Archive for the ‘ecology’ Category

Pesticides in U.S. Streams and Rivers: Occurrence and Trends during 1992–2011

September 12, 2014 Comments off

Pesticides in U.S. Streams and Rivers: Occurrence and Trends during 1992–2011
Source: Environmental Science & Technology

During the 20 years from 1992 to 2011, pesticides were found at concentrations that exceeded aquatic-life benchmarks in many rivers and streams that drain agricultural, urban, and mixed-land use watersheds. Overall, the proportions of assessed streams with one or more pesticides that exceeded an aquatic-life benchmark were very similar between the two decades for agricultural (69% during 1992−2001 compared to 61% during 2002−2011) and mixed-land-use streams (45% compared to 46%). Urban streams, in contrast, increased from 53% during 1992−2011 to 90% during 2002−2011, largely because of fipronil and dichlorvos. The potential for adverse effects on aquatic life is likely greater than these results indicate because potentially important pesticide compounds were not included in the assessment. Human-health benchmarks were much less frequently exceeded, and during 2002−2011, only one agricultural stream and no urban or mixed-land-use streams exceeded human-health benchmarks for any of the measured pesticides. Widespread trends in pesticide concentrations, some downward and some upward, occurred in response to shifts in use patterns primarily driven by regulatory changes and introductions of new pesticides.

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Urbanisation at Multiple Scales Is Associated with Larger Size and Higher Fecundity of an Orb-Weaving Spider

September 11, 2014 Comments off

Urbanisation at Multiple Scales Is Associated with Larger Size and Higher Fecundity of an Orb-Weaving Spider
Source: PLoS ONE

Urbanisation modifies landscapes at multiple scales, impacting the local climate and changing the extent and quality of natural habitats. These habitat modifications significantly alter species distributions and can result in increased abundance of select species which are able to exploit novel ecosystems. We examined the effect of urbanisation at local and landscape scales on the body size, lipid reserves and ovary weight of Nephila plumipes, an orb weaving spider commonly found in both urban and natural landscapes. Habitat variables at landscape, local and microhabitat scales were integrated to create a series of indexes that quantified the degree of urbanisation at each site. Spider size was negatively associated with vegetation cover at a landscape scale, and positively associated with hard surfaces and anthropogenic disturbance on a local and microhabitat scale. Ovary weight increased in higher socioeconomic areas and was positively associated with hard surfaces and leaf litter at a local scale. The larger size and increased reproductive capacity of N.plumipes in urban areas show that some species benefit from the habitat changes associated with urbanisation. Our results also highlight the importance of incorporating environmental variables from multiple scales when quantifying species responses to landscape modification.

See: The Urban Environment Is Creating Super-Sized Spiders (The Atlantic)

Categories: ecology, PLoS ONE, urban issues

314 North American Bird Species Threatened by Global Warming, Audubon Scientists Reveal in New Study

September 10, 2014 Comments off

314 North American Bird Species Threatened by Global Warming, Audubon Scientists Reveal in New Study
Source: National Audubon Society

Climate change threatens nearly half the bird species in the continental United States and Canada, including the Bald Eagle and dozens of iconic birds like the Common Loon, Baltimore Oriole and Brown Pelican, according to a new study published today by National Audubon Society (

The study identifies 126 species that will lose more than 50 percent of their current ranges – in some cases up to 100 percent – by 2050, with no possibility of moving elsewhere if global warming continues on its current trajectory. A further 188 species face more than 50 percent range loss by 2080 but may be able to make up some of this loss if they are able to colonize new areas. These 314 species include many not previously considered at risk. The report indicates that numerous extinctions are likely if global temperature increases are not stopped.

The State of the Birds Report 2014

September 10, 2014 Comments off

The State of the Birds Report 2014
Source: North American Bird Conservation Initiative (via Smithsonian Migratory Bird Center)
From press release:

There may have never been a more important time to study birds than now. That’s the idea behind the 2014 State of the Birds report, released this morning and written by the top American ornithologists working today. Some of the findings are cause for celebration. Others have bird experts concerned.

The first State of the Birds came out in 2009, modeled after similar types of reports in Europe. While previous American versions have focused on specific topics related to birds in the United States, such as climate change, this year’s report provides a wider overview. The 16-page document, complete with photographs and illustrations of the feathered creatures, explores population trends and relationships between populations and habitats. The authors come from 23 agencies and organizations, including the Smithsonian Migratory Bird Center, the Fish and Wildlife Service and the American Bird Conservancy.

CRS — Hunting and Fishing: Issues and Legislation in the 113th Congress (July 7, 2013)

August 14, 2014 Comments off

Hunting and Fishing: Issues and Legislation in the 113th Congress (PDF)
Source: Congressional Research Service (via National Agricultural Law Center)

For several years, the House and Senate have been considering various approaches to improve hunting and recreational fishing opportunities both on and off of federal lands. The Bipartisan Sportsmen’s Act of 2014 (S. 2363) is pending in the Senate, and addresses many of the same topics considered by recent Congresses.

Hunting, fishing, and conservation have been linked since the advent of federal wildlife legislation. Among early examples are the Lacey Act of 1900, the first federal wildlife law, which made it a federal crime to ship game killed in violation of one state’s laws to another state, and the Migratory Bird Treaty Act of 1918, which regulated the killing, hunting, buying, or selling of migratory birds. Today’s controversies concern, among other things, exactly what hunting, fishing, or shooting sports should be allowed on federal land, and when. S. 2363 seeks to increase the priority of hunting, trapping, fishing, and recreational shooting on federal lands.

Nesting Gulf Sea Turtles Feed in Waters Filled With Threats

August 4, 2014 Comments off

Nesting Gulf Sea Turtles Feed in Waters Filled With Threats

Nesting loggerhead sea turtles in the northern Gulf of Mexico feed among areas that were oiled by the 2010 Deepwater Horizon spill and where human activities occur, several of which are known to pose threats to sea turtles, a new U.S Geological study showed.

The feeding areas for 10 turtles overlapped with an area that experienced surface oiling during the 2010 Deepwater Horizon oil spill. These sites, and others, also overlapped with areas trawled by commercial fishing operations and used for oil and gas extraction.

The study, which is the largest to date on Northern Gulf loggerheads, examined 59 nesting females, which scientists believe could be 15 percent of the breeding females in the Northern Gulf of Mexico—a small and declining subpopulation of loggerheads that is federally classified as threatened.

Climate Change Could Alter Range of Caribou and May Impact Hunters’ Access

July 30, 2014 Comments off

Climate Change Could Alter Range of Caribou and May Impact Hunters’ Access
Source: USGS (PLoS ONE)

Due to climate change, some communities in rural Alaska and the Yukon Territory of Canada may face a future with fewer caribou according to new research published by the U.S. Geological Survey and the University of Alaska, Fairbanks in the recent issue of PLoS ONE. Scientists examined the future effects of fires on winter habitats of caribou herds and determined that wildfires will reduce the amount of winter habitat for caribou, thus caribou may need to shift their wintering grounds

Warming temperatures will increase the flammability of lichen-producing boreal forests, which are important winter habitat for caribou herds. Caribou serve as nutritional as well as cultural sustenance for certain communities. Caribou avoid burned areas in winter and the changes in their distribution can persist across multiple generations of hunters. Those who rely on caribou in fire-prone areas may therefore have fewer available as climate change increases the number and sizes of fires in the boreal forests.


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