Manumea nears extinction

06/11/2012 12:39


Pacific Scoop:
Report – By Lagipoiva Cherelle Jackson in Apia

The manumea bird, which is endemic to Samoa, is feared to be near extinction after scientists failed to sight the species during a recent Savai’i uplands forest survey.

The situation is so dire for Samoa’s native species, that some scientists estimate the head count at less than 200.

The manumea, or tooth-billed pigeon (Didunculus strigirostris), is listed as endangered on the International Union for the Conservation of Nature red list of globally threatened species.

According to the terms of this list, if no action is taken to halt the decline in populations of these unique species, it is expected that they will become extinct.

During the recent rapid biodiversity assessment (BioRap Assessment) in uplands Savai’i, a group of scientists were airlifted to the top of Mt Silisili where they camped for almost two weeks to survey and assess the situation of flora and fauna in the uplands of Savai’i.

During that time, scientists expected to sight the manumea. But there were no confirmed sightings, therefore leading the scientists to conclude that the number of  species has declined to threateningly low numbers.

The lack of sightings is consistent with the decline in recorded numbers so far.

Drastic decline
Dr Ulf Beichle, who studied the manumea in the 1980s and 1990s, estimated the total population at 4800-7200 birds in the mid-1980s. But in the 1990s the population showed a drastic decline owing to the effects of cyclones such that, in 2000, fewer than 2500 mature individuals were believed to survive.

Birdlife International noted that in 1999 and 2000, surveys on Savai’i showed that it had become rare with pairs scattered in suitable habitat.

According to published reports by the Ministry of Natural Resource and Environment (MNRE) an11-month survey in 2005-2006 reported the species from only 10 locations, and the population was estimated to number only a few hundred, although the remote and largely intact uplands of Savai’i remained largely unsurveyed at the time.

The recent BioRap Assessment surveyed that last part of Samoa which MNRE believed would host a number of manumea. However, this was not the case.

One of the scientists who took part in the BioRap was ornithologist Rebecca Stirnmann, who is currently pursuing a National Geographic-sponsored PhD on the study of manumea and m,aomao.

According to Stirnmann the lack of sightings in Savai’i confirmed a suspicion that the numbers of manumea were “really low”.

“Prior to the BioRap, we thought that Savai’i uplands would be a stronghold for the manumea. However, when we were up there we discovered that we didn’t find any.”

She said there was one potential sighting but it was “unconfirmed”.

“There expectation was that many would be seen, but having not seen any at that time this indicated it was very low.”

According to Stirnmann there is still hope for the manumea if recovery efforts are put into place.

Recovery plan
The options for saving the manumea are clearly outlined in the 2006-2016 Recovery Plan for the manumea, collated and published by MNRE.

In the recovery plan, four options are outlined to bring back the numbers of manumea:

Option 1: Indicates “doing nothing” which would lead to the continuing decline in the numbers and range of the species and bring it closer to extinction, to which now is the case according to the recent survey.

Option 2: Suggests focussing only on conserving forest habitats. The report states: “This option would involve focussing all the effort on securing the forest areas currently occupied by the manumea.

However hunting would continue to be a threat and there would be very limited public support for addressing this issue. It is also uncertain how productive the species is currently in the face of other threats like invasive species.

Option 3: Suggests conserving forest habitats and manage hunting and investigate ways to increase the number of birds and populations. The Recovery Plan states that developing public support is key to this option. “The more secure populations the species has in different locations the greater the chance of it surviving and recovering from localised natural disasters like cyclones.”

Option 4: Suggests investigating the breeding and feeding ecology of the species in detail. “It is uncertain whether the species would maintain or increase its numbers if all the measures in option 3 were put in place. For we know nothing about current breeding success and mortality and it could be that other threats like introduced predators need addressing as well.”

The cause of the decline in numbers of manumea and threats continue to be attributed to natural disasters, hunting, feral cats, rats, loss of forest quality, disease and parasites and climate change.

Lagipoiva Cherelle Jackson is an independent Samoan environmental journalist