Reproductive Effort in Anoline Lizards

Abstract

Lizards in the large neotropical genus Anolis exhibit an unusual mode of reproduction; all species lay a clutch of a single egg. In contrast, the more typical pattern for lizards is a multi—egg clutch in which the number of eggs increases with female size both inter— and intra—specifically. In Anolis low clutch number is associated with a potential for frequent ovipositions. Field rates for several tropical forest species are one egg every 1—2 wk. Thus, high rates of egg production coupled with a generation time of about 4 mo gives these species very high reproductive potentials. The evolution of low clutch number in relatively small tropical lizards has several non—exclusive explanations. One, which is specific to arboreal lizards (Anolis, geckonids, and some scincids), involves their adhesive toe pads, which facilitate climbing. Because pad area increases by the square of linear dimensions while body weight increases by the cube, pad area may put a limit both on lizard size and the weight of reproductive materials carried at any one time. A second and more general explanation involves the association between clutch size and climatic regime. Lizards in temperate and seasonal tropical habitats have a larger clutch number than do lizards of relatively equable tropical habitats. In these latter habitats short—term fluctuations in rainfall (associated with reproductive success) favor genotypes that are opportunistic reproducers, and relatively high predation intensity favors r—selected life history patterns. Anoline lizards are “extreme” examples of species living under such selective regimes.

Autoecology of Dryadosaura nordestina (Squamata: Gymnophthalmidae) from Atlantic forest fragments in Northeastern Brazil

“…Aquino, unpubl. data), Leposoma scincoides (TEIXEIRA & FONSECA 2003), Cercosaura eigenmannii (Griffin, 1917) (VITT et al 1998), Alopoglossus angulatus (Linnaeus, 1758) and A. atriventis (TINKLE et al 1970), leading females to produce clutches in a fast, consecutive, and continuous fashion (ANDREWS & RAND 1974, VITT 1986, DOUGHTY 1997, PIANKA & VITT 2003. Indeed, most reproduction of D. nordestina occurs from May to June (when most reproductive females and the only gravid ones were found), with most juveniles emerging subsequently from July through November.…”

The Evolution of Maternal Investment in Lizards: An Experimental and Comparative Analysis of Egg Size and Its Effects on Offspring Performance

“…Comparative studies suggest that offspring size is correlated with adult life-history traits (Blueweiss et al, 1978;CluttonBrock and Harvey, 1979;Peters, 1983;Calder, 1984) in a variety of taxa, including mammals (Leutenegger, 1976(Leutenegger, , 1979Steams, 1983;Harvey and Clutton-Brock, 1985;Gittleman, 1986), reptiles (Andrews and Rand, 1974;Steams, 1984;Dunham and Miles, 1985), and amphibians (Kaplan and Salthe, 1979). These allometric relationships are thought to reflect underlying physiological and functional constraints on life histories and, as such, show taxon-specific relationships (Steams, 1980;Dunham et a1., 1988).…”

Size and Environmental Predictability for Salamanders

“…Also, traits that help reduce the variability in reproductive output produced by a variable pattern of energy availability have not received much attention. Andrews and Rand (1974) suggested that flexibility in the timing of egg deposition was an important adaptation of Anolis lizards to unpredictable, short-term climatic fluctuations. This flexibility generally seems optimal to an individual when selection favors both increased longevity and high reproductive output, as was argued for B. attenuatus.…”