A half-ounce songbird makes an epic three-day flight while migrating between eastern Canada and the U.S. to Venezuelan winter grounds, according to a new tracking study.

The blackpoll warbler (Setophaga striata) has long been thought to barrel straight across the Atlantic Ocean in its migration to southern climes, but scientists have finally confirmed it with the help of new tracking devices small and light enough to equip on the birds.

“What makes this quite amazing is that blackpolls weigh 12 grams — the weight of a couple of loonies [a Canadian one-dollar coin],” said Ryan Norris, a biology professor at the University of Guelph and the senior author of a paper released yesterday in Biology Letters.

Indirectly, people have assumed the birds travel straight across the ocean on their way south for a number of reasons. During bad weather conditions, sailors in the ocean have noticed the bird often lands on their ships in certain parts of the Atlantic. Radars also picked up evidence of warbler-sized birds setting due south from Nova Scotia in Canada but it was difficult to confirm whether the blips were actually blackpolls. The last clue, according to Norris, was “the lack of observation evidence of blackpolls in the fall in the Southeast U.S.”

“Where do they go?” he asked.

The Things a Bird Does for Science

New technology in the form of miniscule geo-locaters that weighed less than 0.01 ounces was harnessed and equipped to 37 birds departed from Vermont and Nova Scotia, Canada.

The devices were too small to live-transmit location data, so they had to be recovered once the birds returned from wintering grounds in Venezuela. But blackpolls aren’t particularly loyal to their summer breeding areas, so it wasn’t easy for scientists to find their avian research assistants. Only five birds were recovered — two in Nova Scotia and three in Vermont.

“It is like searching for a needle in a haystack in a sense,” Norris said.

All five of the devices they recovered showed the birds had made three-day journeys south across the ocean, taking a brief, weeklong pit-stop in Haiti, the Dominican Republic or Puerto Rico before continuing to Venezuela. The maximum total distance of the birds’ flights was about 1,740 miles, Norris said.

One of the birds wasn’t quite as brave about the open ocean flight, though. Data showed it didn’t leave landfall until somewhere around Cape Hatteras. Norris said that there may be variation, since they only recovered the five devices. Part of this could have been that while the locaters are tiny, they may have weighed enough to affect the birds’ journeys.

But blackpolls occur fairly commonly across the Boreal Forest, from Alaska all the way to the U.S. Northeast, meaning some birds may travel even farther, including pit stops on the North American continent. Norris said plans are in the works to track the journeys of western warblers.

He also said that the tracking work is important because proper ranger information needs to be defined if conservation efforts are needed in the future.

“We can’t do a good job of conservation migrating birds if we don’t understand where they winter.”

Polar bear populations whose main diet sources are disappearing with melting icebergs may not be able to subsist long on terrestrial food sources.

“Although some polar bears (Ursus maritimus) may eat terrestrial foods, there is no evidence the behavior is widespread,” said Karyn Rode in a release. Rode is a research wildlife biologist with the U.S. Geological Survey and lead author of a study released yesterday in Frontiers in Ecology and the Environment. “In the regions where terrestrial feeding by polar bears has been documented, polar bear body condition and survival rates have declined.”

Polar bears usually subsist on a high-fat diet based on different seal species and other marine food sources, Rode said in a phone interview. But she and others conducted a study that consisted of a large-scale review of available literature to assess whether bear populations could be sustained by feeding on birds, eggs and other food sources based on land as they lose their main nutrition sources due to disappearing ice and increasingly difficult hunting conditions.

Some researchers hypothesized that polar bears might be able to subsist on alternative diets after observing bears eating bird eggs in the western Hudson Bay region. But Rode said that only around 30 bears were seen doing this from a population that numbers around 900 in that area. And the western Hudson Bay population of polar bears is only one of 19 spread over the five countries where they live.

The researchers in the study did calculations on whether the entire 900 bears in that population would be able to subsist on eating bird eggs and found that on average, the eggs each bear could eat would only sustain each individual for a day and half. Rode said that eating eggs is likely to benefit individual bears as diet supplements — especially adolescent or smaller bears — but the entire population couldn’t be sustained on the eggs alone.

These extravagant feasts would also be unsustainable in the long run as they would likely result in the collapse of bird colonies.

Other polar bears also have been observed eating land-based food, and Rode said her team made calculations on the bears’ diets and metabolisms to see whether eggs and other food sources like kelp, berries, some mammals and other things could sustain the animals. But polar bears aren’t well-suited to eating plants and terrestrial prey is too protein-heavy and light on fat for them. Few foods provide as much energy as the high-fat marine prey.

