Monitoring population trends is important for evaluating the effectiveness of conservation interventions. An annual aerial census of three crane species, the Grey Crowned Crane Balearica regulorum, Blue Crane Anthropoides paradiseus and Wattled Crane Bugeranus carunculatus, was performed in KwaZulu-Natal province, South Africa over the past 23 years. These crane species are listed as ‘Endangered’, ‘Vulnerable’, and ‘Vulnerable’, respectively, on the IUCN Red List. KwaZulu-Natal was chosen as a key site for monitoring as it covers an important region for cranes that has received concerted conservation effort since the 1980s. These annual surveys are conducted by Ezemvelo KwaZulu-Natal Wildlife, a provincial conservation agency, and the Endangered Wildlife Trust, a conservation non-profit organisation. We estimated crane population trends from data collected by means of standardised surveys conducted between 2003 and 2019. Results from the surveys show a steady and significant increase in the population size of all three crane species. Interventions including power line collision mitigation and engagement with landowners have been implemented in formal conservation programs to protect these cranes. Results from the annual census suggest that conservation interventions have been effective.

A long standing problem, which has its roots in low-dimensional homotopy theory, is to classify all finite groups G for which the integral group ring ℤG has stably free cancellation (SFC). We extend results of R. G. Swan by giving a condition for SFC and use this to show that ℤG has SFC provided at most one copy of the quaternions ℍ occurs in the Wedderburn decomposition of the real group ring ℝG. This generalises the Eichler condition in the case of integral group rings.

The Pugh Method of Controlled Convergence is evaluated based on social choice theory, both from an axiomatic basis, and by examining all possible cases of attribute ranks for a range of numbers of alternatives and numbers of attributes. The evaluation shows that, for a typical Pugh application, concept selection varies with the arbitrary choice of datum or is simply incorrect in about one-third of the cases. While there are merits to the iteration steps and creation of new alternatives within the Pugh method, a simpler and more expressive concept ranking procedure can give far superior results.

This paper represents an interim report of the Burnswark Project that has utilised the techniques of battlefield archaeology to locate and accurately identify missiles across a substantial field of conflict in SW Scotland. The distribution, characteristics, dating and proposed historical context of these missiles are argued to support their use in a dramatic episode of ‘exemplary force’ by the Roman army. The magnitude of the event might be seen to be compatible with an emperor establishing his legitimacy as a military leader.