The Mariana Fruit Dove is a small, brightly colored fruit dove native to the Mariana Islands in the western Pacific Ocean. This elusive bird inhabits forests on a handful of islands across its limited range, where it feeds on fruit and builds its nest high in the canopy.
The Mariana Fruit Dove is classified as endangered by the IUCN Red List due to its small population size and the many threats it faces across its range. Some major threats include habitat loss from development and deforestation, predation by invasive species, and the impacts of typhoons and climate change.
What is the Mariana Fruit Dove?
The Mariana Fruit Dove (Ptilinopus roseicapilla) is a medium-sized, colorful fruit dove that is endemic to the Mariana Islands in the western Pacific. It measures around 9 inches (22 cm) in length and weighs between 3.5-5.5 oz (100-155 g).
Some key identification features include:
– Iridescent green upperparts and head
– Pale grey underparts
– Bright maroon-red crown and nape
– Yellowish bill with a dark tip
– Red legs and feet
The female Mariana Fruit Dove is slightly duller in coloration than the male. Juveniles have a grayish head and breast.
This species inhabits forest across a number of islands in the Mariana archipelago, including Guam, Rota, Tinian, and Saipan. It can be found from sea level up to 650 feet in elevation.
The Mariana Fruit Dove feeds mainly on various fruits and berries. It will occasionally take insects and flower nectar as well.
Breeding takes place from March to July. The female builds a flimsy nest out of twigs, which is placed high in a tree. A single white egg is laid, and the parents take turns incubating it. After a 14-16 day incubation period, the chick hatches.
Population and Distribution
The Mariana Fruit Dove is endemic to the Mariana Islands, located in the western Pacific Ocean. This archipelago consists of 15 islands, with the largest and southernmost being Guam.
The species’ global population is estimated at just 1,000-2,499 mature individuals. It has a very limited range, with an extent of occurrence of only about 250 square miles.
According to the latest surveys, the Mariana Fruit Dove’s population is distributed across the following islands:
Guam
– Native population possibly extinct
– Introduced population of unknown size present
Rota
– Estimated 228-370 mature individuals
Aguijan
– Unknown population size, likely very small
Tinian
– Estimated 300-400 mature individuals
Saipan
– No recent population estimate, but native birds assumed to still be present
Across these islands, the total population is precariously low. The species is now absent across much of its former range. Unsuitable habitat and predation by non-native species continue to limit populations on many islands.
Major Threats
The Mariana Fruit Dove faces a number of serious threats across its restricted island range:
Habitat Loss
Native forest habitat continues to be lost across the Mariana Islands due to agricultural and urban development. Logging, fires, and land clearance are also degrading and fragmenting remaining forest. This limits and isolates dove populations.
Invasive Species
Several invasive animals are major predators of the Mariana Fruit Dove or compete for its food sources, including rats, macaques, monitor lizards, and parrots. These non-native species are able to access dove nest sites in the forest canopy.
Hunting and Poaching
Historically, the Mariana Fruit Dove has been heavily hunted for food and feathers across some islands, although this threat has lessened. Poaching may still occur on occasions.
Climate Change
Projected increases in severe weather, drought, and sea level rise due to climate change are likely to further degrade the dove’s island habitats in the coming decades.
Small Population Size
With just 1000-2500 mature birds remaining, a severe typhoon or disease outbreak could decimate a significant portion of the population. Small populations are vulnerable to extinction. Limited genetic diversity may also impact on reproductive fitness.
Conservation Status
The Mariana Fruit Dove is considered Endangered by the IUCN Red List and ESA due to its precariously small population size and ongoing threats. Its numbers have declined severely since the 1970s when it was still locally common.
Here is a summary of its conservation status:
– IUCN Red List: Endangered
– ESA Status: Endangered
– CITES: Not listed
Under the United States Endangered Species Act, the Mariana Fruit Dove was listed as endangered in 1984. A recovery plan was published in 1991. Captive breeding, invasive species control, habitat protection, and research into its populations are key conservation actions.
While still endangered, populations on Rota and Tinian appear to have stabilized in recent years thanks to conservation efforts. On other islands such as Guam, however, its long-term future remains uncertain. Protection of habitat and control of invasive predators will be crucial across its range.
Interesting Facts
Bright Coloration
The bright red cap and metallic green plumage of the male Mariana Fruit Dove make it a very beautiful and visually striking bird. The dove’s colors may help attract a mate.
Diet
At least 24 different fruit species make up the diet of the Mariana Fruit Dove. Important food sources include figs and the fruits of native laurels. It swallows the fruits whole.
Nesting
The dove’s nest is a very flimsy platform of just a few twigs. It is thought the thin nest makes it harder for predators like snakes to access the egg and chick.
Cooing Call
The Mariana Fruit Dove has a soft, low-pitched call that sounds like “coo-OOO-oo”. This helps the birds keep in contact across the rainforest.
Taxonomy
The Mariana Fruit Dove belongs to the pigeon and dove family, Columbidae. It is the only member of the genus Ptilinopus found in the Mariana Islands.
Frequently Asked Questions
How many Mariana Fruit Doves are left in the wild?
It is estimated there are around 1,000-2,500 mature Mariana Fruit Doves left in the wild. Exact figures are uncertain for some island populations. Overall numbers continue to decline.
Why is the Mariana Fruit Dove endangered?
Habitat destruction, invasive species, poaching, small population size, typhoons, and climate change have all contributed to the decline of the Mariana Fruit Dove, classifying it as endangered.
What islands can you find the Mariana Fruit Dove on?
The dove occurs on the islands of Guam, Rota, Aguijan, Tinian, and Saipan in the Mariana archipelago of the western Pacific Ocean. Populations have been decimated or wiped out from some former range areas.
How can we protect the Mariana Fruit Dove?
Key conservation actions needed include habitat protection, control of invasive predator populations, captive breeding programs, banning of hunting, and ongoing population monitoring. Increased public awareness and funding for conservation are also important.
Is the Mariana Fruit Dove’s population increasing or decreasing?
Overall the population is still decreasing, however on some islands such as Rota, numbers appear to have stabilized in recent years thanks to conservation efforts. But threats are still ongoing and they remain endangered.
Conclusion
The Mariana Fruit Dove is a endangered bird found only in the forests of a handful of small Pacific islands. With a population of fewer than 2500 mature individuals left, it faces a high risk of extinction in the wild if conservation efforts are not maintained and ramped up across its range.
Key threats that have contributed to its endangered status include deforestation, non-native invasive predators, poaching, severe weather, and climate change impacts. But there is still hope – stabilised populations on some islands show that with the right conservation interventions, this rare and unique bird can recover. Protection of remaining habitat and control of invasive species are crucial first steps to secure its future survival.
