(June 17, 2015, The Auk: Ornithological Advances)—Among birds, the line between species is often blurry. Some closely related species interbreed where their ranges overlap, producing hybrid offspring that can even backcross with either parent species, until a whole population of mixed-species birds forms in the area and creates what’s known as a “hybrid zone.” In the coastal marshes of New England, this has been happening between two sparrows—Saltmarsh Sparrow and Nelson’s Sparrow. A new study published this week in The Auk: Ornithological Advances shows that appearance alone is not enough to identify these hybrid zone birds: there is no single, intermediate “phenotype” or physical appearance common to all of the first-generation hybrids found, and birds from further backcrossed generations were often indistinguishable from the parent species. Fifty percent of birds identified as “pure” Nelson’s or Saltmarsh Sparrows in the field turned out be the descendants of hybrids when their DNA was analyzed.

Jennifer Walsh and Adrienne Kovach of the University of New Hampshire, along with Gregory Shriver of the University of Delaware, Brian Olsen of the University of Maine, and Kathleen O’Brien of the U.S. Fish and Wildlife Service, collaborated on this project to capture and examine the birds in the hybrid zone on the coast of Maine, New Hampshire, and Massachusetts. Each bird was classified based on its appearance as a Saltmarsh Sparrow, Nelson’s Sparrow, or a hybrid, and then a blood sample was taken so that the accuracy of this identification could be double-checked with DNA.

“Hybridization between species is quite common in birds and we often assume that the hybrids are going to be obvious intermediates between parental species. By combining detailed data on each bird’s appearance with genetic data that clearly identifies hybrids, Walsh and her colleagues have nicely demonstrated that the world is much more complex and that, in the case of these sparrows, the number of hybrids is much higher than we previously knew. This result is particularly relevant given the threats that saltmarsh nesting birds currently face,” says Chris Elphick of the University of Connecticut, an expert on tidal marsh birds who was not involved with the study.

Walsh and her colleagues recommend that future studies of hybrid zone birds need to include DNA sampling to confirm field identifications. Both species are considered high priorities for conservation in the region, and the Saltmarsh Sparrow in particular is considered globally vulnerable to extinction. In order to ensure that both species have a secure future, the first step is making sure we know for certain which is which.

“Sampling for this study was a big undertaking,” says Walsh, who carried out the study as part of her Ph.D. work. “We sampled 34 sites, spanning about 750 km. Traveling to and accessing all the sites was logistically challenging and we had a lot of support from USFWS and other conservation partners. Every marsh is hugely different in terms of bird density and accessibility. You never really know what to expect until you get there—some days we would trap 10 birds in 2 hours, some days we would trap 2 birds in 12 hours! In general, salt marshes are challenging too—there are a lot of holes and mud and ditches, and you are always working around the tides. It is amazing how quickly the marsh changes—very accessible at low tide, but at high tide you can find yourself swimming back.”

Saltmarsh Sparrows (shown) produce hard-to-identify hybrids with Nelson’s Sparrows. Image credit: K. Papanastassiou

Relationship of phenotypic variation and genetic admixture in the Saltmarsh–Nelson’s sparrow hybrid zone is available at http://www.aoucospubs.org/doi/full/10.1642/AUK-14-299.1. Contact: Adrienne I. Kovach, adrienne.kovach@unh.edu.

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. In 2009, The Auk was honored as one of the 100 most influential journals of biology and medicine over the past 100 years, and it currently holds the top impact factor among ornithological journals.

(June 10, 2015, The Condor: Ornithological Applications)—We all like things that are bad for us sometimes, and birds are no different. When a bird or other animal makes choices that are actually harmful for it, by reducing their lifespan, reproductive success, or something else, this is known as an “evolutionary trap.” If birds prefer to build their nests in non-native plant species but these nests are less successful, they’ve fallen into such a trap. A group of researchers recently set out to determine whether this is the case for Veeries (Catharus fuscescens) nesting in invasive shrubs in the forests of New York.

Lydia Meyer and Bruce Robertson of Bard College, along with Kenneth Schmidt of Texas Tech University, monitored 84 Veery nests during the spring 2013 breeding season in a forest where invasive shrubs such as Japanese honeysuckle, barberry, and multiflora rose are abundant. They recorded a variety of characteristics related to nests’ location, including nest height and visibility, the type of plant a nest was placed in, and the type of vegetation within a 5-meter radius around the nest. Their results, published this week in The Condor: Ornithological Applications, show that while these Veeries did prefer to locate their nests in non-native plants, this choice didn’t hurt their nesting success at all.

