Interim profile, incomplete information
Taxonomic name: Norops grahami Gray 1845
Synonyms: Anolis grahami Gray, 1845, Anolis heterolepis Hallowell, 1856, Anolis iodurus Gosse, 1850, Anolis punctatissimus Hallowell, 1856
Common names: common lizard (English), Graham's anole (English), Jamaican anole (English)
Organism type: reptile
The Jamaican anole Norops grahami was introduced to Bermuda from Jamaica in 1905 to reduce populations of the fruit fly (Ceratitis capitata). In 1958 it was observed to predate heavily on beneficial insect species brought in to control introduced scale insects, subsequently resulting in the introduction of the great kiskadee (Pitangus sulphuratus), now a serious threat in itself. More recently N. grahami has been observed to predate on, and compete with juveniles of the 'Critically Endangered (CR)' Bermudian rock lizard (Eumeces longirostris).
Norops grahami has a mean snout to vent length of 68.9 mm for males (Losos, 1996).
planted forests, ruderal/disturbed, scrub/shrublands, urban areas
Although primarily aboreal, Norops grahami occupies a very wide range of habitats on Bermuda. It is observed commonly on trunks and branches of trees, on houses, stone walls, fences, piles of timber or rubble, in the taller weeds of open fields, and on open ground up to 25 feet from cover (Wingate, 1965). This species remains active all year on Bermuda although on windy overcast days it generally takes shelter near the ground in dense shrubbery, grasses, or in rubble walls. It commonly takes refuge from danger by running down into matted ground cover and crevices of walls, but will also escape upwards in larger shrubs and trees (Wingate, 1965).
Noted to feed mainly on insects,Norops grahami and other introduced anole lizards were observed feeding heavily on insect biological control agents that were brought in to control introduced scale insect (Simmonds, 1958); this is thought to be partly resposible for the failure of the Coccinellidid Cryptolaemus montrouzieri to establish itself (Bennett & Hughes, 1958).
N. grahami has also been observed to prey on juveniles of the 'Critically Endangered (CR)' Bermudian rock lizard (Eumeces longirostris) (Griffith & Wingate, 1994; in Bacon et al., 2006) and predate on the eggs of the native, eastern blue bird (Sialia sialis) (Thomas, 2004; in Bacon et al., 2006). Although primaily aboreal, juvenile N. grahami can be observed foraging on the ground in skink habitats, and therefore almost certainly competing directly at times with hatchling and juvenile E. longirostris (Edgar, pers. comm.; in Bacon et al., 2006).
Norops grahami was first introduced to Bermuda as a biocontrol agent to reduce populations of the fruit fly (Ceratitis capitata) in 1905 (Bennett & Hughes, 1959; Wingate, 1965).
Subspecies Norops grahami grahami is reported from western Jamaica and Cabarita Island off Port Maria; and N. g. aquarum from Portland and St. Thomas parishes, Jamaica (Reptiles Database, 2010).
N. grahami is the most widespread and common of three introduced anole lizards present on Bermuda; the others are the Barbuda Bank tree anole (see Anolis leachii) and the Barbados anole (Anolis extremus) (Wingate, 1965). The effects of these lizards, particularly N. grahami led to the introduction of the great kiskadee (Pitangus sulphuratus) as a biocontrol agent in 1957. However, this biocontrol attempt was a failure; P. sulphuratus has been implicated in the population declines of native insect, bird and reptile species on Bermuda (Cheesman & Clubbe, 2007; Davenport et al., 2008).
Native range: Jamaica (Reptiles Database, 2010).
Known introduced range: Bermuda (Reptiles Database, 2010).
Introduction pathways to new locations
Biological control: Norops grahami was introduced to Bermuda to control populations of the fruit fly Ceratitis capitata in 1905 (Wingate, 1965) as they were believed to be responsible for suppressing various fruit fly populations on Jamaica (Bennett & Hughes, 1959).
Local dispersal methods
Intentional release: As a novel species in Bermuda, Norops grahami is reported to have been collected by people and released in gardens at the far ends of the island (Wingate, 1965).
Biological control: The great kiskadee (Pitangus sulphuratus) was introduced as a biocontrol agent for introduced anole lizards including the brown anole (Norops sagrei) in 1957. However, this biocontrol attempt was a failure, with P. sulphuratus playing a significant role in the population declines of native insect, bird and reptile species on Bermuda (Cheesman & Clubbe, 2007; Davenport et al., 2008).
The diet of Norops grahami was found to consist almost entirely of minute foliage insects (Simmonds, 1958). In order of abundance these included: Hymenoptera, especially Brachymyrmex, Pheidole, Iridomyrmex (Formicidae), Aphytes (Eulophidae) and Chalcids (Chalcidae). Homoptera, especially Aphis (Aphidae), Pulvinaria (Coccidae) and Psocidae. Diptera, various species, especially Hippelates. Coleoptera, various small species, especially Ayza, Cybocephalus, Lindorus (Coccinellidae). Lepidoptera, various species, adults and larvae (Simmonds, 1958). There was little seasonal variation in either quantity or variety of food taken, but individuals exhibited great variation in the composition of their diet; this was thought to be due to local variation in insect populations and possible habituation of some individuals to eating one particular species (Simmonds, 1958). In addition to insects, N. grahami has also been observed to feed on juveniles of native skinks and the eggs of native birds on Bermuda (see General Impacts).
Compiled by: IUCN SSC Invasive Species Specialist Group (ISSG) with support from the Overseas Territories Environmental Programme (OTEP) project XOT603, a joint project with the Cayman Islands Government - Department of Environment
Last Modified: Tuesday, 8 June 2010