Invasions By Alien Plants Have Been Mapped In European Union

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ScienceDaily (Jan. 27, 2009) — Biological invasions are one of the major threats to biodiversity and in many cases they have considerable impact on economy and human health. For their effective management it is important to understand which areas and ecosystems are at the highest risk of being invaded.

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Giant Knotweed, an invasive species from the Far East Sakhalin Island, which threatens biodiversity of natural habitats in Europe. (Credit: Image courtesy of Milan Chytr)

The first map of the level of alien plant invasions in European Union was published in the Wiley-Blackwell journal Diversity and Distributions.
An international team of Czech, Spanish and British plant ecologists investigated species composition of vegetation in more than 50 000 sites in northwestern, southern and central Europe. In each of these sites they quantified the proportion of alien to native plant species.
“We found that the highest risk of alien plant invasions was in agricultural and urban ecosystems. Low levels of invasion were in natural and semi-natural grasslands and most woodlands, and the lowest levels in the Mediterranean evergreen vegetation, heathlands and peatlands. This pattern was quite consistent among European regions with contrasting climates, biogeography, history and socio-economic background”, said senior author Milan Chytrý from Masaryk University, Brno, Czech Republic.
“The level of plant invasions basically depends on the distribution of different ecosystem types across Europe. High levels of invasion are typical of lowland areas of western and central Europe while low levels are found in northern Europe and mountain regions across the continent. Low levels of invasion also occur in the Mediterranean region except its coastline and irrigated fields”, added Petr Pyšek from the Institute of Botany Pruhonice, Academy of Sciences of the Czech Republic.

Climate Change Affecting Europe's Birds Now, Say Researchers

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ScienceDaily (Mar. 6, 2009) — Climate change is already having a detectable impact on birds across Europe, says a Durham University and RSPB-led scientific team publishing their findings to create the world's first indicator of the climate change impacts on wildlife at a continental scale.

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Lapwings Vanellus vanellus. (Credit: Copyright Jodie Randall/Royal Society for the Protection of Birds)

Published in the journal PLoS One, Durham University scientists working with the Royal Society for the Protection of Birds have shown a strong link between recent population changes of individual species and their projected future range changes, associated with climate change, among a number of widespread and common European birds, including the goldfinch and the lesser spotted woodpecker.
By pulling together Europe-wide monitoring data, the team has compiled an indicator showing how climate change is affecting wildlife across Europe. The European Union has adopted the indicator as an official measure of the impacts of climate change on the continent's wildlife; the first indicator of its kind.
The paper and the indicator were produced by a team of scientists from the RSPB, Durham University, Cambridge University, the European Bird Census Council, the Muséum National d'Histoire Naturelle, the Czech Society for Ornithology, and Statistics Netherlands. European population data for birds was compiled by The Pan-European Common Bird Monitoring Scheme (PECBMS), a partnership involving the European Bird Census Council (EBCC), the RSPB, BirdLife International, and Statistics Netherlands funded by the RSPB and the European Commission.
Dr Stephen Willis, of Durham University, said: "The impact of climatic changes, both positive and negative, can now be summarised in a single indicator which we've called the Climatic Impact Indicator. A period of stable annual average temperatures in Europe ended in the early 1980s, and this new Indicator shows that climate change is affecting many species but in different ways. Climate change is having an adverse effect on many birds, though some species are actually benefiting from the recent changes.
"Our indicator is the biodiversity equivalent of the FTSE index, only instead of summarising the changing fortunes of businesses, it summarises how biodiversity is changing due to climate change. Unlike the FTSE, which is currently at a six year low, the climate change index has been increasing each year since the mid-80s, indicating that climate is having an increasing impact on biodiversity.
"Those birds we predict should fare well under climate change have been increasing since the mid-80s, and those we predict should do badly have declined over the same period. The worry is that the declining group actually consists of 75 per cent of the species we studied."
The Climate Change Indicator combines two independent strands of work; bioclimate envelope-modelling and observed populations trends in European birds, derived from the Pan-European Common Bird Monitoring Scheme.
When a bird's population changes in line with the projection, the indicator goes up. Species whose observed trend does not fit the projection cause the indicator to decline.
The RSPB's Dr Richard Gregory said: "We hear a lot about climate change, but our paper shows that its effects are being felt right now. The results show the number of species being badly affected outnumbers the species that might benefit by three to one. Although we have only had a very small actual rise in global average temperature, it is staggering to realise how much change we are noticing in wildlife populations. If we don't take our foot off the gas now, our indicator shows there will be many much worse effects to come. We must keep global temperature rise below the two degree ceiling; anything above this will create global havoc."
The research shows that a number of species are projected to increase the populations across Europe. Of the 122 species that were surveyed, the top ten increasing species (in order) are: Sardinian warbler (P); subalpine warbler (P); bee-eater (P); cirl bunting (B); Cetti's warbler (B); hoopoe (P); golden oriole (B); goldfinch (B); great reed warbler (P); and collared dove (B). Species in this list marked with a (B) already breed regularly in the UK. Species marked with a (P) are potential colonists to the UK if they continue to respond to climatic warming in the way the models predict, and in the absence of other barriers (such as the ability to disperse and the availability of suitable habitat).
Of those species surveyed the worst performers across Europe (in order) are: snipe (B); meadow pipit (B); brambling (occasional B); willow tit (B); lapwing (B); thrush nightingale; wood warbler (B); nutcracker; northern wheatear (B); and lesser spotted woodpecker (B).
Of the 122 species included (out of 526 species which nest in Europe), 30 are projected to increase their range; while the remaining 92 species are anticipated to decrease their range.
Dr Gregory added: "This new work emphasises again the role played by skilled amateur birdwatchers right across Europe in advancing our understanding of the environment and the growing threat posed by climate change."