“While it is disappointing that exotic understory plants are displacing their native counterparts in forests throughout the Northeastern U.S., it is encouraging to see that at least one native bird is able to find that these exotic replacements also make safe locations to place a nest,” says study author Bruce Robertson. The Veeries’ choice to nest in non-native shrubs wasn’t bad for them after all—instead, they were just taking advantage of a new suitable habitat.

“Meyer et al. provide a critical test of whether non-native plant species can act as ecological traps for nesting birds. Nest site preferences in birds evolve over time based upon nest survival rates in different habitats, and may be confounded by the novel cues introduced by non-native plants,” adds Anna Chalfoun of the University of Wyoming, an expert on wildlife–habitat relationships. “Interestingly, in the example of the Veery, Meyer et al. conclude that parents were able to exploit the novel nesting sites provided by non-native plants, with no apparent effects on the probability of nest survival.”

About the journal: The Condor: Ornithological Applications is a peer-reviewed, international journal of ornithology. The journal began in 1899 as the journal of the Cooper Ornithological Club, a group of ornithologists in California that became the Cooper Ornithological Society.

(The Condor: Ornithological Applications, May 6, 2015)—Shifting to renewable energy sources has been widely touted as one of the best ways to fight climate change, but even renewable energy can have a downside, as in the case of wind turbines’ effects on bird populations. In a new paper in The Condor: Ornithological Applications, a group of researchers demonstrate the impact that one wind energy development in Kansas has had on Greater Prairie-Chickens (Tympanuchus cupido) breeding in the area. Virginia Winder of Benedictine College, Andrew Gregory of Bowling Green State University, Lance McNew of Montana State University, and Brett Sandercock of Kansas State University monitored prairie-chicken leks, or mating sites, before and after turbine construction and found that leks within eight kilometers of turbines were more likely to be abandoned.

Leks are sites at which male prairie-chickens gather each spring to perform mating displays and attract females. The researchers visited 23 leks during the five-year study to observe how many male birds were present and to record the body mass of trapped males. After wind turbine construction, they found an increased rate of lek abandonment at sites within eight kilometers of the turbines as well as a slight decrease in male body mass. Lek abandonment was also more likely at sites where there were seven or fewer males and at sites located in agricultural fields instead of natural grasslands.

This paper is the latest in a series of studies on the effects of wind energy development on prairie-chickens. “To me, what is most interesting about our results is that we are now able to start putting different pieces of our larger project together to better understand the response of Greater Prairie-Chickens to wind energy development at our field site,” says study co-author Virginia Winder. “We have found that both male and female prairie-chickens have negative behavioral responses to wind energy development. The data we collected to monitor this response have also allowed us new insights into the ecology of this species. For example, lek persistence at our study site depended not only on distance to turbine, but also male numbers and habitat.”

The findings of this study reinforce the U.S. Fish and Wildlife Service recommendation that no new wind energy development should be done within an eight-kilometer buffer around active lek sites. “It is critical to have rigorous evaluations of direct and indirect effects of wind energy facilities on species such as prairie-chickens,” according to grassland wildlife management expert Larkin Powell, who was not involved with the research. “The potential for trade-offs between renewable energy and wildlife populations on the landscape is one of the key questions of our day.”

Responses of male Greater Prairie-Chickens to wind energy development is available at http://www.aoucospubs.org/doi/full/10.1650/CONDOR-14-98.1. Contact: Brett Sandercock, bsanderc@ksu.edu.

About the journal: The Condor: Ornithological Applications is a peer-reviewed, international journal of ornithology. The journal began in 1899 as the journal of the Cooper Ornithological Club, a group of ornithologists in California that became the Cooper Ornithological Society.

(May 6, 2015, The Auk: Ornithological Advances)—How to protect your chicks from predators? Build a dome over them! There is tremendous diversity among the nests of birds, in nest location, structure, materials, and more, but we know very little about the forces that shaped the evolution of this incredible variety. In a new paper published this week in The Auk: Ornithological Advances, Zachary Hall, Sally Street, Sam Auty, and Susan Healy of the University of St. Andrews in Scotland test the hypothesis that domed-shaped nests arose as a result of some species transitioning to nesting on the ground, where the risk from predators is greater.

