Highlights from the latest issue
October 2019 | Vol. 161, issue 4
The latest issue of our 2019 volume contains 13 Original articles, 5 Short Communications and a Viewpoint article, plus our usual book reviews.
Here are just four of the many highlights in this issue.
Original Article: Methods
- Assessing population size and structure for Andean Condor Vultur gryphus in Bolivia using a photographic ‘capture‐recapture’ method
Diego Méndez, Stuart Marsden, Huw Lloyd
The Andean Condor is a globally threatened and currently declining species. Diego Mendez and colleagues from Manchester Metropolitan University, UK and the Peregrine Fund, USA used sighting‐resighting modelling to estimate the size and structure of an Andean Condor population in Bolivia using photographs of individuals taken at established feeding stations. Condors were recorded visiting each feeding station and observers were able to identify more than 456 different individuals. Using open population capture‐recapture models Mendez et al. estimated that there were likely to be greater than 1300 individuals using these sites, 20% of the estimated Andean Condor global population. These researchers conclude that similar methods may increase survey accuracy of Andean Condors and other bird species with unique individual characteristics.
Original Article: Speciation
- Diversification of a ‘great speciator’ in the Wallacea region: differing responses of closely related resident and migratory kingfisher species (Aves: Alcedinidae: Todiramphus)
Darren P. O’Connell, David J. Kelly, Naomi Lawless, Adi Karya, Kangkuso Analuddin, Nicola M. Marples
One of the most widespread ‘great speciator’ lineages of the Indo‐Pacific is the Collared Kingfisher. Darren O’Connell and co-workers from Trinity College Dublin, Ireland and from Universitas Halu Oleo, Indonesia investigated the effect of isolation on several closely related species by comparing their populations on mainland Sulawesi and its larger continental islands, with populations on the small, oceanic Wakatobi Islands. Their results confirmed the distinctiveness of the Sulawesi Collared Kingfisher population, which was probably isolated by the deep water barrier of Wallace’s line. Using morphology and analysis of mitochondrial DNA, O’Connell et al. found that populations of Collared Kingfisher on the Wakatobi Islands had diverged from those on mainland Sulawesi and suggest that differences in habitat use caused this divergence. These results provide insight into the adaptability of this widespread avian lineage and highlight the need for further taxonomic revision.
Short communication: Conservation
- Use of microsatellite‐based paternity assignment to establish where Corn Crake Crex crex chicks are at risk from mechanized mowing
Rhys E. Green, Patricia Brekke, Hannah Ward, Matt Slaymaker, Marco van der Velde, Jan Komdeur, Hannah L. Dugdale
Rhys Green from the RSPB, together with an international team of researchers from UK and Netherlands used microsatellite DNA to assign probable parentage of young Corn Crakes to estimate distances between broods of chicks and juveniles and the night‐time singing place of their father. Estimated distances for broods of young chicks were similar to previous measurements by radiotracking, but distances were greater for older unfledged independent chicks not studied previously. From this study Green et al. demonstrate that changes to the timing and method of mowing to reduce losses of nests and chicks should be implemented and conclude that the required safe area should now be doubled.
- Evolution of avian egg shape: underlying mechanisms and the importance of taxonomic scale
Mary Caswell Stoddard, Catherine Sheard, Derya Akkaynak, Ee Hou Yong, L. Mahadevan, Joseph A. Tobias
Egg shape is always an intriguing subject for ornithologists and in recent years there has been much debate surrounding factors influencing egg morphology. In this Viewpoint article Mary Caswell from Princeton University, USA and her co-authors evaluate recent discussions around their examination of eggs shape in 1400 bird species. Contrary to the argument that incubation provides an opposing explanation for egg shape variation in birds, these researchers assert that egg shape is a complex phenotype driven by multiple selective forces and highlight that different conclusions drawn may be due to the taxonomic scale of study. Caswell et al. hope that by understanding egg formation more fully we will be able to obtain greater insights into the function and evolution of egg shape, and therefore encourage future work in this area.
Image credits from top:
Andean Condor | Erik Kilby CC BY SA 2.0 Flickr
Tractor mowing field | Graham Robson CC BY SA 2.0 geography.org.uk
Collared Kingfisher | JJ Harrison CC BY SA 3.0 nv.m.wikipedia.org
Eggs | British_Museum (BHL8388204) CC0 PD Wikimedia Commons