Archive for the ‘ecology’ Category

New report says world’s largest primate is on fast track to extinction

June 22, 2016 Leave a comment
Grauer's gorilla infant

An infant Grauer’s gorilla is carried on the back of an adult. Photo courtesy Wildlife Conservation Society, photo by A.J. Plumptre.

The eastern lowland gorilla, Earth’s largest primate, is in rapid decline and has seen its population decline by nearly 80 percent since the late 1990s. There are now fewer than 4,000 individuals of the subspecies remaining in the wild.

Such is the bleak conclusion of a report released in April.

Persistent war in the animal’s home range, which is limited to a forested region in eastern Democratic Republic of Congo, is the leading culprit for the rapid extermination of the great ape species.

“Since 1996, the entire range of Grauer’s gorilla has been consumed in conflict,” the report said. “This has resulted in an almost complete breakdown in government control, including wildlife protection activities.”

Grauer's gorilla - courtesy FFI, photo by Stuart Nixon

Image of adult Grauer’s gorilla courtesy Fauna & Flora International, photo by Stuart Nixon.

The civil war in DRC began in in the aftermath of the 1994 genocide event in Rwanda. Hundreds of thousands of refugees streamed into DRC. Upon arrival, they engaged in deforestation in the eastern region of the country. The inflow of Rwandans refugees also helped set off a conflict that killed millions of people between 1996-2003.

Although the war is over, the militias who participated in it have not disappeared. They control areas in the eastern DRC that are the only habitat for Grauer’s gorillas and, in that territory, they tolerate mining and engage in bushmeat hunting.

The mining, which is done on a small scale and often illegally, is aimed at extracting minerals used in the production of elecronic devices such as cellular phones, laptop computers, and gaming consoles.

Grauer’s gorillas, as well as chimpanzees, are hunted by the militia soldiers to feed the miners, which fund them, and themselves. Although protected by law, the large size of a Grauer’s gorilla means it can provide enough meat to feed multiple humans. Because the animal moves in a troop through its forested habitat, hunters can take multiple gorillas and feed even more humans.

Disarming the militias and imposing legal controls on the small-scale mining within Grauer’s gorilla habitat is a crucial step toward assuring the subspecies’ survival, said the report’s authors.

“Significantly greater efforts must be made for the government to regain control of this region of DRC,” Andrew Plumptre, a wildlife biologist with Wildlife Conservation Society and the lead author of the report, said. “In particular, the government needs to quickly establish Reserve des Gorilles de Punia and the Itombwe Preserve, and reinforce Kahuzi-Biega National Park efforts, which have community support, and to establish strong communication between [Institut Congolais pour la Conservation de la Nature] and the DRC military to tackle armed militias that control mining camps in Grauer’s gorilla heartland.”

The report also concluded that agriculture, poaching for body parts, and “socio-economic depression from over a decade of civil war” are contributing to the rapid decline of Grauer’s gorilla and other plant and animal species.

Stuart Nixon, a wildlife biologist at the United Kingdom’s Chester Zoo and a co-author of the report, emphasized that a speedy government response to these stressors is vital.

“Unless greater investment and effort is made, we face the very real threat that this incredible primate will disappear from many parts of its range in the next five years,” he said.

The most recent prior population survey of Gorilla beringei graueri occurred during the mid-1990s. Researchers concluded that a population of about 17,000 individuals remained at that time.

The current conflict is not the first occasion in which Grauer’s gorillas have suffered extensive losses at the hands of humans.

During the 1960s and 1970s many individuals were killed as grassland areas of their range were converted to agriculture and farmers used shotguns provided by the government of Zaire to kill the gorillas.

Gorilla beringei graueri is one of four gorilla subspecies. Like individuals of the other three subspecies, Grauer’s gorillas live in groups. They are thought to organize themselves into harem-like assemblages that include two males. A female matures at about eight years of age, while a male reaches full development after about 12 years.

A full-grown male Grauer’s gorilla can weigh up to 400 pounds.

Both females and males leave the group at maturity, with male Grauer’s gorillas staying together until each can attract females and form new groups. Females join a group or ally themselves with a single adult male.

Also known as the eastern lowland gorilla, Grauer’s gorilla is closely related to the smaller western lowland gorilla (Gorilla gorilla gorilla) that is endemic to central African forests.

The report’s authors recommend that the status of Gorilla beringei graueri be downgraded from endangered to critically endangered by the International Union for the Conservation of Nature.

A species listed as “critically endangered” is just one step, on the IUCN hierarchy of classification, from extinction in the wild.

The report was published by the Wildlife Conservation Society, Flora and Fauna International and the Congolese Institute for the Conservation of Nature.


Bee learning ability slowed by pesticides, study finds

April 28, 2016 Leave a comment
Bumble bee - courtesy Wikimedia

This image shows a bumble bee loaded with pollen. Image courtesy Wikimedia.

Bees exposed to pesticides might have a harder time learning how to pollinate flowers than those who are not exposed to the substances, a new study suggests.

The paper, which was published in the March 14 edition of Functional Ecology, is the first to show that neonicotinoids, a class of pesticides that is now commonly used to protect a variety of agricultural crops, may impact the ability of individual bees to forage for nectars and pollen. It examined the impact of a compound called thiamethoxam on bumblebees.

