Feather by exposure to emulsifying agents due to human pollution. Feathers can then become waterlogged, causing the bird to sink. It is also very difficult to clean and rescue birds whose feathers have been fouled by oil spills. The feathers of cormorants soak up water and help to reduce buoyancy, thereby allowing the birds to swim submerged. Bristles are stiff, tapering feathers with a large rachis but few barbs. Rictal bristles are found around the eyes and bill. They may serve a similar purpose to eyelashes and vibrissae in mammals. Although there is as yet no clear evidence, it has been
Calamus rotang plants. It has pinnate, alternate leaves, 60–80 cm long, armed with two rows of spines on the upper face. The plants are dioecious, and flowers are clustered in attractive inflorescences, enclosed by spiny spathes. The edible fruits are top-shaped, covered in shiny, reddish-brown imbricate scales, and exude an astringent red resin known medicinally and commercially as "Dragon's blood". The canes are sought-after and expensive, but have to a large extent been replaced by sticks made from plants, such as bamboos, rushes and osier willows. Calamus rotang Calamus rotang is a plant species native to India, Sri Lanka and Myanmar (Burma).