bubo lacteus) is a member of the family Strigidae. This eagle-owl is a resident primarily of dry, wooded savanna and is widespread in sub-Saharan Africa. A member of the genus Bubo, it is the largest African owl, measuring up to 26 inches in total length. Verreaux's eagle-owl is mainly grey in color and is at once distinguished from other large owls by its bright pink eyelids, a feature shared with no other owl species in the world.
Despite the alternate common name of giant eagle-owl, the Verreaux's eagle-owl is not the largest owl or eagle-owl in the world. It is, however, a very large and powerful owl species. This species is both the largest owl found in Africa and the world's largest owl to occur in the tropics. Among all the world's owls, it is fourth heaviest living owl and is also the fourth longest living owl (measured from the bill to the tip of the tail).
Verreaux's eagle-owl ranges from 23 to 26 inches in total length. This species has been reported as having an average wingspan of 4 ft 7 in, but Mikkola referenced this as the wingspan of a smaller male. The largest known wingspan from a wild female measured nearly 164 cm (5 ft 5 in). While female owls are almost always larger than males, Verreaux's eagle-owl stands out as one of the most sexually dimorphic living owl species, some studies showing the female can average 35% heavier than the male. The full range of reported body mass in the species ranges from 1,615 to 2,000 g in males against a body mass of 2,475–3,150 g in females.
Overall, Verreaux's eagle-owl are a fairly uniform and somewhat pale gray, with light and fine brownish vermiculations on the underside. The back is more solidly light brown with white spots on the shoulder. The oval facial disc is paler, sometimes ranging into a whitish color, than the rest of the front side of the bird with strong black borders bracketing either side. One other feature that immediately distinguished adult Verreaux's eagle-owls in good light are its pink eyelids. The ecological purpose of their colorful eyelids are not known, however Brown (1965) opined that they replace the colorful yellow to orange eyes of eagle-owls in breeding and territorial displays, since they were very conspicuous in displaying males. Their eyes are dark-brown in color and like all eagle-owls, they have ear-tufts.
The male's song is an exceptionally deep gwok, gwok, gwonk-gwokwokwok gwokwokwok gwonk. The depth and quality of the song makes confusion by sound more likely with a leopard than any other bird. The female's call is similar but higher pitched, as in all owls to some extent because the larger female tends to have a smaller syrinx. Like most Bubo owls, breeding pairs not infrequently call together. The alarm calls of both sexes are often a sonorous whok or hook but variable grunting notes and raspy screams also seem to indicate alarm. Both the female and the young engage in high, piercing calls when begging for food at the nest.
Verreaux's eagle-owls are nocturnal birds and roost by day in trees, with large, shaded horizontal branches of tall, old trees being preferred. Despite normally choosing dense foliage to rest in, sometimes they may sit wherever their hunting path ends from the prior night, including relatively exposed perches. During extremely hot days, this species may flutter its throat for cooling purposes and has been known to bathe in rain and shallow water during extreme heat in the middle of the afternoon but usually drinks when possible during nighttime. Each breeding pair of Verreaux's eagle-owl defends a territory and these may be extremely large, ranging in size up to 7,000 ha.
Verreaux's eagle-owl is considered an avian apex predator. In many known aspects of its hunting behavior, it is typical of the members of the genus Bubo. This species hunt predominantly in early evening, however they have been observed to swoop on prey during daylight. The wing size of eagle-owls in general limits their flying speed and abilities in the open and so they require perches to execute most of their hunting behavior.
Even among the Bubo owls, most species of which are known to be highly opportunistic predators with indiscriminating diets, the Verreaux's eagle-owl is a particularly opportunistic predator. To date, more than 100 prey species have been counted for this eagle-owl. Studies have indicated that for the Verreaux's eagle-owl only around 56% of its diet is comprised by mammals and no single prey type predictably dominates their prey selection by biomass in multiple regions.
In the heart of their distribution, i.e. east Africa, breeding activity in this species can peak any time from February to September, but can occur nearly any month at the species level. The timing of breeding is said to be correspondent roughly to the regional dry season, so averages earlier in the northern part of the range (before February) and later (July to September) in the southern part of the range. The monogamous pair is quite stable, most likely mating for life. As in most owls, a courtship display is both to establish mates for a newly mature pair of eagle-owls or to strength pair bonds prior to nesting. Verreaux's eagle-owls normally uses old nests built by other birds as their own nests.
