It’s go time for Hawaiian bird conservation, and luckily there’s a playbook

Condor-18-25_'I'iwi_Lucas Behnke

‘I’iwi (Photo credit: Lucas Behnke)

A new study in The Condor: Ornithological Applications presents some of the best guidance to date on the priorities and actions that can be taken to help Hawaii’s endemic birds. Hawaii’s ecosystems, including its native bird populations, are struggling. Of the 21 species of forest birds left on the islands, almost two thirds (12 species) of are endangered or threatened. The current conservation status of the wildlife and vegetation on the island is almost entirely attributable to humans. The actions needed to stabilize or reverse these trends need stronger support and coordination, however funding and resources are limited. This new paper lays out a plan to better guide and empower conservation efforts for Hawaiian birds.

Eben Paxton of USGS Pacific Island Ecosystems Research Center and colleagues synthesized the key points that came out of a collaboration of more than 60 stakeholders in Hawaiian bird conservation. The focus is on actionable research and management approaches that can be employed today. Habitat loss, invasive plants, non-native predators, and introduced diseases were identified as the largest threats to Hawaiian birds. Climate change is projected to exacerbate all threats. Given limited resources, the stakeholders decided on eight main priorities as well as several actions specific to the island of Kauai. In addition to helping Hawaii and its birds directly, the goal of this collaborative report is to make Hawaii a model for other areas of the world, especially islands, that are in need of strong conservation efforts.

Lead author, Eben Paxton comments, “Our challenge in Hawaii is how do we conserve forest birds from multiple threats with just a fraction of the resources needed to fully address all the threats. Our solution was to bring researchers and managers together to share ideas, and as a community, identify priority research and management needs necessary to save these unique species. We believe these priorities will help focus resources where most needed and bring together different organizations to work together for the maximum benefit of the birds.”

“New Technology is being proposed to help stem the tide of extinctions in Hawaiian native birds. Eben Paxton and his co-authors recognize that all the native birds in Hawaii are Conservation Reliant Species and propose utilizing new technologies to assist with the preservation of this unique island avifauna,” adds Charles van Riper III, a ST Research Ecologist and Professor Emeritus, USGS and SNRE, University of Arizona. “This very complete paper also recommends enhancing Citizen Science and captive breeding in the Islands, along with continued monitoring and translocations to unoccupied habitat. The immediate target for this plan are the birds on Kauai – the authors feel that the native avifauna on this island is rapidly approaching extinction, and time will tell how successful this proposed plan is in implementing conservation actions in time to save these unique birds.”

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Research and management priorities for Hawai’i forest birds is available at http://www.bioone.org/doi/full/10.1650/CONDOR-18-25.1.
Research contact: Eben Paxton, epaxton@usgs.gov

About the journal: The Condor: Ornithological Applications is a peer-reviewed, international journal of ornithology published by the American Ornithological Society. The journal began in 1899, and in 2016 The Condor had the number one impact factor among 24 ornithology journals.

 

When You’re a Sitting Duck, You Learn to Adapt

AUK-17-239_common loon_Linda Grenzer

Common Loon on nest dealing with black flies (Photo credit: Linda Grenzer)

When sitting on a nest to incubate eggs, a bird is physically stuck and most vulnerable to attacks of any kind, so coping without stress and other significant costs is important. For Common Loons, black flies are a common blood-feeding pest and can cause nest abandonment and decreased fledging rates. This has impacts on not only individual pair success, but on population dynamics as well. A new study from The Auk: Ornithological Advances presents some of the best data to date supporting hypotheses about the effects that black flies have on Common Loon nesting behavior and success.

Chapman University’s Walter Piper and colleagues monitored Common Loon nests for 25 years in northern Wisconsin, USA. They marked individuals to track each bird’s behavior, nesting success, and interaction with black flies. More than 2,050 nests were included in the study to apply the impacts of black flies on loons’ population level. If the black fly concentration around an individual bird was high or there was a particularly intense fly outbreak year, loon incubation time decreased and nest abandonment increased. It was discovered that nest abandonment could be predicted using lake size, female age, and wind. The team found that the smaller the lake, the older the female, and the greater the distance across water that wind has to travel to reach the nest the more likely the nest will be abandoned. The cost associated with severe black fly outbreaks appears to be high enough that a nest can be abandoned and a second attempt made following the peak of the outbreak. The second nest is likely to be in the original location unless a predator destroyed the nest. In that case, the pair is more likely to choose a new and hopefully safer nest site.

