Archive for March, 2007

Mar

30

2007
 
 

Lean, green, killing machine



fly the gauntlet!Wind turbines are getting more bird-friendly, but bats are still suffering

Wind turbines kill bats as well as birds, according to a recent report in the Canadian Journal of Zoology. The University of Calgary study, led by Robert Barclay, found a sharp rise in the number of bat fatalities linked with increasing height of turbine towers: the technological trend has been towards fewer, taller structures. One possible cause of the flying mammals’ demise, say the study’s authors, is that the speed of the whirling rotor – some 200 km/h at the tips of the largest blades – is simply too fast for them to avoid. Although changes in turbine design, placement and lighting have probably resulted in fewer bird fatalities, nothing is currently being done to save bats from the chop.

Source: Barclay RMR, Baerwald EF & Gruver JC (2007) Variation in bat and bird fatalities at wind energy facilities: assessing the effects of rotor size and tower height. Canadian Journal of Zoology DOI: 10.1139/Z07-011

Image © Maxfx

Related story in Conservation magazine: Getting it right the first time

Read more on Climate change, Monitoring, Socio-political issues, Tools and technology | Post a Comment

Email This Post Email This Post

Mar

29

2007
 
 

Death rays



Sharks. Good if you're a mollusc.With the great sharks gone, the bivalves are in trouble

The more philosophical bay scallops along the eastern seaboard of the United States are no doubt wondering where the big sharks have gone. But a study published today in Science shows why the disappearing predators – great whites, sand tigers, bull and blacktip among them – have had such a catastrophic effect on the musing mollusks. The study’s authors, a collaborative team led by Dalhousie University’s Julia Baum and the University of North Carolina’s Charles Peterson, found that the precipitous decline of great shark populations – driven by the surging global demand for their fins – has allowed seven families of rays, skates and smaller sharks to increase. Cownose rays Rhinoptera bonasus, for example, could now number as many as 40 million. And what do they eat? You’ve guessed it: those poor, thoughtful bivalves.

Source: Myers RA, Baum JK, Shepherd TD, Powers SP & Peterson CH (2007) Cascading effects of the loss of apex predatory sharks from a coastal ocean. Science DOI: 10.1126/science.1138657

Image © Kathy Wynn

Related story in Conservation magazine: Healing powers

Read more on Endangered species, Restoration, Marine, Monitoring, Economics and conservation | Post a Comment

Email This Post Email This Post

Mar

28

2007
 
 

Keystone hops



run rabbit runCritically endangered European species depend on rabbit prey

The humble European rabbit Oryctolgaus cuniculus should be a conservation priority, a recently published study suggests. Protecting the hoppy ones will provide much needed food for species such as the Iberian lynx Lynx pardinus – the world’s most endangered cat – and Spanish imperial eagle Aquila adalberti – Europe’s most endangered raptor. It makes a change to consider an animal like the rabbit as a keystone species, but according to Miguel Delibes-Mateos at the Instituto de Investigación en Recursos Cinegé, and his international colleagues, the long-eared lagomorph fits the bill. The study, published in Biological Conservation, shows that where there are more rabbits there are more raptors, including the imperiled imperial eagle. So jump to it, conservationists, and save those rabbits!

Source: Delibes-Mateos M, Redpath SM, Angulo E, Ferreras P & Villafuerte R (2007) Rabbits as keystone species in southern Europe. Biological Conservation DOI: 10.1016/j.biocon.2007.01.024

Image © Jiri Castka

Read more on Endangered species, Restoration, Monitoring | Post a Comment

Email This Post Email This Post

Mar

27

2007
 
 

Disappearing hotspots



Amazon forests likely to burnClimate change will obliterate major biodiversity centers, especially in tropics

Entire climatic regions could disappear from the face of the planet by the year 2100, according to a study published this week in PNAS. The worst hit areas, say University of Wisconsin geographer Jack Williams and colleagues, correspond closely with some of the world’s most important biodiversity hotspots, suggesting that many already embattled species are doomed to extinction. Even current measures to assist species’ adaptation to climate change, such as “rewilding” and the establishment of connected habitat networks, won’t be enough to deal with the “ecological surprises” in store. The worst predictions are based on a “business as usual” approach to greenhouse gas emissions: the question is, can we change our habits fast enough to avert this mess?

