Study found 35% fewer bird species in agricultural habitats

Research led by the University of Exeter has found a substantial reduction in bird species living in cultivated mango orchards compared to natural habitats in Southern Africa. The results, which are published today in the journal Landscape Ecology, highlight the value of assessing habitats prior to land use change to predict the impact of agriculture on biodiversity. The researchers monitored bird populations across cultivated mango orchards and natural habitats in the Kruger to Canyons Biosphere region in South Africa. They found that replacing a natural habitat with an agricultural landscape can result in a substantial decline in the richness of species living within the region. The scientists were aiming to ascertain whether agriculture could add novel habitat elements and thereby support additional bird species complementary to those already present in the natural areas - but found that in contrast, there was a loss of 35% of the bird species within the farmed land. During the study, the team conducted 150 counts each at both natural habitat and mango orchard locations and measured aspects of habitat structure. Across all 300 survey points, a total of 14,278 birds representing 151 species were recorded.

Pope Francis Slams Pesticides for Environmental and Social Damage

Pope Francis slams both GMOs and pesticides in a draft of his major environmental document that was leaked Monday. On pesticides Pope Francis states; “We get sick, for example, due to inhalation of large amounts of smoke produced by fuels used for cooking and heating. This is added to by….fertilizers, insecticides, fungicides, herbicides and toxic pesticides in general. Technology that is linked to finance, claims to be only solving problems…this solves a problem by creating others. “It creates a vicious circle in which the intervention of the human being to solve a problem often worsens the situation further. For example, many birds and insects die out as a result of toxic pesticides created by technology, they are useful to agriculture itself, and their disappearance will be compensated with another technological intervention that probably will bring new harmful effects… looking at the world we see that this level of human intervention, often in the service of finance and consumerism, actually causes the earth we live in to become less rich and beautiful, more and more limited and gray, while at the same time the development of technology and consumerism continues to advance without limits.”

Mixture Toxicity of Imidacloprid and Cyfluthrin to Two Non-target Species

Two species, the fathead minnow Pimephales promelas and the amphipod Hyalella azteca, were tested to examine acute toxicity to two insecticides, cyfluthrin and imidacloprid individually and as a mixture. Cyfluthrin was acutely toxic to P. promelas and H. azteca with EC50 values and 95 % confidence intervals of 0.31 µg L−1 (0.26–0.35 µg L−1) and 0.0015 µg L−1 (0.0011–0.0018 µg L−1), respectively. Imidacloprid was not acutely toxic to P. promelas at water concentrations ranging from 1 to 5000 µg L−1, whereas it was toxic to H. azteca with a EC50 value of 33.5 µg L−1 (23.3–47.4 µg L−1). For the P. promelas mixture test, imidacloprid was added at a single concentration to a geometric series of cyfluthrin concentrations bracketing the EC50 value. A synergistic ratio (SR) of 1.9 was found for P. promelas, which was calculated using the cyfluthrin-only exposure and mixture-exposure data. Because cyfluthrin and imidacloprid were toxic to H. azteca, the mixture test was designed based on an equipotent toxic unit method. Results from the mixture test indicated a model deviation ratio (MDR) of 1.7 or 2.7 depending on the model. Mixture test results from the simultaneous exposure to cyfluthrin and imidacloprid with both species indicated a greater than expected toxic response because the SR or MDR values were >1. Because these two insecticides are commonly used together in the same product formulations, nontarget species could be more affected due to their greater-than-additive toxicity observed in the current study.

Evidence Against Neonicotinoids Mounts

Two studies published in Nature last week have raised more concerns about whether neonicotinoid pesticides adversely affect bee health. One study shows that bees are drawn to neonicotinoids, possibly because the insects catch a “buzz” from the pesticides similar to the one humans get from nicotine (2015, DOI: 10.1038/nature14414). The other study suggests that neonicotinoids affect bee behavior and growth under realistic conditions in a crop field (2015, DOI: 10.1038/nature14420).

No Fish, No Fowl: European Fish and Birds in Decline

Two new reports on Europe’s endangered fish and bird species were released this week by the International Union for Conservation of Nature (IUCN). The first report is itself a milestone: the first full assessment of all of Europe’s 1,220 marine fish species. The study found that 7.5 percent of those species were threatened with extinction. Worst hit, as we’ve seen before, were sharks, rays and chimaeras. A full 40.4 percent of those European species (known collectively as chondrichthians) face the threat of extinction and nearly that many have declining populations. The second report looked at all 533 bird species that spend at least part of their time in Europe and found that 13 percent are threatened. Four species have been declared regionally extinct in Europe. Others, such as the sociable lapwing (Vanellus gregarius), aren’t far behind. Another 28 species have been assessed as endangered or critically endangered on the continent. Most of these are also at risk through the remainder of their ranges.

Imidacloprid impairs olfactory learning in Asian honey bees (Apis cerana) exposed as larvae or as adults

We studied the effects of sublethal doses of imidacloprid on olfactory learning in the native honey bee species, Apis cerana, an important pollinator of agricultural and native plants throughout Asia. We provide the first evidence that imidacloprid can impair learning in A. cerana workers exposed as adults or as larvae. Adults that ingested a single imidacloprid dose as low as 0.1 ng/bee had significantly reduced olfactory learning acquisition, which was 1.6-fold higher in control bees. Longer-term learning (1-17 h after the last learning trial) was also impaired. Bees exposed as larvae to a total dose of 0.24 ng/bee did not have reduced survival to adulthood. However, these larval-treated bees had significantly impaired olfactory learning when tested as adults: control bees exhibited up to 4.8-fold better short-term learning acquisition, though longer-term learning was not affected.

