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Tag Archive: birds

  1. Russian cuckoo invasion spells trouble for Alaskan birds: Striking difference in response to expanding brood parasites by birds in western and eastern Beringia

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    • Out of 22 experiments the researchers ran in Siberia, 14 rejected the fake cuckoo eggs. But out of the 96 experiments that we ran in Alaska, only one pair rejected one of the fake cuckoo eggs.
    • The Siberian birds are better at rejecting the cuckoo eggs perhaps because they have encountered the brood parasites before but the North American hosts have no defenses against invading cuckoos. They will be parasitized.

    May 7, 2018 University of Illinois at Urbana-Champaign  Read full ScienceDaily article here

    Common cuckoos and oriental cuckoos in eastern Russia appear to be expanding their breeding range into western Alaska, where songbirds are naive to the cuckoos’ wily ways, researchers report. A new study suggests the North American birds could suffer significant losses if cuckoos become established in Alaska.

    Like brown-headed cowbirds, cuckoos are “brood parasites,” laying their eggs in the nests of other species….. Cuckoos time their egg-laying so that their chicks will hatch first. The chicks then kick the other eggs out of the nest, “thereby eliminating the entire reproductive success of their hosts,” Hauber said….

    Vladimir Dinets, Kristaps Sokolovskis, Daniel Hanley, Mark E. Hauber. Striking difference in response to expanding brood parasites by birds in western and eastern Beringia. Journal of Field Ornithology, 2018; DOI: 10.1111/jofo.12247

  2. Hungry birds as climate change drives food ‘mismatch’

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    • With spring coming earlier due to climate change, leaves and caterpillars emerge earlier and birds need to breed earlier to avoid being mismatched.  Researchers in England found that the earlier the spring, the less able birds are to do this.

    April 23, 2018 University of Exeter Read full ScienceDaily article here

    Warmer springs create a “mismatch” where hungry chicks hatch too late to feast on abundant caterpillars, new research shows.

    With continued spring warming expected due to climate change, scientists say hatching of forest birds will be “increasingly mismatched” with peaks in caterpillar numbers.

    The researchers, from the RSPB and the universities of Exeter and Edinburgh, used data collected across the UK — largely by citizen scientists — to study spring emergence of oak tree leaves and caterpillars, and timing of nesting by three bird species: blue tits, great tits and pied flycatchers….

    …”Forests have a short peak in caterpillar abundance, and some forest birds time their breeding so this coincides with the time when their chicks are hungriest,” said Dr Malcolm Burgess, of the University of Exeter and the RSPB. “With spring coming earlier due to climate change, leaves and caterpillars emerge earlier and birds need to breed earlier to avoid being mismatched.

    “We found that the earlier the spring, the less able birds are to do this. The biggest mismatch was among pied flycatchers — as migratory birds, they are not in the UK in winter and therefore are much less able to respond to earlier spring weather.”…

    Malcolm D. Burgess, Ken W. Smith, Karl L. Evans, Dave Leech, James W. Pearce-Higgins, Claire J. Branston, Kevin Briggs, John R. Clark, Chris R. du Feu, Kate Lewthwaite, Ruedi G. Nager, Ben C. Sheldon, Jeremy A. Smith, Robin C. Whytock, Stephen G. Willis, Albert B. Phillimore. Tritrophic phenological match–mismatch in space and time. Nature Ecology & Evolution, 2018; DOI: 10.1038/s41559-018-0543-1

  3. Birds migrate away from diseases

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    • Immune systems of migratory birds show a similarly low variation to that of European sedentary birds,a surprising result since migratory birds don’t have to resist diseases during breeding and during their migration.
    • To explain the surprising result, the researchers propose the idea that the costs associated with a strong and complex immune system could be much higher than anyone previously thought.

    10 Apr 2018  Read full ScienceDaily article here

    In a unique study, researchers have mapped the origins of migratory birds. They used the results to investigate and discover major differences in the immune systems of sedentary and migratory birds. The researchers conclude that migratory species benefit from leaving tropical areas when it is time to raise their young — as moving away from diseases in the tropics enables them to survive with a less costly immune system….