“What we found is that bees exposed to pesticide initially collected more pollen, but it took them more visits to flowers to properly ‘learn’ this behavior,” Dr. Dara Anne Stanley, the lead author of the paper and a researcher at the University of KwaZulu-Natal in South Africa, said. “Control bees collected less pollen, but learned the behavior properly after visits to less flowers. Therefore control bees may be investing more time in learning this behavior properly.”

That result is consistent with the findings of other recent studies. For example, a paper published last year showed that bumblebees exposed to pesticides suffer memory loss. Another paper published in 2015 demonstrated that bumblebee colonies that encounter neonicotinoids tend to forage for pollen less than those colonies that do not come into contact with the compounds.

Neonicotinoids appear to target the area of a bee’s brain that governs the insect’s behavior.

“Neonicotinoid pesticides in particular target a region of the insect brain called the nicotinic acetylcholinase receptors (nAChRs) where they target cholinergic signaling by inhibiting acetylcholinesterase,” Stanley said in an e-mail message. “As the nAChRs have been associated with behavior in insects, in particular learning and memory, this means these pesticides at sub-lethal doses have the potential to cause changes in insect behavior.”

The term cholinergic signaling refers to the movement of neurotransmitters in an organism’s nervous system. Those compounds carry information across synapses.

If the pesticide is used near a bee colony, then its impacts on the ability of individual bees to obtain pollen could negatively affect the whole colony.

“As bees in particular display a range of sophisticated behaviors involved in navigation, foraging etc, these pesticides have the potential to effect foraging success and ultimately colony health,” Stanley said.

That may be less of a worry for honeybees, which live in large colonies. Stanley explained that a recent study conducted in Sweden indicated that honeybees are affected by exposure to pesticide-treated crops less rapidly than bumble bees.

“Honeybee colonies are extremely large with thousands of workers, and therefore the effects of pesticides on individuals would have to be very strong to see any impacts on the whole colony, and if there are impacts it could take many years to become apparent,” she said. “However, bumblebee colonies are much smaller and therefore any impacts on individuals are likely to be much more influential on the colony as a whole. When it comes to solitary bees, each individual female builds her own nest, so they are likely to be even more susceptible to any behavioral effects on individuals.”

While sale of neonicotinoids are now worth about $2.6 billion per year to manufacturers, the substances are thought to be dangerous to many other organisms. A series of papers published in 2014 indicated that they “exhibit very high toxicity” to many invertebrates and that some bird and fish species are especially vulnerable to harm caused by the use of neonicotinoids.

New study points to peril for ocean life

January 16, 2015 Leave a comment
© har

Today’s New York Times includes an article that discusses a new study with bad news about the fate of Earth’s marine life.

The study finds that human activities may be causing historically unique damage to the oceans.

“Current ocean trends, coupled with terrestrial defaunation lessons, suggest that marine defaunation rates will rapidly intensify as human use of the oceans industrializes,” the abstract of the study, published in Science, said.

The NYT piece, written by the esteemed science writer Carl Zimmer, quoted a lead author of the Science paper, Douglas J. McCauley of the University of California at Santa Barbara, as saying that the researchers’ conclusions indicate that a mass marine extinction is possible.

The basic gist of the Science paper is that the same patterns of events that have led to the extinction of hundreds of terrestrial mega-fauna are also at work in the oceans. One of the biggest threats, as on land, is industrialization.

“There are factory farms in the sea and cattle-ranch-style feed lots for tuna,” Dr. Stephen R. Palumbi, a marine ecologist at Stanford University and a co-author of the paper, said. “Shrimp farms are eating up mangroves with an appetite akin to that of terrestrial farming, which consumed native prairies and forest. Stakes for seafloor mining claims are being pursued with gold-rush-like fervor, and 300-ton ocean mining machines and 750-foot fishing boats are now rolling off the assembly line to do this work.”

The paper’s authors also discuss the likely impacts of climate change.

A more detailed analysis of the Science paper will be posted here at a later date.

Image of Atlantic Dawn factory ship courtesy; copyright as indicated above.

Air pollution’s 2012 toll: 7 million

March 26, 2014 1 comment


Polluted air killed seven million human beings in 2012.

So concludes a new report from the World Health Organization, which also found that one-third of the deaths occurred in Asia.

Air pollution is now Earth’s most dangerous environmental threat to health, the WHO study says, and it accounts for one out of every eight deaths.

Emissions of pollution to the atmosphere raises the risk that individuals will suffer heart attacks, strokes, and cancer. About 40 percent of heart disease victims and about 40 percent of stroke victims die as a result of outdoor air pollution. Indoor air pollution, such as from smoke and soot, accounts for 34 percent of stroke deaths and 26 percent of ischemic heart disease fatalities.

Overall, WHO estimates that 4.3 million people died as a result of exposure to indoor air pollution, while 3.7 million individuals perished due to outdoor air pollution.

“Cleaning up the air we breathe prevents noncommunicable diseases as well as reduces disease risks among women and vulnerable groups, including children and the elderly,” Dr. Flavia Bustreo, a WHO assistant director with oversight of general family, women’s, and children’s health, said in a statement.

Image courtesy Wikimedia.


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