Crocodile tears please thirsty butterflies and bees

EMBARGOED until: 12:01 am EDT on Thursday, May 1, 2014
Contact: Liza Lester  (202) 83308773 x211;


A Julia butterfly (Dryas iulia) and a solitary bee (Centris sp.) sip tears from the eyes of spectacled caiman (Caiman crocodilus) on Costa Rica’s Puerto Viejo River. Credit, Carlos de la Rosa

A Julia butterfly (Dryas iulia) and a solitary bee (Centris sp.) sip tears from the eyes of spectacled caiman (Caiman crocodilus) on Costa Rica’s Puerto Viejo River. Credit, Carlos de la Rosa

The butterfly (Dryas iulia) and the bee (Centris sp.) were most likely seeking scarce minerals and an extra boost of protein. On a beautiful December day in 2013, they found the precious nutrients in the tears of a spectacled caiman (Caiman crocodilus), relaxing on the banks of the Río Puerto Viejo in northeastern Costa Rica.

A boat carrying students, photographers, and aquatic ecologist Carlos de la Rosa was passing slowly and quietly by, and caught the moment on film. They watched and photographed in barely suppressed excitement for a quarter of an hour while the caiman basked placidly and the insects fluttered about the corners of its eyes.

De la Rosa reported the encounter in a peer-reviewed letter in the May 2014 issue of the Ecological Society of America’s journal Frontiers in Ecology and the Environment.

“It was one of those natural history moments that you long to see up close,” said de la Rosa, the director of the La Selva Biological Station for the Organization for Tropical Field Studies in San Pedro, Costa Rica. “But then the question becomes, what’s going on in here? Why are these insects tapping into this resource?”

Though bountiful in the ocean, salt is often a rare and valuable resource on land, especially for vegetarians. It is not uncommon to see butterflies sipping mineral-laden water from mud puddles. When minerals are rare in the soil, animals sometimes gather salt and other rare minerals and proteins from sweat, tears, urine, and even blood.

A solitary bee (Centris sp) drinking the tears of a yellow-spotted river turtle (Podocnemis unifilis). Olivier Dangles and Jérôme Casas 2012. The bee and the turtle: a fable from Yasuní National Park. Frontiers in Ecology and the Environment 10: 446–447.

A solitary bee (Centris sp) drinking the tears of a yellow-spotted river turtle (Podocnemis unifilis). Olivier Dangles and Jérôme Casas (2012). The bee and the turtle: a fable from Yasuní National Park. Frontiers in Ecology and the Environment 10: 446–447. [Download PDF]

De la Rosa had seen butterflies and moths in the Amazon feeding on the tears of turtles and a few caimans. Tear-drinking “lachryphagous” behavior in bees had only recently been observed by biologists. He remembered a 2012 report of a solitary bee sipping the tears of a yellow-spotted river turtle in Ecuador’s Yasuní National Park. But how common is this behavior?

Back at the field station, he did a little research. He was surprised to find more evidence of tear-drinking than he expected in the collective online record of wilderness enthusiasts, casual tourists, professional photographers, and scientists. He now thinks the phenomenon may not be as rare as biologists had assumed—just hard to witness.

“I did a Google search for images and I found out that it is quite common! A lot of people have recorded butterflies, and some bees, doing this,” said de la Rosa.

A search of the scientific literature produced a detailed study of bees drinking human tears in Thailand, as well as the remembered October 2012 “Trails and Tribulations” story about the Ecuadorian bee and the river turtle by Olivier Dangles and Jérôme Casas in ESA’s Frontiers (pdf).

This experience reminds us that the world still has many surprises for ecologists, de la Rosa said. There so much still to be studied. De la Rosa is a specialist in the biology of non-biting midges, and a natural historian, with his eyes always open to new discoveries. Scientists at La Selva have discovered hundreds of species of aquatic insects that are still unnamed and undescribed.

A new species of dragonfly emerges. A species of Erythrodiplax, only the second dragonfly found that lays its eggs in the small pool of water caught in the cupped leaves of bromeliad plants. Credit, Carlos de la Rosa.

A new species of dragonfly emerges. A species of Erythrodiplax, it is only the second dragonfly found that lives in bromeliad plants. Credit, Carlos de la Rosa.