    …”When the migratory birds breed, they have moved away from many diseases and therefore do not need an immune system that is equally varied. Another advantage is that the risk of damage caused by the immune system drops considerably if the immune system is less complex,” says researcher Emily O’Connor.

    All vertebrates, including human beings, have an immune system built up in a similar way to that of birds. The Lund biologists therefore believe their findings could also be significant in a broader perspective.

    Emily A. O’Connor, Charlie K. Cornwallis, Dennis Hasselquist, Jan-Åke Nilsson & Helena Westerdahl. The evolution of immunity in relation to colonization and migration. Nature Ecology and Evolution, 2018 DOI: 10.1038/s41559-018-0509-3

  4. 50 years on the Farallones–and still counting!

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    • Today, we’re kicking off a celebration to mark this remarkable milestone. Join us on Twitter and on Facebook in the weeks and months ahead as we use the hashtag #Farallones50 to share photos, videos, stories, and highlights of our work on the “Galapagos of California.”

    By | April 3, 2018

    Farallones50_blogfeaturedimage Exactly fifty years ago today Point Blue scientists officially began our research program on the Farallon Islands, 27 miles west of San Francisco. When our boat landed on April 3, 1968, we had no idea that it was the start of a continuous research operation on the island that hosts the largest seabird breeding colony in continental United States. Since then, we’ve maintained a presence on the island 24 hours a day, 365 days a year, working in close partnership with the US Fish and Wildlife Service.

    Former Point Blue Farallon Intern, Jen Aragon, measuring the weight of a seabird Photo credit: Annie Schmidt/Point Blue

    Former intern, Jen Aragon, measuring a seabird. Photo credit: Annie Schmidt/Point Blue.

    Over these five decades, we’ve amassed invaluable long term data sets that are crucial for understanding and addressing threats to our climate, the ocean, seabirds, sea lions, seals, whales, white sharks, and the marine food web.

    Our research has led to significant outcomes including: the 1987 ban on gill-netting to protect seabirds from being killed as bycatch; the 1993 state law banning the hunting of White Sharks in California; the establishment of Marine Protected Area regulations around the Farallones in 2010; and, new actions by NOAA and the US Coast Guard to reduce ship strikes on whales.

    Today, we’re kicking off a celebration to mark this remarkable milestone. Join us on Twitter and on Facebook in the weeks and months ahead as we use the hashtag #Farallones50 to share photos, videos, stories, and highlights of our work on the “Galapagos of California.”

    But we’re not just looking to the past. As we’ve shared with you before, with all that’s going in Washington, D.C., our Farallones Islands program needs your support more than ever. With your generous support, we will continue our groundbreaking science and stewardship on the island, day in day and day out, for the next 50 years!

    Please join us in celebrating this amazing milestone by investing today in the future protection of the Farallon Islands!

    Cassin's Auklet. Photo credit: Brett Hartl/ Point Blue

    Cassin’s Auklet. Photo credit: Brett Hartl/ Point Blue.

     

  5. US national parks increasingly important for bird conservation in face of climate change

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    • Projected average national park may have 29 percent more species in winter, 6 percent more in summer
    • their findings reinforce the importance of the U.S. National Parks to the conservation of birds in the face of climate change and the value of monitoring species distribution to better inform conservation and management strategies.

    March 21, 2018  PLOS read full ScienceDaily article here

    See related: Point Blue Spring 2018 Quarterly on Our Public Lands and Waters: A Living Laboratory to Secure our Future

    US national parks could become even more important for the conservation of bird species in the face of climate change, according to a new study.

    ….Wu and colleagues related species distribution models from the North American Breeding Bird Survey (summer) and Audubon Christmas Bird Count (winter) observations to climate data from the early 2000s and projected to 2041-2070. The researchers analyzed climate suitability projections over time for 513 species across 274 national parks, under a high and low greenhouse gas emission scenario. They then classified climate suitability for birds as improving, worsening, stable, potential colonization, and potential extirpation….

