Three Asian Bird Families You Must See
One of the main attractions of travelling overseas to new places is to see new and unfamiliar birds and what could be newer and more unfamiliar than birds that are in families that one has never experienced before? For those who have not birded in Asia before, and indeed those that have, there are some mouth-watering bird families to discover; here are three Asian bird families you must see and, when encountered, are likely to leave you wanting to travel further within the continent to see more.
Hornbills (Bucerotidae)
Hornbills are the undeniable masters of Asian forests and they are a key indicator species of the quality of the forest community. Although hornbills occur in Africa too, it is in Asia that they reach their most flamboyant in terms of colouration and eccentric behavior with aerial casque-butting having been recorded in Great Hornbills and the dragon-like appearance of Helmeted Hornbill giving it a prehistoric look.
Asian hornbills occur from western India through mainland Southeast Asia, the Indonesian archipelago and The Philippines all the way to Papua New Guinea but not reaching Australia. All species are characterized by their large size and massive bills that are often adorned with a large ridge or protuberance on the upper mandible of the bill that is known as a casque and in the larger species this can become quite elaborate and colourful as in the case of the magnificent Rhinoceros Hornbill. It is assumed that these casques play some role in display and in the larger species may amplify the bird’s call as in some species that possess hollow casques. However, the impressive casque of Helmeted Hornbill is solid and this has led to it being hunted for the “red ivory” trade through much of its range in Sumatra and Borneo although it remains relatively well-protected in Peninsula Malaysia and parts of southern Thailand.
Although the bills of hornbills are massive and look like they must be made for some sort of heavy duty crushing and pecking, they are actually tools for tasks that require a high degree of dexterity. All Asian hornbills feed on arboreal fruits to varying degrees, with the small fruits of towering strangler fig trees being their favourite and when one watches them feed on these they are surprisingly delicate as they pick off ripe figs with the very tips of their bills before throwing them back into their crops with a backward tilt of their head. In this way their bills are used more like chopsticks than nut crackers. It is quite a memorable sight to see a flock of Oriental Pied Hornbills crashing around in a giant fig trees gobbling up the fruits before flying away. Many species of hornbill also use their bills as a precision tool for catching insect and reptilian prey too as well as seizing eggs and nestlings from unfortunate smaller breeding birds; Tickell’s Brown Hornbill and Austen’s Brown Hornbill are particularly prone to an animal-based diet with up to seventy percent of the diet being of this origin. Lizards seem to be a particular favourite of these species.
However, hornbill’s love of figs and other trees that produce small fruits (large fruits are rarely if ever taken although Sri Lanka Grey Hornbill and other smaller hornbills will come to bird tables to feed on papaya and bananas) makes them important to the overall ecology of the forest as a major disperser of seed for the trees. Hornbills, and particularly the larger hornbills, can have large territories and will fly large distances and as such can disperse the seeds from the fruits they consume over a wider area than is typical for smaller fruit-eating birds. It is often these very trees that when they become massive with cracked and rotten limbs that provide the nest holes that all hornbills rely upon to raise their young. In this way the relationship between hornbills and the trees they nest in is mutually beneficial and this is why they are a key indicator species of a healthy forest. Without the hornbill there are fewer massive trees and without the massive trees to nest in, there are fewer hornbills. It then does not take much imagination to predict the devastation to hornbill populations that even selective logging can wreak upon these amazing birds in the reduction of nesting opportunities that removing large, old trees creates.
The nesting behavior of hornbills is something quite remarkable indeed. Obviously cavity nesting is not unique in this family of birds but hornbills have their own unique take upon this behavior. Once a nest cavity has been selected the female will enter and then the male will reduce the cavity opening in size to a very narrow slit using mud while the female will also help using droppings and fruit pulp created from food delivered to her by the male. A few other birds such as some wrens and treecreepers will use mud to reduce the aperture of a nest hole but being imprisoned for the entirety of the nesting cycle is unique to hornbills. During this period the female, and consequently the offspring, is completely dependent on the male to provide food for up to several months in the larger hornbill species.
Although hornbills share large, elaborate bills with the toucans, toucanets and aracaris of South and Central America they are not all related. Their similar appearance and ecological role is a classic example of convergent evolution where unrelated species, in different parts of the world have evolved to fill the same, or similar, niche and end up resembling one another. Hornbill’s closest relatives are Hoopoes and Wood-hoopoes of Eurasia and Africa.
Hornbills are always a spectacular sight and a highlight of any birding trip in Asia be it the incredibly colourful, endemic Knobbed Hornbill of Sulawesi, the elusive Rufous-necked Hornbill of Himalayan forests or the unforgettable sound of the wingbeats of Great Hornbill. To paraphrase Dr Johnson, if a birder is tired of hornbills, they are tired of birding itself.