Hall was completing his Ph.D. work on the neurobiology of nest-building behavior when he noticed that very little work had been done on trying to understand why different bird species build such drastically different nest structures. “I thought this was strange,” he explains, “because the shape of a nest seems to be the most striking and diverse feature across bird species.” The hypothesis that dome-shaped nests resulted from the increased predation risk when competition for nest sites led some birds to begin nesting on the ground was first proposed almost twenty years ago, but techniques at the time did not provide a way to test it. Applying statistical techniques he had previously used in his neurobiology study, Hall and his colleagues collected previously published descriptions of the nests of 155 species of babbler and mapped nest height and structure to the birds’ family tree.

Their analysis confirmed that babblers’ ancestors likely built above-ground, cup-shaped nests, and that the addition of a dome to cover the nest corresponded with switching to nesting at ground level. “This new study by Hall, Street, Auty, and Healy looks at the evolution of two key aspects of animals as architects: how they shape their homes and where they put them. It shows very nicely how we can take advantage of recent progress in avian phylogenetics to test ideas about the evolutionary history behind the modern-day co-occurrence of particular pairs of traits,” according to Don Dearborn, an expert in the evolution of reproductive strategies in birds. “I am very happy how well nest structure integrated into our analyses, but this study is only the tip of the iceberg, and we hope future work can use a similar approach to identify other factors that may have influenced the evolution of nest structure,” adds Hall.

The coevolution of building nests on the ground and domed nests in Timaliidae is available at http://www.aoucospubs.org/doi/full/10.1642/AUK-15-23.1. Contact: Zachary J. Hall, zach.hall@utoronto.ca.

About the journal: The Auk: Ornithological Advances is a peer-reviewed, international journal of ornithology. The journal has been the official publication of the American Ornithologists’ Union since 1884. In 2009, The Auk was honored as one of the 100 most influential journals of biology and medicine over the past 100 years, and currently holds the top impact factor among ornithological journals.

(April 22, 2015, The Condor: Ornithological Applications)—How aware are you of the birds that live in your neighborhood? Do you know how many different species there are? Do enjoy your local birds, or find them annoying? J. Amy Belaire of St. Edward’s University, Lynne Westphal of the U.S. Forest Service, and Emily Minor and Christopher Whelan of the University of Illinois at Chicago visited urban neighborhoods in the Chicago area to answer these questions and learn more about how people see their backyard birds. Their results, published in a new paper in The Condor: Ornithological Applications, provide a fascinating look at the relationship between people and nature in a city setting.

Belaire and her colleagues surveyed the breeding birds in 25 neighborhoods adjacent to forest preserves in Cook County, Illinois, recording a total of 36 species, and sent questionnaires to the families in each neighborhood. While most people were excited to participate in a scientific study, according to Belaire, someone looking through binoculars in a residential neighborhood is bound to attract some attention; “The police were called several times to check up on us,” she says.

The researchers found that residents’ feelings toward birds were generally very positive, although a few people found bird droppings, nests in gutters, and other nusiances to be annoying, especially in neighborhoods where specific problem birds such as House Sparrows and Common Grackles were more abundant. Though the questionnaire asked respondents to estimate how many bird species were found around their homes, there was no relationship between residents’ perceptions of bird diversity and the actual species numbers observed in the bird surveys. Instead, the more favorable someone’s feelings about local birds, the more species they guessed were present.

“The interdisciplinary approach for this study stemmed from the knowledge that many of today’s pressing environmental questions can’t be answered by a single discipline alone,” says Belaire. “The social surveys helped shed light on the many things people value about birds in the neighborhood, especially the birds’ aesthetic qualities and the role they play in local ecosystems. Although residential neighborhoods in our study sites had surprisingly high bird diversity, we found that people didn’t seem to be entirely aware of this biodiversity.” The researchers suggest that programs such as citizen science projects can increase people’s awareness of their neighborhoods’ avian diversity. Even though the results showed a range of individual awareness of birds, this study reinforces the idea that birds are an important point of connection between city dwellers and the natural world.

Urban residents’ perceptions of birds in the neighborhood: Biodiversity, cultural ecosystem services, and disservices is available at http://www.aoucospubs.org/doi/full/10.1650/CONDOR-14-128.1. Contact: J. Amy Belaire, jbelaire@stedwards.edu.

About the journal: The Condor: Ornithological Applications is a peer-reviewed, international journal of ornithology. The journal began in 1899 as the journal of the Cooper Ornithological Club, a group of ornithologists in California that became the Cooper Ornithological Society.

