Category Archives: Conservation/Conservation Science

The Wetter the Better for Daddy Longlegs — And Birds

 

Crane fly holding onto wet grass after a rain storm. (Credit: iStockphoto/John Crongeyer)

ScienceDaily (Apr. 4, 2011) — Keeping moorland soils wet could prove vital in conserving some of Britain’s important upland breeding bird species — by protecting the humble daddy longlegs, according to new research.

In spring, thousands of adult crane-flies (daddy longlegs) emerge from the peat soils of UK mountains and moorland, providing a vital food source for breeding birds, such as Golden Plover, and their chicks.

New research by scientists at the University of York, the Royal Society for the Protection of Birds and Aberystwyth University provides experimental evidence that management to restore the condition of our upland peat bogs may also make these vulnerable habitats more resilient to climate change.

In a paper published in Global Change Biology, they have shown that more crane-flies emerge from wetter areas of upland peat bogs, and that ongoing efforts to restore degraded peat soils can benefit crane-fly populations too. The researchers believe that the reduction in crane-fly populations caused by peatland drainage could intensify as the climate changes, posing a real risk to upland birds.

Matthew Carroll, the lead author of the paper and a PhD student in the Department of Biology at York, said: “Although upland peat bogs seem very wet, some areas can actually be fairly dry. In these drier areas, we always found lower numbers of crane-flies. Where the peat was wetter, crane-flies were more abundant. This is particularly important as climate change could cause peat surfaces to become drier. We urgently need to find ways to make upland ecosystems more resilient to these changes.”

Large areas of British peat were drained in the 20th Century in an attempt to improve upland agriculture, though many drains are now being blocked often to improve water quality.

“We wanted to know if there are also conservation benefits. Our experiment compared areas with blocked and open drains. We found that not only was peat around the blocked drains wetter, but more crane-flies emerged,” he added.

Author Dr Peter Dennis, from the Centre for Integrated Research in the Rural Environment at Aberystwyth University, said: “Mountain species of crane-flies are adapted to the cold and wet conditions of peatlands. A larger proportion of small, young leatherjackets (the larval stages of the crane-flies) dry out and die if conditions become too warm and dry.”

Author Chris Thomas, Professor of Conservation Biology at York, added: “Climate change projections show that the British uplands will experience warmer, drier summers. This could be damaging enough to cause crane-fly numbers to crash. If we lose the crane-flies, then the birds that rely on them are likely to decline.

“Peat soils are one of the most important terrestrial stores of carbon. If they become too dry, they will stop accumulating carbon as new peat, and could even become sources of carbon, through erosion or oxidation of the peat. It will be the driest areas, such as those subject to drainage, that will show these problems first. Ensuring that upland peat soils remain wet will be a vital step if we are to conserve our unique upland ecosystems and the vital ecosystem services they provide.”

Dr James Pearce-Higgins, of the British Trust for Ornithology, said: ‘Crane-flies are an important food source for many upland birds, such as Golden Plovers, but are sensitive to hot summer conditions. Golden Plover chicks tend to survive better when there are lots of crane-flies, and therefore Golden Plover populations are vulnerable to future warming.”

Dr Steven Ewing, RSPB conservation scientist said: “This study shows that we need to keep our upland peat bogs wet to ensure they continue to support important wildlife. The wetter the bogs are, the more resilient they are to climate change and the better they are for crane-flies and the birds that rely on them.

“On our nature reserves in the Pennines and the North of Scotland, we are blocking drains and raising water levels to restore bogs. Away from our own land, we are working with farmers, water companies and Government agencies to promote peatland restoration and make sure that both people and wildlife can benefit from healthy uplands.”

The research was funded by a Natural Environment Research Council CASE PhD studentship with the RSPB.

