|Scientific Name:||Leptotila wellsi|
|Species Authority:||(Lawrence, 1884)|
|Red List Category & Criteria:||Critically Endangered C2a(i) ver 3.1|
|Contributor(s):||Collar, N., Ellard, J., Rusk, B. & Wege, D.|
|Facilitator/Compiler(s):||Benstead, P., Bird, J., Butchart, S., Calvert, R., Capper, D., Sharpe, C J, Symes, A., Wege, D., Khwaja, N.|
This species is considered Critically Endangered because it has an extremely small and fragmented population which has declined owing to habitat loss and fragmentation caused by hurricanes, fire, clearance for residential housing, roads and other development, as well as grazing and predation by invasive species. A 2008 recovery plan aims to urgently prevent further population decline due to habitat loss and other threats, and increase the wild population through protection and restoration to allow for four self-sustaining subpopulations.
|Range Description:||Leptotila wellsi is endemic to Grenada in the Lesser Antilles. Historically, it was more widespread in coastal and possibly offshore islands (B. L. Rusk in litt. 1998), but may always have been rare (Devas 1943). The population declined by c.50% in 1987-1990 (Blockstein 1991), and by 1998 numbered only c.100 individuals, with strongholds on the Mt Hartman estate, and on the Perseverance and adjacent Woodford estates in the west (Rusk 1998). The population increased to an estimated 182 individuals by 2003-2004, but in 2004 hurricane Ivan had a devastating impact upon the island and the dove's population. This resulted in declines, particularly severe along the west coast, where the population declined from 36 calling males to 3-12 calling males, but also within the Mt Hartman area, from 55 males to 30-48 males (B. L. Rusk in litt. 2005, 2006, 2008, 2010). Three years following hurricane Ivan the population was estimated at 68 calling males with 136 individuals in total (Rusk 2007, B. L. Rusk in litt. 2005), however this assumes an even sex ratio, and there is a tendency for such relict populations to be male-dominated. The total population may therefore be as small as 100 mature individuals or c.30 reproductive pairs (N. J. Collar in litt. 2008). Of all remaining known territories, 28 are within protected areas, 11 on unprotected crown land and 29 on private land. Forty-three per cent of remaining birds are thought to occur in the Mt Hartman Estate (B. L. Rusk in litt. 2012).|
|Range Map:||Click here to open the map viewer and explore range.|
|Population:||The global population is estimated at c.130 individuals, roughly equivalent to 87 mature individuals.|
|Habitat and Ecology:||It inhabits a successional stage of dry, coastal scrub-woodland in the south-west, which comprises a closed canopy of leguminous (often thorny) trees and shrubs c.3-6 m high, a sparse understorey of shrubs and saplings, sparse to absent ground-cover and much exposed soil (Blockstein 1991). On the west coast, its habitat includes some mixed deciduous/evergreen vegetation. It may have been always confined to xeric, coastal areas where climax vegetation was deciduous, seasonal forest and thorn woodland, but frequent natural disturbances (particularly hurricanes) kept the vegetation in a sub-climax condition. This temporary occupation of ephemeral patches and recolonisation of developing patches may be the normal life history pattern. Breeding is limited to the rainy season in the south-west, but is more extended on the less xeric west coast (Rusk 1998).|
|Major Threat(s):||Habitat loss due to clearing for small plantations and charcoal production has been replaced in recent years with chronic and continuing habitat loss for residential housing, roads and other development. Population declines are likely to be compounded by introduced mongooses, cats, rats and manicous predating eggs and fledglings, of which rats were found to be the most widespread, followed by mongooses and manicous (B. L. Rusk in litt. 2012, Twyman and Hyslette unpubl. data). It is possible that mongooses and cats are able to climb diagonal branches and trunks to reach the birds. Cutting was substantially reduced at Mt Hartman (B. L. Rusk in litt. 1998) but, in 1995, 50% of Perseverance was clear-cut for a planned quarry, with half the site now a sanitary land-fill (Rusk and Temple unpubl. data). A lease was granted for a new quarry at this site in 2008, but that was temporarily halted in 2009 (B. L. Rusk in litt. 2006, 2008, 2010). Increases in squatters and cattle in the 1990s resulted in more disturbance at Perseverance, though currently habitat degradation is due to garbage and toxic fumes invading the site from the garbage dump across the road as well as spillover from the adjacent hurricane debris site (B. L. Rusk in litt. 2006, 2008, 2010). Following strong opposition to initial proposals, which would have proved disastrous for the species, modified plans for the development of a Four Seasons resort and golf course at Mt Hartman are now predicted to result in the displacement or loss of four pairs, or 6% of the total population (D. Wege in litt. 2008). Hurricanes pose a pertinent threat now that the remaining population is so small. Following hurricane Ivan in 2004 calling frequency by males during the breeding season appeared to have fallen significantly, possibly as a result of stress owing to limited resources (B. L. Rusk in litt. 2005). The hurricane damaged habitat structure and allowed the invasion of alien vines into suitable dove habitat.|