“I have over 450 undescribed species from Costa Rica in my laboratory. If I did nothing for the rest of my life but collaborate with taxonomists and try to describe those, I would never get done,” he said.

De la Rosa’s job as director of La Selva Biological Station brings him an unusual number of serendipitous encounters with wildlife. He lives on site in the lowland rainforest, and he never needs an alarm clock. Howler monkeys wake him every morning.

“I learned I have to carry a camera with me 24/7, because you never know what you’re going to find when you’re walking to the office or the dining hall,” he said. One day, he spied a new species of dragonfly on his way to breakfast. It had emerged from its larval form in the small pool of water caught in the cupped leaves of a bromeliad plant. He did a double-take. Dragonflies don’t live on bromeliads. Or do they?

 “Those are the kinds of things that, you know, you don’t plan for them, you can’t plan for them,” de la Rosa said. There was only one known species of dragonfly in the world that lives in bromeliads. Now there will be two. “You just keep your eyes open and have curiosity, and when you see something that doesn’t seem to fit, dig.”








Carlos L de la Rosa (2014) Additional observations of lachryphagous butterflies and bees. Frontiers in Ecology and the Environment 12(4): 210 [PDF]

Author contact:
Carlos Luis de la Rosa
skype: carlos.delarosa_otsls
phone: +50.627.666.5659

Journalists and public information officers can gain access to full texts of all ESA publications by contacting the public affairs office. Email Liza Lester,


Carlos de la Rosa -- higher res image available on request.

Credit, Carlos de la Rosa. Higher res image available on request.

The Ecological Society of America is the world’s largest community of professional ecologists and a trusted source of ecological knowledge. ESA is committed to advancing the understanding of life on Earth. The 10,000 member Society publishes five journals, convenes an annual scientific conference, and broadly shares ecological information through policy and media outreach and education initiatives. Visit the ESA website at

La Selva Biological Station and its parent institution, the Organization for Tropical Studies, manage a 1,600-hecter lowland rainforest preserve connected to large conservation areas in northeastern Costa Rica. The station is nearly 60 years old, and maintains some of the longest running tropical ecology datasets. Each year, it hosts 250 to 340 researchers from over 100 institutions, and many specialized courses in biology.


To subscribe to ESA press releases, contact Liza Lester at 




April 21, 2014

In This Issue


The Nobel Prize-winning United Nations Intergovernmental Panel on Climate Change (IPCC) released two new reports in late March and early April that reaffirm climate change is currently affecting natural ecosystems and human well-being around the world.

The March 31 report from “Working Group II: Impacts, Adaptation and Vulnerability” stated that we are experiencing the consequences of climate change across all sectors: agriculture, human health, ocean and land ecosystems, and water supplies. The working group found that governments’ measures to combat climate change are not keeping pace with the consequences of climate change. At an IPCC meeting in Yokohama, Japan, 100 governments unanimously approved the report. 

“Read this report and you can’t deny the reality: Unless we act dramatically and quickly, science tells us our climate and our way of life are literally in jeopardy,” asserted Secretary of State John Kerry in a press statement. “Denial of the science is malpractice.” Secretary Kerry referenced “the security risks of water scarcity and flooding; widespread land and marine species extinction; and devastated crop yields in some of the poorest nations on earth” in rationalizing the Obama administration’s commitment towards implementation of its Climate Action Plan.

On Capitol Hill, the report generally earned praise among Democratic leaders on key committees, who embraced the science as a call for urgent action. Meanwhile, their Republican counterparts did not issue a formal statement on the report. Senate Environment and Public Works Committee Chairwoman Barbara Boxer (CA) and House Energy and Commerce Committee Ranking Member Henry Waxman (CA), senior Democrats on the committees with primary jurisdiction over the US Environmental Protection Agency, each posted press statements praising the report on their respective committees’ websites. House, Science, Space and Technology Committee Chairwoman Eddie Bernice Johnson did not release a committee press statement directly commenting on the report, but it was referenced in a climate change panel discussion the Congresswoman was holding in Dallas, TX the day the report was released. 

“The latest IPCC report adds a tremendous sense of urgency for Congress to wake up and do everything in its power to reduce dangerous carbon pollution,” stated Chairwoman Boxer. “In California, we can just look out the window to see climate change’s impacts—from the driest year on record in 2013 to the increased frequency and intensity of wildfires. This new IPCC report identifies the serious threats to human health, vital infrastructure, and the world’s economy that will multiply as temperatures warm. It confirms that we must cut carbon pollution now to avoid lasting changes to our planet. 

