volunteer costa rica
 
Our Services
Homestay
Prices
Our Environment
Testimonials
Site map
Contact us
Links

Visit us at

volunteer costa rica

and let your testimonials!

 

Monday, June 29, 2009

First comprehensive study of insect endangerment: ten percent of dragonflies threatened


A lot of time, effort, and funds have been spent on programs evaluating the threat of extinction to species around the world. Yet insects have not benefited from these programs, which have largely focused on more 'charismatic' species such as mammals, birds, amphibians, and reptiles. This gap is clearly shown by the fact that 42 percent of vertebrates have been assessed by the International Union for the Conservation of Nature (IUCN), and only 0.3 percent of invertebrates.

Given this dearth of knowledge regarding the threat level of extinction to invertebrates, conservationists concerned about the current extinction crisis have largely had to do without hard data on insects and other invertebrates to make predictions regarding the level of extinction possible.

A new study in Biological Conservation has begun the long and difficult process of evaluating the state of insect populations around the globe, focusing on the order of Odonata, which includes dragonflies and damselflies.



Assessing the threat

Viola Clausnitzer, one of the paper’s lead authors, told mongabay.com that assessing the Odonata order was a natural choice to begin this process.

"Odonata are an easy to study group: they are active at daytime, have a striking appearance and courtship behavior, the taxonomy is more or less solved (unlike most other insect groups), they are used as indicator organisms for assessments, they can serve as flag-ship species for environmental health ('guardians of the watershed')," Clausnitzer said, a geographer at the Phillips University of Marburg, Germany. "For most other insect groups a global approach is not yet possible because of problems with taxonomy and too many yet undescribed species."

To determine the overall threat level to dragonflies and damselflies, researchers assessed individual threat levels for 1,500 randomly selected species out of the total 5,680 described Odonata species (26.5 percent). Clausnitzer and her team assessed threat status by looking at the availability and state of habitat within each species' range.






Researchers were surprised to find that only 10 percent of these species appeared to be under threat of extinction. This was a better than expected, especially considering that 31 percent of amphibians, 20 percent of mammals, and 12 percent of birds are threatened.


The highest ratio of threatened Odonata species were found in Australia and islands off Southeast Asia. Australian species are increasingly threatened by climate change’s affect on freshwater environments, while island dragonflies and damselflies face constricted habitats and deforestation. To date only two Odonata species has been recorded going extinct in modern times, both on islands: Megalagrion jugorum from Maui and Sympetrum dilatatum from Saint Helena.

Data Deficient

In addition to 10 percent of dragonflies and damselflies considered threatened, the researchers also found that 35 percent, or 527 species, were classified as Data Deficient. In other words, the scientists simply did not have enough information on the species to make determination of their status.


The higher the Data Deficient category the poorer the results," Clausnitzer admits. "But the percentage of Data Deficient species was equally high in the global amphibian assessment and is only lower with birds and mammals. Nevertheless much effort is needed to lower the number of Data Deficient species."

While the percentage of Data Deficient species is relatively high for vertebrates, Clausnitzer says that it is unique for invertebrates.

"If you assess other groups [of invertebrates, the percentage of Data Deficient] will be much higher. Still, the data deficient areas are tropical countries and much more surveys, ecological and biodiversity field work and taxonomica work is necessary to lower the Data Deficient category," Clausnitzer says. Nearly 60 percent of the world's Odonata species live in the Neotropics and the Indo-Malayan realms.

According to the paper, the percentage of Data Deficient species could raise the number of threatened Odonata species to approximately fifteen percent, rather than ten, but this is still only half the number of threatened amphibians.

These findings call into question predictions of the current extinction crisis that tend toward the higher end. For example, even if fifteen percent of Odonata species are threatened it is difficult to imagine an extinction crisis that exceeds this percentage if other insect species are similar.