Lead author Walter Piper comments, “Black flies, which we think of as a nuisance and no more, actually impact population reproductive success. This was a matter of studying an animal for 25 years and almost ignoring one aspect of their biology — until you finally look straight at that aspect of biology and realize it’s crucially important! Loons get slammed by black flies, but they make a very good response by reusing the nest sites where the flies hounded them, instead of abandoning those sites altogether — as they do when raccoons get their eggs. This makes sense, because the raccoons are their main enemies (that is, egg predation is a more severe problem then black flies), and a safe nesting site from raccoons is a vital resource.”

“This study is one of the first that examines the negative influence of black flies on a population of birds rather than on individuals alone. Perhaps more importantly, by studying a marked population of loons for almost a quarter century, it is possible to determine the stochastic influence of black fly outbreaks on the population as well as understand the nuances of how these mechanisms might work,” adds Jeb Barzen, an ecologist with Private Lands Conservation, who was not involved with this study. “Black flies severely reduce reproductive effort of loons periodically but not every year, a finding that is important to understanding the population dynamics of this iconic species. The more subtle examination of individual response to black flies provides insight into differences in how males and females, as well as individuals in different habitats and individuals of different ages, respond to black fly infestations. Collectively these results inform ecologists and managers alike in issues relevant to the conservation of loon populations and other long-lived, territorial bird species.”

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Common Loons respond adaptively to a parasite that impacts nesting success is available at http://www.bioone.org/doi/full/10.1642/AUK-17-239.1
Researcher contact: Walter Piper, wpiper@chapman.edu

About the journal: The Auk: Ornithological Advances is a peer-reviewed, international journal of ornithology published by the American Ornithological Society. The Auk commenced publication in 1884, and in 2009 was honored as one of the 100 most influential journals of biology and medicine over the past 100 years.

Original habitat is best, but restoration still makes a big difference

CONDOR-17-189_YBCHnest_Melissa C. Roach

Yellow-breasted Chat nest with chicks. (Photo Credit: Melissa C. Roach)

A new study in The Condor: Ornithological Applications presents some of the best evidence to date that restoration efforts in Missouri’s Ozark Highlands make a difference for nesting songbirds that breed there. The reduction of Missouri pine savannah and woodland areas has caused birds that rely on these habitats to decline. Current efforts to bring these habitats back are under way and include prescribed fire and thinning tree stands. Recent studies support that these efforts are making a positive impact on the ecosystem and increasing the survival of bird species that breed there.

Melissa Roach of the University of Missouri and colleagues investigated the relationship between daily nest survival and habitat and restoration efforts. Her team studied six species comprising two groups: shrub-nesters and canopy-nesters. Eastern Towhee, Prairie Warbler, and Yellow-breasted Chat were representative of shrub-nesting species, while canopy-nesting species included Eastern Wood-Pewee, Pine Warbler, and Summer Tanager. After monitoring nests for two years, researchers found that predation was the number one cause of nest failure. Current restoration efforts (fire and tree thinning) directly influenced the ground layer of vegetation. This changed the cover available to both hunting predators and hiding prey, changing the predator–prey dynamics. Thus, restoration efforts and maintaining a varied landscape for wildlife is important for the success of these songbirds.

Lead author Melissa Roach comments, “We found strong results that should help guide land managers when it comes to important management decisions regarding the restoration and maintenance of rare or sensitive habitats. Not only were we able to show that these species are responding positively to pine woodland restoration, we provided baseline nest survival data for some understudied species. We also hope that this study increases the public’s awareness and appreciation of just how important prescribed fire and tree thinning can be for wildlife.”

“As the Coordinator of the Central Hardwoods Joint Venture, the regional partnership guiding bird conservation across the Ozarks and Interior Low Plateaus ecoregions, I find it gratifying to see research showing that the restoration of fire-dependent natural communities like shortleaf pine woodlands has such a positive effect on populations of bird species of conservation concern,” adds Jane Fitzgerald, of the American Bird Conservancy and Central Hardwoods Joint Venture Coordinator. “While we have, in the past, focused much of our planning on increasing carrying capacity by increasing the amount of high-quality habitat available to a species, we are learning that it’s just as important to evaluate how management impacts the vital rates that drive population growth. I hope we see more and more research that provides that kind of ‘big picture’.”