In Berlin, Germany on April 13 a subsequent IPCC report from “Working Group III: Mitigation of Climate Change” warned greenhouse gas emissions that push warming above two degrees Celsius will lead to dangerous and costly climate change events. The report stated that worldwide emissions must decline between 40-70 percent below 2010 by the middle of the century to avoid such consequences. The report called for cutting green-house gas emissions from energy production, transportation, infrastructure and business to meet this goal.

“The IPCC’s new report highlights in stark reality the magnitude and urgency of the climate challenge,” asserted White House Office of Science and Technology Policy Director John Holdren, referencing the Working Group III report. “It shows, even more compellingly than previous studies, that the longer society waits to implement strong measures to cut greenhouse-gas emissions, the more costly and difficult it will become to limit climate change to less than catastrophic levels. 

The Working Group III report was the final contribution to the IPCC’s Fifth Assessment Report of the IPCC, titled “Climate Change 2014: Mitigation of Climate Change.” The Working Group I report, released in Sept. 2013, outlined the physical science basis of climate change. The larger Fifth Assessment Report will be completed by a synthesis report on track to be finalized in October.

For additional information on the Working Group II report, click here. For additional Information on the Working Group III report, click here.


On April 10, the House Science, Space and Technology Committee convened for a hearing reviewing the US Department of Energy’s scientific and technology priorities as outlined in the president’s budget proposal for Fiscal Year 2015.

Chairman Lamar Smith (R-TX) took issue with DOE’s investments in renewable energy in comparison to its fossil fuel investments. DOE’s Office of Energy Efficiency and Renewable Energy (EERE) funding would increase by 21.9 percent in the president’s FY 2015 budget. Meanwhile, the Fossil Energy Research and Development account would decrease by 15.4 percent with the brunt of those cuts coming from coal-related activities. 

“The administration should not pick winners and give subsidies to favored companies that promote uncompetitive technologies,” said Chairman Smith.  “Instead, we should focus our resources on research and development that will produce technologies that will enable alternative energy sources to become economically competitive without the need for subsidies. Basic energy research is the stepping stone to our continued success.”

Department of Energy (DOE) Secretary Ernest Moniz countered that the investment numbers for EERE constitute three separate energy priorities ($521 million for renewable energy, $705 million for sustainable transportation and $858 million for energy efficiency). Secretary Moniz asserted that the proposed EERE funding levels are comparable to the $475 million proposed for fossil energy and $863 for nuclear energy. Together, these funding levels in the president’s budget will constitute an all-of-the-above energy approach. Moniz subsequently noted that DOE made the initial investments in the research that fostered hydraulic fracturing.

Ranking Member Eddie Bernice Johnson (D-TX), noted the importance of fossil fuels, but is also supportive of federal funding for alternative energy sources. “I continue to strongly support research to make today’s technologies safer, cleaner, and more efficient, but we also have to find the greatest value for our investment of taxpayer dollars,” said Ranking Member Johnson. “Today it is the emerging energy technology sectors that can most benefit from government support. That is where the priorities set by the Fiscal Year 2015 budget request come into play.”

View the full committee hearing here.


On April 9, a bipartisan group of 51 senators issued a letter to the Senate Interior, Environment and Related Agencies Appropriations Subcommittee expressing support for the Land and Water Conservation Fund (LWCF) and the Forest Legacy program.

Sens. Patrick Leahy (D-VT), Jeanne Shaheen (D-NH), Richard Burr (R-NC) and Susan Collins (R-ME) spearheaded the letter. The senators asserted that these programs support and protect wildlife habitats and provide the public with hunting and fishing recreational opportunities while also promoting job creation .The letter asserted that the programs also save taxpayer dollars through protecting land that provides valuable water resources, guards against incompatible development and reduces fire risk while contributing to state, local and private conservation investments.

“The entire suite of LWCF programs protect natural resource lands, outdoor recreation opportunities and working forests at the local, state and federal levels, ensuring that critical wildlife habitat, hunting and fishing access, state and local parks, Civil War battlefields, productive forests and other important lands are protected for current and future generations,” the senators stated in the letter. “We ask that you include a strong investment in LWCF and Forest Legacy that will support public land conservation and ensure access to the outdoors for all Americans.”