On average, the female lays two white eggs. he eggs are reportedly laid at up to 7 day intervals and may take up nearly seven days as well between hatching. Most nest reportedly contain two eggs, but some may contain only one, and no more than two has been recorded in this species. The adult female incubates the eggs for 33 to 39 days. Due to the extreme interval between the hatching of the first and the second egg, the older owlet is always considerably larger than the second. As is widely reported in different kinds of raptorial birds, the smaller chick usually dies in the nest. This may be due to starvation upon being outcompeted for food by the older chick or the smaller chick may be being attacked and killed by its older sibling. Usually the smaller chick is gone within two weeks after hatching in this species. In rare cases, both chicks are reared and survive to leave the nest.
On average, the young Verreaux's eagle-owl leaves the nest at around 62–63 days but cannot fly at this point. It may take roughly anywhere from another two weeks to a month after this before the fledgling is a competent flier. Young Verreaux's eagle-owls may fall to the ground, often as a result of mobbing. If the young bird is discovered on the ground, it may feign death, lying prone with its head lax and its eyes closed. Even if picked up while death-shamming, the young eagle-owl may remain moribund. Upon being left without disturbance after "playing dead", the young Verreaux's eagle-owl will gradually open its eyes and return to a normal state.
It is not until they are about 5 months old do most young Verreaux's eagle-owl show the ability to capture prey for themselves. However, the stage at which the young of this species becomes independent appears to remarkably variable. One ringed 9-month-old moved 15 miles away from its nest area and was thus seemingly fully independent. On the other hand, Verreaux's eagle-owls of over half-a-year in age who presumably can fly and hunt on their owl have been seen to linger and continue to beg its parents to be fed into the next breeding season and may even be feed by their father while he is also feeding the mother and a new nestling. The tendency of young eagle-owls to linger into the next breeding season sometimes results in "family groups" being seen roosting together, a very unusual occurrence for an eagle-owl species. One such group consisted of five birds together, including two parents and three owls from the preceding past three years and apparently the younger eagle-owls even helped bring food for the chick once the egg hatched.
Verreaux's eagle-owl is a seldom-encountered species, occurring at low densities and needing large territories for hunting and breeding purposes. The threats faced by this species are sadly typical of many large birds of prey from around the world. In some areas, however, they’ve been shown to be able to nest in peri-urban or suburban areas, showing greater adaptability to human based land changes than many other large birds of prey. In Swaziland, the species is considered Near Threatened and the species has been recommended for threatened status in southern Africa overall. At the species level, they are widespread and to date are not currently considered to be threatened with extinction.
The vermiculated fishing owl (Scotopelia bouvieri) is a species of owl in the family Strigidae. The vermiculated fishing owl is endemic to a large area of tropical west central Africa extending from southern Nigeria in the west to South Sudan in the east and northern Angola to the south. Its habitat is gallery forests along rivers that are at least 10 m (33 ft) wide as well as pools and flooded areas in forests, and it sometimes occurs away from water. Within this range the bird seems relatively common and the population trend stable, so the international Union for Conservation of Nature lists its conservation status as being of "least concern".
The vermiculated fishing owl is a large earless owl with a total length of 18 to 20 inches. The facial disc is a pale reddish-brown with an inconspicuous darker brown rim. The eyes are dark brown and the bill yellowish-brown with a darker tip. The crown is streaked with dark brown. The upper parts are cinnamon-brown finely marked with dark brown vermiculations. Across the shoulders, the outer webs of the feathers are whitish making a pale horizontal streak. The flight feathers and the tail feathers are barred. The underparts are whitish, heavily marked with dark streaks. The underwing and undertail coverts and the thighs are whitish and unstreaked. The legs and feet are yellow and unfeathered.
Its voice is a low, croaking hoot, followed by four to eight staccato notes. A pair of owls often sing in duet, and being a fairly common species, several pairs of owls can sometimes be heard from the same locality.
The vermiculated fishing owl is nocturnal and fishes from a perch on a low branch beside a large river, snatching fish from the water and also feeding on frogs, crabs, small mammals and birds. In southern Nigeria its favourite food appears to be Clarias catfish which have primitive lungs and rise to the surface periodically to breathe. In many places, crustaceans may be the most frequently eaten food. It roosts during the day in a tree near the river.
Breeding takes place from May to at least October and possibly later. The courtship involves much vocal duetting and the nesting site may be a pre-existing large stick nest. The young are slow to mature.
