The Caribbean islands are a global conservation hotspot, because of the numerous rare and endemic species that are found there, many on just a single island. Montserrat, although only about 100 km2 in area, supports one endemic bird – the Montserrat Oriole, plus several endemic reptiles and plants, and numerous unique invertebrates.
However, the unique wildlife is under threat from the combined effects of hurricanes, volcanic eruption, and a threat that is common to most islands around the world: invasive alien species that can predate and out-compete the unique, endemic wildlife. On Montserrat, rats, pigs, goats and cats are numerous and potentially devastating.
In addition to alien species, natural events such as droughts, hurricanes and an active volcano periodically affect the remaining natural habitats on the island. Determining the impacts of these various problems on Montserrat’s wildlife, and identifying potential conservation solutions, is therefore a vital task.
- estimate population size of Montserrat orioles
- identify factors that limit the population and are amenable to conservation management
- protect the remaining forest habitat of the Montserrat oriole
Key dates so far
- established long-term bird monitoring programme
- described the basic ecology of Montserrat orioles
- identified rain, rat, and pearly-eyed thrasher predation as important factors limiting reproductive output
- established that adult survival is high, but subject to fluctuations during periods of volcanic ashfall and little rain
- protection of the Centre Hills as a National Park
Work planned or underway
Since 1997, we have been involved in an alliance of UK conservation organisations, working with the Montserrat Department of Environment to conserve the island's wildlife through the volcanic crisis and beyond.
- Helped develop a Forest Bird Monitoring Scheme. Running since 1997, this is now one of the best long-term data-sets in the region
- Led research into the reasons for the decline of the critically endangered, endemic, national bird, the Montserrat oriole
- Taken part in a major assessment of the biodiversity of the Centre Hills – the last intact forest on the island
- Developed a research programme into the impacts of rats on the forest's wildlife.Assisted in the development of Species Action Plans for Montserrat oriole, and subsequently for other threatened wildlife
- Supported the management of invasive alien species in the Centre Hills.
The long-term trends in forest bird populations have been examined and show that most species recovered impressively in the years following the peak of the volcanic eruption in 1997. Most now show fluctuating trends, with no major causes for concern at present.
The Montserrat oriole population declined between 1997 and 2002, resulting in its designation as ‘critically endangered’. Our research indicates that the decline of the oriole was caused by several negative factors that arose in sequence. Volcanic ash fall reduced the insect food supply; this was followed by a drought in 2001 which greatly reduced breeding success. High levels of rat predation on nests took place in both 2000 and 2001.
Since 2003, the Montserrat oriole population appears to have stabilised, but the small size of the population (~800-1000 Individuals), its very restricted range in the Centre Hills, and the potential threats of future draughts, volcanic eruptions, and the abundance of invasive rats are alarming.
In February 2010 a major volcanic incident produced huge amounts of volcanic ash, which caused widespread leaf fall in the forests across Montserrat. In early 2011, the lack of rain rendered forests very dry and insect numbers were very low. The bird survey in March 2011 indicated the lowest density of Montserrat Orioles since 2003, and it is likely that both the ashfall in 2010 and the recent drought on Montserrat have lowered food supply and led to increased mortality in Montserrat Orioles over the last year.
Species affected (not UK birds)
The RSPB has ringed Montserrat Orioles (here an adult male) to estimate the annual survival probability of the species.
male Montserrat Oriole
Montserrat has two main hill ranges, the Centre Hills (left) and the Soufriere Hills (right) with the active Soufriere Hills volcano. Most of the Montserat Oriole population lives in the Centre Hills.
Who to contact
Senior Conservation Scientist
Montserrat Department of Environment http://www.malhe.gov.ms/
Durrell Wildlife http://www.durrell wildlife.org or http://www.durrell.org/Conservation/Where-we-work/Caribbean-Islands/
Royal Botanic Gardens – Kew http://www.kew.org/scihort/directory/teams/UKOverseasTerritories/index.html
Montserrat National Trust http://www.montserratnationaltrust.ms/
Environment Fund for Overseas Territories (Foreign & Commonwealth Office)
Darwin Initiative for the Survival of Species (Defra) http://darwin.defra.gov.uk/
American Bird Conservancy http://www.abcbirds.org/