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    Blame It on the Rain

    The Impact of Extreme Weather Events on Upland Bird Populations

    “How many times will hunters go on a hot, early season hunt that’s tough on their dogs and without seeing many birds before they just decide to give up?” asks Steve Belinda, Executive Director of the North American Grouse Partnership.

    How true that is. Last September, temperatures in the mid-80s – at an elevation of 8,000 feet – played a major role in our decision to cancel our family’s annual sage and Columbian sharptail grouse hunt in Colorado. This was almost 10 degrees higher than the historic average. With an older and somewhat out-of-shape dog, that kind of heat could be devastating. For one weekend of hunting, it just didn’t seem worth it.

    Vegetation cover not only hides game bird nests, such as this greater prairie chicken nest, from potential predators, but it also moderates temperature due to solar radiation that can lower energy costs to the incubating adult. (Photo/Dwayne Elmore)
    Vegetation cover not only hides game bird nests, such as this greater prairie chicken nest, from potential predators, but it also moderates temperature due to solar radiation that can lower energy costs to the incubating adult. (Photo/Dwayne Elmore)

    Belinda continues, “The human connection to these birds and these landscapes is as important as the birds and habitats themselves. We love what we know, and we know what we visit. If we quit knowing about the places where the birds are, we’re not going to care about what happens to them.”

    And it’s often during the closed seasons that bird populations take tremendous hits from nature.

    The boom and bust cycles of grouse, quail and woodcock are well-known – good weather and great habitat lead to boom periods, while variability in either brings a down cycle. The goal of wildlife managers is to ensure that, when the bust times come, there will still be a boom on the other end of the cycle. There’s no denying that over the last two decades, erratic weather patterns have made extreme events more common. There is also no denying the connection between such events and upland bird productivity.

    A Year of Extremes

    This past year, 2017, will undoubtedly be remembered for the record-breaking weather events that took place across the continental U.S. Taking advantage of the warmth and bare ground of an early spring in the Northeast, woodcock began migrating in March only to be stranded when winter storm Stella dumped more than a foot of snow on the region.

    In South Dakota, temperatures in the spring began to soar and precipitation stopped – a bad combination at brood-rearing time. The South Dakota Game, Fish and Parks pheasant brood survey reported a statewide population drop of 45 percent from 2016 and a 65 percent drop from the 10-year average.

    Woodcock huddle together in Central Park in New York City following a March 2017 snowstorm. Food-stressed woodcock are at increased risk of starvation and predation. (Photo/Thomas Schuchaskie, from Facebook March 15, 2017)
    Woodcock huddle together in Central Park in New York City following a March 2017 snowstorm. Food-stressed woodcock are at increased risk of starvation and predation. (Photo/Thomas Schuchaskie, from Facebook March 15, 2017)

    Northeastern Montana and western North Dakota saw extreme drought conditions through the summer – total pheasant observations were down 61 percent from 2016 in North Dakota, and brood observations were down 63 percent. Prairie sharptail and Hungarian partridge were undoubtedly also affected by the bad nesting and brood-rearing conditions.

    The dry conditions in Montana and throughout the West spawned raging wildfires that torched over 8.5 million acres – 2.5 million acres more than the 10-year average and the third worst fire year ever. Much of the acres burned were on the public lands valued by upland hunters because of the diversity of wild birds.

    Then two Category 4 Atlantic hurricanes hit the mainland U.S. for the first time. Hurricane Harvey devastated the southeast coast of Texas, dumping more than 50 inches of rain. Hurricane Irma came just two weeks later, pounding the Southeast with heavy winds, rain and storm surge. Harvey leveled its crosshairs on the endangered Attwater’s prairie chicken refuge west of Houston. Of the 29 individuals being tracked before the storm, only five were confirmed alive. Undoubtedly, bobwhite quail were also affected by Harvey and Irma.

