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3 Posts tagged with the bird_research tag

A comprehensive catalogue of the world's bird species, which used thousands of specimens from the Museum's collections, is the new gold standard for the taxonomy and conservation of birds.


The first volume of the Illustrated Checklist of the Birds of the World, released earlier this summer, defines more than 400 new species of bird.


Species for conservation


The book was authored by Josep del Hoyo and BirdLife International author and Museum scientific associate Nigel Collar. Part of Collar's job at BirdLife is to help feed into the IUCN Red List - a global record of the conservation status of the world's plants and animals.


For this, he needed a robust list of the world's bird species. Whether a bird gets defined as a separate species or not is important for its conservation. If a bird is defined as a subspecies (a variant of a species) many birds will go extinct without ever getting proper conservation attention.


Conversely, if too many birds are defined as species, the concept of a species becomes devalued and the idea of conservation becomes difficult to manage.


Determining differences


In the Illustrated Checklist, birds up for consideration as a new species were scored on a number of characteristics, with particular focus on plumage and voice - the traits important for determining whether breeding can occur between two birds.


The results of the first volume estimate that bird diversity may have been previously underestimated by around 10%, meaning one-in-ten birds have been ignored by conservation efforts.


In addition to 462 new bird species, the criteria also merged 30 existing species into other species, creating new subspecies.



The Bearded Helmetcrest hummingbird is now recognised as four different species - one of which hasn't been seen in nearly 70 years.

© Francesco Veronesi, Flickr Creative Commons.


Camped out in the collections


For the physical characteristics of birds, Collar says that our Museum collections at Tring have been indispensable:

To look carefully at the characteristics of birds you need them right under your nose. The Museum has the best collection in the world with the best reputation. It's utterly invaluable.


He looked at thousands of specimens for the first volume of the book, and is now ‘camped out' at Tring researching for volume two.


Thousands of birds


Collar, del Hoyo and their co-authors assessed the species status of around 1,000 birds for the first volume, which covers non-passerines. Passerine birds account for over half of all the world's bird species and are often called ‘perching birds' thanks to the arrangement of their toes.


The authors have another 1,000 birds in the passerines group to consider before they release volume two of the Illustrated Checklist, due out in 2016.



The spotted green pigeon, a mysterious species collected in the 1700s, turns out to have been a flying relative of the dodo that likely lived in the trees of the South Pacific.


Only two specimens of the pigeon were ever described, in 1783, and since then one has gone missing. The location they were collected from was not recorded, but they are associated with South Pacific voyages. The only remaining specimen is held at the World Museum (formerly Liverpool Museum), National Museums Liverpool.


Quest for identity


In its original description, the spotted green pigeon was said to closely resemble the Nicobar pigeon, a bird native to Indonesia that prefers to live on small remote islands. This, and it's obscurity, led some to speculate that the spotted green pigeon was just an unusual variety of the Nicobar pigeon.


Determined to find out once and for all, the World Museum asked our bird expert Hein van Grouw and colleagues in Australia to investigate their specimen. Using detailed morphological analysis and genetic testing, the team identified the spotted green pigeon as a distinctive species in its own right.



The only remaining specimen of the spotted green pigeon.

Photo by Hein van Grouw.


Dodo connections


Preliminary results from the genetic testing reveal the pigeon is in the same family as the dodo and its extinct flightless relative the Rodrigues Solitaire. It's somewhat of a mystery how the specialised flightless dodo got to its isolated island habitat, but finding more relatives can help clarify the picture. The addition of the spotted green pigeon to the lineage may add some evidence to the 'stepping stone hypothesis', which suggests ancestors of the family island-hopped from India or Southeast Asia.


van Grouw is completing his morphological analysis that will help determine what kind of lifestyle the spotted green pigeon had. It was originally described as having short wings, suggesting a ground-dwelling lifestyle like the dodo, but this turns out not to be the case, and it is more likely that it lived in the trees eating fruit and berries.


Gone already


Determining the spotted green pigeon as a separate species has another consequence. Since no others have ever been seen, it can confidently be added to the extinct species list.


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Egg arms race

Posted by Hayley Dunning Jul 8, 2014

Birds targeted by cuckoos develop sophisticated egg patterns to help them recognise the fakes.


Cuckoos infamously lay their eggs in the nests of other birds, forcing them to care for their young. But species that are repeatedly targeted by cuckoos have developed a range of complex egg patterns to help distinguish the invader's eggs and kick them out of the nest.


Cuckoos will hatch before their nest-mates and throw them out, so that the parent birds will only raise the cuckoo. When a host bird recognises a cuckoo egg, they may puncture it or throw it out the nest before it hatches.


Signature patterns


Scientists from Harvard and Cambridge Universities developed a pattern-recognition software called NaturePatternMatch that mimics the way birds see the world. Using the extensive egg collections of the Natural History Museum at Tring, they then analysed the eggs of eight bird species commonly targeted by cuckoos.


They found that where cuckoos had developed accurate copies of host-bird eggs, the host birds had in turn developed more complex egg patterns. 'The egg patterns on cuckoo and host eggs reveal an evolutionary arms race,' said lead author Dr Mary Caswell Stoddard from Harvard University.



Samples of cuckoo's eggs in host bird clutches from the Museum's collections. Cuckoo's eggs are often bigger than their host's.


'In many cases, cuckoos have evolved excellent egg mimicry in order to trick host birds into accepting foreign eggs. In these instances, host birds have evolved excellent egg pattern signatures on their own eggs as a defence.'


The host birds studied used different techniques to set their eggs apart. Some females of the same species, such as the great reed warbler, laid very different eggs to each other, but very similar eggs within their own nest. Others, such as the brambling, lay eggs with unevenly spaced, sparse markings, making a good signature.


Collections and tools


Museum egg and nest curator Douglas Russell said he was 'fascinated by the insights [this paper] provides into the particular mechanisms that appear to be involved.' The extensive bird collections, which cover 95% of all bird species alive today, are involved in numerous studies.


'They can contribute to research as diverse as understanding migratory routes and investigating chemical contamination of the environment over time.'


The NaturePatternMatch software may also be used in a range of projects. 'How do animals recognize their neighbours, enemies and kin? How have visual signals evolved to maximize distinctiveness? Computer vision tools like NaturePatternMatch will help us answer these important evolutionary questions,' said Dr Stoddard.