Knowing the ages of animals in wild populations is important for conservation modelling. But for many species it is not possible to determine an adult individual’s age. By looking at how long individuals of unknown ages live, this report uses a hypothetical population of unicorns to illustrate a method of working out the proportion of animals in a population that are any particular age, and then applies the same method to a population of wild platypuses. Photograph by Joanne Connolly.

We conducted molecular identification of the highly depredated remains of a cetacean specimen found on a beach in the Jurabi Coastal Park, Western Australia. The specimen was identified as Shepherd’s beaked whale (Tasmacetus shepherdi). This represents the most northern occurrence record for this poorly known beaked whale species. Photograph by Michael Cox, Department of Biodiversity, Conservation and Attractions.

Growth of two species of the endangered lizard in the genus Tympanocryptis (T. lineata and T. osbornei) from around the Canberra, ACT, and Cooma, NSW, respectively, is similar over three years, as is the population age structure. Individuals of each species are also able to survive over multiple years. Colour changes with reproduction in females is most obvious for both species in spring and autumn during the year for both species. Image Paul Cooper.