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Idaho Fish And Game Designs Innovative Way To Survey Wildlife Using Remote Cameras
Posted on Friday, February 08, 2019 (PST)

An innovative approach using trail cameras to capture wildlife will allow Idaho Fish and Game biologists to estimate deer and elk populations in a safer, less-invasive, and less-expensive way than the traditional method of biologists flying in aircraft and counting them.


During November, biologists deployed a network of trail cameras on winter range of mule deer in eastern Idaho, as well as elk range in the St. Joe River and the South Fork of the Clearwater River. In each location, cameras were deployed at randomly selected GPS points across the animals’ winter range.


During December, and at least through February, the remote cameras will snap a picture any time they sense movement, much in the same way hunters use them to scout for game.


More important in IDFG’s population surveys, all the cameras are synchronized to take photos at exactly the same time at 10-minute intervals. Those photos will be used in statistical modeling that allows biologists to estimate populations across the entire study area with statistical confidence.


“It is a big deal,” said Mark Hurley, IDFG’s wildlife research manager. “This is quite a breakthrough to discover some of these different techniques for estimating populations.”


Biologists also believe the photos will help them generate more reliable estimates of sex ratios for the mule deer in Southern Idaho than their current helicopter surveys. The current process for generating sex ratio estimates involves sampling a small portion of a winter range from the air, and expanding that over the entire range. Because bucks aren’t always congregated with does and fawns on winter range, there can be some inconsistencies in those sex ratios. The new remote camera method samples the entire winter range, which can eliminate those inconsistencies.


For elk herds being surveyed farther north, where dense vegetation makes traditional helicopter surveys impractical or impossible to conduct, it will lead to the first population and sex ratio estimates ever.


Sex ratios are important measurements for managing populations to ensure there’s adequate numbers of breeding-age females, enough young animals to sustain or grow the herds, and enough males to support harvest.


The idea of using remote cameras to generate population estimates in Idaho goes back about five years. IDFG put together a team of biologists to look at alternative methods to aerial surveys where biologists fly in a helicopter and count animals in the open and semi-open areas of Southern Idaho. They also wanted a method that could be applied to portions of North and Central Idaho where dense vegetation makes spotting animals from a helicopter difficult.


Even in areas where aerial surveys are typically done, pilots have to fly in rugged terrain, at low elevations and during winter weather while a biologist counts animals, which makes surveys potentially hazardous.


“One of the biggest reasons we wanted to find an alternative was to reduce the amount of time we put department employees at danger in helicopters,” IDFG Deer and Elk Coordinator Daryl Meints said.


Also, traditional helicopter surveys are expensive and getting progressively more so every year, and surveys are tough to conduct during mild winters. Light snow means animals are dispersed throughout the landscape and at different elevations rather than congregating on low-elevation winter range.


The concept of using trail cameras in wildlife management is not entirely new: IDFG biologists have used them since the early 2000s, but only to determine the presence or absence of a given species.


Wildlife managers in other states have used various methods of employing trail cameras to generate population estimates, but typically with animals with distinct, individual markings.


Those methods present challenges when applied to mostly identical-looking animals, such as deer and elk. To use existing methods, biologists would have to mark individual animals, which would still require extensive helicopter use.


To find a new approach, IDFG researchers worked with Anna Katherine Moeller, a graduate student at the University of Montana, to test a trio of methods designed to allow biologists to estimate populations of unmarked animals without tracking individuals over time. She referred to the three methods as “Instantaneous Sampling,” “Space-to-Event” and “Time-to-Event.”


Elk herds in the Idaho Panhandle and the Beaverhead Mountains were counted in a February, 2016 case study, and the results were promising, particularly Moeller’s “Space-to-Event” model.


“You’ve got this randomly placed camera grid out there, and they all take pictures at exactly the same time, which is used for a population estimate,” Hurley said. “You get these multiple detection estimates every hour. Each hour is a sampling event, and you kind of roll those up for 24 hours to get a true abundance estimate every day.”


For fairly dense herds of deer and elk on winter range, the “Space-to-Event” method works pretty well.


“It gives an idea, spatially, where animals are, and also in what type of habitat you are most likely to see an animal,” Hurley said. “You can put that together with the area that the camera is actually taking a picture of, and you can roll a density estimate up to abundance."


Abundance estimates for the Beaverhead study area near the Montana border between Salmon and Island Park were comparable to prior abundance estimates done with aerial surveys.


Comparing the new camera-based surveys with traditional aerial surveys, which are time-tested and proven accurate, and coming up with similar population estimates signaled to biologists that cameras are likely a viable alternative.


In the Panhandle study area – where other abundance methods are difficult to implement – cameras produced the first-ever elk abundance estimates for an area consisting mostly of dense forests.


“When all was said and done, we knew we were onto something,” Meints said.


Meints said white-tailed deer surveys in Northern Idaho will be added next – using photos from the same cameras used in the elk survey – and future applications of remote cameras for surveys are nearly unlimited.


