Tuesday, 1 September 2015

Nesting behaviour of Red-throated Barbets

Depiction of Red-throated Barbets (female, at rear, is not correctly portrayed))

Barbets are included in the Order Picoformes which is made up of the woodpecker family Picidae plus 8 other families. It includes Puffbirds, Barbets, Toucans, Piculets and Woodpeckers. In general Picoformes are insectivorous but a minority eat mostly fruit. Nearly all Picoformes have parrot-like feet; two toes forward and two back, an arrangement that is advantageous for birds that spend most of their time on tree trunks. Picoformes do not have downy feathers at any stage with true feathers at all stages. All nest in cavities.

The related Common Flameback Woodpecker (male)

The related Common Flameback Woodpecker (female)

Battle of the Picoformes; A Lineated Barbet and a Streak-breasted
Woodpecker fight over a nest hole

Barbets consist of 83 species, 5 of which are threatened. are tropical birds originally designated in the family Capitodinae (see modification below). Barbets are named after the bristles at the base of their stout, sharp bills. They are big headed, short-tailed birds, 9-30cm (3.5-12 inches) long, greenish or brownish with splashes of bright colour or white. The smallest Barbets are known as tinkerbirds. The distribution of the family spans Central America, northern South America, sub-Saharan Africa and South-east Asia…. eastward to Borneo and to Bali. All species are non-migratory. Barbets sit solidly on treetops feeding on insects, lizards, birds’ eggs, fruit and berries. 


Related to Barbets the Collared Aracari, a Toucan from Costa Rica


Usambiro Barbet (an African Barbet species of the Lybiidae family)


Originally all Barbets were placed in the family Capitonidae but over time taxonomists have determined the family is more complex. The original Capitidonae (new World Barbets) with 14 species and Semnornithidae (Toucan Barbets) with 2 species (Toucans and Prong-billed Barbets). These American Barbets are more closely related to Toucans than they are to Barbets of other continents. In Asia 30 Barbet species are placed in their own family Megalaimidae and in Africa the 42 species are in the family Lybiidae.

Coppersmith Barbet

Coppersmith Barbet exiting nest hole

Coppersmith Barbet; removing the poop

Coppersmith Barbets; feeding the chick

RED-THROATED BARBETS

The Red-throated Barbets (syn Gaudy Barbets, German; Harlekinbartvogel; French; Barbu arlequin) as mentioned were previously classified as Megalaima mystacophanos but more recently as Psilopogon mystacophanos are found in Brunei, Indonesia, Malaysia, Myanmar, Singapore and Thailand. Its natural habitat is sub-tropical moist lowland forest and subtropical and tropical swamps. It is thought to be threatened by habitat loss but no numbers have been accurately recorded. The male has a red throat, yellow forehead, red crown, broad black eye line, blue cheeks and band across upper breast. The female has green head, red patches on lores, hind-crown and upper breast side. The breeding pair tends 2-4 white and glossy eggs in cavities with incubation time thought to be 13-15 days.

Distribution of the Red-throated Barbets

Male Red-throated Barbet

Male Red-throated Barbet
Female Red-throated barbet

The sound made is a single ‘tok’ or a series of 4 ‘toks’. A recording can be found here: http://www.xeno-canto.org/sounds/uploaded/EHGWCIGILC/XC173931-red-throated-barbet1.mp3

Red-throated Barbets are regarded by some observers as 'common' in certain forests but they are difficult to photograph except when nesting. I followed a nesting pair near Taiping during several morning sessions. 


Location of the nest hole (red circle)

It was interesting to compare it with the nesting of Coppersmith Barbets photographed earlier in the year. The Red-throated Barbet nesting seemed quite late in the year but my observation is that a nesting pair will base their nesting time on the availability of fruit and berries in the vicinity. In this case there was a fruiting tree 30 metres away and clearly others in the area. I had three visits essentially one week apart. On my first session the visits to the nest cavity was irregular with the male making most appearances with fruit. It was noticeable that the female was the only one that went into the nest to remove fecal material. Barbets are fastidious nest cleaners and earlier I had noted that faecal material was removed regularly from the Coppersmith Barbet nest. As the male and female look similar it was not possible to assign who was doing that task. On the first visit to the Red-throated Barbet nest no chicks were apparent peering from the nest entrance. 


