Mr John Gould

For oviparous animals such as amphibians, the presence or absence of conspecifics can influence site selection, with each life history stage potentially influencing the decision-making process in a different manner. In the present study, we tested the effect of conspecific life history stage on oviposition site selection in the sandpaper frog, Lechriodus fletcheri. We quantified preferences for spawning in pools that were unused by conspecifics, as well as pools with conspecific spawn or tadpoles present, or both. The study included two ecological contexts: a system of naturally occurring breeding pools and a field experiment with 40 artificial pools that controlled for habitat variation. Mothers preferred to oviposit in pools that already contained conspecific spawn, despite the likelihood of intense resource competition upon offspring hatching. This could be due to the potential benefits obtained by providing offspring access to a significant nutrient supply upon hatching via cannibalism of conspecific tadpoles and might be an important adaptation for completing tadpole development in highly ephemeral and resource-limited pools prior to desiccation. In contrast, mothers avoided ovipositing in pools with conspecific tadpoles, a probable adaptation to avoid their own offspring from becoming victims of cannibalism themselves prior to hatching. Such nuances in the effect of conspecific presence on offspring survival highlight the often complex decision-making process that amphibians need to make when selecting oviposition sites, as well as the influence cannibalism can have on the evolution of reproductive behaviour.

Human modification of natural landscapes is a key threatening process contributing to the decline of global biodiversity. Amphibians are particularly vulnerable to this threat, with over a third of species threatened as a direct result. However, some habitat modifications may be less detrimental than others, with some species known to successfully thrive in certain artificial habitats while others undergo further declines. Yet, recognizing how amphibians respond to different habitat modifications remains limited, particularly on a global scale. Herein, we examine the known artificial habitat associations of amphibian species globally, demonstrating artificial habitat use is dependent on their conservation status, life history, taxonomic order, and geographical location. Approximately one-third of all amphibians were found to use artificial habitats, including nearly half of all non-threatened and one-sixth of threatened species, with usage decreasing as conservation status increased. Terrestrial, generalist, and caecilian species were much more likely to use artificial habitats. Non-threatened species were more likely to utilize artificial habitats such as aquaculture ponds, pastureland, canals, excavations, urban areas, and rural gardens. Plantations, heavily degraded former forests, and wastewater treatment areas contained a greater proportion of threatened species, particularly in Afrotropical, Indomalayan, and Oceanian regions. Countries with the most amphibians utilizing artificial habitats were Brazil, Colombia, Peru, Madagascar, and Ecuador. However, the greatest number of threatened species using artificial habitats were found in Mexico, Madagascar, India, Sri Lanka, and China. We highlight the potential value or threat of each artificial habitat type, which may be used to better focus valuable conservation efforts.

The amphibian chytrid fungus, Batrachochytrium dendrobatidis (Bd), is an infectious disease responsible for the worldwide decline of amphibian species. To mitigate these declines, it is necessary to identify the various vectors by which the fungus can be transmitted between individuals and populations. The objective of this study was to determine whether adult female mosquitoes can carry and transfer Bd fungal cells. Mosquitoes were exposed to netting soaked in a live Bd zoospore suspension to determine whether they are able to externally acquire the fungus. Another group was placed into containers with a sterile and Bd-inoculated agar plate to determine whether mosquitoes could transfer Bd between these surfaces. Bd DNA was found to be present on mosquito legs exposed to inoculated netting and agar plates suggesting that Bd can be transmitted by the mosquito over short distances. This is the first study to demonstrate that an insect host may be a mechanical vector of Bd and suggests that we should begin to consider the role of mosquitoes in the dissemination and control of the fungus.