Bird Population Estimates Are Flawed, New Study Shows

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ScienceDaily (Nov. 29, 2008) — Most of what we know about bird populations stems from surveys conducted by professional biologists and amateur birdwatchers, but new research from North Carolina State University shows that the data from those surveys may be seriously flawed – and proposes possible means to resolve the problem.

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European robin. Researchers found that even small amounts of background noise, from rustling leaves or automobile traffic, led to a 40 percent decrease in the ability of observers to detect singing birds. (Credit: iStockphoto/Andrew Howe)

Bird populations are the focus of thousands of environmental research and monitoring programs around the world. A group of researchers led by NC State's Dr. Theodore Simons has been evaluating factors that confound estimates of bird abundance. For example, background noise can influence the ability of observers to detect birds on population surveys, and can result in underestimates of true population size.
In order to explore these questions, Simons and others worked to develop "Bird Radio:" a series of remotely controlled playback devices that can be used to accurately mimic a population of singing birds. Researchers could then control variables, such as background noise, to see whether it affected birdwatchers' ability to estimate bird populations.
The study found that even small amounts of background noise, from rustling leaves or automobile traffic, led to a 40 percent decrease in the ability of observers to detect singing birds. What's more, said Simons, "we also learned that misidentification rates increased with the number of individuals and species encountered by observers at a census point." In other words, the researchers found that traditional means of estimating the abundance and diversity of bird species are flawed due to complications such as background noise and the accuracy of the data observers collect on surveys of breeding birds.
But the Bird Radio research also points the way toward possible solutions. Simons explains that the Bird Radio findings are helping researchers develop better sampling methods and statistical models that will provide more accurate bird population estimates. For example, researchers are attempting to identify data collection methods that will help account for background noise or other outside factors in estimating bird populations.
The research, "Sources of Measurement Error, Misclassification Error, and Bias in Auditory Avian Point Count Data," is published in the upcoming book "Modeling Demographic Processes in Marked Populations Series: Environmental and Ecological Statistics, Vol. 3" (Springer, 2009). Simons, a professor of biology and forestry at NC State and an assistant unit leader of the U.S. Geological Survey's North Carolina Cooperative Fish & Wildlife Research Unit, was the lead author of the study. The research was co-authored by Dr. Kenneth H. Pollock, professor of biology and statistics at NC State; John M. Wettroth, an engineer with Maxim Integrated Products; Dr. Mathew W. Alldredge, who was a research associate at NC State; and Krishna Pacifici and Jerome Brewster, who were both graduate students in biology at NC State.

