Plants- Animals Science News

The ability of gray squirrels to learn from observing others is highlighted in a new study. The research shows how squirrels can quickly learn from watching their peers, particularly if it relates to stealing food. The research adds to growing evidence that animals are primed to learn quickly about what is most important to their survival and that they learn by observing others. It is the first study to test the ability of gray squirrels to learn from observation.

The research team tested the squirrels' ability to learn to choose between two pots of food after watching another squirrel remove a nut from one of the pots. One group was rewarded for choosing the same pot as the previous squirrel, the second group was rewarded for targeting the other pot.

Those that were rewarded for choosing food from the other pot learned more quickly than those that were rewarded for choosing the same pot. This suggests that grey squirrels learn more quickly to recognise the absence of food.

The study was repeated, but instead of observing another squirrel, the animals were trained with the use of a card. In this test, the squirrels showed no significant difference in their ability to learn to choose the same or opposite pot.

The study suggests that squirrels are primed to recognise other squirrels as potential food thieves. It also shows that they learn more quickly from real life observations.

Corresponding author Dr Lisa Leaver of the University of Exeter, said: "Our study is significant because it is the first to show that grey squirrels learn from observing others. It adds to growing evidence that all kinds of animals, from humans and other primates to many species of birds, learn from observation and that they have evolved to learn quickly about those things that are most important to their lives – in the case of grey squirrels, gathering and storing nuts."

The research team now hopes to conduct further studies into the psychology of grey squirrels to learn more about how the animals learn from – and possibly deceive – one another.


http://www.exeter.ac.uk/

Why do some plants defend themselves from insect attacks better than others? New evidence shows that the difference might be due to whether they're getting any plant love.


In research published in Proceedings of the National Academy of Sciences, scientists from North Carolina State University and Duke University discovered that sexually produced evening primrose plants withstand attacks from plant-eaters like caterpillars better than plant relatives that reproduce by themselves.

The findings are important steps to learning more about how plants have evolved defenses against insect herbivores, says Dr. Marc Johnson, assistant professor of plant biology at NC State and the lead author of the research paper.

"The variation in sexual reproduction has a large impact on the ability of plants to evolve defenses against herbivores," Johnson says.

In the study, the researchers performed both lab and field experiments on evening primrose (Onagraceae) plants, a plant family that has 259 different species – 85 percent of which reproduce sexually with the remainder reproducing asexually – to gauge the effects of plant sex on defense mechanisms. The researchers found that so-called generalist herbivores – those that eat a variety of plants – preferred to feed on the asexual species and lived longer while doing so.

The results were a bit different for so-called "specialist" plant-eaters, however. Those insects that prefer just one kind of food were more apt to munch on sexually reproduced species of plant. This most likely occurs, Johnson says, because specialized plant-eaters evolve alongside their hosts and have found ways to co-opt plant defenses. Instead of being deterred by certain chemical compounds produced as defenses by the plant, the specialized plant-eaters are attracted to them.

Johnson says the nuanced results make sense.

"Sex shuffles up genes and allows individual plants to get rid of bad genes and keep good ones," he said. "That helps them evolve defenses against generalist herbivores. Though there are short-term benefits to asexual reproduction – populations can grow more rapidly and propagate even when pollination is not possible – losing sex puts plants at a long-term disadvantage.

The research was funded by NC State, the Natural Sciences and Engineering Research Council of Canada, the National Science Foundation, Duke University and the National Institutes of Health. Johnson's co-authors from Duke University are Dr. Mark D. Rausher, professor of biology, and Dr. Stacey D. Smith, a post-doctoral researcher in biology.


http://www.ncsu.edu/

http://www.plos.org/

No human is a clone of their parents but the same cannot be said for other living things. While your DNA is a combination of half your mother and half your father, other species do things differently. The advantage of clonal reproduction is that it produces an individual exactly like an existing one—which would be very useful for farmers who could replicate the best of their animals or crops without the lottery of sexual reproduction. Clonal reproduction of crop species took a step closer to being realised with new research published in PLoS Biology.
The type of cell division that creates eggs and sperm is called meiosis, and it differs from 'normal' cell division (mitosis) because instead of producing two genetically identical daughter cells, it produces four cells each containing only half of the parental amount of DNA. Meiosis occurs in all species that reproduce sexually, from microorganisms such as yeast to plants, animals and human beings. This new paper blurs the line between the two different types of cell division by showing a plant where three specific mutations are experimentally combined. These divisions are normally meiotic – which make pollen and egg cells – and are replaced by mitotic divisions.

