Highlights from the latest issue
January 2019 | Vol. 161, issue 1
The first issue of our 2019 volume contains a Review paper, 13 Original articles, 7 Short Communications and a Viewpoint article.
Here are just four of the many highlights in this issue.
- The relationship between latitude, migration and the evolution of bird song complexity
Nadje Najar & Lauryn Benedict
How does latitude and migratory behaviour drive large‐scale geographical patterns of song complexity? Nadje Najar and Lauryn Benedict from the University of Northern Colorado, USA address this interesting question by reviewing previous studies in this field. Hypotheses suggest that sexual selection pressures co‐vary with latitude and/or migration or that large‐scale changes in environmental sound transmission properties, may influence song complexity. Interestingly, only 55% of studies showed that song complexity increased with latitude and/or migration, allowing the authors to conclude there was no strong evidence for this geographical pattern in all birds. Najar and Benedict recommend that future studies should focus on simultaneously examining multiple hypotheses to unravel how latitude, migration and song complexity interact.
Original Article: Genetics and evolution
- The behavioural response of Great Tits to novel environment and handling is affected by the DRD4 gene
Killu Timm, Marko Magie, Kaisa Telve & Vallo Tilgar
In humans, a single nucleotide polymorphism in the dopamine receptor D4 gene (DRD4) has been associated with novelty seeking and impulsive behaviours. The extent to which bird behaviour is also influenced by this gene was examined in Great Tits Parus major by Killu Timm and colleagues from the University of Tartu, Estonia. They measured exploration and anxiety behaviours in captivity before the start of egg‐laying, to exclude potential effects of breeding and the natural environment. In comparison to their previous study in the wild, both males and female with the heterozygous genotype (SNP830) performed more actively in different contexts compared with homozygotes. Heterozygotes respond more boldly than homozygotes to a novel object in different environments and breeding stages. Clearly, individual behaviour of Great Tits is a product of gene interaction with the environment.
Original Article: Migration and movement
- Segregation in space and time explains the coexistence of two sympatric sub‐Antarctic petrels
Hanna M. V. Granroth‐Wilding & Richard A. Phillips
Northern Macronectes halli and Southern Macronectes giganteus Giant Petrels are two sympatric sexually dimorphic seabird species that appear to coexist through differences in timing of breeding. Until now, little has been known of any differences in foraging behaviours and areas used by the two species and between the sexes. Hanna Granroth‐Wilding from the University of Helsinki and Richard Phillips from the British Antarctic Survey therefore tracked males and females of both species in all breeding stages at Bird Island, South Georgia. They found that within each breeding stage, both species took trips of comparable duration to similar areas, but due to timing of breeding they segregated temporally. Northern Giant Petrels had smaller foraging ranges than Southern Giant Petrels related to their preference for local carrion. Within species, females generally had longer, more pelagic trips than males. Granroth‐Wilding and Phillips conclude that in giant petrels, temporal segregation reduces interspecific competition and sexual segregation reduces intraspecific competition.
Short Communication: Genetics
- Superb Lyrebird Menura novaehollandiae mycophagy, truffles and soil disturbance
Todd F. Elliott & Karl Vernes
Todd Elliott and Karl Vernes from the University of New England, Australia, report mycophagy (fungivory) in Superb Lyrebirds Menura novaehollandiae found in high‐elevation Nothofagus forests in New South Wales. Although several bird species have previously been observed feeding on fungi, this study used microscopy to identify fungal spores present in faeces. The study showed that fungal spores were present in the majority of faeces sampled and were from a range of species found within the region. Elliott and Vernes suggest that ground feeding birds such as Superb Lyrebirds may be providing an important ecosystem function related to soil aeration and mycorrhizal spore dispersal, and highlight the need for further research on the relationships between birds, fungi, plants and ecosystems around the world.
Read Todd and Elliot’s authors’ blog post about their paper
Eurasian Blackbird | Manfredrichter | CC0 | pixabay.com
Great Tit | Ian Kirk | CC BY 2.0 | Wikimedia Commons
Northern Giant Petrel | Liam Quinn | CC BY SA 2.0 | Wikimedia Commons
Superb Lyrebird | Patrick Kavanagh | CC BY 2.0 | Flickr