Many hornbills are under threat due to deforestation, logging and hunting but in areas where there are plenty of nest sites and they are not hunted they can still be quite common. In protected forests in Peninsula Malaysia and North Borneo the garrulous Bushy-crested Hornbill can be quite abundant, the Sri Lanka Grey Hornbill is a garden bird in some parts of this island and the huge Blyth’s Hornbill is amazingly abundant in West Papua.
Broadbills (Eurylaimiidae & Calyptommenidae)
The Asian broadbills are actually within two families each with their own signature “style” or “look” but we will deal with them as one here. The broadbills are a group of old world passerines characterized by their broad, flat beaks and vivid plumage primarily within tropical Asia, although there are few species within Africa, inhabiting high quality forest habitats.
Broadbills are all thickset birds with large heads but what they lack in grace they generally make up for in plumage, often combined with incredible bills. These broad bills that are the common feature of this family have evolved for them to consume insect prey, but not any old insects but rather very large species that most other insectivorous birds are unable to cope with such as katydids and mantises. The sighting of a Dusky Broadbill, with its comical deep pink bill, trying to swallow a gigantic mantis is an experience that is not soon forgotten and similarly all of the other broadbills are adapted to their own habitat and prey micro-niches within the forest; the remarkable Black-and-red Broadbill particularly loves very wet forest and rivers whereas the cartoonish Long-tailed Broadbill favours montane forest. Frequently the prey of broadbills is so large and tough that this group of birds will frequently beat food items against a perch to kill it and to soften it up for consumption. In order to help in detection of insect prey the bills of broadbills are all endowed with rictal bristles, stiff but sensitive whisker-like structures that help the birds to sense insects upon contact when gleaning for food in dense foliage.
While the bills of broadbills are impressive indeed, especially the blue and yellow bill of Black-and-red Broadbill, it is the striking nature of the plumage of most species that really catches the eye. Long-tailed Broadbill of higher altitudes looks like a Disney character with plumage that has been imagined by a child, while the clashing pink, white, yellow and black of Black-and-yellow Broadbill is definitely not to be copied by birders in dense, often dark, forests. However, the group of three species of Green Broadbills (Green Broadbill of the Thai-Malay peninsula, Sumatra and Borneo as well as Hose’s and Whitehead’s Broadbills of Borneo) have quite a different colour palette from the others, all three being a vivid green with various black patterning as adornments. Indeed, the very shape of these green broadbills sets them apart from the other species in the group with a cluster of bushy feathers above the bill giving them a peculiar bull-headed shape.
Vocally, the broadbills can be impressive and quite varied. The manic, bubbling trill calls of Banded Broadbill and Black-and-yellow Broadbill are a signature sound of Southeast Asian rainforests. All of the broadbills have very distinctive calls and can be extremely aggressive when they hear another individual particularly, but not exclusively, in the breeding season and when they fly in to look at a potential territorial usurper their flight path is fast and direct with no undulation, as if they have been fired out of a gun. This can be helpful in identifying them when they fly overhead.
One commonality that ties the Asian broadbills together is their nesting behaviour. All species construct an egg-shaped nest that is suspended from a single vine or hanging branch, usually over an exposed clearing, pool of water or, as is frequent in Kaeng Krachan National Park in Thailand and Cat Tien National Park in Vietnam, over a forest road. This often shambolic-looking bundle of twigs is woven into a capsule with a small aperture for entry and exit, usually with the addition of a remarkable canopy-like structure over the “front door” that protect the inhabitants from direct sunshine and rain. In most species this nest is created and attended by a pair but in Dusky Broadbills there are almost always “helper” birds, with up to five or six individuals building the nest and feeding the young. Presumably the helper birds are the previous year’s young gaining experience, although it may also represent an opportunity for non-dominant males to sneakily pass on their genes when the dominant male is not attentive.
For birders, once a first species of broadbill has been seen they can become addictive, such is their impact and whether it is (Javan) Banded Broadbill at Cibodas Botanical Gardens in Java, Whitehead’s Broadbill in the foothills of Mount Kinabalu in Borneo or dapper Silver-breasted Broadbill in Thailand these birds are always a highlight of birding in this region.
Broadbills are not usually hunted or collected for the cage bird trade, although this latter may be a problem in Indonesia, but as they are restricted to forest habitats, deforestation is the main threat to their existence. Where the right habitat exists broadbills are usually doing well, although as they are highly territorial they are not usually found at high density anywhere. Taxonomically broadbills are mostly closely related to the Asities of Madagascar and Pittas of Asia/Africa.
Pittas (Pittidae)
Distinct and unrelated to the Antpittas of South America, but occupying a similar niche, birds in this family are often considered the “Holy Grail” of birding in Asia and, indeed, an old, colloquial name of “Jewel-thrush” identifies what a treasure these birds can be. Although not restricted to Asia (there are a few species in Australasia and Africa) this family is at its most diverse and numerous here where they are among the most vividly-coloured and captivating birds of the forest floor. Pittas are compact, short-tailed birds with often brilliant combinations of green, blue, red, yellow and black but despite their often striking appearance they are famously elusive, more often heard calling than seen, which is what makes a sighting all that more special.