Ecological Monitoring On Bird Populations in Europe Re-Evaluated

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ScienceDaily (Aug. 30, 2012) — Biodiversity and environmental monitoring is of crucial importance to diagnose changes in the environment and natural populations in order to provide conservation practice with relevant data and recommendations. The information from monitoring is required, for example, for the design and evaluation of biodiversity policies, conservation management, land use decisions, and environmental protection.

Birds are headline indicators of biodiversity due to their worldwide distribution and popularity. More than 600 bird monitoring programs are in place in Europe, resulting in huge investment of effort. Nearly 28,000 people have been involved in the 144 monitoring programs analyzed in the Nature Conservation paper, spending almost 80,000 person days per year. The evaluation was performed in SCALES, a large-scale integrated project funded by the 7th Framework Program (FP7) of the European Union.

At a dedicated SCALES symposium at the 3rd European Congress of Conservation Biology (ECCB) in Glasgow on 28th-31st of August 2012, the lead author Dr Dirk Schmeller from the CNRS, France and guest researcher at the Helmholtz Centre for Environmental Research -- UFZ in Leipzig, Germany, commented: "Although popular among conservationists, bird-monitoring practices have never been characterized quantitatively. We undertook a focused questionnaire-based survey to objectively explore the strengths and weaknesses of the massive bird-monitoring effort in Europe. The results indicate a high potential for further improvements to bird monitoring in sampling design, data analysis and involvement of volunteers from the public."
"Variation in space and time can cause a significant deviation in the monitoring results, which may lead to incorrect conservation policy decisions," added Dr Klaus Henle from UFZ and coordinator of SCALES. "Therefore increasing awareness of the spatial or temporal scale at which monitoring has been performed can be of crucial importance!"
To optimize the monitoring practices, the scientists have proposed a range of recommendations. For most monitoring programs, the best data type to be collected is quantitative (count) data, such as number of individuals, which provide an early warning for conservation and policy. Further, monitoring could optimize resource allocation between independent monitoring sites. Importantly, even low variation between sites or years can induce spurious conclusions; hence repetitive sampling of the same sites within a year should be the rule.
In case of limited manpower, Schmeller and colleagues recommend an increase in the number of monitoring samples, even at the expense of the size of each sample. Further, more collaborations between monitoring programs at different scales need to be established, so that the sampled data may be integrated and re-used.
Finally, monitoring coordinators have to make special efforts to attract volunteers. Coordinators need to keep in mind several important points: 1) the specific characters of the local community; 2) having a recruitment strategy for volunteers interested in monitoring; 3) maintaining good communication with the volunteers; 4) having low hierarchies and treat volunteers with respect, and 5) making links to other voluntary organizations to add value to the work. Schmeller adds: "There is no one clear recipe to recruit and keep volunteers, but what is important is to keep in mind that the volunteers sacrifice their spare time for monitoring activities, which are of interest to all society!"

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For the Rooster, Size Matters: How Size of Hen's Comb Is Linked to Ability to Lay More Eggs

ScienceDaily (Sep. 4, 2012) — A lone rooster sees a lot of all the hens in the flock, but the hen with the largest comb gets a bigger dose of sperm -- and thus more chicks. This sounds natural, but behind all this is humanity's hunger for eggs.