Source: Williams JW, Jackson ST & Kutzbach JE (2007) Projected distributions of novel and disappearing climates by 2100 AD. Proceedings of the National Academy of Sciences USA DOI: 10.1073/pnas.0606292104

Image © Brasil2

Related story in Conservation magazine: Where the wild things were

Read more on Climate change, Endangered species, Habitat, Restoration, Monitoring, Socio-political issues, Tools and technology | Post a Comment

Email This Post Email This Post

Mar

26

2007
 
 

Too much of a good thing



Grasses like it toughCatastrophic grassland biodiversity loss follows nutrient enrichment, study finds

The complex, delicate balance of grassland species is easily upended with a burst of nutrients, according to findings published this week. Writing in Nature, Stan Harpole, a community ecologist at the University of California, Irvine, and University of Minnesota colleague David Tilman, describe how adding a range of chemical nutrients — alone or in combination — changes the composition of plant species and their growth rates. Multiple additions caused dramatic declines in the number of different grasses, even though those that remained enjoyed greater productivity. The reason, the authors suggest, is that nutrient impoverishment creates more ecological niches, allowing a greater number of specialist species to move in. Pump the ground with goodies, as we do all to often, and the scene is set for a winner-takes-all battle for dominance.

Source: Harpole WS & Tilman D (2007) Grassland species loss resulting from reduced niche dimension. Nature DOI: 10.1038/nature05684

Image © Heather Craig

Related story in Conservation magazine: Restoring Destroyed Grasslands in China

Read more on Habitat, Restoration, Monitoring | Post a Comment

Email This Post Email This Post

Mar

25

2007
 
 

Good for the goose



Here, ducky, ducky...Denmark’s hunters self-limit shooting to save birds from injury

A Danish scheme to reduce the number of birds shot, but only wounded, by hunters has produced dramatic results according to a study published this week in the Journal of Applied Ecology. Prior to 1997, for every hundred Svalbard pink-footed geese Anser brachyrhynchus shot at least seventy more were wounded. The Danish Council for Wildlife Management offered hunters a simple voluntary solution to the carnage: shoot from less than 25 metres. A trio of scientists led by Henning Noer at Aarhus University monitored the effect of the restrictions, using x-rays of cannon-netted birds to detect embedded pellets. The self-imposed 25 m rule appears to have brought about a reduction in wounding of at least 50%: even the geese should be happy about such an ethical turn of events!

Source: Noer H, Madsen J & Hartmann P (2007) Reducing wounding of game by shotgun hunting: effects of a Danish action plan on pink-footed geese. Journal of Applied Ecology DOI: 10.1111/j.1365-2664.2007.01293.x

Image © Lawrence Sawyer

Related story in Conservation magazine: Hunting for Sport Can Boost Conservation

Read more on Monitoring, Economics and conservation, Socio-political issues | Post a Comment

Email This Post Email This Post

Mar

23

2007
 
 

Our fault again



Left a bit, right a bit, straight on...Bird migration routes don’t chart the spread of avian influenza, roads do

Avian influenza H5N1 might be on its way to a farm near you, but the chances are it won’t be delivered by migrating wild birds, according to a review of the evidence published this week in Ibis. Michel Gauthier-Clerc, an ecologist at the Station Biologique de la Tour du Valat, France, and colleagues argue against the hypothesis that “bird ’flu” is spread by migrating birds: the recorded disease outbreaks just don’t match migration routes that take in south-east Asia. Instead, the most likely cause is the movement of poultry – both legal and otherwise – along trade routes. The trafficking of large numbers of wild birds for the pet trade, in particular between Asia and Europe, opens another potentially devastating route for the disease. So ask yourself a question: do you really need that extra pet Steller’s sea eagle?

