Mountain Lake Biological Station

Apple Mountain Lake, VA, United States

Mountain Lake Biological Station

Apple Mountain Lake, VA, United States

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News Article | May 17, 2017
Site: www.eurekalert.org

Male birds that have already paired up with a female aren't above looking for a little action on the side. A new study from The Auk: Ornithological Advances explores how male juncos adjust their courtship behavior to their social landscape, finding that while both paired and unpaired males will try to get the attention of a new female on their turf, they go about it in different ways. A male bird's courtship behavior can be affected by factors like his size and hormone levels, but ornithologists are increasingly realizing that social context--whether or not the male already has a mate, and what other birds are around to witness his exploits--also plays a role. Dustin Reichard of Ohio Wesleyan University (formerly Indiana University) and his colleagues set out to tease apart the roles these different issues play in the courtship of Dark-eyed Juncos, comparing how unpaired males, paired males whose mates were present, and paired males whose mates were elsewhere behaved when presented with a new female. They found that paired males approached females more rapidly, spent more time close to the females, were more active, and spent more time with their body feathers erect than unpaired males. Paired males also sang fewer long-range songs than their single counterparts, perhaps not wanting other birds to overhear, although the actual presence or absence of their mates didn't affect their behavior. Reichard had noticed variation in male juncos' behavior during previous work to record their courtship songs, which led him to start developing hypotheses about what might underlie those differences. "Our results highlight the importance of considering both intrinsic and extrinsic factors when investigating the causes of variation in male courtship behavior," says Reichard. "The focus of the field has generally been intrinsic factors, such as male condition or circulating hormone levels, but our results suggest a potential role for eavesdroppers and social context in addition to condition-dependent factors." Reichard and his colleagues conducted their experiments at Mountain Lake Biological Station in Virginia, placing caged female juncos in front of free-living males and observing the males' reactions. After each trial, the researchers captured the male to record his size and weight and take a blood sample. "Often the male's mate would respond aggressively to the caged female, diving at the cage while pausing occasionally to chase her mate away from the area. The males were usually shameless during this process and continued to approach while singing and displaying, but to our knowledge none of the pairs in our study divorced as a result of this brief infidelity," says Reichard. "People called me a 'junco homewrecker' during these experiments, but there's little evidence to support that accusation." In the future, Reichard hopes to explore the possibility that males use different strategies to target potential social mates--females they'll raise chicks with--versus "extrapair" mates. According to Auburn University's Geoffrey Hill, an expert on mate choice in birds who was not involved in the research, "This study shows the potential for extremely complex behavioral interactions in birds that were long thought to be bland monogamists." "Condition- and context-dependent factors are related to courtship behavior of paired and unpaired males in a socially monogamous songbird" will be available May 17, 2017, at http://americanornithologypubs. (issue URL http://americanornithologypubs. ). 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.


News Article | May 17, 2017
Site: www.sciencedaily.com

Male birds that have already paired up with a female aren't above looking for a little action on the side. A new study from The Auk: Ornithological Advances explores how male juncos adjust their courtship behavior to their social landscape, finding that while both paired and unpaired males will try to get the attention of a new female on their turf, they go about it in different ways. A male bird's courtship behavior can be affected by factors like his size and hormone levels, but ornithologists are increasingly realizing that social context -- whether or not the male already has a mate, and what other birds are around to witness his exploits -- also plays a role. Dustin Reichard of Ohio Wesleyan University (formerly Indiana University) and his colleagues set out to tease apart the roles these different issues play in the courtship of Dark-eyed Juncos, comparing how unpaired males, paired males whose mates were present, and paired males whose mates were elsewhere behaved when presented with a new female. They found that paired males approached females more rapidly, spent more time close to the females, were more active, and spent more time with their body feathers erect than unpaired males. Paired males also sang fewer long-range songs than their single counterparts, perhaps not wanting other birds to overhear, although the actual presence or absence of their mates didn't affect their behavior. Reichard had noticed variation in male juncos' behavior during previous work to record their courtship songs, which led him to start developing hypotheses about what might underlie those differences. "Our results highlight the importance of considering both intrinsic and extrinsic factors when investigating the causes of variation in male courtship behavior," says Reichard. "The focus of the field has generally been intrinsic factors, such as male condition or circulating hormone levels, but our results suggest a potential role for eavesdroppers and social context in addition to condition-dependent factors." Reichard and his colleagues conducted their experiments at Mountain Lake Biological Station in Virginia, placing caged female juncos in front of free-living males and observing the males' reactions. After each trial, the researchers captured the male to record his size and weight and take a blood sample. "Often the male's mate would respond aggressively to the caged female, diving at the cage while pausing occasionally to chase her mate away from the area. The males were usually shameless during this process and continued to approach while singing and displaying, but to our knowledge none of the pairs in our study divorced as a result of this brief infidelity," says Reichard. "People called me a 'junco homewrecker' during these experiments, but there's little evidence to support that accusation." In the future, Reichard hopes to explore the possibility that males use different strategies to target potential social mates -- females they'll raise chicks with -- versus "extrapair" mates. According to Auburn University's Geoffrey Hill, an expert on mate choice in birds who was not involved in the research, "This study shows the potential for extremely complex behavioral interactions in birds that were long thought to be bland monogamists."