Journal Reference:

CARROLL, M. J., DENNIS, P., PEARCE-HIGGINS, J. W. and THOMAS, C. D. (2011), Maintaining northern peatland ecosystems in a changing climate: effects of soil moisture, drainage and drain blocking on craneflies. Global Change Biology, 17: no. doi: 10.1111/j.1365-2486.2011.02416.x

 

 

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Madagascar’s Radiated Tortoise Threatened With Extinction

A team of biologists from the Wildlife Conservation Society and the Turtle Survival Alliance have reported that Madagascar’s radiated tortoise — of the world’s most beautiful tortoise species — is being hunted to extinction. (Credit: Julie Larsen Maher/Wildlife Conservation Society)

ScienceDaily (Apr. 12, 2010) — A team of biologists from the Turtle Survival Alliance (TSA) and Wildlife Conservation Society (WCS) reported April 5 that Madagascar’s radiated tortoise — considered one of the most beautiful tortoise species — is rapidly nearing extinction due to rampant hunting for its meat and the illegal pet trade.

The team predicts that unless drastic conservation measures take place, the species will be driven to extinction within the next 20 years.

The team recently returned from field surveys in southern Madagascar’s spiny forest, where the once-abundant tortoises occur. They found entire regions devoid of tortoises and spoke with local people who reported that armed bands of poachers had taken away truckloads of tortoises to supply open meat markets in towns such as Beloha and Tsihombe. Poaching camps have been discovered with the remains of thousands of radiated tortoises, and truckloads of tortoise meat have been seized recently.

“Areas where scores of radiated tortoises could be seen just a few years ago have been poached clean,” said James Deutsch, director of the Wildlife Conservation Society’s Africa Program. “Back then one could hardly fathom that this beautiful tortoise could ever become endangered, but such is the world we live in, and things can — and do — change rapidly.”

“The rate of hunting of radiated tortoises is similar to the hunting pressure on American bison during the early 19th century, where they were nearly hunted to extinction when they once numbered in the tens of millions,” said Brian D. Horne, turtle conservation coordinator for the Wildlife Conservation Society’s Species Program.

Tortoise populations near urban centers have crashed with poachers moving closer and closer to protected areas; it is simply a matter of time before those areas are targeted too, the biologists predict.

“Radiated tortoises are truly under siege now as never before, and if we can’t draw a line in the sand around protected areas, then we will lose this species” said Rick Hudson, president of the TSA. “I can’t think of a tortoise species that has undergone a more rapid rate of decline in modern times, or a more drastic contraction in range, than the radiated tortoise. This is a crisis situation of the highest magnitude.”

Formerly occupying a vast swath of the southern portion of the island nation of Madagascar — the radiated tortoise was once considered one of the world’s most abundant tortoise species, with an estimated population in the millions. It is now ranked as Critically Endangered by the IUCN Red List.

One of the most troubling trends is that poachers are now entering protected areas (Special Reserves, National Parks, World Heritage Sites) to collect tortoises and the staff there are poorly equipped to patrol and protect populations. The situation is exacerbated by several factors:

  1. Years of extreme drought that have led to diminished agricultural production and increased poverty, which leads people to tortoise hunting for survival;
  2. Enforcement action is often days away so that local officials do not have the capacity to stop poachers;
  3. Severe habitat degradation has made the spiny forest the most endangered forest type in Madagascar. After burning and clearing for agriculture invasive plant species take over and today thick stands of opuntia (prickly pear) and sisal (agave) dominate the landscape;
  4. Current political instability has resulted in an increased open access to natural resources and illegal pet trade.

The radiated tortoise is still able to “make a living” and survive in this degraded habitat. However, the tortoise cannot survive the current threat of wholesale collection for food markets. Community mobilization linked to sustainable habitat protection is needed to save this unique critically endangered species.

Story Source:

Wildlife Conservation Society (2010, April 12). Madagascar’s radiated tortoise threatened with extinction. ScienceDaily. Retrieved May 11, 2010, from http://www.sciencedaily.com­ /releases/2010/04/100405152555.htm