Mega-evolutionary dynamics of the adaptive radiation of birds

facebooktwitter 

Nature bills

The idea to 3D scan the bills of the world’s 10,000 bird species from museum collections has always seemed like an ambitious undertaking. However, after two years of data collection, months of analysis and the input of hundreds of citizen scientists, the first study resulting from our work was published in Nature last month.

This initial, wide-ranging exploration of bill diversity, compared over 2000 species from across all genera, considering the full range of present-day bill shapes.

The diversity we see in bill shape today is extraordinary and studying this characteristic can tell us a lot about species and how they interact with their environment- from foraging, hunting and eating food, to preening and nest building. Traditional methods of gathering information relating to bill form have often relied on length, depth and width measurements alone, missing many key elements of shape, such as curvature. By 3D scanning bills, we have been able to capture far more detailed information, providing a true reflection of bill diversity.

It would have been impossible to collect this information from birds in the wild so our study has been reliant on the incredible ornithology collections at Manchester Museum and the Natural History Museum in Tring. These archives of biodiversity have allowed us to create fantastically detailed models through access to such a broad variety of species, alongside curatorial expertise and work space.

One of the most novel aspects of our study was the way in which much of our initial data- the 3D scans- was processed through the input of citizen scientists from around the world. With each scan requiring landmarking by at least 3 different people, this in itself was a huge task and one that would not have been possible without such a collaborative effort. By helping us place key points and trace edges on every scanned bill, online volunteers assisted in turning these hugely complex 3D models into data that could then be analysed.

From this we have been able to highlight that the majority of bill diversification evolved quickly and, once extremes of shape were reached, the amount of change slowed down significantly as birds began to fill increasingly narrow ecological niches. As a result of this initial fast change and huge variety of form, birds have been able to exploit the equally wide range of habitats and sources of food.

The full paper can be read here and, excitingly, has also received some fantastic press attention, including a discussion of our findings with project PI Dr Gavin Thomas on both the Nature podcast and BBC Inside Science (interview starts at 20:00 minutes) – if you prefer a good listen, rather than a good read. A selection of our online coverage is listed here:

Audubon – Post-docs Dr Chris Cooney and Dr Jen Bright spoke to Audubon magazine about our findings and how they build upon our previous understanding of bill diversity.
BBC Science & Environment – ‘How birds of a feather evolved together’
New York Times – ‘Finding the Speed of Evolution in a Study of Bird Beaks’
Natural History Museum – Our study wouldn’t have been possible without the incredible ornithology collections at the Natural History Museum. This statement highlights our reliance on this resource as well as how our data can be used in the future.
University of Sheffield – A summary of our project and findings as part of the Department of Animal & Plant Sciences at the University of Sheffield.

If reading about our work has caught your interest, it’s not too late to contribute. Our crowdsourcing site markmybird.org is still very much up-and-running as we continue to increase our data relating to all extant species. Whether you want to browse our scan gallery or have a go at landmarking, everyone is welcome.

The Prong-Billed Barbet (Semnornis frantzii)

facebooktwitter 

Time for another #BeakoftheWeek species profile! We’re hitting up the Semnornithidae family today with the prong-billed barbet.

Prong-billed barbet

Prong-billed barbet (Semnornis frantzii)

The prong-billed barbet is confined to a small range between the Caribbean slope of Costa Rica and western Panama.  You will usually encounter them foraging in the forest canopy in pairs or in groups of 12+ birds.

Although not the biggest of birds at 18cm and around 60g, or the most flamboyantly coloured, they do have a fancy beak, which you might expect given their name.  There beak is a little unusual given that there are two little prongs on the lower mandible and a hook on the upper mandible that fits between them. I am yet to find out why this is, but when I do I will be sure to let you know.  I do know that they are mainly frugivorous with the odd insect thrown in for good measure.

The pair excavate dead trees or branches between 3 and 18m high to make their nests over 8 days in which 4-5 eggs will be laid.  Both adults incubate that eggs over 14-15 days and then take care of feeding and brooding duties between them after their altricial chicks hatch.  The pair actively defends their territory during the breeding season (March to June).

This species is of ‘Least Concern’ on the IUCN redlist as it is common within its range.  Check out this link to a website I am sure you all know by now for some prong-billed calls.  Also a new feature for the blogs is this onezoom link which I will let you explore for yourselves.

References

BirdLife International 2012. Semnornis frantzii. The IUCN Red List of Threatened Species. Version 2015.2. <www.iucnredlist.org>. Downloaded on 10 July 2015.

Buckio, Brandon. 2011. Prong-billed Barbet (Semnornis frantzii), Neotropical Birds Online (T. S. Schulenberg, Editor). Ithaca: Cornell Lab of Ornithology; retrieved from Neotropical Birds Online: http://neotropical.birds.cornell.edu/portal/species/overview?p_p_spp=298456.

Short, L.L., Horne, J.F.M. & Kirwan, G.M. (2013). Prong-billed Barbet (Semnornis frantzii). In: del Hoyo, J., Elliott, A., Sargatal, J., Christie, D.A. & de Juana, E. (eds.) (2013). Handbook of the Birds of the World Alive. Lynx Edicions, Barcelona. (retrieved fromhttp://www.hbw.com/node/56068 on 10 July 2015).

Images

Prong-billed barbet” by Flickr-user Clickor is licensed under CC BY 2.0.