Jean-Marc Bonmatin, researcher at the French National Centre for Scientific Research (CNRS), reviews ecotoxicological risks of neonics

On May 29th, the Day of the Honey Bee in Quebec, Équiterre, in collaboration with the David Suzuki Foundation, hosted a public talk presenting the results of the most important literature review on the impacts of neonicotinoïd pesticides, that kill pollinators. The comprehensive assessment of more than 1,000 peer-reviewed reports was conducted by the international Task Force on Systemic Pesticides, an international group of 50 independent scientists. The talk was given by Jean-Marc Bonmatin, researcher at the French National Centre for Scientific Research (CNRS) and Task Force vice-chair, and Madeleine Chagnon, PhD, associate professor at the Department of Biological Sciences at the Université du Québec à Montréal, who also participated to the Task Force. "As a scientist, I can now say conclusively that the evidence of harm is clear and points to the urgent need for action to reduce the quantities of these pesticides entering the environment," said Bonmatin.

Two decades of neonicotinoids use in agriculture have almost wiped out the aerial insectivores in North America

The guild of ‘aerial insectivores’ – birds that specialize on feeding on flying insects – includes Whip-poor-wills, nighthawks, swifts, swallows, martins, and flycatchers. Early results from the second Ontario Breeding Bird Atlas indicated some startling declines and even range contractions for this guild. Now that the 2001-2005 Ontario Atlas is complete, the plight of aerial insectivores is gaining increasing attention. The patterns of decline are mirrored very closely by the Breeding Bird Survey, not only in Ontario, but also across much of North America. Early results from the second Maritimes Breeding Bird Atlas and data from the recently completed second New York State Atlas also point to similar patterns. The magnitude of the declines, especially within the past 20 years or so, is alarming. The proverbial clock may well be ticking down on many common species of aerial insectivores in Canada. In the last two decades alone, populations have fallen by over 70% in the case of Bank Swallow, Common Nighthawk, Chimney Swift, and Barn Swallow, and by over 50% for Cliff Swallow, Olive-sided Flycatcher, Eastern Wood-Pewee, Northern Rough-winged Swallow, Eastern Kingbird, and Purple Martin. Declines have been so severe that Chimney Swift, Common Nighthawk, and Olive-sided Flycatcher were recently designated as nationally Threatened species. Barn Swallow, Bank Swallow, and Eastern Wood-Pewee may not be far behind.

Study finds huge decreases in Californian bird populations

Many bird species commonly found in California have suffered steep population declines, as much as 96%, part of a nationwide trend, according to a study that for the first time combines 40 years of data. The study, combining the National Audubon Society's Christmas season bird counts with summertime surveys by the U.S. Geological Survey, documented declines of 75% to 96% in several California species, including the northern pintail, horned lark and loggerhead shrike. Greg Butcher, Audubon bird conservation director and analysis leader, said of the birds surveyed nationally, "about half are in decline and of these half are in significant decline." Overall, Butcher said, his organization is concerned about decreasing numbers of 200 to 300 kinds of birds. Because they have been so numerous, the birds that were surveyed often don't get the attention that small, endangered populations such as California condors have received. However, Gary Langham, Audubon California's director of bird conservation, said that although many bird populations may number in the millions, the large reductions that were documented are statistically significant. Kimball Garrett, collection manager for ornithology at the Natural History Museum of Los Angeles County, said that while the surveys must be interpreted cautiously, they are in line with other studies that show steep declines. "Some trends are just undeniable," he said. The evening grosbeak fared the worst in Audubon's California survey, with a 96% decline statewide. Nationally, grosbeak numbers fell from 17 million 40 years ago to 3.8 million today, according to both surveys.

Thirthy-three common U.S. birds have lost more than half their global population over the past four decades

A team of scientists from the North American Bird Conservation Initiative (NABCI) identified the 33 U.S. common bird species in steep decline: Northern Pintail (Anas acuta), American Wigeon (Anas americana), Cinnamon Teal (Anas cyanoptera), Greater Scaup (Aythya marila), Long-tailed Duck (Clangula hyemalis), Scaled Quail (Callipepla squamata), Northern Bobwhite (Colinus virginianus), Purple Gallinule (Porphyrio martinicus), Franklin’s Gull (Leucophaeus pipixcan), Herring Gull (Larus argentatus), Black Tern (Chlidonias niger), Yellow-billed Cuckoo (Coccyzus americanus) , Snowy Owl (Bubo scandiacus), Short-eared Owl (Asio flammeus), Common Nighthawk (Chordeiles minor), Chimney Swift (Chaetura pelagica), Loggerhead Shrike (Lanius ludovicianus), Horned Lark, Bank Swallow, Verdin, Varied Thrush, Snow Bunting, Cape May Warbler, Blackpoll Warbler, Wilson’s Warbler, Field Sparrow, Lark Bunting, Grasshopper Sparrow, Eastern Meadowlark, Rusty Blackbird, Brewer’s Blackbird, Common Grackle and Pine Siskin. These are common birds that do not meet Watch List criteria, yet according to long-term monitoring surveys are rapidly declining throughout their range. They have lost more than half their global population over the past four decades.

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