    Wild weather events are nothing new. However, we’re seeing a lot more variability with more frequency. Over the last two decades, the National Oceanic and Atmospheric Administration’s Climate Extremes Index has used data on temperatures and precipitation to determine the percent of the country that faced extreme weather conditions. In 2012, about 52 percent of the country saw extreme conditions; 2015 and 2016, 42 percent; well above the mean of 20 percent.

    Getting Used to Variability

    Upland bird managers know that ill-timed weather events can affect population recruitment of chicks surviving to maturity for an entire year and beyond if there are fewer birds during the next breeding season. Snow and ice storms can kill individual birds that don’t have adequate thermal cover. Heavy rains during nesting season can wash out nests or cause hens to abandon them. Conversely, persistent drought reduces food sources, including insects and seeds that are critical during brood-rearing.

    The concern for upland game birds is the literal seesaw effect between hot and cold, wet and dry conditions. Birds have a remarkable resiliency over longer periods of time to rebound after weather events. But it takes time for recruitment to catch back up to the loss. If birds face weather extremes year after year, the population booms never fully catch back up causing long-term trends of decline.

    Surprise weather events can be a death sentence for bobwhite quail, like this covey killed on their roost after a spring blizzard. (Photo courtesy of Quail Forever)
    Surprise weather events can be a death sentence for bobwhite quail, like this covey killed on their roost after a spring blizzard. (Photo courtesy of Quail Forever)

    “Most upland game birds depend on annual recruitment and generally have a very short lifespan. Any quail in southeast Texas that hadn’t fully fledged yet most likely died in the flooding from Harvey – that will certainly impact recruitment for the coming year,” comments Robert Perez, upland game bird coordinator for the Texas Parks and Wildlife Department. “If we see more frequent catastrophic events like hurricanes or the severe drought we just came through, it will have a much greater effect on species with a shorter lifespan that depend on annual recruitment. Ultimately, it will cut into the overall population.”

    Severe weather can bring some positives. Woodcock, ruffed grouse, quail and many other species depend on what are known as early successional or “young forest” habitats. Tornadoes, straight-line winds and hurricanes often blow down trees and in doing so reset the successional clock in forested habitats. Combined with increasing efforts by state agencies and conservation partners to increase young forest habitats, these severe weather events can provide positive benefits.

    One key example happened after a massive 2011 windstorm in Wisconsin. The state’s Department of Natural Resources and partners coordinated a timber salvage operation to clear out approximately 90,000 acres of wind-damaged timber. The habitat improvements were targeted for the at-risk golden-winged warbler, another species dependent on young forest habitat, but they also benefited woodcock and ruffed grouse.

    “Generally, most people saw the blowdown as massively destructive,” says Wisconsin DNR Wildlife Biologist Bob Hanson. “However, with the correct management prescription, it actually has provided some great habitat for this potentially endangered species. The shotgun pattern the storm left created new areas of young forest, a requirement of the golden-winged warbler.”

    Turning Up the Heat

    Temperature extremes can also make life difficult for upland game birds. Oklahoma State University researcher Dwayne Elmore has been looking at the impacts of temperature on habitat use by quail, greater prairie chickens and greater sage grouse. Not unexpectedly, there is significant temperature variation where these birds live. Radio telemetry shows that on hot days, birds move to areas where they can more easily regulate their temperature and then hold tight. This can increase predation and limits foraging opportunities on days when the mercury soars in the morning and doesn’t drop again until the evening. Temperatures also affect nesting.

    High elevation habitat for ptarmigan, like this meadow in Alaska, may be at risk if anticipated range shifts occur. (Photo/Andrew Bogan)
    High elevation habitat for ptarmigan, like this meadow in Alaska, may be at risk if anticipated range shifts occur. (Photo/Andrew Bogan)

    “I didn’t anticipate that temperature was going to play such a large role, but we found that solar radiation was the most important indicator of nest success in greater prairie chickens,” Elmore said. “Nests in cooler sites had better survival while those with higher solar radiation had lower survival – and these findings are consistent across many of the ground nesting upland game bird species.”