(April 8, 2015, The Auk: Ornithological Advances)—After decades in ornithological obscurity, one of the world’s least-known birds is finally coming to light thanks to the persistence of a small group of researchers. Pablo Negret, Oscar Garzón, Pablo Stevenson, and Oscar Laverde-R. of the Universidad de los Andes have just published the results of their year-long study of the Black Tinamou (Tinamus osgoodi hershkovitzi) in The Auk: Ornithological Advances, including new ecological information as well as some of the first video and sound recordings of this elusive species.

The Black Tinamou is a chicken-sized bird found in the foothills of the eastern Andes, where it lives in tall, dense primary forest. It is extremely difficult to observe due to its secretive habitats and cryptic coloration. For their study, Negret and his colleagues focused on the southern Colombia subspecies, doing daily censuses in Alto Fragua Indi Wasi National Park, recording vocalizations, and setting up camera traps to capture images and video.

“The most challenging part of the fieldwork was the 4 to 6 kilometer walk along the transect’s steep trails each morning, from 800 to 1600 meters above sea level. However, these walks also gave me extraordinary moments like the observation of a Puma concolor along the trail or the moment when I had the chance to photograph the elusive Tinamus osgoodi after almost 9 months of trying,” says Negret. Through their observations, he and his colleagues were able to determine that Black Tinamous likely breed in March and April (when their vocal activity peaks), are most active in late morning, and eat primarily fallen fruit and seeds.

Black Tinamous live in an area where they are threatened by logging, cattle ranching, and hunting, and this study is an important step forward in gathering the information needed to effectively protect them. “Tinamous are widespread in Central and South America, and yet we know very little about the ecology and general biology of most species,” according to Patricia Brennan, a University of Massachusetts Amherst professor and tinamou expert. “However, tinamous are ancient birds, with a combination of many unique traits that include male parental care, female communal egg laying, and some of the most beautiful and conspicuous eggs in nature. The authors of this paper have gathered new information about one of the least-known tinamou species, and therefore they contribute significantly to our knowledge of this fascinating group of birds.”

New ecological information for the Black Tinamou (Tinamus osgoodi hershkovitzi) is available at http://www.aoucospubs.org/doi/full/10.1642/AUK-14-116.1. Contact: Pablo J. Negret, pablo.tiputini@hotmail.com.

About the journal: The Auk: Ornithological Advances is a peer-reviewed, international journal of ornithology. The journal has been the official publication of the American Ornithologists’ Union since 1884. In 2009, The Auk was honored as one of the 100 most influential journals of biology and medicine over the past 100 years, and currently holds the top impact factor among ornithological journals.

(March 11, 2015, The Auk: Ornithological Advances)— From museum drawers to the new species list: tapaculos add to the biodiversity of the New World tropics! After being misidentified and sitting in a museum drawer for more than seventy years, a group of bird specimens collected in Colombia and Venezuela has been determined to represent a previously unknown species, now dubbed the Perijá Tapaculo (Scytalopus perijanus). In a new paper in The Auk: Ornithological Advances, Jorge Avendaño of the Universidad de los Llanos and his colleagues describe how the Perijá Tapaculo differs from the other birds in its genus in its genetics, appearance, ecology, and vocalizations.

Tapaculos are a family of mostly small black or brown songbirds found in South and Central America, which forage for insects in grasslands and forest undergrowth. In 1941 and 1942, ornithologist Melbourne Carriker, Jr. explored the western slope of the Serranía de Perijá mountain range on the Colombian–Venezuelan border, where he collected 27 tapaculo specimens and sent them to the Smithsonian. At the time, they were mistakenly identified as Scytalopus atratus nigricans, a similar bird found at lower elevations, and in the following decades these upper montane tapaculos remained overlooked and unstudied.

In 2008 and 2009, however, a new set of specimens and sound recordings was collected in the same region visited by Carriker, and Dr. Avendaño and his colleagues were able to conduct a genetic analysis as well as analyzing the birds’ appearance and calls. The newly-named Perijá Tapaculo is a small bird with a buffy belly, gray back, and brown nape, and its song and calls are distinctly different from those of other tapaculos. Its high level of genetic divergence from its closest relatives suggests that that its high mountain habitat has isolated it from its cousins for a significant amount of time. “While it was known that two species occurred in the Perijá mountains, it was a distinct surprise that the upper elevational form differs as much as 8–9% from its closest relatives,” says tapaculo expert Niels Krabbe. “This emphasizes the importance of the Perijá mountains as an evolutionary center, and calls for further studies of its flora and fauna.”