“Focused research will help us determine whether terrestrial foods could contribute to polar bear nutrition despite the physiological and nutritional limitations and the low availability of most terrestrial food resources,” Rode said. “However, the evidence thus far suggests that increased consumption of terrestrial foods by polar bears is unlikely to offset declines in body condition and survival resulting from sea ice loss.”

For the first time, researchers have empirical evidence that links the presence of the invasive Burmese python (Python bivittatus) to a decline in marsh rabbit (Sylvilagus palustris) populations in the Everglades.

As part of a recent study, published in the journal Proceedings of the Royal Academy, researchers with the U.S. Geological Survey and the University of Florida radio-tracked marsh rabbits in Everglades National Park in Florida from September 2012 to July 2013, and found almost 80 percent of the rabbits that died were eaten by Burmese pythons. “When we tracked the rabbits, we found them inside the pythons,” said lead author of the study Robert McCleery, who is also an assistant professor in wildlife ecology at UF and a member of The Wildlife Society.

McCleery and his team collaborated with scientists who had worked on an earlier study — published in 2012 — that showed small mammals were declining in the 1.5 million acre park at the same time that pythons were proliferating in and around the park. “We designed the experiment to tell us if the pythons were the problem, or the cause of mammal decline,” he said. “We couldn’t go back in time to find out why they died, but we could make predictions.”

The researchers completed a manipulative experiment where they introduced marsh rabbits to selected areas inside and outside the park that supported the marsh rabbit population. “We chose marsh rabbits because they’re pretty resilient to predation and shouldn’t have been susceptible to pythons,” McCleery said. “They also are very common in the Everglades.”

Since the researchers couldn’t find any marsh rabbits in the park, they introduced 31 marsh rabbits to select areas in the park where they suspected pythons would be present. They also put 15 rabbits in Loxahatchee National Wildlife Refuge and 49 in Fakahatchee Strand State Park in control groups where they knew there would be few, if any, pythons. All rabbits were radio-collared so their location could be recorded.

Initially, the population numbers increased due to reproduction, according to McCleery. But over time, the researchers discovered 77 percent of marsh rabbits that died in the Everglades were consumed by the pythons. They also found no sign of marsh rabbits in the areas in which they were released one year earlier. But in the areas outside the park which served as control groups, the populations remained.

The researchers also found warmer and wetter weather was associated with more marsh rabbits being consumed by pythons. “They had stable home ranges in January or February,” McCleery said. “As it got hot and wet, predation pressure from pythons increased the population of marsh rabbits, and they were gone by July.” Higher water levels which allow pythons to swim long distances when searching for food and the fact that pythons feed more frequently when it’s hot, are possible reasons for this correlation, according to McCleery.

While biologists determine next steps in terms of addressing this invasive issue, McCleery is looking toward new research, which involves examining how mammals change their behaviors around pythons. “The next step is to have a concerted effort to address this problem,” he said.

Small black, orange and white checkered butterfly wings flittering through Washington State were once a rare sight.

But just last week the Oregon Zoo and Washington Department of Fish and Wildlife (WDFW) released 500 federally endangered, aptly-named Taylor’s checkerspot caterpillars (Euphydryas editha taylori) on one of six historically-occupied field sites in western Washington.

This particular effort began last month, when zoo conservationists resumed feeding over 500 Taylor’s checkerspot caterpillars in the Oregon Zoo’s Imperiled Butterfly Conservation Lab, after their 7-month winter dormancy.

The Oregon Zoo and WDFW hope the caterpillars will continue to survive after they are released in the wild, becoming chrysalises and then adult butterflies. “Researchers will continue releasing larvae at each new site for several years and then monitor those populations,” said Mary Linders, a species recovery biologist with WDFW. “The reintroductions are meant to increase the species’ population sizes to the point they can survive on their own,” she said.

“Releasing caterpillars back into the wild is part of our ongoing effort to reestablish this imperiled species at sites where it was once abundant,” Linders said. “Without large, connected populations, the butterflies struggle to survive.”

Prior to their release, WDFW, which has a partnership with Oregon Zoo, identified the most suitable habitats for the checkerspot on prairies in western Washington.