    Warmer temperatures are expected to change the ranges of wildlife species, generally shifting upward in elevation and northward in latitude. However, movements away from areas that become more arid could also occur. These range shifts can be due to temperature changes as well as vegetation changes within a region.

    In a 2013 vulnerability assessment of wildlife species, the Michigan Department of Natural Resources noted that, while generally stable, ruffed grouse could range farther north and even be entirely out of Michigan by 2050. This shift is associated with anticipated changes in aspen and conifer communities. Similar changes in vegetation, and the species that depend on them, are possible in many of the northern tier states.

    The upland species most vulnerable to changes in range are ptarmigan. Habitat models for the ptarmigan on Vancouver Island predict a decline of 44 percent of summer habitat and a 52 to 79 percent reduction in habitat patch sizes within the next three decades. With the average elevation of suitable habitat increasing, ptarmigan could be “squeezed off the mountain” – there simply is nowhere else they could go.

    Temperature changes could expand the ranges of some key upland birds. Woodcock need warmer winters to survive and predictions suggest that their winter range could expand to middle latitude states in the next few decades. Bobwhite quail might also be more successful in states that are considered part of the northern edge of their current range.

    Burning Changes

    There can be side effects to weather variability that may not be as obviously connected. The wildfires that raged across the West are clearly tied to hot, dry conditions. But following the burns, the disturbed soils are more vulnerable to invaders. Cheat grass, medusa head and other nonnative plants move in quickly due to their prolific seed dispersal.

    The National Oceanic and Atmospheric Administration’s Climate Extremes Index shows the percentage of the country beseiged by extreme weather each year since 1910. The three years highest in percentage have occurred since 2012. (Photo/NOAA)
    The National Oceanic and Atmospheric Administration’s Climate Extremes Index shows the percentage of the country beseiged by extreme weather each year since 1910. The three years highest in percentage have occurred since 2012. (Photo/NOAA)

    Cheat grass, a native of the Mediterranean region, is an annual with a short life cycle that is dead and dried out by mid-June. When fire season starts, cheat grass is typically the first and fastest to burn. It then outcompetes native sagebrush and other grasses and forbs to colonize new areas, increasing potential for future fires. The historical fire regime in sagebrush country is once every 60 to 100 years, but drops to less than five years when cheat grass takes over.

    The result of more frequent and intense fires in western rangelands is apparent. Individual birds can be killed, particularly during fires that occur during nesting and brood-rearing seasons when hens and their chicks are less mobile. In addition, the fires (and the resulting invasion of nonnative grasses) significantly decrease availability of forage – both the plant and the insect variety. Fires have long been recognized as a concern for greater sage grouse, and in 2017, more than 2 million acres of their habitat burned – three times the amount burned the year before.

    Fire is not always bad, and prescribed burns are used to “reset the ecological clock” in fire-dependent habitats like grasslands and southeastern pine forests. Patch fires are being used extensively in Kansas to benefit the native prairie grasses and shrubs on which lesser prairie chickens rely. Bobwhite quail have been nicknamed the “firebird” since the early 1930s because of how well they respond to habitats after a burn. The difference between catastrophic wildfires and healing-prescribed burns is timing and intensity, and habitat managers are working to find a positive balance that works.

    During the 2011 drought in Texas, watering holes and rivers dried up, and habitat was impacted resulting in significant declines in populations of scaled and bobwhite quail in the region. (Photo/Eric Grahmann)
    During the 2011 drought in Texas, watering holes and rivers dried up, and habitat was impacted resulting in significant declines in populations of scaled and bobwhite quail in the region. (Photo/Eric Grahmann)

    Fighting Off Disease

    A side effect of changing weather patterns can be an increase in disease, and most worrisome for upland bird hunters is West Nile Virus (WNV), a disease that originated in Africa. A strain that had been circulating in Israel and Tunisia was “imported” to New York in 1999, and it quickly spread across the country. Birds are the “reservoir host” of the West Nile Virus, and mortality in birds where WNV originated is rare. However, since being introduced to the U.S., where native birds have not developed resistance, there have been significant mortality events.