Source: Gauthier-Clerc M, Lebarbenchon C & Thomas F (2007) Recent expansion of highly pathogenic influenza H5N1: a critical review. Ibis DOI: 10.1111/j.1474-919x.2007.00699.x

Image © Shane Link

Related story in Conservation magazine: No easy way out

Read more on Monitoring, Economics and conservation, Socio-political issues | Post a Comment

Email This Post Email This Post

Mar

22

2007
 
 

Jungle fever



It's not easy being a gorillaGorillas and chimpanzees could be infecting each other with deadly virus

The Zaïre strain of the Ebola virus has devastated gorilla Gorilla gorilla and chimpanzee Pan troglodytes populations in West Africa, but little is known about how the disease is transmitted between groups. However, observations published this week in American Naturalist suggest that there are plenty of opportunities for the deadly virus to jump between not only groups of animals but also different species. An international team of biologists, led by Peter Walsh at the Max Planck Institute for Evolutionary Anthropology, Leipzig, present several lines of evidence that the virus can easily spread. Gorillas, for example, inspect their dead. Potentially infectious material – blood, saliva, faeces and even body parts – can quickly be scattered by scavengers, raising the chances of transmission. Gorillas and chimpanzees have also been seen feeding in the same tree, where their close proximity could easily prove fatal.

Source: Walsh PD, Breuer T, Sanz C, Morgan D & Doran-Sheehy D (2007) Potential for Ebola transmission between gorilla and chimpanzee social groups. American Naturalist DOI: 10.1086/513494

Image © Fanelie Rosier

Related story in Conservation magazine: No easy way out

Read more on Endangered species, Monitoring | Post a Comment

Email This Post Email This Post

Mar

21

2007
 
 

Jumpers and splitters



It's_a_frog's_lifeFrog species splits into two, but both are endangered

In little more than a century, the yellow-legged mountain frog Rana muscosa has all but disappeared from the high Sierra Nevada and Transverse ranges, where once it was the most abundant vertebrate. A study published this week in the Journal of Zoology piles the conservation pressure on: it’s not just one species — it’s two. To make matters worse, according to lead author Vance Vredenberg and colleagues, the “population segments”, which equate to conservation management units, don’t match up with the ranges of the proposed species split. Understanding how species — a concept even Darwin couldn’t precisely pin down — are distributed is essential for efforts to save biodiversity. For example, even though one of the “new” frog species is limited to eight tiny populations in the mountains of southern California, others exist in the southern Sierra Nevada. Introduced fish — especially trout — are the frog’s biggest threat, although an infectious disease has been muscling in of late. A hundred years is a long time in a frog’s history.

Source: Vredenburg VT, Bingham R, Knapp R, Morgan JAT, Moritz C & Wake D (2007) Concordant molecular and phenotypic data delineate new taxonomy and conservation priorities for the endangered mountain yellow-legged frog. Journal of Zoology DOI: 10.1111/j.1469-7998.2006.00258.x

Image © Chris Brown

Read more on Endangered species, Habitat, Fresh water, Monitoring | Post a Comment

Email This Post Email This Post

Mar

20

2007
 
 

Tough school



You all look so tempting!Predatory reef fish selectively target rare prey to avoid confusion

If you’re rare – at least if you’re a juvenile reef fish – your chances aren’t good. A series of experiments by James Cook University’s Glenn Almany and colleagues suggest that predators target rare fish species, making them particularly prone to local extinction. Almany’s study, published in Oecologia, examined how a common reef fish, the brown dottyback Pseudochromis fuscus, selected its dinner from a smörgåsbord of juvenile damselfish species. The dottyback repeatedly went for the rarer prey. Almany and colleagues explain the counterintuitive result as being a way for a hungry predator to avoid confusion: too many brightly-colored moving targets can hinder success, whereas concentrating on the odd one out increases the chance of enjoying a tasty meal.

Source: Almany GR, Peacock LF, Syms C, McCormick MI & Jones GP (2007) Predators target rare prey in coral reef fish assemblages. Oecologia DOI: 10.1007/s00442-007-0693-3

Image © Tommy Schultz

Read more on Endangered species, Marine | Post a Comment

Email This Post Email This Post

keep looking »