This delicate damselfly was assessed as Data Deficient (DD) on the IUCN Red List, because it was known from only a few males from two localities close to each other in the Amazon forest of northern Peru. During a visit to the Research Station of Tiputini, located in eastern Ecuador this last January, R. W. Garrison and Natalia von Ellenrieder found it also inhabiting several narrow streams within the Ecuadorian forest. This discovery considerably enlarges the range of distribution of this beautiful damselfly, and hopefully many other rare species of Odonates which are insufficiently known are found more widely distributed upon further search of this vast and rich forest. The adults fly very close to the water surface, and perch horizontally on sticks and leaves overhanging the water. In the shaded streams they are rendered inconspicuous, and can usually be noticed only after examination of the vegetation growing along the stream banks. Text credit: Natalia von Ellenrieder. Photo by: Rosser W. Garrison.
"Some of the predictions seem to be largely exaggerated," Clausnitzer says, adding that "insects can survive in small pockets of habitats."

In addition dragonflies and damselflies do not face the same hunting pressures as many mammals, birds, reptiles, and amphibians. The bushmeat and wildlife trafficking has become one of the leading causes behind species endangerment worldwide, but it is a threat that insects, other than butterflies, have avoided.

Conservation and research

Although not as media-friendly as polar bears and pandas, Clausnitzer believes that conserving dragonflies and damselflies is important to saving ecosystems in general.

"Odonata are key-predators and are sensitive to changes to the aquatic and terrestrial environment. Because they are easy to observe and survey they are excellent indicator organisms to monitor environmental health. Since most people know dragonflies, they are good flag-ship species to teach people about the importance of conservation and monitoring. Thus dragonflies can be regarded as 'guardians of the watershed'," Clausnitzer says.

To conserve these 'guardians'—and the ecosystems they inhabit—Clausnitzer urges "serious global attempts to protect forests, springs, streams and rivers. In Europe we can currently watch an increase in water quality, while third world countries, which often rely directly on river water, have a drastic decrease in water quality and availability. For example it would help to have a 10m wide strip along streams and rivers, which remains untouched."


Still, there is a lot more research and work that needs to be done. "Odonata only comprise a small invertebrate order, with above-average dispersal ability and relatively wide distribution ranges," Clausnitzer and the other authors write in the paper. "For conservation science and policy to be truly representative of global biodiversity a representative cross-section of invertebrates needs to be included."

What insect orders would they recommend next?

"In terms of feasibility grasshoppers and butterflies might be possible," Clausnitzer said. "But more important would be an assessment of hymenoptera, since these play an important role in pollination and as predators of pest-insects (key ecosystem-services)."

Hymenoptera is a large order of insects, comprising everything from bees and ants to sawflies and wasps.

Clausnitzer says that in order to move forward there needs to be "funding for more surveys, field work and taxonomic work," adding that, "nevertheless with the current economic situation it is even more difficult to get funding for basic biodiversity research."

If scientists are ever to make accurate estimates regarding the extinction crisis already under way, more research will be necessary.


Taken from:

Mongabay.com

Labels: , , , , , , , ,

Tuesday, June 23, 2009

Frogs species discovered living in elephant dung.


Three different species of frogs have been discovered living in the dung of the Asian elephant in southeastern Sri Lanka. The discovery—the first time anyone has recorded frogs living in elephant droppings—has widespread conservation implications both for frogs and Asian elephants, which are in decline.

"I found the frogs fortuitously during a field study about seed dispersal by elephants," Ahimsa Campos-Arceiz, a research fellow from the National University of Singapore, told Monagaby.com. "I thought it was an interesting phenomenon and commented it with some colleagues, experts on elephant and amphibian ecology. None of them had heard about such a thing before. Local people in the study area…seemed also unaware of it."





Mushroom growing out of dung pile. Photo by Campos-Arceiz.
Campos-Arceiz examined 290 elephant dung piles and found six frog individuals in five dung piles, representing three species: the ornate narrow-mouthed frog Microhyla ornata, another narrow-mouthed species Microhyla rubra, and a frog species in the Sphaerotheca genus.


While Campos-Arceiz is uncertain why the frogs were residing in the elephant dung, he speculates that "elephant dung provides a good shelter. I found the frogs in an arid area during the dry season. Under such conditions and in the absence of litter, elephant dung is probably a good alternative to spend the day in. Elephants digest food very poorly. Their feces contain a large proportion of undigested material and are highly fibrous. When fresh, elephant dung is humid and probably cooler than the environment during the day. Moreover, frogs could eat some of the many invertebrates present in elephant dung."