    Joanna X. Wu, Chad B. Wilsey, Lotem Taylor, Gregor W. Schuurman. Projected avifaunal responses to climate change across the U.S. National Park System. PLOS ONE, 2018; 13 (3): e0190557 DOI: 10.1371/journal.pone.0190557

  6. Should some species be allowed to die out?

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    ….The nest belonged to an akikiki, a small gray-and-white bird that feeds on insects, doesn’t sing much and has noticeably large feet. As head of the Kauai Forest Bird Recovery Project, Crampton is tasked with saving the akikiki, along with the rest of the island’s endangered birds. Even by conservation standards, this can be dispiriting work. Of Kauai’s eight remaining native forest birds, four are listed as endangered or threatened, including a honeycreeper so rare that researchers have managed to find just 14 of its eggs in three years, of which only four have survived.

    ….Because akikiki numbers dropped so rapidly — the population is estimated to have fallen by 83 percent in 10 years, thanks to a combination of avian malaria and invasive rats, leaving just 468 birds — the government approved a plan to start a captive-breeding program in 2015, using eggs harvested from nests in the wild….

    Under the rules of the Endangered Species Act, once a species is discovered to be at risk of extinction, government agencies are required by law to take steps to save it. For years, critics have challenged that mandate, arguing that it undercuts the ability to weigh a species’ value or to consider the economic impact of its preservation — for instance, the cost of prohibiting logging in a valuable tract of forest. Since Donald Trump took office, these objections have gained ground; there are currently six bills pending in Congress, all aimed at overhauling (some would say gutting) the Endangered Species Act….

    ….Assigning value to species is a nearly impossible undertaking, because it involves a bewildering number of variables, including ecological importance, utility (coral reefs can act as breakwaters during coastal storms), the species’ place in our heritage, even its beauty or symbolism. Conservation has no formula for weighting these factors, either alone or in combination, and it’s hard to imagine one that people could agree on. How do we decide whether the wolf or the snow leopard is more valuable?

    In response, some conservation groups have argued that we should put our efforts toward saving the most genetically diverse species, with the goal of increasing our long-term ecological resiliency. (In this view, saving the akikiki, which is one of 18 living species of Hawaiian honeycreeper, would be a low priority.) Others have suggested prioritizing “functional diversity”: the preservation of key species, like predators and pollinators, whose presence can radically affect an ecosystem.

    All of which makes the akikiki a complicated case in point: In the face of growing political and environmental pressures, how should we decide what to save?…

    Of the 1,280 endangered animals and plants listed by the United States Fish and Wildlife Service, 557 are from Hawaii, including the short-tailed albatross, the Hawaiian hoary bat and the Kauai cave wolf spider, as well as four species of turtle, six damselflies, two varieties of pond shrimp, four snails and seven kinds of yellow-faced bee. Conservationists have called the islands “the extinction capital of the world.”…

    ….our role as stewards of the earth is becoming more and more like that of doctors in a global intensive-care unit, trapped in a cycle of heroic, end-of-life measures. Many conservationists now operate in a state of constant maintenance: endlessly working to weed out invasive plants and predators, while trying to prop up species that have fallen into decline. At worst, an endangered animal becomes a literal ward of the state: preserved only in breeding facilities or in tiny, meticulously maintained “wild” habitats. “They’re like patients that are never going to be discharged from the hospital,” the environmental writer Emma Marris told me. “It’s a permanent situation.”

    The official term for such species is “conservation-reliant.” When I spoke with Michael Scott, a wildlife biologist at the University of Idaho who helped direct the California condor research effort, he estimated that roughly 84 percent of species on the United States endangered list are currently conservation-reliant. Of those, he added, a vast majority are in Hawaii. “Hawaii is the world capital of conservation-reliant species,” Scott said….

    …In short, it’s fair to ask why, exactly, biodiversity matters. As Thomas says: “Even if we were to lose 10 percent of all species in the next hundred years, would biology stop? Would ecology stop? No. In fact, most people wouldn’t even be aware of the loss.” Given how radically we’ve already altered the landscape, how bad would it be if we just kept doing what we’re doing: paving the land, overfishing the oceans and letting the chips fall where they may?