 

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Songbird nest success is positively related to restoration of pine–oak savanna and woodland in the Ozark Highlands, Missouri, USA is available at http://www.bioone.org/doi/full/10.1650/CONDOR-17-189.1.
Research contact: Melissa C. Roach, roach.mc1@gmail.com

About the journal: The Condor: Ornithological Applications is a peer-reviewed, international journal of ornithology published by the American Ornithological Society. The journal began in 1899 and in 2016 The Condor had the number one impact factor among 24 ornithology journals.

For Disappearing Bicknell’s Thrushes, Statistical Models are Lifesavers

Bicknell's Thrush, East Mt, Vermont

Bicknell’s Thrush (Photo Credit: Steve Faccio)

Bicknell’s Thrush has been identified as a globally vulnerable Nearctic-Neotropical migratory bird in need of serious conservation efforts. This species travels each year between its breeding grounds in the Canadian maritime provinces and upper northeastern United States and its winter home in the Greater Antilles. Males and females use different habitats in winter, with females preferring middle elevation forests that are more vulnerable to human disturbance than the higher, more remote forests used by males.   A new study from The Condor: Ornithological Applications identifies key habitat for females in the remaining fragmented montane wet forests of the Dominican Republic.

“Today’s multiple environmental threats and stressors (e.g., deforestation, predation by invasive species, climate change, bioaccumulation of heavy metal pollutants, etc.) are crafting an uncertain future for species with complex life cycles in their breeding grounds, stopover sites, and wintering grounds,” adds Eduardo E. Ingio Elias, a senior research associate of the Cornell Lab of Ornithology who was not involved with this research. “However, to conserve key suitable habitat for any species, ornithologists and land managers need to identify where that habitat is, what the population survival is within that habitat, and what threats birds face there.”

Vermont Center for Ecostudies scientist Kent McFarland and colleagues used a combination of field and GIS methods to predict areas that would be the best to conserve for Bicknell’s Thrushes. A model to predict Bicknell’s Thrushes’ distribution and habitat use was created using occurrence data and environmental variables collected from field surveys, combined with land cover data from remote sensing. Thrush presence and abundance in an area was best predicted by the combination of elevation (densities peaked at ~600 m), aspect (northeastern slopes), the amount of forest cover within 1 km, and forest density.

Lead author Kent McFarland emphasizes the importance of this work, which has demonstrated putting research into conservation action, “We used our results to help identify, purchase, and create the Dominican Republic’s first-ever private reserve, the 400-ha Reserva Privada Zorzal, where 70% of the land is to be forest and ‘forever wild’ while the remainder is for compatible crops such as organic chocolate. We are hoping that our work will be used to identify and prioritize additional lands for conservation of the Bicknell’s Thrush in the region and elsewhere.”

 

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Modeling spatial variation in winter abundance to direct conservation actions for a vulnerable migratory songbird, the Bicknell’s Thrush (Catharus bicknelli) is available at http://www.bioone.org/doi/full/10.1650/CONDOR-17-234.1.
Research contact: Kent McFarland, kmcfarland@vtecostudies.org

About the journal: The Condor: Ornithological Applications is a peer-reviewed, international journal of ornithology published by the American Ornithological Society. The journal began in 1899 and in 2016 The Condor had the number one impact factor among 24 ornithology journals.

For flickers, looks can be deceiving

Northern Flicker (male)

Red-shafted Flicker (Photo Credit: Glenn Lahde)

The North American woodpeckers known as “flickers” stand out for their distinctive wing and tail feathers of bright reds or yellows, and for their rampant interbreeding where these birds of different colors meet in the Great Plains. Despite the obvious visual differences between the Red-shafted Flicker of the west and the Yellow-shafted Flicker of the east, scientists have never before found genetic differences between them. A new study from The Auk: Ornithological Advances uses data from thousands of regions across the genome to distinguish these birds molecularly for the first time.

Stepfanie Aguillon and her colleagues at the Cornell Lab of Ornithology explored patterns across the genomes of these birds and find them to be incredibly similar at the molecular level. In spite of the strong similarity, they still have the ability to distinguish the western Red-shafted Flickers from the eastern Yellow-shafted Flickers for the first time through the use of new genomic methods. Genomic technology is advancing at such a rapid rate that genetic sequence differences that were undetectable in the 1980s using (then) cutting-edge methods are now readily apparent using next-generation sequencing techniques.

“Flickers have intrigued ornithologists and naturalists at least as far back as Audubon, but only recently has it become possible to understand these birds genomically,” says lead author Stepfanie Aguillon. “I was unsure what we would find, given how much trouble previous researchers have had with these birds. I was surprised—and excited—by how similar we found them to be since we now had thousands of markers across the genome. I think this paper underlies a theme that has become more and more apparent over the last few years—even when two birds look very different, they may not be very different genetically.”