LWCF allows revenues generated from offshore oil and gas drilling fees to be diverted towards funding federal land acquisition, land and water recreation, endangered species conservation, and grants to states. Yet, since the law’s establishment in 1965, Congress has redirected $18 billion of LWCF revenue, resulting in a backlog in conservation initiatives. The president’s budget proposes full funding for LCWF. The program is currently funded at $300 million. Additional information on the program is available here.

The Forest Legacy program seeks to protect environmentally sensitive forest lands. Additional information on the Forest Legacy program is available here. View the full Senate letter here.


On April 15, 26 members of the House and Senate from Idaho, Montana, Oregon and Washington sent a letter to President Obama expressing support for the 1964 Columbia River Treaty.

The Columbia River Treaty aids in the coordination of hydropower development and flood control between the United States and Canada along the Columbia River basin. Beginning this year, either side can seek to terminate the treaty with 10 years notice. The US State Department is expected to start negotiations with the Canadian government on potential updates to the treaty as early as September of this year.

“The Columbia River provides significant economic and cultural benefits to our region and how it is managed through the Treaty will have major impacts into the future,” noted the bipartisan group of lawmakers. “Therefore, it is important that you remain in regular and close communication with the Pacific Northwest Congressional Delegation during the Interagency Policy Committee process and keep us apprised of potential negotiations with Canada.”

The letter was spearheaded by Sen. Patty Murray (D-WA), House Natural Resources Committee Chairman Doc Hastings (R-WA) and House Natural Resources Committee Ranking Member Peter DeFazio (D-OR). To view the full letter, click here:


On April 9, the US Department of Interior and the US Department of Agriculture jointly released a new holistic vision for wildfire management “To safely and effectively extinguish fire when needed; use fire where allowable; manage our natural resources; and as a nation, live with fire.”

The strategy seeks to restore and maintain landscapes by using tactics such as prescribed burns to increase forest resiliency. The strategy also seeks to build “fire-adapted communities” by reducing the amount of surrounding flammable materials such as fuel and vegetation that could cause or exacerbate a wildfire. Additionally, the strategy strives to highlight programs and activities that would prevent fire ignitions directly caused by humans. Effective and efficient response to wildfires is the last prong in the strategy.

A comprehensive strategy to address wildfires was first mandated in the Federal Land Assistance, Management, and Enhancement (FLAME) Act of 2009 (P.L. 111-88).

View the full strategy here.


On April 17, President Obama announced that he was dedicating $15 million towards a new program that would help state and local governments invest in solar energy infrastructure.

The $15 million will be implemented through the administration’s new Solar Market Pathways program. It will fund the development of initiatives to help communities across the US expand installation of solar panels. The program will also provide technical assistance and cost reductions for solar installations in federally-assisted housing.

The program is a part of the Department of Energy’s SunShot Initiative, which seeks to make solar energy cost-competitive with other forms of electricity. The White House reports that solar power installation has increased 11 fold since the year before the president took office. Between 2008, it has climbed from 1.2 gigawatts in 2008 to an estimated 13 gigawatts today, enough to power over 2.2 million homes.

For additional information, click here.


On April 10, 2014, biologists from across the US fanned out across Capitol Hill, visiting over 60 congressional offices to talk about how federal investment in science research yields benefits to society. 

Organized each year by the Ecological Society of America (ESA) and the American Institute of Biological Sciences (AIBS), the Biological Ecological Sciences Coalition event helps raise awareness among policymakers about how federal research benefits the communities they represent.

This year’s participants included 2014 ESA Graduate Student Policy Award winners, Sarah Anderson (Washington State University), Andrew Bingham (Colorado State University), Amber Childress (Colorado State University), Brittany West Marsden (University of Maryland) and Johanna Varner (University of Utah).

Participants in the BESC Hill visits came prepared with personal stories about how federal funding aids their research, how their work helps them advance their professional development and benefits the respective states where they conduct their research. While firm commitments to support science funding varied from office-to-office, the graduate students and other participants mostly received collegial receptions from Congressional staff and elected officials, using local commonalities to relate with the congressional staff and lawmakers with whom they met.

