Tracking Pacific walrus, impacts of early-life stress, and plant traits matter more than origin
Monitoring Pacific Walrus: With the end of summer fast approaching, US Geological Survey (USGS) researchers are once again gearing up to radio-tag walruses on Alaska’s northwestern coast as part of the agency’s ongoing study of how the marine mammals are coping with declining sea ice.
“Sea ice is an important component in the life cycle of walruses. These tracking studies will help us to better understand how top consumers in the arctic ecosystem may be affected by changes in sea ice habitats,” said USGS Alaska Science Center research ecologist Chad Jay in yesterday’s USGS press release.
Walruses, which can dive hundreds of feet in search of food, rely on sea ice to rest between dives. When sea ice is not available, the animals haul out on beaches, something they have been doing more frequently as the extent of sea ice has decreased in recent summers. Read more at www.usgs.gov/blogs/features/
Far-reaching impact of stress: A new study published in the Proceedings of the Royal Society B. shows that when zebra finches (Taeniopygia guttata) are briefly exposed to stress early in life, the jolt of stress hormones reduced not only their own lifespan, but that of their breeding partner as well. Pat Monaghan (University of Glasgow) and co-authors report that “only 5 percent of control birds with control partners had died after 3 years, compared with over 40 percent in early stress pairs. Interestingly, a pair’s reproductive success did not seem to be compromised by the early-life exposure to stress.
Traits trump plant origins: Nonnative plants often get a bad rap as being a potential threat to wildlife habitat and many state agencies spend time and energy getting rid of them. An In Press study with Ecological Applications suggests that might be a misplaced effort in some cases. Jillian Cohen (Cornell University) and colleagues compared the impacts of native and nonnative wetland plants on three species of native larval amphibians. They found no difference in metamorphosis rates and length of larval period between habitats dominated by native and nonnative plants. Say the authors: “We suggest that to improve habitats for native fauna managers should focus on assembling a plant community with desirable traits rather than only focusing on plant origin.”
Rising sources of nitrate to Gulf of Mexico: The results of a new study by the US Geological Survey (USGS) published in Environmental Science and Technology found that in spite of decreases along some portions of the Mississippi River Basin, overall efforts to curb this nutrient have been unsuccessful. Excessive nitrate contributes to the Gulf of Mexico’s dead zones—areas unable to support marine life because of minimal oxygen. The USGS study found that nitrate transport to the Gulf was 10 percent higher in 2008 than in 1980 and that increases of nitrate in groundwater is contributing to the transport of nitrate to the Gulf.
Also, a look at how climate change may result in mismatched timing between plants and pollinators, how vampire bats hone in on veins, bacterial attack strategy, and MacArthur Fellow Marla Spivak talks about her work on honey bees.