"Elephants (and their dung!) can play a facilitative role for other organisms," Campos-Arceiz says explaining the many roles elephant dung plays in the larger forest ecosystem. "For plants, elephant dung provides a suitable germination environment after being dispersed by elephants. Fungi are also dispersed by elephants and some are extremely common growing in elephant dung. Invertebrates are extremely common as well. I was indeed impressed with the quantity and diversity of invertebrates in some dung piles…Vertebrates like jungle fowls and land monitors pick elephant dung to feed on these invertebrates; others like small birds and mammals can consume undigested material from the dung, sometimes acting as secondary seed dispersers. Elephant dung plays some role in nutrient cycling as well, moving nutrients from the vegetation to the soil. Elephants are capable of controlling the availability of resources for other organisms modifying the physical environment acting thus as ecosystem engineers."


To test the importance of elephant dung regarding forest biodiversity, Campos-Arceiz searched through an additional 180 dung piles of free-ranging cows and buffaloes and found no frogs and far less diversity of invertebrates.

Classified as Endangered by the IUCN Red List, Asian elephants are threatened by the illegal ivory trade and habitat degradation and loss. Their range has shrunk significantly over the last centuries, and many researchers worry it will contract further.

Taken from:

mongabay.com

Labels: , , , , , ,

Friday, June 19, 2009

World’s rarest tortoises stolen

Four of the world’s rarest tortoises have been stolen from a captive breeding program in Madagascar. The critically endangered animals were part of a group of 44 due for release by the Durrell Wildlife Conservation Trust and were being held in pre-release enclosures at a secret location.

The Trust fears the stolen ploughshare tortoises are destined for Europe, USA or Asia where collectors will pay thousands of dollars for individuals due to the rarity of the species. It is estimated that only 500 adults remain in the wild and they are only found in Baly Bay national park, where the tortoises were taken from. After extensive investigations in the area arrests have been made but the tortoises are yet to be recovered.



"As with many other species around the world, greed is proving to be the major threat facing the ploughshare tortoise. The selfish desires of foreign collectors could in the end send this species to extinction” says Andrew Terry, Durrell's Conservation Manager.


Traffickers pay poor local people to find the animals but the real problem lies with private collectors and buyers who continue to make the illegal trade of such rare species a lucrative business. Malagasy and foreign authorities have made attempts to put a stop to the smuggling, but recent political unrest and consequent lack of law enforcement has provided opportunities for traffickers.

“Durrell, the government of Madagascar and our partners are doing what we can to protect and restore the ploughshare, but if the international demand remains this high we will end up fighting a losing battle” Terry continues. “We have to work with local authorities to increase enforcement of the law within Madagascar, but equally we need to increase pressure on the collectors in Europe and Asia."



Taken from:

mongabay.com

Labels: , , ,

Wednesday, June 17, 2009

How to Save Tropical Rainforests



Today tropical rainforests are disappearing from the face of the globe. Despite growing international concern, rainforests continue to be destroyed at a pace exceeding 80,000 acres (32,000 hectares) per day. World rainforest cover now stands at around 2.5 million square miles (6 million square kilometers), an area about the size of the contiguous 48 United States or Australia and representing around 5 percent of the world's land surface. Much of this remaining area has been impacted by human activities and no longer retains its full original biodiversity.





Five Basic Steps to Saving Rainforests

"TREES" is a concept originally devised for an elementary school audience but serves well as set of principles for saving rainforests and, on a broader scale, ecosystems around the world.
  • Teach others about the importance of the environment and how they can help save rainforests.
  • Restore damaged ecosystems by planting trees on land where forests have been cut down.
  • Encourage people to live in a way that doesn't hurt the environment.
  • Establish parks to protect rainforests and wildlife.
  • Support companies that operate in ways that minimize damage to the environment.