The work, by a team of researchers in France and Austria, is potentially very important commercially, because it makes the creation of stable new mutant crops—such as plants of a different colour, or with a different yield, etc.—much simpler. It is now much closer to being possible to reproduce a plant that produces perfect potatoes, maize or rice, without the lottery of reassortment that each meiotic division and ensuing fertilization introduces.

The first steps of both meiosis and mitosis are the replication of the dividing cell's DNA. Once replication has occurred, the chromosomes condense into tightly bound structures, and in mitosis these form an X shape in which each half of the X is a chromatid, comprising one complete copy of the chromosome. The double-chromatid chromosomes line up along the centre of the cell. In mitosis, the two chromatids are pulled apart—the X is divided along one axis of symmetry—and these then pass into two genetically identical daughter cells. In meiosis, there are two lining up and dividing phases. The first lining up is of homologous chromosomes—all chromosomes in an adult cell have a partner, members of the partnership coming from the mother and father of the cell—and these homologous chromosomes are each made up of two chromatids. The first division divides homologous pairs of chromosomes while the second meiotic division is just like the mitotic di vision: the chromosomes line up at the middle of the new cell and the chromatids divide at the centre of the X.

Thus the differences between mitosis and meiosis are that meiosis has two rounds of division; co-segregation of sister chromatids at the first division; and recombination that occurs during the first division—a swapping over process that adds more genetic diversity to offspring. The new work, led by Raphael Mercier, identifies a gene that controls one of these three features—entry into the second meiotic division—in the sexual plant Arabidopsis thaliana. By combining a mutation in this gene with two other previously described mutations—one that eliminates recombination and another that modifies chromosome segregation—the authors have created a strain of plant (called MiMe for 'mitosis instead of meiosis') in which meiosis is totally replaced by mitosis.

MiMe plants produce pollen and eggs that are genetically identical to their parent. If MiMe eggs are self-fertilized by MiMe sperm, the offspring plant has twice as much DNA as the parent generation, and has all the genes from this single parent.

Thus the authors have made a form of asexual reproduction possible in a normally sexual species. Turning meiosis into mitosis is not enough to reach clonal reproduction, but it's a giant leap towards it. This has potential revolutionary applications in crop improvement and propagation.

This work was supported by an INRA postdoctoral fellowship to Id'E. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.

http://www.rspb.org.uk/ The latest assessment of the status of all of the UK’s 246 regularly occurring birds – Birds of Conservation Concern 3 – shows 52 are now of the highest conservation concern and have been placed on the 'red list'.

The revised red list now includes even more familiar countryside birds, including the cuckoo, lapwing and yellow wagtail, joining other widespread species such as the turtle dove, grey partridge, house sparrow and starling.

Alarmingly, red listed species now account for more than one-in-five (21 per cent) of all the UK’s bird species. This is a far higher proportion than compared to the last assessment in 2002, when 40 species (16 per cent) were red listed. Most species on the red list have suffered a recent halving of range or population in the UK, or have undergone a historical decline since 1800.

Amongst the species new to the red list is a suite of birds visiting the UK in summer, notably the cuckoo, wood warbler, and tree pipit. These birds, are widespread, but rapidly-declining, summer visitors to the UK.

Their addition to the red list is highlighting the concern that many long-distance migratory birds nesting in Europe and wintering in Africa are increasingly in trouble. Currently 21 of the birds on the red list are summer visitors to the UK, with the majority of these spending the winter in sub-Saharan Africa.

The continued decline of widespread farmland and woodland birds is a theme which has developed since the compilation of the last list in 2002. Lapwing, a formerly much-more widespread wading bird, and the hawfinch, a woodland bird largely confined to England, have both joined the red list in the latest assessment.

Three species of seabird join the red list for the first time. The Balearic shearwater - a smaller relative of the albatross - visits the UK from its Mediterranean breeding grounds regularly each autumn. This seabird, which is thought to face a higher risk of global extinction even than the giant panda - is the rarest bird to regularly occur in the UK.

Highlighting concerns about the fortunes of seabirds around the northern coasts of the British Isles, the Arctic skua has joined the red list straight from the 2002 green list: the only species to do so. The familiar herring gull also joins the red list as its population has more than halved in recent times.