Conservation Actions Underway
A recovery plan was drafted in 1998 (Rusk et al. 1998) and a four-year GEF/WB funded Dry Forest Biodiversity Conservation Project based on stakeholder input was implemented from 2001-2006. In 2008, an updated 10 year conservation and recovery plan was drafted (B. L. Rusk in litt. 2006, 2008, 2010). In 2011, critical dove habitat on crown lands at the Beauséjour Estate (c.100 acres) received Government of Grenada cabinet approval for its protection and addition to the Perseverance Protected Area (B. L. Rusk in litt. 2012). This species is legally protected from hunting and egg-collecting, but these threats are insignificant. Grenada Dove is the national bird of Grenada, has been a focus of environmental education in schools and ecotourism, and features on stamps. In 1996, parts of the Mt Hartman and Perseverance estates were declared a national park and a protected area, respectively (B. L. Rusk in litt. 1998). The Four Seasons resort development on the Mt Hartman Estate has been extensively modified to minimise impacts on the dove, and the national park has been redesigned and will now comprise one contiguous area of habitat, including 50 of 58 doves known from the Mt Hartman Estate within the new boundaries. The redesigned park will also include significant opportunities for habitat creation (D. Wege in litt. 2008). A predator control programme has been agreed to ensure that land disturbance from construction does not also encourage the migration of predators such as mongoose to the sanctuary. Developers of the Four Seasons resort will fund the construction of traps and hire local residents to set and monitor the traps, and the predator control programme will be monitored by the government of Grenada (J. Ellard in litt. 2008, B. L. Rusk in litt. 2012). The developers agreed to permanent (dove-sensitive) fencing around the perimeter of the national park (D. Wege in litt. 2008, B. L. Rusk in litt. 2012). Clearance for the golf course was to begin in 2009, but no construction has taken place except for a road built across the valley, which was supervised by a dove biologist and did not impact dove territory (B. L. Rusk in litt. 2006, 2008, 2010, 2012). The timing and sequence of hole clearing will be designed to minimise disturbance near dove habitat during the breeding season and allow for the movement of doves into protected habitat before territorial behaviour begins. Recent clearing on the development lands for farming and veterinary activities can limit this movement, and is being addressed. Dove habitats on private lands at Beauséjour, Grenville Vale and Woodford, all IBAs, are recommended for protection in the 2010 Conservation and Management Plan for Perseverance Protected Area. All dove habitat are IBAs and are included in Grenada's System Plan for Parks and Protected Areas. Currently, all remaining dove habitat is on unprotected, privately owned land. A legislative review to address private lands slated for protection has taken place (B. L. Rusk in litt. 2012). Conservation Actions Proposed
Eliminate/minimise further habitat loss. Formally protect important habitat that falls within private lands (Rusk 2011). Carry out regular surveys to monitor population trends and determine the sex ratio (and therefore the actual population) of remaining birds. Monitor rates of habitat loss and degradation. Finalise and implement the revised recovery plan. Ensure that the Mt Hartman and Perseverance reserves are effectively protected. Develop incentives/regulations for protection of dove habitat on private residential lots in the south-west (adjacent to Mt Hartman), and Beauséjour and Woodford on the west coast (B. L. Rusk in litt. 2012). Restore habitat at existing and new sites. Establish two new subpopulations (Rusk et al. 1998) and consider establishing a captive breeding population.
|Citation:||BirdLife International 2013. Leptotila wellsi. The IUCN Red List of Threatened Species. Version 2014.2. <www.iucnredlist.org>. Downloaded on 22 September 2014.|
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