A Global Review of Lizard Clutch Sizes

by Biologic Environmental Survey
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In a new paper recently published in the journal Global Ecology and Biogeography, Biologic Senior Zoologist Ryan Ellis and group of international collaborators presented the results of a global review of lizard clutch sizes and what influences their diversity and distribution.

 The paper, titled The global diversity and distribution of lizard clutch sizes found that lizards generally lay larger clutches at higher altitudes, and in more productive and seasonal environments, showing a similar pattern to that seen in birds. Species occurring at low altitudes and on islands tend to lay smaller fixed sized clutch sizes. Environmental influences such as temperature and precipitation was not shown to be related to clutch size overall. With the exception of Africa, these patterns were consistent across continents where lizards occur. In Africa however, clutch sizes were often larger at lower altitudes.

 This led the authors to suggest that shorter activity seasons and the abundance of resources were the main drivers for species evolving to produce larger clutches in higher altitude and highly seasonal regions, and that the occurrence of these conditions may also be unfavorable for, and therefore influence the limited distribution of, fixed-clutch species.

 For more information or a copy of the paper, please feel free to contact the Biologic Admin Team or Ryan directly.

Photo: A dinosaur like hatchling plain tree Gehyra (Gehyra gemina) emerges from its egg (R.J. Ellis).
Photo: A dinosaur like hatchling plain tree Gehyra (Gehyra gemina) emerges from its egg (R.J. Ellis).




A large-scale Automated Radio Telemetry Network for Monitoring Movements of Terrestrial wildlife in Australia

by Biologic Environmental Survey
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Congratulations to Biologic’s zoologist Tom Rasmussen, who is the co-author of a recently published paper “ A large-scale automated radio telemetry network for monitoring movements of terrestrial wildlife in Australia”.

The paper discusses a rapidly expanding cooperative automated radio-tracking global network (Motus) which Tom helped to introduce to Australia and which Biologic have used to monitor movements of multiple threatened species in WA.

The article is publicly available from here: https://publications.rzsnsw.org.au/doi/pdf/10.7882/AZ.2019.026


More new Gehyra species!

by Biologic Environmental Survey
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More new Gehyra species, six to be exact, were just described in a recent paper co-authored by one of Biologic’s Senior Zoologists, Ryan Ellis.

The paper (available open access HERE) resolves the taxonomy of the Gehyra australis and Gehyra koira species complexes, which occur across the monsoon tropics of northern Australia.

The paper provides a redescription of two species (G. australis and G. koira), redescription of G. ipsa as a full species (formerly G. koira ipsa), description of three new species within the G. australis complex (G. arnhemica, G. gemina, and G. lauta) and three within the G. koira complex (G. calcitectus, G. chimera and G. lapistola).

The new species are a great example of cryptic species (i.e. species that are genetically distinct yet still look very similar) and that species can evolve to be genetically distinct without the way they look differing great deal (why change if you don’t need to?). For example, one of the new species (G. chimera) is genetically more closely related to G. koira but looks more similar to species in the G. australis complex.

The Biologic team is looking forward to getting up into the Kimberley and getting some of these new species in hand in the near future.


Photo: Gehyra Koira at Theda Station, Western Australia. Taken by R.J. Ellis