Population age structure is an important parameter for wildlife population modelling. However, for many species it is not possible to accurately assess the age of adult individuals. We present a hypothetical example to illustrate a previously described method of determining population age structure from the survivorship of individuals of unknown ages that to our knowledge is unused in the fields of zoology and ecology. We then apply this method to data collected over 10 years for a population of wild platypuses (Ornithorhynchus anatinus), a species whose adult individuals cannot be accurately aged and for which only limited data on life history characteristics are available. Our results show a lower mortality rate over the first years of life of platypuses than the one previous study available for comparison, and suggested a Type I or Type III survivorship curve.

Two threatened species of Tympanocryptis (T. lineata and T. osbornei) (the grassland earless dragon clade) are compared for population structure, growth and reproduction from sites around the Australian Capital Territory (ACT) and near Cooma in New South Wales (NSW). Both species showed similar proportions of adults, intermediates and juveniles, as well as similar proportions of adult males and females. Growth patterns had a rapid increase in snout–vent length (SVL) in juveniles. Predicted adult SVL was the same in both species, and females in both species had greater SVL than males. In one year, the appearance of juveniles in the populations was later in T. osbornei than in T. lineata, but that may have been a result of cooler temperatures in the austral summer. Body condition was slightly better in adults of T. osbornei than T. lineata as the former were heavier and shorter. Longevity in the field was similar for both species, being slightly greater than two years, but reproduction may have occurred only once during their lifetime. Colouration associated with reproduction appeared to be the same for both species. Future work can use this information to determine how populations of Tympanocryptis sp. vary in response to environmental changes.

Shepherd’s beaked whale (Tasmacetus shepherdi) is one of the least known beaked whales. Its distribution has been described as circumpolar, between latitudes 26°S and 50°S in the Southern Hemisphere based on scarce at-sea sightings and strandings. In March 2024, the remains of a cetacean were found in the Jurabi Coastal Park in North West Cape, Western Australia, 21°48′S, 114°06′E. Heavy predation on the carcass did not allow morphological identification. DNA sequencing was used to verify its identity as T. shepherdi, representing a 600 km extension to the previous northernmost record for this species.