The nesting ecology of the Allen Cays rock iguana was studied on Leaf Cay and Southwest Allen's Cay (= U Cay) in the northern Exuma Islands, Bahamas, during 2001 and 2002. Mating occured in mid-May, and females migrated 30–173 m to potential nest sites in mid to late June. Females often abandoned initial attempts at digging nest burrows, and average time from initiation of the final burrow to completion of a covered nest was six days. At least some females completely buried themselves within the burrow during the final stages of burrow construction and oviposition. Females defended the burrow site during the entire time of construction, and most continued that defense for at least three to four weeks after nest completion. Nests were completed between mid-June and mid-July, but for unknown reasons timing was seven days earlier on U Cay than on Leaf Cay. Nest burrows averaged 149 cm in length and terminal nest chambers usually angled off the main burrow. Depth to the bottom of the egg chamber averaged 28 cm, and was inversely correlated with shadiness of the site, suggesting that females may select depths with preferred temperatures (mean, 31.4 C in this study). Overall, only about one in three females nested each year, although nesting frequency increased with female size such that the largest females usually nest annually. Nest fidelity was common, despite the potential for observer effects; seven of 13 two-year nesters placed nests within 0.7 m of that constructed the previous year.

Nesting females averaged 32 cm snout–vent length (SVL) and 1336 g body mass, and larger, older females nested earlier than smaller, younger ones. Sexual maturity is reached at 26–27 cm SVL, about 750 g body mass, and twelve years of age (nearly twice as old as any previously studied lizard). Longevity of females apparently exceeds 40 years. Clutch size ranged from 1–10 eggs (mean 4.6) and was correlated with female body size and age. Eggs averaged 66 mm in length, 35 mm in width, and 49 g in mass. Egg mass was not correlated with female body size, although egg length was negatively correlated, and egg width was positively correlated with female size. The production of elongate eggs in the smaller females allowed them to invest the same total mass in each egg as a larger female, while being constrained by the limits of the pelvic opening. No trade-off existed between standardized clutch size versus egg size. Relative clutch mass (clutch mass/gravid female body mass × 100) averaged 16.5 and did not vary with female size or age. Hatching apparently occurs in late September and early October after about 80–85 days incubation, with emergence within just a few days. Hatchlings averaged 9.5 cm SVL and 33 g body mass. Survivorship to emergence was 78.9%, and was inversely correlated with soil moisture.

The reproductive ecology of other iguanids (sensu strictu) is reviewed for comparison with that of the Allen Cays rock iguana. Comparisons of these data with those available for other rock iguanas of the genus Cyclura suggest that colonization of smaller islands has produced reductions in adult female body size, clutch size, clutch mass, and relative clutch mass, but no change in egg or hatchling mass. Because this pattern is also demonstrated by a population of Cuban iguanas introduced to a small island only 40 years ago, it may primarily be a proximal response to decreased resource availability and/or physiological processability on small islands rather than an evolved response to reduced predation rates or other factors affecting survivorship.

I present a phylogenetic analysis of the lizard genus Anolis using new morphological data in combination with diverse data from the literature. Ninety-one characters of osteology and external anatomy were completely or partially scored for 174 Anolis species and seven outgroups. These data were combined with data from chromosomes, DNA sequences, allozymes, and immunology and analyzed with parsimony to produce an estimate of Anolis relationships. The genus Anolis was supported as monophyletic. Anolis occultus is sister to the rest of the genus. A South American and Southern Lesser Antillean clade is sister to the Greater Antillean and Northern Lesser Antillean Anolis and a clade of mainland species. Successive clades of Caribbean Alpha Anolis are sister to the Beta Anolis (Norops) clade. Within the Betas, the Jamaican Betas are sister to the remaining Betas, and the Cuban Betas are sister to the monophyletic mainland forms. Other higher-level groupings of previous authors were not supported, but members of some previously-recognized lower-level groups formed clades: roquet series, “Phenacosaurus”, cybotes series, cristatellus species group, bimaculatus series/species group, hendersoni species group, chlorocyanus series, equestris series, grahami series, sagrei series, crassulus species group, gadovii species group, laeviventris species group, nebulosus species group.