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Three eighth generation advanced intercross siblings, demonstrating the extreme variation present in the cross. (Credit: Photo by Dominic Wright)

For thousands of years, people have tinkered with the development of domestic chickens. Through selective breeding for a few characteristics such as large muscle mass and increased egg-laying, we have at the same time caused numerous other radical changes in appearance and behaviour. A research group at Linköping University in Sweden has now shown how the size of a hen's comb is bound up with the ability to lay more eggs. The results have been presented in the scientific journal PLoS Genetics.
Compared with the original wild jungle hen, domestic hens have larger combs as well as denser bones. This influences egg-laying, as the hen's bone tissues provide calcium for the eggshells. The greater the bone mass, the more eggs she can lay.
After having spotted a clear correlation between comb size and bone mass in chickens from a cross between red junglefowl and domestic chicken, the research group -- under the leadership of evolutionary geneticist Dominic Wright -- set up a study where such chickens were crossed for several generations. In this way the genome was split up into smaller and smaller regions, which allowed the "mapping" of the functions of individual genes.
In the eighth generation, the researchers found an area that had a strong effect on the weight of the comb -- but also on bone mass and fertility.
The genetic variation has gradually decreased over the course of domestication. In domestic chickens there are now some 40 known small regions with stable genes that potentially govern their typical "domestic" characteristics. LiU researchers have now discovered two "pleiotropic" genes: two genes connected to each other that influence several characteristics simultaneously. By regulating the production of cartilage, they influence combs (which consist of cartilage throughout) as well as bone growth (where cartilage is the base material) and, ultimately, egg production.
"The original hens have smaller combs, thinner legs, and lay fewer eggs. When people bred for the characteristic of laying many eggs, the comb grew automatically," Dominic Wright says.
In nature, the comb is an example of a sexual ornament. Individuals -- often males -- with the most impressive ornaments are favoured by females, thereby obtaining more numerous offspring than their competitors. In domesticated animals, sexual selection -- like natural selection -- has lost its role, as it was humans who determine breeding.

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Can Blue Tits Can Save Our Conker Trees?

ScienceDaily (Aug. 28, 2012) — Blue tits, a familiar garden bird, could be the salvation of our imperiled conker trees (horse-chestnut trees, Aesculus hippocastaneus), which are under severe attack by a tiny non-native moth that has spread from continental Europe.

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A blue tit in front of horse-chestnut leaves that are covered with brown patches of damage caused by the caterpillars of the leaf mining moths. (Credit: Richard Broughton/CEH)

Conker fans from across the country are being called upon to discover how many of the moth's caterpillars, hidden inside the leaves, are being discovered and preyed upon by birds.
The leaf-mining moth arrived in London just ten years ago, and has since spread across most of England and Wales. The moth caterpillars eat the leaves while hiding inside them, so damaging the leaves and causing them to turn brown and making the tree appear as if autumn has come early.
Experts at the NERC Centre for Ecology & Hydrology and the University of Hull are asking for the public's help to find out how many moth caterpillars are eaten by birds, such as blue tits. They are asking volunteers to check leaves from a horse chestnut tree for the distinctive damage caused by the birds to the leaf mines and report it through the Conker Tree Science website.
Dr Michael Pocock, from the NERC Centre for Ecology & Hydrology, said, "It's a big mission and we're reliant on people's help to discover how much birds are feeding on the alien moths."
"Excitingly, this mission was inspired by comments from some of the 8000 people who have taken part in previous Conker Tree Science missions. It's a great example of professional scientists and members of the public working together."
Dr Darren Evans from the University of Hull added, "The traditional game of conkers may be under threat, because trees infected with the alien moth produce smaller conkers. In discovering whether garden birds, like blue tits, can help to protect conker trees, we will also be learning more about the behaviour of the birds themselves."
The alien moth, which was discovered in the 1980s, has caterpillars that live inside the leaves, forming distinctive patches of damage called 'leaf mines'. Up to 700 leaf mines have been recorded on a single leaf and the damage caused by large numbers of larvae can be striking. A previous Conker Tree Science mission discovered that predatory wasps were not effectively controlling the alien moths, possibly explaining their rapid spread.
This project, where anyone can get involved with genuine scientific research, is one of the largest of its kind in the UK and is funded by the Natural Environment Research Council (NERC).
People can take part in the new 'Bird Attack' mission from 30^th August 2012 to 23^rd September 2012. More information: http://www.conkertreescience.org.uk/