The visits coincided with bicameral letters from the House and Senate in support of $7.5 billion in funding for the National Science Foundation, which was central to the overall message advocated by the BESC participants. The House letter, circulated by Reps. G.K. Butterfield (D-NC) and David McKinley (R-WV), garnered 132 signatures. Sen. Edward Markey (D-MA) authored a similar letter that secured 20 additional signatories.

The day before the Hill visits, the students met informally with several federal agency scientists who gave their perspective as scientists working in policy. Federal entities represented at the briefing included the United States Geological Survey, the White House Office of Science and Technology Policy, the National Park Service and the US Forest Service. The participants were also briefed on the federal budget process and protocols regarding meeting with congressional offices on Capitol Hill.


Considered by House Committee/Subcommittee

On April 3, the House Natural Resources Subcommittee on Fisheries, Wildlife, Oceans and Insular Affairs held a hearing on the following bills:

H.R. 69, Illegal, Unreported, and Unregulated Fishing Enforcement Act of 2013 – Introduced by Rep. Madeleine Bordallo (D-Guam) the bill would authorize new enforcement measures to stop illegal, unreported and unregulated fishing.

H.R. 2646, the Revitalizing Economy of Fisheries in the (REFI) Pacific Act – Introduced by Rep. Jaime Herrera Beutler (R-WA), the bill would direct the Secretary  of Commerce to issue a fishing capacity reduction loan to refinance the existing loan funding the Pacific Coast groundfish fishing capacity reduction program.

H.R.___, the Pirate Fishing Elimination Act – the legislation, drafted and yet to be introduced by Rep. Peter DeFazio (D-OR), would prevent, deter, and eliminate illegal, unreported and unregulated fishing through implementation of the Port State Measures Agreement. 

On April 8, the House Natural Resources Committee held a hearing on four bills to amend the Endangered Species Act:

H.R.4315, 21st Century Endangered Species Transparency Act – Introduced by House Natural Resources Committee Chairman Doc Hastings (R-WA), the bill would require federal agencies to publicly release data used to make decisions to list species for protection under the Endangered Species Act. Current proprietary rights for research currently allow such information to remain private.

H.R. 4316, Endangered Species Recovery Transparency Act – Introduced by Rep. Cynthia Lummis (R-WY), the bill would require the US Fish and Wildlife Service to report to Congress and make publicly available the total amount of federal expenditures used to respond to Endangered Species Act lawsuits.

H.R. 4317, State, Tribal, and Local Species Transparency and Recovery Act – Introduced by Randy Neugebauer (R-TX), the bill would require the federal government to include data from states and tribes in its consideration of the “best available scientific and commercial data” for Endangered Species Act listings.

H.R. 4318, Endangered Species Litigation Reasonableness Act – Introduced March 27 by Rep. Bill Huizenga (R-MI), the bill would place a $125 per hour cap on federal agency reimbursement for attorney fees for endangered species litigation.

Passed House

H.R. 2413, the Weather Forecasting Improvement Act – Introduced by Rep. Jim Bridenstine (R-OK), the bill would redirect National Oceanic Atmospheric Administration resources towards advances in resources that improve forecasting for extreme weather events. The original bill received criticism from committee Democrats for shifting resources from climate research. However, language changes in the bill would grant the agency more flexibility in how it allocates its resources. This helped secure cosponsorship from a number of Democrats, including House Science, Space and Technology Committee Ranking Member Eddie Bernice Johnson (D-TX). The bill passed the House by voice vote on April 1 and has been referred to the Senate Commerce, Science and Transportation Committee.

Signed by President

Green Mountain Lookout Heritage Protection Act (P.L. 113-99) – Introduced by Sen. Patty Murray (D-WA), the law designates lands in the Mount Baker-Snoqualmie and Wenatchee National Forests in the state of Washington as part of the Glacier Peak Wilderness to help preserve the operation and maintenance of Green Mountain Lookout, a popular recreational and tourism destination. The president signed the measure April 15. 

Sources: Department of Energy, Department of Interior, Energy and Environment Daily, E&E News PM, Greenwire, the Hill, House Natural Resources Committee, House Space, Science and Technology Committee, Senate Environment and Public Works Committee, the White House


Sage grouse losing habitat to fire as endangered species decision looms

Post-wildfire stabilization treatment has not aided habitat restoration for the imperiled Great Plains birds.


