The White Tern is, I believe, among the most beautiful of the seabirds nesting and breeding on Midway Atoll. The species is regarded as having 3 or 4 subspecies, Gygis alba rothschildi being on Midway. Fortunately, the terns are widespread around the world and are not considered to be a threatened species.
As I mentioned in a previous blog entry, the species is well known for its habit of laying its egg on bare branches of trees without building a nest as such. This is unusual among tern species which generally nest on the ground. One theory is that it may be a means of reducing exposure to parasites, which can infest the nests of other bird species. The trade-off for this however is that the egg and the chicks are more vulnerable to adverse weather conditions, strong winds can dislodge an egg or chick from its position on a branch. Adaptions the terns have evolved are that the chick is hatched with well-developed feet giving it a greater capability of hanging on to a branch and that in the event of a lost egg or chick, the terns are capable of having a second egg quickly in the same season.
White terns begin breeding at between 3 and 5 years with the parents sharing the tasks of incubating the egg and feeding the chick. Unlike most seabirds that feed their chicks regurgitated food, the terns feed their chicks only whole fish or squid. (Source and further reading: http://www.fws.gov/midway/whte.html)
At the time of compiling this blog entry, there are some issues with the “related posts” widget within WordPress, as a result, I’ve had to deactivate that facility, hopefully only as a temporary measure. Once the software gurus have it sorted, I’ll reinstate it. Sorry for the inconvenience.
This photograph is part of the Midway Atoll image gallery. ~KD.