For the first time two winter-visiting birds have joined the red list. The dunlin, a starling-sized wading bird, and the scaup - a duck - have been placed on the red list because of declines in wintering populations. The ongoing decline of the dunlin population has seen this wader slump to its lowest levels since recording began.

While a link to climate change has not been demonstrated, the addition of five species on the southern edge of their nesting range in Britain (Temminck’s stint, ruff, whimbrel, redwing and fieldfare) to the red list may provide some the evidence of range shifts. These species have only had a toehold in the UK in recent decades and now that appears to be slipping. (However, redwing and fieldfare are still plentiful visitors to the UK in winter).

Good news

However, the 2009 assessment does contain some good news. Six species (stone-curlew, woodlark, quail, Scottish crossbill, bullfinch and reed bunting) have been removed from the 2002 red list, largely because of a recovery in their numbers or range, or a better understanding of their populations. These species are now placed on the amber list.

The stone-curlew is a bird of farmland and open countryside. Virtually confined to Wessex and central East Anglia, the stone-curlew population has increased because of the fantastic efforts by landowners to improve the fortunes of this striking wading bird.

'Conservation works, but with a growing to-do list we have to strive even harder to retain the rich variety of wildlife that our islands possess.'

Improvements in land management, especially of heathland, have also led to a dramatic increase in the UK population of the woodlark, a heathland bird. The bullfinch and the reed bunting have also been placed on the amber list following modest recoveries in their populations.

Scottish crossbill stable

The Scottish crossbill – the only bird species with its total world range confined to the UK – has also been removed from the red list. A survey (funded by RSPB and Scottish Natural Heritage) found approximately 13,000 individuals of this colourful endemic finch, and its population is currently thought to be stable.

Five species assessed in 2002 (bluethroat, scarlet rosefinch, icterine warbler, hoopoe and snow goose) were not considered in the 2009 revision, because they failed to meet the qualifying criteria for inclusion.

Four species not assessed in 2002 (Balearic shearwater; shorelark; yellow-legged gull; and hooded crow) were considered in the 2009 revision for the first time.

Birds of Conservation Concern 3 is compiled by a partnership of organisations, including the British Trust for Ornithology, Countryside Council for Wales, Game & Wildlife Conservation Trust, Joint Nature Conservation Committee, Natural England, Northern Ireland Environment Agency, RSPB, Scottish Natural Heritage, and the Wildfowl & Wetlands Trust,

The full Birds of Conservation Concern 3 report will be published in the June edition of British Birds.

According to a new publication by Wetlands International, more than half the populations of waders in Europe, West Asia and Africa are declining at an accelerating rate.

Waders are a group of relatively small waterbirds including species like lapwings, plovers, godwits, curlews and sandpipers. Many of them undertake long distance migrations from their Arctic breeding grounds to wintering areas as far away as Southern Africa. Some concentrate in huge numbers at just a few sites, making these wetlands critical for their survival.

The new ‘Wader Atlas’ is the first comprehensive overview of key site networks for waders in Europe, West Asia and Africa, and the publication highlights a need for better protection of the key wetlands along their flyways, especially in Africa and the Middle East.

The authors outline that whilst many European Union (EU) Member States have established a fairly comprehensive network of protected areas for waders, many of which are Important Bird Areas (IBAs) identified by the BirdLife Partnership, the protection and management of key sites is still far from adequate beyond the EU’s borders.

“Waders such as Ruff [Philomachus pugnax] are heavily protected in the EU; farmers receive thousands of Euros for nest protection”, said author Simon Delany. However, the new publication outlines that resources outside the EU urgently need to be increased – helping to conserving waterbirds at all stages of their lives.

The wetlands of the African west coast are under enormous pressures. The sparse water resources in the Sahelian zone are tapped by dams which have turned formerly shallow wetlands into permanently dry lands. Irrigation schemes for growing human population disrupt the water flow in wetlands such as the shrinking Lake Chad. The atlas also outlines that wetlands themselves are often converted to agricultural use - such as in the Tana River Delta in Kenya, which is threatened by conversion to sugar cane plantations.

“Migratory waterbirds can only be effectively conserved through international cooperation along their entire flyway”, said Dr Vicky Jones - BirdLife’s Global Flyways Officer. “BirdLife Partners are focusing on joining up site-based action at critical sites for waterbirds within the African-Eurasian area”.