FOR IMMEDIATE RELEASE: Wednesday, 2 April 2014
Contact: Liza Lester (202) 833-8773 x 211;


A summer storm passes over sagebrush country near Hollister, Idaho. The area has not burned in the last 30 years and features mature sagebrush, but also non-native cheatgrass, mustard, and crested wheatgrass, and barbed-wire fencing, which provides perches for predatory birds. Non-native plants and human infrastructure diminish the quality of the habitat for sage grouse.

An early summer storm passes over sagebrush country near Hollister, Idaho. The area has not burned within the 20 year time frame of the study. It features mature sagebrush, but also non-native cheatgrass, mustard, and crested wheatgrass, and barbed-wire fencing, which provides perches for predatory birds. Non-native plants and human infrastructure diminish the quality of the habitat for sage grouse. Credit, Robert Arkle, June 2011.

As fires sweep more frequently across the American Great Basin, the US Bureau of Land Management (BLM) has been tasked with reseeding the burned landscapes to stabilize soils. BLM’s interventions have not helped to restore habitat for the greater sage grouse (Centrocercus urophasianus) reported scientists from the US Geological Survey (USGS) and US Forest Service in the Ecological Society of America’s journal Ecosphere last week, but outlier project sites with good grouse habitat may yield clues to successful management scenarios.

Their report arrives in the shadow of a pending decision by the US Fish and Wildlife Service (FWS) to protect the sage grouse under the Endangered Species Act, and efforts by BLM and FWS to establish voluntary conservation and restoration management plans in lieu of endangered species listing mandates.

Protection of sage grouse under the Endangered Species Act could affect the management of 250,000 square miles of land in the western US. FWS must decide on the grouse’s protection status by the end of FY 2015.

Wildfire is the predominant cause of habitat loss in the Great Basin. The sagebrush ecosystem is not adapted to frequent fires like some forests in California and the central Rockies, and fires have increased in frequency and in size over the last half century.

“The most common species, big sagebrush, doesn’t re-sprout from the stump. After it burns, it’s dead and it has to reseed, and it’s not very good at dispersing seeds long distance,” said author Robert Arkle, a supervisory ecologist for the USGS Forest & Rangeland Ecosystem Science Center at the Snake River Field Station in Idaho. “Seeds aren’t viable very long. Some years they don’t reproduce at all, without the right spring conditions. Getting sage established out in the middle of these big burned areas is a difficult task.”

Arkle emphasized that recovery of sage grouse habitat is not part of BLM’s wildfire response directive. BLM’s Emergency Stabilization and Rehabilitation (ESR) program is designed to reestablish perennial plant cover following wildfire, preventing erosion and limiting the spread of non-native species.

“Accomplishing those goals certainly wouldn’t hurt sage grouse, but whether or not these treatments provide a benefit for sage grouse doesn’t have bearing on the success of the ESR program,” said Arkle. “It’s important to recognize the difficulty of what the land management community is trying to do.”

A sea of non-native crested wheatgrass (left) fills the path of the Poison Creek fire, which burned on Idaho’s remote Owyhee High Plateau in 1996. An abrupt transition to healthy sagebrush marks the edge of the fire. The Jarbidge Mountains sit on the horizon. Credit, Robert Arkle.

A sea of non-native crested wheatgrass (left) fills the path of the Poison Creek fire, which burned on the remote Owyhee High Plateau, tucked into the southwest corner of Idaho, in 1996. Nearly two decades later, an abrupt transition to healthy sagebrush marks the edge of the fire. The Jarbidge Mountains sit on the horizon. Credit, Robert Arkle, June 2011.

Historically, the Great Basin burned in smaller, patchier conflagrations, at intervals on the order of once per century. Managers are now seeing sagebrush country burn every 20 years in parts of the Great Basin, fueled by drought and vigorous non-natives like cheatgrass (Bromus tectorum).

 “Almost a million acres burn each year in the Great Basin and, since 1990, about 6% of the Great Basin has been treated with these ESR projects. Almost all treated acres occur in historic sage grouse habitat,” said Arkle. That’s why the team chose to look at ESR project sites. “We have this problem with non-native plants coming in, changing the fire cycle, and promoting more frequent fires. We wanted to know if ESR treatments had improved conditions for grouse in these vast burned areas.”