Unfortunately, due to habitat loss in the region, this new species is already in trouble. “The species is more seriously threatened on the Colombian slope than on the Venezuelan slope because its habitat is protected by a large National Park in Venezuela,” explains Dr. Avendaño. “So, we recommend establishing a new national park or a network of reserves in Colombia connected to the Sierra de Perijá National Park of Venezuela. This binational park is necessary in order to effectively preserve the high species diversity and endemism of birds and other biological groups of the region.”

A new species of tapaculo (Rhinocryptidae: Scytalopus) from the Serranía de Perijá of Colombia and Venezuela is an open-access article available at http://www.aoucospubs.org/doi/full/10.1642/AUK-14-166.1. Contact: Jorge Enrique Avendaño, jorgeavec@gmail.com.

About the journal: The Auk: Ornithological Advances is a peer-reviewed, international journal of ornithology. The journal has been the official publication of the American Ornithologists’ Union since 1884. In 2009, The Auk was honored as one of the 100 most influential journals of biology and medicine over the past 100 years, and currently holds the top impact factor among ornithological journals.

(January 21, 2015, The Condor: Ornithological Applications)—The Grenada Dove (Leptotila wellsi) is a critically endangered bird found only on the island of Grenada. Past surveys of its population have found only 68-91 calling males (or 136-182 individuals, if they were all paired with females)—but is that accurate? For a new open-access study published in The Condor: Ornithological Applications, Frank Rivera-Milán of the U.S. Fish and Wildlife Service and his colleagues visited a systematic grid of points in Grenada Dove habitat, with the goals of improving survey methods and identifying dove association with habitat features. They detected 160 individuals, plus or minus about 30. According to their results, doves were easiest to detect in early morning and late afternoon, and they were more abundant in areas with plenty of food and vegetation cover and less abundant in disturbed areas. The authors recommend that their survey method could be used to assess the dove population’s response to management strategies such as forest restoration and the removal of non-native predators. Read the open-access paper at http://www.aoucospubs.org/doi/full/10.1650/CONDOR-14-131.1.

(January 14, 2015, The Auk: Ornithological Advances)—Songs and calls aren’t the only sounds birds make. Some, such as the Greater Sage-grouse (Centrocercus urophasianus), also produce mechanical sounds called “sonations” with their feet, feathers, or bills. But do the mechanical “swishes” of male sage-grouse affect their mating success? In a new open-access study published in The Auk: Ornithological Advances, Rebecca Koch of Auburn University and Alan Krakauer and Gail Patricelli of the University of California-Davis reveal that male sage-grouse are most attractive to females when they increase the intensity of their swishing display as females get closer.

For two years, Koch and her colleagues observed and recorded the behavior of male sage-grouse on a breeding ground or “lek” in Wyoming, using microphones and video cameras to record the sounds they made and to keep track of which males got the most mating action. While the effects of the males’ vocalizations on their success had already been studied, the effect of their mechanical swishing noises had not, so the researchers identified which swishes on the sound recordings were produced by which individual birds in the videos and then analyzed whether there was any relationship between the acoustic qualities of the swishes and how many copulations each male achieved.

They found that males definitely varied in the length and frequency range of their swish displays, but these variations did not appear to have any direct effect on their mating success–it was all in the timing. The males that did the best were those who adjusted their displays as the social environment of the lek changed, upping the frequency ranges of their swishes when females got closer. This closely aligns with the results of a previously published study that found that successful males displayed at a higher rate when females approached, and the most successful were able to increase their display rate without any trade-off in display quality. The take-away message is that males track nearby females to display most intensely when it really matters.

“As researchers interested in sexual selection, it is easy for us to assume that all traits involved in mating displays are used as criteria in female mate choice,” explains Ms. Koch. “However, in sage-grouse, it appears that the tactical adjustment of displays as females approach is more important in soliciting mates than is display quality in itself.” Dr. Kimberly Bostwick of Cornell University, an editor at The Auk who studies sonation in manakins and was not involved in conducting the study, adds that this study “places a foundational stone for future work comparing sonations to vocal signals.” The functions of mechanical sounds in courtship are just beginning to be understood, and this paper is an important first step.

“Investigating female mate choice for mechanical sounds in the male Greater Sage-Grouse” is an open-access article that can be viewed at http://www.aoucospubs.org/doi/full/10.1642/AUK-14-63.1. Contact: Rebecca Koch, rek0005@auburn.edu.

About the journal: The Auk: Ornithological Advances is a peer-reviewed, international journal of ornithology. The journal has been the official publication of the American Ornithologists’ Union since 1884. In 2009, The Auk was honored as one of the 100 most influential journals of biology and medicine over the past 100 years, and currently holds the top impact factor among ornithological journals.