Highlights from the latest issue
April 2018 | Vol. 160, issue 2
The April issue of IBIS contains 15 full papers, five short communications and two Viewpoint articles.
Here are just four of the many highlights in this issue.
- High power line collision mortality of threatened bustards at a regional scale in the Karoo, South Africa
Jessica M. Shaw, Tim A. Reid, Maurice Schutgens, Andrew R. Jenkins and Peter G. Ryan
Power line collision mortality of birds is a serious conservation issue worldwide. Jessica Shaw and colleagues at the FitzPatrick Institute of African Ornithology in South Africa undertook extensive surveys along high-voltage transmission and low-voltage distribution lines to examine effects on the endangered Ludwig’s Bustard and two other bustard species. In these surveys they found over 600 carcasses from 30 different bird species, with Ludwig’s Bustards comprising 69% and other bustards a further 18% of carcasses. Collision rates for Ludwig’s Bustard averaged 1.12 and 0.86 bustards/km/year on transmission and distribution lines, respectively. However, the smaller distribution lines are four times as extensive in South Africa and so probably kill more birds. Despite being much less abundant, Kori Bustards were the second most commonly recovered species on transmission lines indicating their vulnerability to this source of mortality. This study adds to growing concern about the impacts of power lines on bustards globally, and therefore Shaw et al. recommend that collision mitigation measures are implemented at all new power lines.
- Odour of King Penguin feathers analysed using direct thermal desorption discriminates between individuals but not sexes
Marianne Gabirot, Bruno Buatois, Carsten T. Müller and Francesco Bonadonna
- Sex identification in King Penguins Aptenodytes patagonicus through morphological and acoustic cues
Hannah J. Kriesell, Thierry Aubin, Víctor Planas-Bielsa, Marine Benoiste, Francesco Bonadonna, Hélène Gachot-Neveu, Yvon Le Maho, Quentin Schull, Benoit Vallas, Sandrine Zahn and Céline Le Bohec
In this issue we have two fascinating papers providing insights into individual and mate recognition in penguins. In the first of these, Marianne Gabirot and co-investigators from Cardiff University and Université de Montpellier investigated the chemical composition of volatile organic compounds (VOCs) from feathers of King Penguins in the Kerguelen Archipelago and their potential to carry information on identity and sex. They found a profile of 26 VOCs present in most individuals which varied between individuals but not between sexes. The researchers conclude that VOCs may be used by King Penguins to locate their colony and recognize different individuals.
View Gabirot et al
In a further study on King Penguins from Possession Island, Crozet Archipelago, Hannah Kriessel and colleagues from Monaco’s Departement de Biologie Polaire, and CNRS, France studied the vocal and morphological sex dimorphism in this species, where our knowledge of their role in mate choice is limited. Using measurements of six morphological features and analysing acoustic parameters of calls of adults, they showed that a single beak measurement can distinguish sexes, but remarkably found that a sex-specific syntax in calls provided a 100% accurate method of telling males and females apart. Kriesel et al. believe that this sex-specific syllable arrangement is rare in non-passerines and is a first step in understanding mate choice processes in this species. Importantly for researchers the method used here also provides a cost-effective, non-invasive technique for identifying the sex of King Penguins in the field.
View Kriesell et al
- Apparent survival of an Arctic-breeding migratory bird over 44 years of fluctuating population size
Kevin A. Wood, Rascha J. M. Nuijten, Julia L. Newth, Trinus Haitjema, Didier Vangeluwe, Panagiotis Ioannidis, Anne L. Harrison, Conor Mackenzie, Geoff M. Hilton, Bart A. Nolet and Eileen C. Rees
Several Arctic-breeding migrants are now undergoing sustained population declines, including the northwest European population of Bewick’s Swan, which declined from around 29,000 wintering birds in 1995 to only 18 000 in 2010. Kevin Wood from the Wildfowl & Wetlands Trust and colleagues from across Europe analysed a dataset of 3929 individually marked and resighted Bewick’s Swans to assess temporal trends and drivers of survival between winters of 1970/71 and 2014/2015. The temporal trend in apparent survival rates over the study period was best explained by different survival rates for each decade, with mean survival rates highest in the 1980s and lowest in the 2010s. The reason for these differences is still not clear but importantly these results provide long-term demographic information needed to help conservationists understand the population dynamics of Bewick’s Swans in northwest Europe.
- The role of size and dominance in the feeding behaviour of coexisting hummingbirds
Gabriel López-Segoviano, Rafael Bribiesca and María Del Coro Arizmendi
Interspecific competition can strongly influence community structure and limit the distribution and abundance of species. Gabriel López-Segoviano and colleagues from the Universidad Nacional Autónoma de México investigated whether body size and the degree of aggressive dominance influence feeding behaviour of hummingbirds in a temperate forest in NW Mexico. Through many careful hours of observation the research team were able to document the dominance hierarchy of as many as 13 hummingbird species (migratory and resident). They found dominance to be correlated with body size but not wing disc loading, and that members of the community exploited nectar resources from different plants. Hummingbirds at the top of the dominance hierarchy defended and fed on the best flower patches, defined by the quantity of calories available from nectar. From this work López-Segoviano et al. clearly showed that body size, aggressive dominance and defence of quality flower patches determines niche partitioning in these species.
- VIEWPOINT | Unnatural history: is a paradigm shift of natural history in 21st century ornithology needed?
Corey T. Callaghan, John M. Martin, Richard T. Kingsford and Daniel M. Brooks
Natural history is essential to the continuation of science, especially as we attempt to identify the myriad of threats that biodiversity faces in this rapidly changing world. In a thought provoking Viewpoint article Corey Callaghan from the Centre for Ecosystem Science in Sydney and co-authors in Australia and USA, argue that natural history in ornithology needs a modern reinvigoration, and should focus on placing natural history observations in the context of an anthropogenically altered world: what they term – ‘unnatural history’. Ornithologists must therefore focus on documenting behavioural adaptations, recent diet choices, hybridisation, and novel adaptations of birds to urbanisation and a changing world. Callaghan et al. suggest that increased accessibility of natural history observations, encouragement of amateur ornithologists’ participation in professional societies (and vice versa), and targeted citizen science projects are the very mechanisms by which to reinvigorate natural history in 21st century ornithology.
Ludvig’s Bustard | Hans Hillewaert | CC-BY-SA-4.0 | Wikimedia Commons
King Penguins | Samuel Blanc | CC-BY-SA-3.0 | Wikimedia Commons
King Penguins and field researcher | © Quintin Schull
Bewick’s Swan | Sciadopitys | CC-BY-SA-2.0 | Wikimedia Commons
Doubleday Hummingbird | Francesco Veronesi | CC-BY-SA-2.0 | Wikimedia Commons