To determine the evolutionary relationships within the Anolis cristatellus series, we employed phylogenetic analyses of previously published karyotype and allozyme data as well as newly collected morphological data and mitochondrial DNA sequences (fragments of the 12S RNA and cytochrome b genes). The relationships inferred from continuous maximum likelihood reanalyses of allozyme data were largely poorly supported. A similar analysis of the morphological data gave strong to moderate support for sister relationships of the two included distichoid species, the two trunk-crown species, the grass-bush species A. poncensis and A. pulchellus, and a clade of trunk-ground and grass-bush species. The results of maximum likelihood and Bayesian analyses of the 12S, cyt b, and combined mtDNA data sets were largely congruent, but nonetheless exhibit some differences both with one another and with those based on the morphological data. We therefore took advantage of the additive properties of likelihoods to compare alternative phylogenetic trees and determined that the tree inferred from the combined 12S and cyt b data is also the best estimate of the phylogeny for the morphological and mtDNA data sets considered together. We also performed mixed-model Bayesian analyses of the combined morphology and mtDNA data; the resultant tree was topologically identical to the combined mtDNA tree with generally high nodal support. This phylogenetic hypothesis has a basal dichotomy between the Hispañolan distichoids and the bimaculatus series, on the one hand, and the cristatellus series inhabiting the Puerto Rican Island Bank, its satellite islands, the Bahamas, and St. Croix, on the other. The trunk-crown species form a clade, while the trunk-ground and grass-bush species do not as A. gundlachi, a trunk-ground species, is nested within a clade of grass-bush species. The patterns of relationships among the trunk-ground and grass-bush species suggest that one of these ecomorphs may have been ancestral to the other and that one or both evolved convergently. In the context of our preferred phylogeny and divergence dates estimated by NPRS analyses, we propose several biogeographical hypotheses that explain the current distribution of the cristatellus series. The presence of endemic species on the islands of the Bahamas, Desecheo, Mona, Monita, and St. Croix are likely due to over-water dispersal. Vicariance resulting from Pliocene or Pleistocene changes in sea levels likely explains the occurrence of A. cristatellus (including A. ernestwilliamsi), A. pulchellus, and A. stratulus on different islands of the Puerto Rican Bank.

We describe two new species of Eleutherodactylus that are hypothesized to belong to the E. orcesi Group. Both species are found in Andean habitats of northern Ecuador at elevations above 3000 m. The presence of an anteriorly exposed frontoparietal fontanelle distinguishes the two new species from most other members of the genus, in which the frontoparietal fontanelle is covered by frontoparietal bones. Additionally, both species have fingers and toes with fleshy lateral fringes, and vomerine teeth reduced or absent. The new species differ from one another mostly by tuberculation and coloration patterns.

The anuran genus Eleutherodactylus occurs in Central and South America, as well as the West Indies, and comprises nearly 700 recognized species. The diversity of Eleutherodactylus makes it difficult to study the genus as a whole; as a consequence, several authors have divided the genus in phenetic species groups. This division is based on similarity and is not necessarily congruent with monophyletic groups within the genus. Nevertheless, species groups can be considered as hypotheses of natural (monophyletic) groups. I focus on the E. orcesi Group, which contains eight species distributed in the paramo and montane forests (3000–4150 m) of Colombia and Ecuador. The main objectives in the present study are to: (1) describe the osteology and osteological variation of the species within the E. orcesi Group, (2) diagnose the group based on osteological characters, and (3) search for homologies that might support the monophyly of the group. Osteological descriptions for the eight species were made from cleared-and-double-stained specimens. To minimize effects of heterochrony and sexual dimorphism, only adult females were examined. To determine the validity of potential synapomorphies of the E. orcesi Group, I examined cleared-and-stained specimens of 135 species of Eleutherodactylus and used published information for another 29 species. The skulls of all the species of the Eleutherodactylus orcesi Group have a large portion of the frontoparietal fontanelle exposed anteromedially. I hypothesize that the presence of an exposed frontoparietal fontanelle is homologous in the E. orcesi Group and supports the monophyly of the group. I discuss the presence of this character in species outside the E. orcesi Group and hypothesize that in those species the exposed fontanelle was acquired independently. I provide a list of diagnostic characters for the E. orcesi Group and discuss the variation of some of these characters in relation to the general pattern of morphology found in the genus Eleutherodactylus and other anurans. Finally, I discuss intraspecific variation in several osteological characters of the cranium and postcranium of species of the E. orcesi Group, especially E. racemus.