“We’re going to capture photos of everything on the landscape, and down the road, we’re hoping to use all of them,” Meints said. “We have a research team that is embarking on a 10-year-plus project looking at all major ungulates and all major predators. The cameras will play a critical role in that.”


Hurley added that as IDFG adapts the program to more species, other methods may work better for estimating abundance.


For deer and elk, biologists are hoping the trail cameras can gather data year after year, allowing the department to fill in the gaps between its comprehensive population surveys, which are done on a rotating basis in different areas of the state about every five years.


The trail camera surveys will allow biologists to take a more real-time approach in managing elk and deer populations for Idaho’s hunters and adjust seasons and tag allocations based on current data so they accurately reflect the number of animals available.


“Cameras are going to enable us to do a better job of managing wildlife,” Meints said. “When we don’t have data, or there are gaps in the data, we’re forced to be more conservative with hunter opportunity.”




* Research On Northwest Forest Plan Shows Bird Species Struggling 25 Years Later


Twenty-five years into a 100-year federal strategy to protect older forests in the Pacific Northwest, forest losses to wildfire are up and declines in bird populations have not been reversed, new research shows.


The findings, published this week in the Proceedings of the National Academy of Sciences, underscore the importance of continuing to prioritize the safeguarding of older forests, the scientists say – forests characterized by a complex structure that includes multiple canopy layers, large trees, downed wood and snags.


The researchers stress it’s vital to remember that upon its adoption in 1994, the Northwest Forest Plan was conceived as a century-long plan, and was not expected to show significant positive impacts on biodiversity for 50 years.


“Trees in the northwestern United States are some of the longest-lived and largest in the world,” said Matt Betts of Oregon State University. “Douglas-fir can live to be more than 800 years old and grow to be more than 100 meters tall, so it shouldn’t be surprising that it is hard to ‘restore’ this forest type, and that any plan to do so will take a long time.


“The plan has been one of the most impressive forest conservation strategies in the world, and there is no doubt that it has had a strong positive impact on the conservation of old-growth forests, but our results show that even with these strong conservation measures, bird species living in this system still aren’t doing too well.”


The NWFP, a series of federal policies put in place at the behest of then President Bill Clinton, encompasses 10 million hectares of land, including national forests, national parks, wilderness areas and Bureau of Land Management parcels, in Oregon, Washington and California.


Betts and OSU research associate Ben Phalan led a collaboration that used region-wide bird surveys, forest data and land ownership maps to gauge the plan’s effect on biodiversity so far. Birds are a key indicator of biodiversity.


The researchers examined population trends for 24 widespread bird species for which the Pacific Northwest holds important populations – some associated with older forests, some with diverse early-seral ecosystems, and some with both.


While there have been other detailed studies of threatened species such as spotted owls and marbled murrelets, this study focused on what populations of more-common birds can tell us about wider forest biodiversity.


Populations of bird species associated with older forests – such as the varied thrush, golden-crowned kinglet, Pacific-slope flycatcher and Townsend’s warbler – are continuing to struggle on both federal and private industrial land, the findings show.


On private industrial land, that’s likely due to ongoing timber harvesting, while on federal land it’s due, at least in part, to the recent uptick in fires in the Northwest, in part because of drought.


“All forests in the region evolved with fires to some degree, but now, at a time when old-growth forests are so depleted, stand-replacing fires have become an important cause of declines in bird populations in older forests,” said Betts, professor of landscape ecology and the IWFL Professor of Forest Biodiversity Research in OSU’s College of Forestry. “Evidence suggests that some of the increase in fires is climate related.”


Another important finding, notes Phalan, now based at the Institute of Biology at the Federal University of Bahia in Salvador, Brazil, is that the area of young, complex preforest vegetation – known as “diverse early-seral ecosystems” – isn't declining as much as the researchers expected, and had increased in some regions.


“Again, that seems to be because new fires are creating quite a bit of early seral,” Phalan said. “There are proposals that more of this vegetation type be promoted via forest management, but our results show that birds in older forests are more likely to be in decline than those in early-seral ecosystems, so we need to be very careful not to reduce our options for recovery of older forests – especially dense, moist forests.”


Diverse early-seral ecosystems support many broadleaf species, shrubs and herbs as well as young conifers, and are important habitats for some bird species. Bird species associated with these habitats that are showing ongoing declines include the rufous hummingbird, willow flycatcher and orange-crowned warbler. For most of these species, however, in contrast to birds of older forests, the declines have not gotten worse.


Betts said that before launching into efforts to create these diverse early-seral ecosystems, more information is needed regarding how much of it there might have been historically in different areas, and how sensitive the associated species are to reduced habitat.


Phalan emphasizes the findings show that efforts to maintain and restore old-growth forests are working, but that it’s harder to prevent stand-replacing fires than to manage logging.


“It was anticipated in the plan that species declines might take decades to arrest,” he said. “It was surprising, though, to learn that species associated with older forests continued to decline much faster than those in early seral. We argue that, because forest regeneration is an inherently slow process, and because fires are going to become more frequent in most forest types, forest plans should continue to emphasize conservation of old-growth habitats.”


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