An experimental assessment of social tolerance and den ecology in a high-density octopus population

Long held notions of the universally asocial octopus are being challenged due to the identification of high-density and interacting octopus populations in Australia, Indonesia, Japan and the deep sea. This study experimentally assessed the social tolerance and presence of potential prey items of Caribbean reef octopus, Octopus briareus, in a tropical marine lake (25°21′40″N, 76°30′40″W) on the island of Eleuthera, The Bahamas, by deploying artificial dens in multi-den groups or ‘units’ in the months of May and June 2019. Fifteen octopus were observed occupying dens (n = 100), resulting in 13 den units being occupied (n = 40). Two examples of adjacent occupation within a single den unit were identified but with zero examples of cohabitation/den sharing. Ecological models showed den and den unit occupation was predicted to increase with depth and differ between sites. Octopus also displayed no preference for isolated or communal units but preferred isolated dens over dens adjacent to others. Additionally, 47 % of occupied dens contained bivalve or crustacean items with no epifauna on their interior surface. The lack of epifauna suggests that these items have been recently ‘cleaned’ by occupying octopus and so represent likely prey. This study presents evidence of possible antisocial den use by O. briareus, a modification of the default ‘asocial’ ignoring of conspecifics typically attributed to octopus. This is likely in response to the high population density and may imply behavioural plasticity, making this system appropriate for further scrutiny as a research location on the influence of large, insular environments on marine species.

Denning behaviour of female spotted-tailed quolls during the breeding season

We monitored some aspects of maternal care in Australia’s second largest extant marsupial predator, the spotted-tailed quoll. We radio-collared six females carrying young at an early pouch stage in the Byadbo Wilderness in southern New South Wales in August–September 2016. When these young were deposited at a maternity den at a still altricial state we monitored den activity of the female and her young with motion-triggered camera traps. Lactating females remained in the same den for up to 39 days before moving to a new den, usually only a few hundred metres away. Females furnished dens with nesting material, but were never observed to carry prey nor were the young seen consuming solid food. They were also surprisingly tolerant towards visits and den use by wombats, rabbits, possums and male quolls. Females showed predominantly nocturnal activity, but usually returned at least once per night. Short daytime activity was also common. In contrast, juveniles were initially exclusively diurnal, probably to facilitate behavioural thermoregulation, and only later extended their playing and exploring towards dawn and dusk. Hence interactions between mother and young were rarely observed. Apparently, the young received little training from their mother and simply ventured further and for longer periods away from the den until independence.

e-Infrastructures Austria 2016: Bericht über das dritte Jahr des Hochschulraumstrukturmittelprojekts für den koordinierten Aufbau und die kooperative Weiterentwicklung von Repositorieninfrastrukturen

Im letzten Jahr des vom Bundesministerium für Wissenschaft, Forschung und Wirtschaft auf drei Jahre geförderten HRSM-Projektes e-Infrastructures Austria konnten die drei Teilprojekte erfolgreich zu Ende geführt werden. An 25 Partnereinrichtungen wurden als In-Kind-Leistungen Repositorien aufgebaut bzw. sind derzeit in Planung. 2016 wurde von einer ExperInnengruppe eine Muster-Policy für Forschungsdatenmanagement; an einzelnen der Partnereinrichtungen wurden Forschungsdatenmanagementpläne erprobt. Das Ziel, Fortbildung und Vernetzung für Forschungsdatenmanagement zu ermöglichen, wurde im Berichtsjahr in Form von Workshops zu den Themen Metadaten und Langzeitarchivierung und insbesondere durch ein viertätiges Seminar für den professionellen Umgang mit Forschungsdaten erfolgreich umgesetzt. Es ist sehr erfreulich, dass mit dem Projektende von e-Infrastructures Austria das Thema Forschungsdatenmanagement nicht wieder aus dem Blickfeld der Universitäten und Forschungseinrichtungen geraten wird, sondern vielmehr – in mehreren Projekten – dieses Thema ab 2017 weiterentwickelt wird. Neben dem Folgeprojekt e-Infrastructures Austria Plus, an dem sich neun Institutionen beteiligen werden, widmen sich noch acht weitere öffentlich geförderte Projekte dem Thema Open Science. Gemeinsam bilden sie den Use Case Austria im Rahmen der European Open Science Cloud.

Response of eastern pygmy possums, Cercartetus nanus, to selective logging in New South Wales: home range, habitat selection and den use

Context Selective logging of native forests creates a mosaic of disturbance histories; however, little is known about how different taxa respond to such a mosaic. Aims We followed adaptive-management principles to test logging and burning impacts on eastern pygmy possums, Cercartetus nanus (Geoffroy and Desmarest, 1817), by undertaking a large-scale field experiment that coincided with harvesting. We predicted that home range would increase after logging because of a reduction in resources (food and/or dens) and because hollows suitable for denning would decrease, resulting in greater use of unlogged patches and alternate dens. Methods We radio-tracked C. nanus in a before-and-after logging experiment to investigate home range, habitat selection and den use. We tracked 50 possums, some individuals for a maximum of 8 months, within control, recently logged and regrowth (5 years since logging) sites. Key results Home ranges were variable (0.04–19.5 ha), with males having significantly larger home ranges. We were unable to detect a difference in home-range size between controls and the first year after logging and burning, or regrowth 5 years after logging. Home ranges comprised a mosaic of disturbed and undisturbed areas, and possums did not avoid logged habitat in their home ranges, indicating that logging did not significantly influence habitat selection. We suggest that possums were not sensitive to selective logging and burning because nectar-producing plants are adapted to fire disturbance and because a variety of den sites were used, most commonly in tree hollows and fallen logs, which were commonly left as logging residue. Indeed, possums frequently denned in logged patches, both recently after logging (63% of dens) and in regrowth 5 years after logging (76% of dens). Counts of fallen hollow logs at each site indicated that their density was not reduced by logging, with regrowth sites having the greatest abundance of logs (260 ha–1). Conclusions The mosaic of disturbance created by selective logging operations did not negatively affect home range or den selection of C. nanus. Implications Ecologically sustainable logging practices that include a range of mitigation measures to protect biodiversity can be compatible with the management of threatened species. Assessment of the effectiveness of these methods often will rely on scientific research.