Entering the small nest hole

Female bringing out the poop

A week later I counted 13 feedings from 7.45am until 11 am. The male fed the nest 10 of those times and the female 3 times but again she was the only one that went in to remove the poop. There were at least two chicks apparent in the nest with differences being noted as each peered from the entrance. One chick looked about 4 days more mature than the other …the latter showing a distinct colour forming. 


Male feeding the nest

Male with the more mature chick

Male with the more mature chick

On the third visit, 6 days later, there were 16 feedings in the same time frame and all were done by the male. The female did not make an appearance and consequently no poop was removed from the nest. The more mature chick had advanced in its colour and had a complete yellow forehead and generally smooth feathers with male colouration.  The other chick had developing colour and was possibly a female. It is interesting to note that in my identification book the chick is represented as having little or no adult colouration; which is clearly not the case. The chicks were fed with a lot of fruit and berries and the occasional insect.
As would be expected there are similarities between the nesting behaviour of Coppersmith Barbets and Red-throated barbets. Some years ago I also photographed the nesting of a pair of Lineated barbets and they too had similar patterns.


Male with the more mature chick

Male with the more mature chick

Male with the more mature chick

The more mature chick

The less mature chick

See 11c; chicks are incorrectly coloured in Robson's 'Birds of South-east Asia'

It seems that attempts to portray some species are not done with rigour. An internet search revealed that Barbets or various descriptions have been portrayed on the stamps of various countries. The Red-throated Barbet was portrayed on a stamp from the Maldives. The legend on the stamp however identified the portrayed bird as a Golden-throated Barbet. This listed species is shown from a bird identification book to be somewhat different from the bird on the stamp.

Red-throated Barbet portrayed on a stamp
but called a Golden-throated Barbet

Golden-throated Barbets are #3
While photographing the Barbets nesting there was other activity in the area. A troop of Pig-tailed Macaques passed through and Dusky Langurs dropped many metres from branch to branch in their foraging efforts. A young White-rumped Shama patrolled the bushes on the edge of the road and another species of Barbet, the Gold-whiskered barbet also plundered the fruiting tree. I was also surprised to see Blue-throated Bee-eaters in a nearby tree as they have long since departed the scene in another of my favourite locations.


Juvenile White-rumped Shama

Dusky Langur

Blue-throated Bee-eater

Gold-whiskered Barbet

Photographic Notes
The nest hole is well located on the side of a wide fairly quiet road. The road runs North/South and the sun rising in the east comes up behind the tree.....which is not ideal but later in the morning the ambient light is even and gets brighter as the sun traverses overhead. A long lens of 500-600mm with a converter is needed for the close detail. Of course this rig needs to be mounted on a sturdy tripod. I set my ISO from 1250 -1600 and was able to shoot at speeds from 1/400 to 1/1250 at my standard f8. the first day we waited in the heat for the sun to move until it was behind us. This did not work too well as the light became blotchy, which it often does in jungle conditions. 
It is most important to line up the background so it is relatively smooth....ie no white highlights. This often requires deft manoeuvring of the tripod as conditions change. The other thing to consider is the depth of the tree and positioning yourself so as much as possible of the wood surrounding the hole is also in focus. 
The nesting had attracted the attention of local photographers and many seemed obsessed with taking flight shots with the adult arriving or taking off. They would pump up the ISO on their cameras to any old value. I advocate determining what is the maximum ISO that you are comfortable with your camera....run a test. With my Canon 1DX is is 2000. I still need to run an anti-noise program for the background at this ISO. The other factor to consider is that for decent flight shots you need to be well over 1/2000th ideally......the faster the better. Unless the conditions are favourable i will not even attempt flight shots. I did see one reasonable flight shot from this nesting situation where a 600mm lens with a 1.4 converter was used and the ISO value lifted to 3200. The main advice here....know your equipment. 
Below is a previous shot of a nesting Lineated Barbet pair where the passage to the nest was open and lent itself to action shots.

Lineated Barbet feeding the nest

The Red-throated Barbet chicks fledged in the last few days of August 2015


1 comment:

  1. I really enjoy reading your posts! They help me become a better wildlife person!

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