The global diversity and distribution of lizard clutch sizes

MEIRI, SHAI; AVILA, LUCIANO; BAUER, AARON M.; CHAPPLE, DAVID G.; DAS, INDRANEIL; DOAN, TIFFANY M.; DOUGHTY, PAUL; ELLIS, RYAN; GRISMER, LEE; KRAUS, FRED; MORANDO, MARIANA; OLIVER, PAUL; PINCHEIRA?DONOSO, DANIEL; RIBEIRO?JUNIOR, MARCO ANTONIO; SHEA, GLENN; TORRES?CARVAJAL, OMAR; SLAVENKO, ALEX; ROLL, URI

Global Ecology and Biogeography

WILEY-BLACKWELL PUBLISHING, INC

Año: 2020

1466-822X

Aim: Clutch size is a key life-history trait. In lizards, it ranges over two orders of magnitude.The global drivers of spatial and phylogenetic variation in clutch have beenextensively studied in birds, but such tests in other organisms are lacking. To test thegenerality of latitudinal gradients in clutch size, and their putative drivers, we presentthe first global-scale analysis of clutch sizes across lizard taxa.Location: Global.Time period: Recent.Major taxa studied: Lizards (Reptilia, Squamata, Sauria).Methods: We analysed clutch-size data for over 3,900 lizard species, using phylogeneticgeneralized least-square regression to study the relationships between clutchsizes and environmental (temperature, precipitation, seasonality, primary productivity,insularity) and ecological factors (body mass, insularity, activity times, and microhabitatuse).Results: Larger clutches are laid at higher latitudes and in more productive andseasonal environments. Insular taxa lay smaller clutches on average. Temperature and precipitation per se are unrelated to clutch sizes. In Africa, patterns differ fromthose on other continents. Lineages laying small fixed clutches are restricted to lowlatitudes.Main conclusions: We suggest that the constraint imposed by a short activity season,coupled with abundant resources, is the main driver of large-clutch evolution at highlatitudes and in highly seasonal regions. We hypothesize that such conditions ? whichare unsuitable for species constrained to laying multiple small clutches ? may limit thedistribution of fixed-clutch taxa.