Most burrow and tree cavity nesters are beautiful and fascinating birds, they are either from the order of Coraciformes or Piciformes, which include the bee-eaters, kingfishers, rollers, hoopoe, hornbills, woodpeckers, barbets and toucans.
Bee-eaters and kingfishers are usually nest in the burrows, whereas hornbill and woodpeckers hack their way into the living wood. Barbets, on the other hand, usually prefer dead or softer wood. Their unique breeding behaviour in cavities has made them an environment-sensitive birds. They need a robust and healthy forest, stable soil or burrow to build their nests.
Moreover, the woodpecker is very important to the hornbill's breeding cycle. The used and abandoned woodpecker's nest is in turn occupied by the hornbill if the cavity is still in good condition. Therefore, further observations of woodpecker behaviour would be interesting as it would allow for the better understanding of the biological relationship between the woodpecker and hornbill.
I spotted four species of woodpeckers in Singapore Botanic Gardens (SBG). Besides SBG, many woodpeckers can also be found in other forest reserves in Singapore. The woodpeckers that I spotted in Singapore are shown as follows:
All these species are either small or medium size woodpeckers, I do not know whether their used nest will be useful to the hornbill. I had seen many large size woodpecker, the Great Slaty Woodepeckers in Temengor Forest Reserve in Malaysia during the Hornbill Volunteer Program. The high population of Great Slaty point to the presence of a sustainable forest for the woodpeckers and the hornbills. But in Singapore, I have yet to encounter any large size woodpecker, namely the Great Slaty Woodpecker and White-bellied Woodpecker.
So, will the hornbill need to rely on the man-made cavities from now onwards? In order to secure the future of the hornbills, should their conservation programme include the ensuring of a healthy population of large size woodpeckers as well?