The majority of species in the scincid genus Emoia (Squamata: Scincidae) have a fixed clutch size of two eggs per clutch and produce between two and four clutches per year. One lineage within Emoia, the Emoia samoensis species group, consists of 13 species occurring in Melanesia and the islands of the southwestern Pacific Ocean, and exhibits variation in clutch size, with previously reported clutch sizes of two to five eggs. Little is known about reproduction in several members of this lineage including Emoia sanfordi, a large-bodied lizard endemic to the archipelago of Vanuatu in the South Pacific. We analyzed reproduction and clutch size in E. sanfordi females and discovered that there is a substantial amount of intraspecific variation, with clutch size ranging from two to seven eggs, with a modal clutch size of five eggs. Females were reproductively active throughout the study period of June through October and appear to be laying multiple clutches. The variation in clutch size seen in E. sanfordi is congruent with the variation previously reported within other closely related species.
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http://dx.doi.org/10.2108/zsj.25.843 | DOI Listing |
Environ Toxicol Chem
January 2025
Centro di Referenza Nazionale per l'Analisi e Studio di Correlazione tra Ambiente, Istituto Zooprofilattico Sperimentale del Mezzogiorno, Portici, Italy.
A statistical procedure has been developed to derive a screening value from an observational study related to the developmental toxicity observed in loggerhead turtle (Caretta caretta) eggs exposed to long chain per- and polyfluoroalkyl substances (PFAS). A dataset of 41 nests in which the hatching rate was inversely correlated with the increase in the PFAS concentration in unhatched eggs was processed via a categorical regression approach. After outliers identification and removal, categorical regression analysis tested the relationships of the outcomes with the following parameters: perfluoro-nonanoic (PFNA), decanoic (PFDA), undecanoic (PFUdA), and dodecanoic (PFDoA) acids; perfluoroctansulfonate (PFOS); polychlorobiphenyls (PCBs) 28, 52, 101, 138, 153, 180; lead (Pb), total mercury (Hgtot), and cadmium (Cd); and other factors, such as "nest site," "clutch size," "incubation duration," and "nest minimum depth," as confounders/modifiers of the hatching rate.
View Article and Find Full Text PDFSci Rep
January 2025
School of Life and Environmental Sciences, University of Lincoln, Lincoln, LN6 7DL, UK.
Community science can provide crucial insights into population dynamics and demography. To date, its effectiveness for understanding human-wildlife interactions has not been tested. This is vital for designing effective wildlife management plans.
View Article and Find Full Text PDFSci Total Environ
January 2025
Aquatic Health Program, UC Davis, 1 Shields Ave, Davis, CA 95616, USA.
Health and nutrition of individuals are tied to reproductive success, which determines population viability. Environmental variability and anthropogenic effects can affect the health and nutrition of a species leading to reproductive repercussions which can hinder recovery of endangered populations. Indices of health and nutrition were examined for an imperiled species, delta smelt, Hypomesus transpacificus, in relation to their reproductive status to evaluate the effects of hydrologic conditions in the San Francisco Estuary and Sacramento-San Joaquin Delta.
View Article and Find Full Text PDFR Soc Open Sci
January 2025
Laboratory of Animal Sociology, Department of Biology, Graduate School of Science, Osaka City University, Osaka 558-8585, Japan.
In animals where males engage in multiple matings, sperm depletion can substantially reduce the reproductive success of both sexes. However, little is known about how successive matings affect sperm depletion, fertilization rates and mating behaviour. Here, we investigated this phenomenon under laboratory conditions.
View Article and Find Full Text PDFAbstractThe ability to secure food for offspring and withstand the cost of reproduction favors high-quality mothers that overproduce the larger sex, typically sons, only if they will receive adequate food, as this should enhance these sons' fitness returns. However, high-quality daughters ensure that grandoffspring receive quality parental care and may possess greater reproductive value than their brothers, favoring daughters also from high-quality mothers. Using a mixed cross-fostering approach, we investigated effects of early rearing conditions, covariance between breeders and their genetic parents in parental quality, and primary offspring sex ratios in Carolina wrens.
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