Laced Woodpecker

Laced Woodpecker attacking ant nest

Laced woodpecker

Scientific Name : Picus vittatus
Malay Name : Belatuk-Hijau Bakau
Chinese Name : 花腹绿啄木鸟

Pinyin : huā-fù lǜ-zhuómù-niǎo

On 26 Jan.2022, while walking with my wife along Sungei Tampines near Pasir Ris carpark B, we came across a female Laced woodpecker attacking an ant nest lodged within a tree trunk.

From the video we can see that the woodpecker uses its strong, sharp claws and long stiff tail to help maintain an upright posture on the vertical tree trunk. This stable posture enables it to deliver strong hammering blows, creating holes in the ant nest hidden within the tree trunk.

The woodpecker protrudes its long sticky tongue into the holes to gather up ants and larvae for a good snack. The protrusion of the tongue is aided by a peculiarly long hyoid bone. The tongue is attached to the base of the hyoid bone on the floor of the beak. The two horns of the hyoid bone extend backwards, passing on either sides of the cervical vertebrae, curl upwards over the back of the skull, over the top of the skull and finally both horns insert into the right nostril. The hyoid bone is outside the skull bone but within a muscle sheath. When the muscle sheath contracts, the base of the hyoid bone is push rostrally, aiding in the tongue protrusion.

This peculiar hyoid bone is also suspected by scientists to help in preventing brain injuries when the woodpecker vigorously hammers into the tree trunk, (the impact velocity is of the order of 600 to 700 cm/s; and the impact deceleration is of the order of 1,000 gravity). How it does that is still not fully understood. Other protective features include (1) the minimum amount of fluid filled space between brain and skull bone, (this minimises the transmission of fluid shock wave) and (2) the presence of thickened, spongy plate-like skull bone facing the anterior and posterior aspect of the brain, and (3) the unequal length of the upper and lower beak, (The outer tissue layer covering the upper beak is 1.5 mm longer than that of the lower beak; on the contrary, the bone structure of the upper beak is about 1.2 mm shorter than the lower beak. Beak length was found to affect impact force, brain strain. It was shown that most of the pecking forces were usually carried by the longer beak during pecking). All these features together, and not any particular ones, helps the woodpecker to prevent head injuries.

Although the laced woodpecker forages mostly on tree trunks and branches, it is also known to forage on the ground. This has been documented on several BESGroup posts.

https://besgroup.org/2011/05/16/ground-pecking-laced-woodpecker/

https://besgroup.org/2012/05/26/laced-woodpecker-foraging-on-the-ground-2/

Photo 1 by Wong Kais. Female laced woodpecker. note tongue. Use of stiff tail as a prop to maintain stable posture.

Photo 2 by Wong Kais. Strong and sharp claws enable the woodpecker to cling onto the bark.

The female laced woodpecker has a black crown, unlike a male which has a red crown. The black colour stretches from the forehead all the way to the nape. The lores are also black in colour. The face is whitish-grey with a blackish eye. There is a black mustachio band and a white super-ciliary stripe. The chin, neck and breast are yellowish in colour. The back and wings are olive green. The flight feathers and long, stiff tail are blackish with white markings. The belly and vent are covered with white feathers, bordered by “V” shaped brownish markings just before their edges. This gives it a lace appearance and result in its namesake. Its bill is blackish except for the proximal 2/3 of the lower mandible which is yellowish. The legs and claws are pinkish white.

The above video by Wong Kais shows some strange behaviors of the female woodpecker. Is this a courtship ritual or is this a defensive territorial posturing?

Calls of the laced woodpecker.

Laced Woodpecker (Source: xeno-canto.org)

Another form of woodpecker communication is drumming. see link to previous BESGroup post of Sunda pygmy woodpecker drumming – https://besgroup.org/wp-admin/post.php?post=36327&action=edit

Article by Michael Wong

References