The rare Many-colored Fruit Dove (manuma)royal bird
One of the rarest birds that nest on Tutuila is also one of the most beautiful: the manuma, or Many-colored Fruit-Dove.
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| Used with permission from Dick Watling from “Birds of Fiji, Tonga and Samoa” and “Birds of Fiji and Western Polynesia” (Pacificbirds.com). |
The manuma here is considered a different subspecies than those from Fiji and Tonga because they have a slightly different color pattern. The male manuma is creamy white below and pale yellow above, with a dark crimson band across the back, a crimson patch on the forehead, and a purplish-red blotch on the breast. The female is very different and looks like the much more common manutagi, or Purple-capped Fruit-Dove. She is mostly green above and gray below, with a crimson forehead patch. Unlike the manutagi, the female manuma doesn't have a yellow band on its tail.
The manuma was not rare on Tutuila in the 19th and early 20th centuries, according to the journals of the early scientific expeditions. It was usually found in flocks; in 1923 a collector killed 10 birds with a single shot into a feeding tree on Ta'u. However, when the first modern studies of American Samoa's birds were done in mid-1970, only a small number of manuma could be found. Follow-up in the mid-1980's confirmed the manuma's rarity. They estimated that the population size on Tutuila was only about 80 birds.
After the hurricanes in the early 1990s, even fewer manuma were seen, and perhaps less than 50 remained on all of Tutuila. Today, however, manuma are regularly seen at some locations on Tutuila, although not in very large numbers. Biologists would call their current distribution rare and local, but they are occasionally sighted at many places around American Samoa. Interestingly, manuma are much more common in Fiji, Samoa and Tonga, sometimes being found well away from mature forests.
We know very little about the biology of manuma in American Samoa, or why it is less common here than elsewhere. These are social birds, often being seen in small flocks, but they are also very protective of feeding areas, driving other manuma away from their spot in the canopy of a fruiting tree. One odd thing is that you rarely see the same numbers of each sex -- almost always there are several more males than females in any flocks. We do know that they seem to have a very strong preference for the fruits of banyan (aoa) trees, and in American Samoa it is almost always seen near or in these trees. They are also known (from Fiji and Tonga) to eat moso'oi, o'a and magele fruits, all of which occur in America Samoa. Perhaps there are still so few manuma here that they are seldom forced to eat anything but their favorite food, but would eat other fruits if necessary.
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| Banyan tree used with permission by
Le Vaomatua (American Samoa). |
It is dangerous for animals to specialize too much on any one food, especially on remote islands like American Samoa. This can be shown with an example from business. While a store that sells only antique cuckoo-clocks might do fine in New York, Los Angeles, or another big market, it would certainly fail very quickly in American Samoa. There isn't enough business here for such a specialized service. Similarly, an island animal that concentrates on only one kind of food may find itself in trouble when that food supply fails. An animal that lives on a continent can move in search of the food it needs, but island animals have nowhere else to go. On larger islands like Upolu, Savai'i or Viti Levu, manuma may be able to travel long distances to get the food they like the best. This may be difficult on small islands like those of American Samoa, and means that animals can only specialize on very reliable food trees such as banyan trees (aoa).
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| Used with permission from Dick Watling from “Birds of Fiji, Tonga and Samoa” and “Birds of Fiji and Western Polynesia” (Pacificbirds.com). |
These giant banyan trees, which are so important to manuma, face many problems of their own. The Tafuna Plain used to have many huge banyans, but most of these have been cut down to make way for the exploding human populations in that area. Moreover, banyans, with their large size and spreading crowns, are very vulnerable to storm damage. Many were killed or severely damaged by Hurricanes Ofa and Val in the early 1990s. Even those that survived the hurricanes had their leaves and fruit stripped off, leading to a prolonged period of famine for manuma.
There are two things that must happen if the manuma is to survive and remain a special part of Samoa's wildlife. First, the birds must be protected from hunting. Although the manuma is too rare to be sought by hunters, a few may have been killed every year by hunters out for lupe and manutagi. When a population is as small as the manuma's, even a few preventable deaths per year are a significant problem.
The second thing that must be done if the manuma is to survive is to protect banyan trees on which they depend. Without enough banyans to assure a year-round supply of its favorite food, the manuma may well become extinct on Tutuila. People need to protect these magnificent trees, which are important food sources for many other Samoan wildlife species, including the fruit bats (flying foxes).
Pepper Trail, Joshua Seamon, DMWR