    Faced with this dilemma, some conservationists have tried to shift the focus to an economic argument known as “ecosystem services”: the idea that we benefit from preserving biodiversity either because it saves us money (mangroves prevent coastal erosion that we would otherwise have to handle with an expensive engineering project) or because it contains something of value to us, either now or in the future. For instance, a biodiverse planet may provide a first defense against global warming. Or it may act as a repository of potential discoveries: new materials that mimic the strength of spider silk; drones modeled after insects; an anticancer drug derived from Amazonian moss….

    ….The true problem, then, is not whether we would notice those vanished species and ecosystems; it’s that there’s no good way to quantify the opportunity cost of our loss, which in turn can lead us to underestimate it. “The species we have now are the ancestors of all future species,” Thomas says. “And I don’t think we know enough about ecology or evolution, or how humans are going to affect the planet over the next thousand years, to bet on which animal or plant to keep.”….

    The biologist E.O. Wilson eloquently argued against living in a world of crows and rats, and against the loss of beautiful, fragile species like snow leopards, white rhinos and tiny mouse lemurs; even if you never see a lemur or an arctic fox in person, the world can be a richer place by having such creatures in it. Others simply see conservation as a moral duty: because we’re the ones creating these problems, isn’t it up to us to fix them?…

    Whether we regard conservation as an ethical or an economic issue, we’re still faced with the question of how we decide what to save. In an ideal world, Michael Scott told me, conservation science would have the resources to study this question, rather than being stuck reacting to the latest crisis. “Figuring out which species and ecosystems are the most important to protect is a complicated project,” Scott says. “At this point, just coming up with a list of qualities we want to investigate would be a good start.”…

  7. Feeding wildlife can influence migration, spread of disease

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    March 13, 2018 University of Georgia read full ScienceDaily article here

    Animal migration patterns are changing as humans alter the landscape, according to new research. Those changes can affect wildlife interactions with parasites-with potential impacts on public health and on the phenomenon of migration itself….
    …”When you get resident populations forming, you might extend the parasite transmission season, and additionally if those residents are supported by food subsidies through the winter, the infected individuals might be more likely to make it through,” said Hall. “So now these migrants are returning to areas where there’s already a larger number of infected individuals, so those mechanisms for escaping parasitism become less effective.”Another concern is that resident animal populations with supplemented diets might support more virulent parasites….

    Leone M. Brown, Richard J. Hall. Consequences of resource supplementation for disease risk in a partially migratory population. Philosophical Transactions of the Royal Society B: Biological Sciences, 2018; 373 (1745): 20170095 DOI: 10.1098/rstb.2017.0095

  8. Fracking tied to reduced songbird nesting success

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    February 14, 2018 American Ornithological Society Publications Office Read full ScienceDaily coverage here

    The central Appalachian region is experiencing the country’s most rapid growth in shale gas development, or ‘fracking,’ but we’ve known almost nothing about how this is affecting the region’s songbird populations — until now. A new study demonstrates that the nesting success of the Louisiana waterthrush — a habitat specialist that nests along forested streams, where the potential for habitat degradation is high — is declining at sites impacted by shale gas development in northwestern West Virginia…

    Mack W. Frantz, Petra B. . Wood, James Sheehan, Gregory George. Demographic response of Louisiana Waterthrush, a stream obligate songbird of conservation concern, to shale gas development. The Condor, 2018; 120 (2): 265 DOI: 10.1650/CONDOR-17-130.1

  9. Wildfire management of CA’s chaparral ecosystem can devastate wild bird populations and fire-risk reduction is only temporary- new study

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    • Although bird species diversity and abundances rebounded after one-time use of prescribed fires, most birds never returned to masticated sites. Mastication reduced the number of bird species by about 50 percent and reduced total numbers of birds by about 60 percent.
    • “The best available science tells us that managing chaparral imperils wildlife and increases fire risk…Our study continues to build the case that we should live densely and away from chaparral.”

    February 14, 2018 University of Arizona read full ScienceDaily article here

    On the tail of California’s most destructive and expensive year of firefighting ever, it might seem obvious that vegetation removal would reduce the risk of such a year happening again. But scientists are showing that in chaparral, California’s iconic shrubland ecosystem, management can devastate wild bird populations and that fire-risk reduction is only temporary.

