Chemical capture of wild swamp buffalo (Bubalus bubalis) in tropical northern Australia using thiafentanil, etorphine and azaperone combinations

BACKGROUND

Studying wild animals in situ is fundamental to collecting baseline information, but generally they need to be immobilised for examination, sampling, marking and/or equipping with tracking apparatus. Capturing wild animals is inherently risky and there is a need for immobilisation methods that are safe for both the animals and researchers.

METHODS

A total of 16 free-ranging swamp buffalo (Bubalus bubalis) were chemically captured by dart for the application of satellite tracking collars in tropical northern Australia; 7 animals were anesthetised with a thiafentanil-etorphine-azaperone (TEA) combination and 9 animals with a thiafentanil-azaperone (TA) combination. Anaesthesia was reversed with intravenous naltrexone. Mean dosages of etorphine and thiafentanil for animals in the TEA group were 0.01 mg/kg of each drug and mean dosage of thiafentanil for animals in the TA group was 0.02 mg/kg. Total dose per animal of azaperone and naltrexone was 80 mg and 150 mg, respectively. Anaesthetic monitoring was by physical observation of physiological variables, pulse oximetry and capnography. Blood laboratory parameters including creatine kinase (CK), aspartate transaminase (AST), serum bicarbonate and anion gap were measured.

RESULTS

All subject animals recovered well from anaesthesia despite the occurrence of subclinical acidosis in some patients. There was no significant difference between the treatment groups. Conversely, chase time had an adverse effect on body temperature, irrespective of the anaesthetic combination used.

CONCLUSIONS

Thiafentanil and azaperone, with or without etorphine, delivered rapid safe, effective, reversible field anaesthesia in healthy swamp buffalo.

Reviewing research priorities in weed ecology, evolution and management: a horizon scan

Weedy plants pose a major threat to food security, biodiversity, ecosystem services and consequently to human health and wellbeing. However, many currently used weed management approaches are increasingly unsustainable. To address this knowledge and practice gap, in June 2014, 35 weed and invasion ecologists, weed scientists, evolutionary biologists and social scientists convened a workshop to explore current and future perspectives and approaches in weed ecology and management. A horizon scanning exercise ranked a list of 124 pre-submitted questions to identify a priority list of 30 questions. These questions are discussed under seven themed headings that represent areas for renewed and emerging focus for the disciplines of weed research and practice. The themed areas considered the need for transdisciplinarity, increased adoption of integrated weed management and agroecological approaches, better understanding of weed evolution, climate change, weed invasiveness and finally, disciplinary challenges for weed science. Almost all the challenges identified rested on the need for continued efforts to diversify and integrate agroecological, socio-economic and technological approaches in weed management. These challenges are not newly conceived, though their continued prominence as research priorities highlights an ongoing intransigence that must be addressed through a more system-oriented and transdisciplinary research agenda that seeks an embedded integration of public and private research approaches. This horizon scanning exercise thus set out the building blocks needed for future weed management research and practice; however, the challenge ahead is to identify effective ways in which sufficient research and implementation efforts can be directed towards these needs.

Helpers increase the reproductive potential of offspring in cooperative meerkats

In both animal and human societies, individuals may forego personal reproduction and provide care to the offspring of others. Studies aimed at investigating the adaptive nature of such cooperative breeding systems in vertebrates typically calculate helper 'fitness' from relationships of helper numbers and offspring survival to independence. The aim of this study is to use observations and supplemental feeding experiments in cooperatively breeding meerkats, Suricata suricatta, to investigate whether helpers influence the long-term reproductive potential of offspring during adulthood. We show that helpers have a significant and positive influence on the probability that offspring gain direct reproductive success in their lifetimes. This effect arises because helpers both reduce the age at which offspring begin to reproduce as subordinates and increase the probability that they will compete successfully for alpha rank. Supplemental feeding experiments confirm the causality of these results. Our results suggest that one can neither discount the significance of helper effects when none is found nor necessarily estimate accurately the fitness benefit that helpers accrue, unless their effects on offspring are considered in the long term.

Intrasexual competition and sexual selection in cooperative mammals

In most animals, the sex that invests least in its offspring competes more intensely for access to the opposite sex and shows greater development of secondary sexual characters than the sex that invests most. However, in some mammals where females are the primary care-givers, females compete more frequently or intensely with each other than males. A possible explanation is that, in these species, the resources necessary for successful female reproduction are heavily concentrated and intrasexual competition for breeding opportunities is more intense among females than among males. Intrasexual competition between females is likely to be particularly intense in cooperative breeders where a single female monopolizes reproduction in each group. Here, we use data from a twelve-year study of wild meerkats (Suricata suricatta), where females show high levels of reproductive skew, to show that females gain greater benefits from acquiring dominant status than males and traits that increase competitive ability exert a stronger influence on their breeding success. Females that acquire dominant status also develop a suite of morphological, physiological and behavioural characteristics that help them to control other group members. Our results show that sex differences in parental investment are not the only mechanism capable of generating sex differences in reproductive competition and emphasize the extent to which competition for breeding opportunities between females can affect the evolution of sex differences and the operation of sexual selection.