“The hybrid zone between the yellow- and red-shafted flickers is particularly striking, but despite very apparent morphological and ecological differences, genetic studies beginning in the late 1980s found few differences between these two ‘subspecies,’” adds flicker expert William S. Moore, a Wayne State University professor who was not involved with this research. “Hybrid zones are often described as “natural laboratories” for studies on speciation. Despite the low level of genetic divergence across the flicker hybrid zone, it is certain that selection is operating on genes involved in plumage divergence and ecological adaptation. Aguillon’s study will be a foundation stone for studies that identify the adapted genes and will bring us to a new understanding of the processes of speciation.”

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A flicker of hope: Genomic data distinguish Northern Flicker taxa despite low levels of divergence is available at http://www.bioone.org/doi/full/10.1642/AUK-18-7.1
Researcher contact: Stepfanie M. Aguillon, sma256@cornell.edu

About the journal: The Auk: Ornithological Advances is a peer-reviewed, international journal of ornithology published by the American Ornithological Society. The Auk commenced publication in 1884, and in 2009 was honored as one of the 100 most influential journals of biology and medicine over the past 100 years.

Whiskered Auklets Lack Wanderlust, Are Homebodies Instead

Auk-17-235_Whiskered Auklet_Ian Jones

Whiskered Auklet (Photo Credit: Ian Jones)

A new study from The Auk: Ornithological Advances presents some of the best evidence that Whiskered Auklets are an outlier in the auklet family by not migrating and instead staying close to “home” (their breeding colonies) year-round. Most migratory birds lead two opposite lifestyles in the same year. During the breeding season a bird’s location is constrained and their habits are repetitive given a nest full of chicks that require food, warmth, and protection. For some birds it is the only time they congregate or otherwise come together. Comparatively, during the non-breeding season their only true task is to survive. Whether migratory or residential, as long as the bird makes it back to the breeding grounds to reproduce, they can go almost wherever they want. Whiskered Auklets are consistent through the year though and don’t wander far at all.

Carley Schacter and Ian Jones of Memorial University of Newfoundland used light-based archival geolocation tags on Whiskered Auklets in Buldir Island, Aleutian Islands, Alaska, to determine the locations of their full annual life cycle. The data they collected corroborated what researchers have long suspected. This species is unique in the auklet family for not migrating at all. Most seabirds roost on the water at night, but Whiskered Auklets stay in the vicinity of the breeding colony year-round and consistently return to roost at night on land. Such behavior may not only be unique to auklets, but to the entire seabirds group. How could this unusual adaptation have come about? Whiskered Auklets capitalize on the foraging habitat close to their breeding colony which reduces metabolic costs. Given the influence of tradeoffs on animal behavior and life history strategies, this foraging area could be a large contributor to their residential behavior.

But there are risks to this strategy as well. Lead author Carley Schacter notes, “While this non-migratory behavior is very interesting to us on a theoretical level, there are also important implications for the conservation and management of this most vulnerable of auklet species. Year-round residence near the breeding site (an area of high fishing and shipping traffic) makes Aleutian-breeding Whiskered Auklets even more exposed than previously thought to human threats such as oil/fuel spills and light attraction leading to fatal collisions with vessels. Their nocturnal roosting behavior also makes them especially vulnerable to introduced mammalian predators such as rats and foxes.”

“The authors found evidence for an almost unique adaptation of a seabird in a remote, difficult-to-work-in, and isolated environment,” adds Jeff Williams, Assistant Refuge Manager at the Alaska Maritime National Wildlife Refuge, who was not involved with this research. “We now know that Whiskered Auklets are particularly sensitive to human-caused disturbances (oil spills, light attraction, invasive species introductions etc.) and can incorporate this information into management planning.”

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Confirmed year-round residence and land roosting of Whiskered Auklets (Aethia pygmaea) at Buldir Island, Alaska is available at http://www.bioone.org/doi/full/10.1642/AUK-17-235.1
Researcher contact: Carley R. Schacter, crs634@mun.ca

About the journal: The Auk: Ornithological Advances is a peer-reviewed, international journal of ornithology that began in 1884 as the official publication of the American Ornithologists’ Union, which merged with the Cooper Ornithological Society in 2016 to become the American Ornithological Society. In 2009, The Auk was honored as one of the 100 most influential journals of biology and medicine over the past 100 years.