Pittas in Asia are found from the Indian subcontinent, through mainland Southeast Asia, as far north as China, the Korean peninsula and Japan, to the entirety of Indonesia where there are numerous endemic species. Most species favour moist forests, where they forage on the ground for insects, worms, snails, and other small invertebrates. Their strong legs and upright posture give them a distinctive, almost thrush-like stance as they jump around and pause among leaf litter although some species do call from arboreal perches; Mangrove Pitta calls from trees almost exclusively while Garnet Pitta favours palms within swamp forest.
The majority of pitta species in Asia are resident birds but a few species are strongly migratory, usually making their journeys by night and at these times they frequently turn up in parks and gardens. Western Hooded Pitta, Blue-winged Pitta and Fairy Pitta all migrate, spending the non-breeding season in the Thai-Malay peninsula, Sumatra and Borneo before moving further north. Indian Pitta too is migratory breeding in the Himalayan foothills while spending the non-breeding season in more southern parts of India and Sri Lanka where it is one of the more easily seen of the family. These night migrants are particularly prone to window-strike, being drawn to nearby lights as many night-migrants are and the sight of a Blue-winged Pitta corpse can be all too frequent in cities like Singapore, Bangkok and Ho Chi Ming City during spring migration.
Within Southeast Asia, particularly in Borneo and the Indonesian archipelago, there is a high level of regional speciation and endemism in the pitta family. Blue Pitta and the cryptically-plumaged Eared Pitta are restricted to mainland Southeast Asia while Bar-bellied Pitta is more regionalized, restricted to Laos, one site in Thailand, Cambodia and Vietnam, where it is most easily seen, while four species are restricted to the island of Borneo; Bornean Banded Pitta, Black-crowned Pitta, Blue-headed Pitta and Blue-banded Pitta. However, it is in Indonesia where these birds become even more specific to particular islands such as Schneider’s Pitta in Sumatra, Javan Banded Pitta in Java and Bali, the massive Ivory-breasted Pitta of Halmahera and glowingly-plumaged Sulawesi Pitta on the island of the same name. These are just a few of the array of gems in the pitta family across the continent of Asia and the number of species continues to grow as taxonomists study populations on isolated islands.
Outside of the breeding season pittas can be extremely hard, if not impossible in many cases, as they keep to the shady forest floor, are shy and remain silent but when the breeding season arrives they become quite vocal. Males call to attract a mate and to deter other males from encroaching on their territory but frequently both male and female will utter contact calls to remain in touch when foraging. It is at this time that birders have the best chance of seeing these jewels of the forest and their elusiveness while persistently calling from a hidden location only increases the anticipation of a sighting. Pittas are frequently attracted to feeding stations and this gives birders the best of chances to see these birds in the open. Both Bar-bellied and Blue-rumped Pittas are frequently seen this way in southern Vietnam, Blue Pitta sporadically visits feeding stations in Thailand, while Javan Banded Pitta is very reliably seen in this way in Bali and several of Borneo’s endemic pittas are often seen from permanent hides. In recent times Sulawesi Pitta, Schneider’s Pitta and Ivory-breasted Pitta have become habituated to other locations in Indonesia.
Pittas exhibit a characteristic nesting strategy that reflects their secretive, ground-oriented ecology. Nests are typically domed or globular structures, constructed from leaves, roots, grasses, and other plant fibers, and are usually placed on or very near the ground, often concealed among dense vegetation, buttress roots, or forest debris. An entrance opening on the side or near the top allows access while minimizing visibility to predators. Both sexes commonly participate in nest construction, incubation, and care of the young. Breeding is generally synchronized with seasonal peaks in rainfall and invertebrate availability, ensuring sufficient food for nestlings with many species that share a habitat having their own time specific niche; Eared Pitta is a very late breeder for example. The concealed placement and robust structure of pitta nests are key adaptations for breeding in humid, predator-rich tropical forest environments.
Pitta’s attractive plumage has recently brought the attention of bird trappers and this is becoming an increasing conservation issue for some species but it is habitat destruction that is the most serious threat to the survival of several species. Giant Pitta and Garnet Pitta are both birds of extreme lowland forest, the type of forest most easily logged, and these birds are only hanging on in areas that are protected within national parks.
The promise of any pitta sighting is a major draw in visiting a particular country and when planning trips, and if these plans come to fruition it is a major highlight of the trip. For many birders visiting Asia seeing a pitta is the most anticipated experience of all and once they have seen one or two species they are hooked and then plan the next trip to look for other species in the family.