BirdLife is a key partner in the Wings over Wetlands (WOW) project which is making an enormous difference to the understanding of migratory waterbirds and their needs, demonstrating best practice in the conservation and wise-use of wetlands, and increasing cooperation along the African-Eurasian flyway.

BirdLife is also involved in a new ‘WetCap’ project to help strengthen waterbird conservation and build capacity for wetland management activities at key sites in Morocco, Tunisia, Algeria, Egypt and Mauritania. “WetCap will promote the wise-use of wetlands which benefit local people by providing clean water and opportunities for fishing, agriculture, recreation and tourism”, said Dr Jones.

On the ground, IBA Caretakers and Site Support Groups are working to protect and monitor key sites for migratory birds. “A wide range of activities are being implemented by the BirdLife Partnership to support the development and growth of this local approach to site conservation, through capacity building, networking, sharing experience and provision of seed-financing”, added Dr Jones.

BirdLife recognises that despite their importance, wetlands are amongst the world’s most vulnerable ecosystems.

Thirty-five percent of the world’s birds, 52 percent of amphibians and 71 percent of warm-water reef-building corals are likely to be particularly susceptible to climate change, the first results of an IUCN study have revealed.

The report identified more than 90 biological traits which are believed to make species most susceptible to climate change. It found that 3,438 of the world’s 9,856 bird species have at least one out of 11 traits that could make them susceptible to climate change.

Albatross, penguin, petrel and shearwater families are all likely to be susceptible to climate change, while heron and egret families, and osprey, kite, hawk and eagle families are among those least likely to be susceptible to climate change.

“This is the first time that a systematic assessments of species’ susceptibility to climate change has been attempted,” says Wendy Foden, of IUCN’s Species Programme. “Climate change is already happening, but conservation decision makers currently have very little guidance on which species are going to be the worst affected.”

The study found 3,217 of the 6,222 amphibians in the world are likely to be susceptible to climate change. Three salamander families are could be particularly susceptible, while 80-100 percent of Seychelles frogs and Indian Burrowing Frogs, Australian ground frogs, horned toads and glassfrog families were assessed as susceptible.

Specialized habitat requirements, such as species with water-dependant larvae, and those unable to disperse due to barriers such as large water bodies or human-transformed habitats are most at risk.

The report found that 566 of 799 warm-water reef-building coral species are likely to be susceptible to the impacts of climate change. The Acroporidae family, including staghorn corals, had particularly high numbers of susceptible species, while the Fungiidae family, including mushroom corals, and the Mussidae family, including some brain corals, possess relatively few.

Coral species qualified due to their sensitivity to increases in temperature, sedimentation and physical damage from storms and cyclones. Poor dispersal ability and colonization potential were used as a further important indicators.

According to the IUCN Red List of Threatened Species, 32 percent of amphibians are threatened with extinction. Of these, 75 percent are susceptible to climate change while 41 percent of non-threatened species are susceptible to climate change. For birds, the overall percentage of those threatened with extinction is lower – 12 percent. However, 80 percent of those are susceptible to climate change.

“There is a large overlap between threatened and climate change susceptible amphibian and bird species,” says Jean-Christophe Vié, Deputy Head of IUCN Species Programme. “Climate change may cause a sharp rise in the risk and rate of extinction of currently threatened species. But we also want to highlight species which are currently not threatened but are likely to become so as climate change impacts intensify. By doing this we hope to promote preemptive and more effective conservation action.”


http://www.iucn.org/

Cyclamen, a common, pretty garden flower, is at risk of extinction because of climate change.

In a study published in the open access journal BMC Evolutionary Biology, researchers show, using mathematical modelling, that the ideal climate for Cyclamen will become increasingly rare and might have totally disappeared by the 2050's. Some species of Cyclamen are adaptable enough and could survive climate change, but many would probably disappear.

Chris Yesson and Alastair Culham, from the University of Reading in the UK built mathematical models based on the current distribution of the 21 different species of Cyclamen, in order to predict the impact of climate change on Cyclamen within the next 50 years.

Yesson and Culham identified distinct climatic niches -- geographic areas with the ideal climate -- for different species of Cyclamen. Most Cyclamen species thrive in a typical Mediterranean climate, with hot, dry summers and cool, wet winters, but many are found in areas with much harsher climatic conditions. Yesson and Culham show that climatic niches are likely to decrease for all species of Cyclamen, and by more than 60% for most species.

Yesson and Culham conclude: "Many of these species are considered to be at high risk of extinction due to climate change."


http://www.biomedcentral.com/