Glover’s Reef Marine Reserve

National populations of several of the plant species found on the cayes of the Atoll have undergone significant decline in recent years, as coastal beaches are cleared and developed for coconut plantations, tourism and residential use. Those cayes with significant areas of littoral forest and herbaceous beach communities, such as Middle Caye and Northeast Caye, in particular, play a crucial role in the continued survival of these ecosystems.

A total of 34 naturally occurring native species of plant, representing 22 families, have been reliably identified as currently occurring within the littoral forest and herbaceous beach community of the cayes of Glover’s Reef Atoll (Meadows 1998; Walker, 2007). Whilst earlier surveys recorded up to 40 species, past anthropogenic impacts have had huge impacts upon the flora of the cayes – and the introduced coconut palm continues to have a very major impact. An comprehensive, updated vegetation assessment of the cayes would be beneficial.

There is quite a diverse species assemblage for this ecosystem type, especially in view of the distance of Glover’s Reef Atoll from other island and mainland populations. As previously noted (Stoddart, 1962), the flora of island ecosystems is dynamic in species occurrence and stature – changes often reflecting both natural cycles and anthropogenic impacts.

Species of the littoral forest and of the herbaceous beach community play critical roles in the stabilization of the cayes, and in providing habitat for the fauna. The main plant assemblages can be seen in the table below.

Mammals

Whilst the cayes themselves have no native mammal fauna, there are reports of small rodents on two of the cayes, presumably transported to the Atoll in materials, from the mainland.

Spotted, bottlenose and spinner dolphins are seen all year in the deeper waters outside the Atoll and bottlenosed dolphins also venture into the Atoll lagoon, through the channels, and a recent sighting of a large West Indian Manatee (Trichechus manatus) on the outer edge of Glover’s Reef Atoll in May, 2007, confirms that this vulnerable species (IUCN, 2007) does occasionally reach the Atoll (Gibson, pers com., 2007).

Birds

The first recorded bird survey of the Atoll was conducted by Salvin in 1862. In 1998 Meadows also carried out a bird survey of Middle Caye (Bright, 1999), and a more recent visit to the Atoll (Balderamas, pers. com. 2007) produced a complimentary species list, bringing the total number of species recorded for the Atoll to 84. These last two surveys, both coinciding with the autumn and spring migrations, emphasized the importance of the cayes for monitoring the movements of these migratory species, and protecting the caye vegetation on which they rely for food. Only a few species, such as brown pelicans (Pelecanus occidentalis), kingfishers, herons and ospreys (Pandion haliaetus), are resident on the caye, as is the near-threatened white-crowned pigeon (Columba leucocephala). Ospreys nest both on the island and artificial nesting platforms (Gibson 1988, Bright 1999). Least terns were reported as nesting on the ground on Long Caye North during April and May, though this small caye has been heavily eroded by Hurricane Mitch, and it is uncertain whether it is still utilized by the terns.

As with the other Atolls of Belize, Glover's Reef is considered important as a migratory bird stopover refueling point. Many thousands of migrants that have meandered off course end up on the Atoll cayes every spring and fall.

The species composition of Glover’s Reef is very comparable with that of Half Moon Caye, on Lighthouse Reef Atoll (Walker and Walker, 2005), - a comparison of the migratory species on these Atolls with those of migratory species surveys on the remote San Andres Island, offshore of Columbia shows an approximately 87% overlap of migratory species. Of these, the bluewinged, golden-winged, yellow, blackburninan, cerulean, magnolia, prothonatory, wormeating, Swainson’s and hooded warblers are largely believed to fly trans-gulf, relying on making landfall on the Yucatan Peninsula (N. Bayly, pers. com.). An interesting addition to the list of migrants making a stopover on the island is the cedar waxwing, with a flock of approximately 80 individuals observed feeding on the fruit of Erythralis fruticosa, an important food source for many of the migratory birds passing through (Figure 31; Walker, 2007). Other migrants that might occur on the caye but have not yet been recorded include the American kestrel, blacknecked stilt, common tern, least tern, white-winged dove, mourning dove, common nighthawk, olive-sided, alder and least flycatcher, gray kingbird, and Lincoln’s sparrow (L.Jones, pers. com.).

Reptiles of Glover’s Reef Atoll

The herpetofauna of Glover’s Reef Atoll is comprised entirely of reptile species. No amphibians have been recorded there, as the saline conditions, absence of freshwater sources, and distance from the mainland are the main determinants precluding their presence.

Seven reptile species have been recorded from Glover’s Reef, four terrestrial (residents of the littoral forest), and the three marine turtles (loggerhead, green and hawksbill). The three marine turtles are all considered to be globally threatened, the hawksbill being listed as ‘critically endangered’, and the green and loggerhead being ‘endangered’. Additionally, the island leaftoed gecko is rated as Near Threatened on Belize’s National List of Critical Species (Meerman, 2005). A crocodile, presumed to be the American Crocodile (C. acutus), has been observed on the Atoll - it is believed that fishermen brought a juvenile crocodile there from Turneffe Islands sometime during the period 1993 -1995 (M. Paz, pers. com). Recent reports suggest that it has possibly been killed.

A second gecko species, St. George’s island gecko (Aristelliger georgeensis), was recorded on Middle Caye for the first time (Walker, 2007), and was found to be significantly more abundant than the endemic Phyllodactylus insularis. Aristelliger georgeensis, is considered to be a human commensal (Lee, 2000), but it is unclear whether it is a recent colonizer on the island, or whether females and sub-adults had previously been mistaken for Phyllodactylus insularis. The Brown anole (Anolis sagrei) is abundant on the cayes, and is principally active on the ground and up to 2m elevation on vegetation. Black iguanas (Ctenosaura similis) are common on the cayes of Glover’s Reef, and are considered part of the natural fauna.

There are two invertebrate species of commercial importance to the Glover’s Reef fishery - the Caribbean Spiny Lobster (Panulirus argus) and Queen conch (Strombus gigas), both of which are fished extensively throughout Belize.

There are a number of fin fishes present on the Atoll but some of the more economically important species include the Nassau Grouper, Black Grouper and Mutton Snapper. Sport fishing fishes include the Permit and Bonefish are present. There are also a number of parrotfish’s and grazers present.