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News in brief

6 Posts tagged with the zoology tag

A species of bryozoan transplanted to an area with increased ocean acidity has been found to grow at half the rate of those living in normal ocean conditions.

Bryozoans are coral-like animals that live in colonies and build their skeletons out of calcium carbonate. An international team including Museum researcher Dr Paul Taylor transplanted several budding colonies from their normal homes in the Mediterranean to an area near an active volcanic vent in Italy.


The undersea vent expels heat and carbon dioxide, simulating the global surface ocean acidity predicted for the year 2100 as a result of increased anthropogenic carbon dioxide emissions. According to Dr Taylor:

Entire ecosystems are threatened by ocean acidification, and this will have economic consequences because animals such as bryozoans are often habitats for the juveniles of commercially exploited fishes and crustaceans or may be in their food chains.

20150211 Bryozoan Calpensia nobilis © Lombardi et al..jpg

The bryozoan Calpensia nobilis showing normal growth at the leading edge © Lombardi et al, 2015.


During a three-month experiment, the bryozoan colonies around the vent suffered slower growth rates, the absence of some growth stages, and the corrosion of their skeletons. However, individual zooids – the tiny creatures that build the colony – were longer than normal.


Dr Taylor thinks this could be an indication of adaptation by the bryozoans to the changing environmental conditions. The colonies seemed to invest more energy in completing zooids that had already started to form rather than budding new generations. In other words, they were strengthening the existing colony rather than expanding.


Longer studies are needed along with more detailed information about how the colonies are reacting to possible future scenarios. Said Dr Taylor:

With this information, better predictions could be made of organism survival and evolution, and thus ecosystem changes, loss or survival in a changing world.

The research is published today in the journal Royal Society Open Science.



A Chinese mitten crab has been recorded in Scotland for the first time, posing a potential threat to local biodiversity and habitats.


The invasive crab species is already known to have populated rivers in the UK as far north as the Tyne, but this sighting in Glasgow's River Clyde confirms its migration over the Scottish border.


The Chinese mitten crab, named for the furry mats covering its claws, is one of the top 100 worst alien species in the world, according to the International Union for Conservation of Nature. It threatens biodiversity by competing for food, preying on native species and causing severe structural damage to riverbanks through burrowing.

Crabs on tour


The specimen found in the River Clyde, the remains of a female mitten crab, is the first recorded sighting north of the border.


The Chinese mitten crab (Eriocheir sinensis), is native to East Asia but is now found across NE Europe and the USA. It was first recorded in the River Thames in 1935, probably introduced by shipping. In the late 1980s the mitten crab began to disperse westwards along the Thames, and there are now well-established populations of E. sinensis in a number of Welsh and English rivers, as well as a single sighting in Ireland in 2006.



The left claw of a male mitten crab (Eriocheir sinensis).


The International Maritime Organisation (IMO) has set out standards for the control and management of ships’ ballast water and sediments, in an effort to control the transport of species to non-native waters.

Potential threat to biodiversity


Mitten crabs may target the eggs of salmon and trout, according to recent research by Royal Holloway University of London (RHUL) student Jessica Webster and supervisors Dr Paul Clark (the Museum) and Dr David Morritt (RHUL).


Dr Clark sees the recent discovery as a major threat:

"An established River Clyde Chinese mitten crab population could pose an enormous environmental risk to the salmon and trout in this catchment (…) if this reported Clyde specimen came from a deliberate human release, the environmental authorities need to urgently consider what appropriate actions are required to prevent such introductions happening again in the future."


Dr Clark is studying the biology and behaviour of mitten crabs to better understand how we might control their migration and ultimately eradicate alien populations outside East Asia.

See live mitten crabs at Science Uncovered


As part of the Museum's annual festival of science on 26 September 2014, Dr Paul Clark and Dr David Morritt will be showcasing some live Chinese mitten crabs and talking about their work on the biology and behaviour of this problem species.


Come along to Science Uncovered to see these and a whole host of other specimens, take part in activities and meet Museum scientists.


A section of the new Infrastructure Bill designed to control invasive species could end up harming important native species such as the barn owl and the red kite.


In an open letter to the UK Government published last week in Nature magazine, 24 leading scientists including Museum researcher Prof Geoff Boxshall called for the bill to be re-written. The letter states that, "If the bill is passed in its present form, it could lead to an irreversible loss of native biodiversity."


The potential problem lies in the way the bill defines a 'non-native' species. According to the letter:

The draft bill defines non-native species as those that are “not ordinarily resident in, or a regular visitor to, Great Britain”. This definition covers past native species that are now extinct, species that may become naturally established under a changing climate, and species listed in Schedule 9 of the Wildlife and Countryside Act.

Schedule 9 contains, among others, several species that have gone extinct in the UK and been reintroduced, such as the barn owl and the capercaillie (a type of grouse).



The barn owl is one species that could have its status changed by the new bill.

© David Tipling Photo Library / The Trustees of the Natural History Museum, London.


The wording of the bill means that species slated for reintroduction, such as the European beaver and wolf, would be classed as non-native and their conservation threatened. Species naturally migrating from Europe as the climate changes, such as butterflies and other insects, would also be punished by the new definition.


Prof Boxshall thinks the definition needs to be changed:

The classification of native versus non-native is an ongoing matter for scientific debate, particularly in the face of climate change. By using such a simplistic definition, the government effectively bars the possibility of reintroduction of locally extinct species and adaptation to climate change.


Amendments have been suggested in the House of Lords to correct the problems in the legislation, but so far these have been rejected.



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.


  • Find out more about our Bird Group and our stunning collections

Sub-millimetre-sized wasp discovered in scientist's son's playground.


Museum wasp expert Dr Andrew Polaszek has identified a new species of tiny wasp living inside whiteflies on a tree in his son's playground in Sevenoaks, Kent.


The wasp is a parasitoid. While true parasites depend on other organisms their whole lives, parasitoids just lay their eggs in other organisms. The larvae of newly discovered wasp, named Encarsia harrisoni, are born inside whiteflies and eat their way out.


It was the whiteflies on a maple tree in the playground that alerted Dr Polaszek to the presence of the wasp:


'I noticed some of the whiteflies looked slightly different to the others so I took them to the laboratory. When I saw the wasp inside I knew it looked different to anything I'd seen before.'




Not a tourist


Dr Polaszek made the discovery five years ago, but there was a lot of work to do to define it as a new species. Even more surprising to Dr Polaszek is that the new species is native to the UK.


'I thought it might be a species from Northern Europe that had come over to the UK. I was really surprised when I realised it was native to the UK and was previously unknown. Finding an undiscovered insect in the rainforests of Borneo is relatively easy but the fauna of England is some of the most studied in the world so to find something new here is a real thrill, and makes it even closer to my heart.'


In those five years Dr Polaszek has been regularly collecting the new wasp, but has never found a male, suggesting that females can lay eggs without them. This is similar to other parasitoid wasps, such as the related Encarsia formosa.


What's in a name


The new species is named after local scientist Dr David Harrison, chairman of the Harrison Institute that promotes taxonomic research to support biodiversity studies and conservation. The institute is only a few hundred yards from the trees where Encarsia harrisoni was discovered.


Dr Harrison has a few species named after him, but finds the new wasp especially intriguing:


'I now have a flea, a bug, a sand cat and a wasp named after me, which is obviously quite an honour. Dr Polaszek's wasp is a particularly interesting one - it was found right here in Sevenoaks just a few hundred yards from my home.'


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.