The average ESR project encompasses 4 square miles. In 2007, the Murphy Complex Fire burned 653,000 square miles in south-central Idaho. To cover such large areas, BLM spreads seed from aircraft or with tractor and rangeland drill seeders, usually in the fall or early winter. They customize a mix of forb, bunchgrass, and shrub seeds to the site. In recent years, BLM has moved to using native species when possible.

Arkle and colleagues examined 101 sites that burned once between 1990 and 2003. To select their sites, they compiled a database of fires and ESR projects from which they randomly chose a set of project sites with a gradient of precipitation and annual temperatures but similar soil types.

“Treated plots were not much more likely to be used by sage grouse than the burned and untreated, on average, but there were outliers. Those are important, because they are sites where the treatments were more effective, in terms of sage grouse habitat,” said Arkle.

Sage grouse prefer land that has not burned at all in recent decades. Arkle and his colleagues found little sagebrush cover at burned sites, whether treated or not.

“I think that’s the most important finding, because some sites burned 20 years ago and still haven’t recovered,” said Arkle. “We did not see a trend of increasing sagebrush cover with time, so time is not the limiting factor in this 20 year window.” If not time, then what does sagebrush need to recover? The limiting factor could be related to climate, or prevalence of non-native plants. It is a question the researchers hope to address in the future.

Robert Arkle collected data at Clover Creek in 2009, near perimeter of a fire that burned on Idaho’s Owyhee High Plateau in 1994. Credit (co-author) David Pilliod.

Robert Arkle collected data at Clover Creek in 2009, near the perimeter of a fire that burned on Idaho’s Owyhee High Plateau in 1994. Credit (co-author) David Pilliod, July 2009.

Sage grouse are picky birds, Arkle and colleagues found, preferring a sagebrush steppe environment featuring very little human development and dwarf sagebrush (Artemisia arbuscula, A. nova, or A. tripartita) but not cheatgrass or other non-native plants. Even in otherwise primo landscapes, if just 2.5% of the land is developed within five kilometers of a site, the birds will be half as likely to use it. If any development, including paved roads, can be seen, they don’t want be there. Seemingly low impact structures like fences and livestock watering stations provide predatory ravens with high perches from which to spy sage grouse nests.

The outlier ESR sites preferred by sage grouse had healthier sagebrush and shared common climate and post-treatment weather conditions. Sagebrush recovery fared better in more northerly, higher elevation sites, with relatively cool, moist springs. Spring weather has big role in successful germination and growth of sagebrush during the crucial first growing season. Sagebrush biology and physiology can be the biggest hurdle for restoration managers.

To Arkle’s mind, the study results argue for maintaining and protecting existing expanses of intact, high quality habitat, and only secondarily trying to fix what’s broken.

Experimental techniques have some promise, and include multiple seedings when the first try fails, out-planting pods of seedlings, and using different types of drill seeding equipment. Reseeding burns with local varietals or close genetic matches could improve recruitment. Controlling non-native plants with herbicides and fungal infections has been tried, with mixed results.

But the factors that ultimately determine the survival of the sagebrush ecosystem may be out of managers’ control. The study, and another tracking the recovery of mountain big sagebrush (A. tridentata subsp. vaseyana) at high elevation, suggest that climate may play a role in the failure of big sage germination and establishment in hotter locations. Managers can try to work with and around climate and weather constraints, but impending climate changes will likely make this task more difficult. Some sites are more resilient than others. It’s possible that parts of the Great Basin will cross a tipping point of climate and species representation, from which they cannot return.

“There is potential for sites to move into a new plant community state,” said Arkle. “It’s possible that some have gone past a threshold. We could have a really difficult time trying to move them back to plant communities that existed historically.”


Robert S. Arkle, David S. Pilliod, Steven E. Hanser, Matthew L. Brooks, Jeanne C. Chambers, James B. Grace, Kevin C. Knutson, David A. Pyke, Justin L. Welty, and Troy A. Wirth 2014. Quantifying restoration effectiveness using multi-scale habitat models: implications for sage-grouse in the Great Basin. Ecosphere 5:art31.

This open access report was funded by the US Geological Survey, the Bureau of Land Management, and the US Forest Service.

USGS press release: Post-Fire Stabilization Seedings Have Not Developed Into Sage-grouse Habitat. Released: 3/24/2014 9:34:33 AM