    …Chaparral is a fire-prone ecosystem in North America that is widespread throughout California. Although it makes up only 6 percent of California by area, it contains one-quarter of the species found in the California Floristic Province, a global biodiversity hotspot. To date, no other studies have compared the effects of different fire management types on California chaparral wildlife….

    …Although bird species diversity and abundances rebounded after one-time use of prescribed fires, most birds never returned to masticated sites. Mastication reduced the number of bird species by about 50 percent and reduced total numbers of birds by about 60 percent….

    …Much of California’s chaparral is burning too frequently to replace itself because of human-caused ignitions and longer wildfire seasons due to climate change. According to Scott Stephens, the principal investigator of the experiment at UC Berkeley, too-frequent fire can cause chaparral to be replaced by invasive grasses, which can increase fire risk.

    This leads to other problems. Grasses don’t hold soils in place, so deadly mudslides may follow wildfires, such as those in Santa Barbara, California….

    …”The best available science tells us that managing chaparral imperils wildlife and increases fire risk,” she said. “Our study continues to build the case that we should live densely and away from chaparral.”

    Erica A. Newman, Jennifer B. Potts, Morgan W. Tingley, Charles Vaughn, Scott L. Stephens. Chaparral bird community responses to prescribed fire and shrub removal in three management seasons. Journal of Applied Ecology, 2018; DOI: 10.1111/1365-2664.13099

  10. Researchers discover specific protein and location in bird retina responsible for magnetic compass

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    • A protein in the birds’ eye helps them take information from light and process it to a travel course: an inner magnetic compass
    • Researchers discovered that the Cry4 protein – unique to birds- expression level in European robin retinae is significantly higher during the migratory season compared to the non-migratory seasons
    • They found these long sought proteins in migratory birds are situated at the outer segment of the double cone photoreceptor cells in the retina per studies on the European Robin.

    February 7, 2018 University of Southern Denmark

    Migratory birds use a magnetic compass in their eye for navigation. Its basic sensory mechanisms have long remained elusive, but now researchers reveal exactly where in the eye, the birds’ control center for navigation is situated.

    …In 2000 researchers suggested that a protein in the birds’ eye helps them take information from light and process it to a travel course: an inner magnetic compass. Since then the basic sensory mechanisms underlying this magnetoreception has remained elusive….

    The magnetic compass sense in migratory birds is light dependent, and we wanted to find out which protein is at play. Theories have been circling around the so-called cryptochromes — but these cryptic proteins come in very different variations — so which one?

    …To date, four different cryptochromes have been found in the retina of several bird species. Three of them show no relevance for magnetoreception, the researchers conclude.

    But the fourth, Cry4, seems to be significantly different from its family members,” Ilia Solov’yov said.

    When light hits cryptochromes in the eye of a migrating bird, they undergo chemical reactions that are influenced by the direction of Earth’s magnetic field, providing a signal of the bird’s orientation.

    …They discovered that the Cry4 expression level in European robin retinae is significantly higher during the migratory season compared to the non-migratory seasons. “This is a strong indicator that the responsible protein is indeed cryptochrome 4.”…

    …Inner compasses are not only found in migratory birds, but also in other animals such as bees.

    “Understanding these inner compasses in animals can give us a fundamental knowledge of nature and maybe we can use it to protect wildlife. Many birds are killed in windmills, because they get disturbed by the turbulence around the mills. If we knew what magnetic fields exist around the mills, we maybe could construct some kind of protection zone around the mills,” said Ilia Solov’yov….

    Anja Günther, Angelika Einwich, Emil Sjulstok, Regina Feederle, Petra Bolte, Karl-Wilhelm Koch, Ilia A. Solov’yov, Henrik Mouritsen. Double-Cone Localization and Seasonal Expression Pattern Suggest a Role in Magnetoreception for European Robin Cryptochrome 4. Current Biology, 2018; 28 (2): 211 DOI: 10.1016/j.cub.2017.12.003