Deforestation of tropical rainforests has a global impact through species extinction, the loss of important ecosystem services and renewable resources, and the reduction of carbon sinks. However, this destruction can be slowed, stopped, and in some cases even reversed. Most people agree that the problem must be remedied, but the means are not as simple as fortifying fences around the remaining rainforests or banning the timber trade. Economic, political, and social pressures will not allow rainforests to persist if they are completely closed off from use and development


So, what should be done? The solution must be based on what is feasible, not overly idealistic, and depends on developing a new conservation policy built on the principle of sustainable use and development of rainforests. Beyond the responsible development of rainforests, efforts to rehabilitate and restore degraded forest lands along with the establishment of protected areas are key to securing rainforests for the long-term benefits they can provide mankind.

Taken from:
mongabay.com

Labels: , , , ,

Monday, June 15, 2009

Brilliant pink moth discovered in Arizona.


A new species of moth with brilliantly-colored pink wings has been discovered at 7,700 feet in the Chiricahua Mountains of southern Arizona.

"This large moth flew in and we didn't think much of it because there is a silk moth very much like it, a Doris silk moth that feeds on pines that has dark wings with pink on the hind wings. It's fairly common there," said University of Arizona biologist, Bruce Walsh, who discovered the species.

On closer inspection of the moth, however, Walsh determined that it was an entirely different species from a different family: Noctuidae. The Chiricahuas is known for its biological richness and new species, however a moth of this color is a rare find.

The moth has been named lithophane leeae, after Walsh’s wife, Lee.

"We can now add L. leeae to this group of large, but quite elusive, species," Walsh noted.







Taken from
Mongabay.com


Labels: , , , , , , , ,

Wednesday, June 10, 2009

Forest Recovery Programs in Madagascar


Despite being one of the last habitable land masses on earth to be settled by man, Madagascar has lost more of its forests than most countries; less than 10% of its original forest cover now remains, and much of that is degraded. Political turmoil that erupted earlier this year continues to rumble on and the ensuing lawlessness has created the opportunity for illegal logging syndicates to plunder national parks, most notably Marojejy and Masoala, for valuable hardwoods and wildlife.

This bleak scenario is a far cry from the rule of ousted President Marc Ravalomanana (July 2002 to March 2009) during which protected areas were tripled to cover 10% of the country’s surface. Madagascar has become exemplary in its approaches to conservation of natural assets, this tripling of protected areas being a mainstay of President Ravalomanana’s ambitious five-year Madagascar Action Plan. However since former mayor of Antananarivo Andry Rajoelina took power of the country in what has been widely viewed as a coup d’état, confusion, chaos and lawlessness have reigned and the conservation initiatives previously in place now appear to be in jeopardy.



Association Mitsinjo’s nursery at Station Forestier d’Analamazaotra, opposite ‘Perinet’ – photo: Derek Schuurman
While rampant deforestation continues in some parts of the island, elsewhere inspiring reforestation initiatives are being carried out, which tourists can visit and get involved with. What better way could there be of – quite literally – putting something back into a country than planting an endemic tree in its natural range? Such gratifying experiences, which allow tourists to make meaningful connections with the environment rather than simply being an observer, are offered by forest recovery projects that are being developed in various habitat types throughout Madagascar.

Endemic tree species are being propagated in a growing number of nurseries, funded and managed by NGOs such as Association Mitsinjo and Man And The Environment; far-sighted hotels such as Anjajavy and Le Domaine de Fontenay; organizations which arrange conservation-oriented tours for volunteer workers such as ReefDoctor; and some foreign tour operators specializing in Madagascar, such as Rainbow Tours. The aim of such projects is usually to grow saplings in nurseries and then use them to restore degraded habitats to a more healthy state.

In this article we will review some of the most accessible forest recovery programs in the very different forest types of Madagascar.

Taken from:
Mongabay.com





Labels: , , , ,

 
 

Contact us

Phone: (506) 2475-9121 / (506) 2475-6696 / (506)8379-3005 Email: info@institutoasis.com

P.O.Box: 117- 4400/ Ciudad Quesada - Costa Rica

Copyright © 2002-2012 Proyecto Asis. All rights reserved.