Although Taylor’s checkerspots were once commonly found in that region, the now federally endangered species lost 99 percent of its habitat due to development, agriculture and habitat degradation, according to the Oregon Zoo. In 2009, the species range included only seven sites in Washington, two in Oregon and one in Canada. In fact, according to the Xerces Society, a nonprofit organization working on invertebrate conservation, the Taylor’s checkerspot is at risk of completely disappearing,

The Oregon Zoo has been working on recovering the species for over 10 years, and has raised about 19,000 checkerspots over the years. According to Linders, the conservation efforts are paying off. To further help the declining species, the Washington Department of Corrections and The Evergreen State College are also helping rear the butterflies.

That partnership has inmates at the Mission Creek Corrections Center for Women in Belfair, Washington operating a captive-rearing facility for Taylor’s checkerspots with oversight and assistance from The Evergreen State College – Sustainability in Prisons Project. Larvae from that facility were released earlier in March.

After releases at a given site are complete, Linders and other biologists will continue to monitor the checkerspot population for five more years before checking the success box, although Linders is seeing plenty of other improvements already. “We’ve started seeing Taylor’s checkerspots at locations where they haven’t been documented in years,” Linders said. “It gives us hope for a species that is very close to disappearing completely.”

The discovery of species unknown to science usually comes with stories of expeditions into remote cloud forests, underwater caves or deep oceanic trenches.

But a new study conducted by the Natural History Museum of Los Angeles County shows that you may only have to go as far as your backyard to discover a wealth of new species.

“We thought this was pretty remarkable,” said Brian Brown the curator of entomology of the museum and coauthor of the study coming out next week in the journal Zootaxa that found 30 new species in the Megaselia genus — a family of small flies that measure no more than a fraction of an inch. “These small flies are poorly known just about everywhere.”

Glen Creason relaxes with an insect field guide in front of the insect trap and weather station that he hosts at his home for the Natural History Museum of Los Angeles County’s BioSCAN project. The project is being helped by 30 citizen scientists who allowed museum researchers to set up these stations in their backyards.
Image credit: Phyllis Sun

Brown is the principal investigator of Biodiversity Science: City and Nature (BioSCAN) — an ongoing three-year project currently in its second year that harnesses the power of citizen scientists across Los Angeles to better understand how urbanization affects the biodiversity of small insects.

As part of the project, researchers and students helped to watch over 30 tents with fly traps put up in the backyards of volunteers across the city in areas that differed in terms of density. Brown and others on the project sorted the roughly 10,000 specimens pulled from traps and examined them under microscopes.

The insects varied greatly among different parts of the city, and while the researchers thought that the traps near open spaces or parks would yield better diversity, they were surprised to find that dense metropolitan areas still yielded a wide variety of bugs. Brown said that they are still trying to understand the reasons why, but it could have to do with humidity levels, or it could have to do with the kind of plants people grow in their gardens.

In one case, the kind of insects discovered — coffin flies (Conicera tibialis) — suggested signs of something rotten underfoot. These small flies specialize in buried cadavers, and after researchers inquired with the volunteer at that backyard site they found that he had buried old pets in the yard after they died from a disease.

“We can find out what people are doing to some extent,” Brown said.

Aside from the 30 unknown species, Brown said that researchers discovered a number of flies that were only previously known to live in Africa or other places. But he said it’s impossible to know yet whether these are invasive species or whether they naturally occur in a number of locations.

“Nobody’s looking at these smaller species that probably make up the majority of what’s being introduced,” Brown said. “They are basically silent because they don’t cause gross agricultural or medical damage to our society.”

Some of the researchers discussing the BioSCAN project. Video credit: The Next Gen Scientists.

It’s also difficult at this point to know about the flies’ ecologies. “Trying to find out what a two millimeter fly does is [like looking for] a needle in the haystack,” he said, adding that many will make a living by preying only on a certain larvae. “A lot of these things have super specific lifestyles.”

The team allowed the families who lent a section of their yards for the three-year experiment to name the new species. Many chose to name it after their family surnames, while others chose their neighborhood or children’s’ names. “They’re doing a lot for us,” Brown said.

One of the citizen scientist families, the Johnson family, describes how they helped the project and found a new species. Video credit: The Next Gen Scientists.

One of the flies was found in the museum’s own backyard, and was named after the Sever family, who Brown said had helped support the project.

The study, which Brown said is possibly the world’s largest urban biodiversity inventory project, has drawn attention from some of his colleagues at the museum, who want to repeat the experiment with birds, reptiles, amphibians and other biological species.

Check out a blog from one of the researchers.