Table 4. Studies reporting the results of observational studies on the use of habitats by communities of lizards.  Some studies conclude that competition is important (either currently or in the past), while other studies conclude that something other than competition is driving the observed habitat use in the community.

Studies concluding competition important
Barbault and Maury (1981); Barbault (1991)

Two or more species may coexist because species-specific preferences allow for coexistence

Dunham (1983)

Overlap in microhabitat use between Sceloporus merriami and Urosaurus ornatus decreased when food abundance is lower and increased when food abundance is higher.

Fuentes and Cancino (1979)

Interaction between habitat use and predation allow Liolaemus platei and L. nigromaculatus to coexist.

Howard and Hailey (1999)        

Four species of sympatric lizards living on rocks in Zimbabwe segregate spatially.  Indirect evidence (e.g., a habitat shift by another species Mabuya striata in the absence of M. quinquetaeniata) possibly implies niche segregation on the basis of habitat use allows coexistence.

Huey et al. (1974)

Two species of fossorial lizards (Typhlosaurus) from the Kalahari desert use different microhabitats perhaps as the result of interference competition, but may also result from species specific adaptations to different habitats that allow coexistence

Jenssen (1973)

When Anolis opalinus is sympatric with A. lineatopus it perches higher than where it is not sympatric with A. lineatopus.

Lister (1976)

In the absence of potential competitors, anoles in the West Indies expand their structural niche (i.e, they use a broader range of perches)

Marcellini and Mackey (1970)

The arboreality of Sceloporus occidentalis and the terrestriality of S. graciosus where they are sympatric reduces competition

Medel et al. (1988)

Liolaemus tenuis shifts to higher perches in the presence of L. pictus, presumably as the result of observed aggressive interactions between members of these two species

Moermond (1979a)

The presence or absence of suitable habitat or suitable perch structures in a given area can determine the presence or absence of Anolis species in a community

Ortiz and Jenssen (1982); Jenssen et al. (1984)

Anolis cooki shift their habitat use in the presence of A. cristatellus, and intraspecific competition might explain male perches in both species

Patterson (1992)

Microhabitat use and food use differs between species of New Zealand skinks (genus Leiolopisma) and may allow coexistence by reducing overlap.  Differences in microhabitat use appear to be enforced by aggressive interactions, suggesting competition may be driving the segregation

Rand (1964a)

Habitat segregation observed in the anoles of Puerto Rico may be explained by competition.

Rose (1976)

Competition is one of many possible explanations for the habitat segregation of Sceloporus occidentalis and S. graciosus

Schoener (1970)

Sympatric Anolis species in the Bahamas often have cycling perch use such that no two species use the same perch at the same time of day

Schoener (1975)

Habitat shifts observed in West Indian Anolis and some species of Leiocephalus are driven by competition

Schoener (1977)

Partitioning of resources based on habitat segregation can reduce competition and allow coexistence of two or more lizard species

Schoener and Adler (1991)

When habitat is taken into account, signs of species interactions based on distributional patterns in the Bahamas become increasingly negative, suggesting habitat may influence the importance of species interactions in affecting species distributions

Vitt (1995)

Lizards of the caatinga of NE Brazil apparently segregate on the basis of microhabitat use

Vitt and Avila-Pires (1998)

Differential habitat use appears to facilitate the coexistence of two sympatric Neusticurus species

Vitt et al. (1998b)

Suggest that the fact that Neusticurus ecpleopus only occurs along the edges of streams and swamps in Amazonian rain forest precludes it from interacting with other lizard species that might be competitors.

Vitt et al. (1999, 2000)

Differences in habitat use are, in part, responsible for niche segregation in Amazonian teiid lizards, as well as a larger group of Amazonian lizards, and may be the result of past species interactions, such as competition

Studies concluding something else important
Ballinger et al. (1990) Did not think that competition influenced the niches of the lizards occurring on Arapaho Prairie in western Nebraska
Barbault and Maury (1981)

Segregation between species in the Chihuahuan Desert need not be the result of competition, in spite of the fact that species appear to be in very distinct habitats

Davis and Verbeek (1972)

Competition for rock perches is "unlikely" between Sceloporus occidentalis and Uta stansburiana

Martín-Vallejo et al. (1995)

Suggested that the difference in microdistribution of Podarcis muralis and P. hispanica may be due to physiological/historical constraints, or competition

Ortega et al. (1982); Barbault et al. (1985)

Habitat specialization of lizards in the Sierra Madre probably not due to competition, but instead is the result of the effects of several other factors

Rand and Humphrey (1968)

Did not believe competition was the primary force driving habitat use in lizards in Panama

Stamps (1983)

Ontogenetic habitat shift of Anolis aeneus not influenced by interspecific aggression.

Vitt et al. (1981)    

Perch use differences among Urosaurus graciosus, U. ornatus, and Sceloporus magister are not necessarily due to competition but instead may be related to responses to the physical environment