    In 2003, an outbreak in sage grouse near the Powder River Basin in Wyoming resulted in a nearly 75 percent decline of males counted on leks the following year. Similar outbreaks have occurred in eastern Oregon and other areas of the sage grouse’s range. In Pennsylvania, ruffed grouse hunters began reporting markedly decreased populations of ruffed grouse.

    “The early 2000s was a tipping point for Pennsylvania grouse. There were more down cycles in the populations, and there really weren’t any ups,” reports Lisa Williams, grouse biologist for the Pennsylvania Game Commission. “Usually we look first at habitat, but something else was suppressing the numbers because even in our best habitats, populations were crashing. We are now very confident that major die-offs that occurred from 2002 to 2005 and from 2010 to 2012 were due to West Nile Virus.”

    Predicted increases in warm, wet springs followed by hot, dry summers promote stagnant water sources where mosquitoes breed and transmission is amplified by extended “shoulder seasons” in spring and fall. In April 2017, Pennsylvania had the earliest detection of WNV in a mosquito, and it portended a bad outbreak year. Like severe weather events, WNV outbreaks might be very localized, but in those local areas the mortality rates are typically high.

    It’s About the Habitat …

    At the risk of sounding dogmatic, one element can help buffer the effects of weather extremes – quality habitat. If there are places where birds can move when ranges change, they will be more adaptable. If there is adequate thermal cover during winter storms or hot spells, birds can survive the extreme weather and temperatures. If there are plenty of grasses and forbs that host a diverse array of insect life, broods are more successful.

    Northern bobwhites require dense patches of shrubs that not only shield them from predation but also provide refuge from extreme heat and cold. (Bobwhite Photo/Texas Parks and Wildlife Department, Sand Plum Photo/Dwayne Elmore)
    Northern bobwhites require dense patches of shrubs that not only shield them from predation but also provide refuge from extreme heat and cold. (Bobwhite Photo/Texas Parks and Wildlife Department, Sand Plum Photo/Dwayne Elmore)

    Larger intact landscapes will provide better ability for all species to be resilient, as will connection between habitats. Where habitat is reduced to increasingly smaller patches, species will have less ability to recover when extreme drought or storms affect their breeding season. Without good habitat, we’ll see more busts and fewer booms.

    South Dakota rancher Jim Faulstich agrees. Weather last year near his Daybreak Ranch north of Highmore seesawed between ice storms and hailstorms in the winter to warm spring weather and then a frost on June 24. Then the furnace turned on with hot, dry summer conditions. But Faulstich has focused on native prairie restoration, shelterbelts and conservation reserve lands – the quality habitat that allows pheasants to survive difficult winters and summer drought. Overall, the state of South Dakota is predicting declines, but Faulstich is optimistic about the number of wild birds on his property this fall.

    “Habitat gets you through these weather extremes – where the habitat is stable, birds can adapt,” Faulstich noted. “If we can get birds through the conditions we’ve had, it’s a testament to good habitat.”

    Conservation organizations bang the drums on the necessity of favorable year-round habitat for the overall good of upland bird populations. Pheasants Forever and Quail Forever have worked hard to support agricultural conservation programs. Groups like the Ruffed Grouse Society and National Bobwhite Conservation Initiative and others are implementing active management of habitats to provide the young forests on which ruffed grouse, woodcock and quail depend. The habitat conservation and restoration efforts employed through the Natural Resources Conservation Service’s Sage Grouse Initiative was a key factor in the decision to not list sage grouse under the Endangered Species Act.

    “Some might suggest there’s nothing they can do about wild temperature swings or extreme weather events,” Elmore commented. “But you can provide the habitat variability that gives birds shelter to stay cool or get warm during temperature extremes.”

    Undoubtedly everyone will be in for a wild weather ride in coming years, and with good planning, the cyclical patterns of upland bird populations will continue to have strong boom years to counter the potential for bigger busts.

    Wolfe Publishing Group