News Article | May 17, 2017
Site: phys.org

A male junco reacts to the site of a caged female. Credit: J. Welklin Male birds that have already paired up with a female aren't above looking for a little action on the side. A new study from The Auk: Ornithological Advances explores how male juncos adjust their courtship behavior to their social landscape, finding that while both paired and unpaired males will try to get the attention of a new female on their turf, they go about it in different ways. A male bird's courtship behavior can be affected by factors like his size and hormone levels, but ornithologists are increasingly realizing that social context—whether or not the male already has a mate, and what other birds are around to witness his exploits—also plays a role. Dustin Reichard of Ohio Wesleyan University (formerly Indiana University) and his colleagues set out to tease apart the roles these different issues play in the courtship of Dark-eyed Juncos, comparing how unpaired males, paired males whose mates were present, and paired males whose mates were elsewhere behaved when presented with a new female. They found that paired males approached females more rapidly, spent more time close to the females, were more active, and spent more time with their body feathers erect than unpaired males. Paired males also sang fewer long-range songs than their single counterparts, perhaps not wanting other birds to overhear, although the actual presence or absence of their mates didn't affect their behavior. Reichard had noticed variation in male juncos' behavior during previous work to record their courtship songs, which led him to start developing hypotheses about what might underlie those differences. "Our results highlight the importance of considering both intrinsic and extrinsic factors when investigating the causes of variation in male courtship behavior," says Reichard. "The focus of the field has generally been intrinsic factors, such as male condition or circulating hormone levels, but our results suggest a potential role for eavesdroppers and social context in addition to condition-dependent factors." Reichard and his colleagues conducted their experiments at Mountain Lake Biological Station in Virginia, placing caged female juncos in front of free-living males and observing the males' reactions. After each trial, the researchers captured the male to record his size and weight and take a blood sample. "Often the male's mate would respond aggressively to the caged female, diving at the cage while pausing occasionally to chase her mate away from the area. The males were usually shameless during this process and continued to approach while singing and displaying, but to our knowledge none of the pairs in our study divorced as a result of this brief infidelity," says Reichard. "People called me a 'junco homewrecker' during these experiments, but there's little evidence to support that accusation." In the future, Reichard hopes to explore the possibility that males use different strategies to target potential social mates—females they'll raise chicks with—versus "extrapair" mates. According to Auburn University's Geoffrey Hill, an expert on mate choice in birds who was not involved in the research, "This study shows the potential for extremely complex behavioral interactions in birds that were long thought to be bland monogamists." Explore further: Drosophila buzzatii fruit fly females may use courtship songs to pick same-species mates More information: "Condition- and context-dependent factors are related to courtship behavior of paired and unpaired males in a socially monogamous songbird" will be available May 17, 2017, at americanornithologypubs.org/doi/full/10.1642/AUK-16-214.1


Castillo D.M.,Indiana University Bloomington | Kula A.A.R.,Mountain Lake Biological Station | Kula A.A.R.,University of Maryland University College | Fenster K.A.D.,Mountain Lake Biological Station | And 5 more authors.
Ecological Entomology | Year: 2013

The outcome of mutualistic interactions depends on the costs and benefits for each of the partners, which have been shown to be both context- and species-dependent. This phenomenon is seen in the interactions between plants in the genus Silene and moths in the genus Hadena. In this study, the interaction between native North American species Silene stellata and Hadena ectypa is examined to understand the factors that influence female H. ectypa oviposition decisions, a behaviour that influences both herbivore and plant fitness. While most studies focus on oviposition preference between different host plant species, here it is shown that for a specialist pollinating seed predator, oviposition preference occurs within a host species (and even within a plant) based upon individual flower age and pollination status. Female H. ectypa preferentially visited and oviposited on young flowers and flowers that were unpollinated. Larvae also preferred to feed on young fruits. Female H. ectypa oviposition choice was consistent with optimal oviposition theory, as oviposition preference was correlated with larval feeding preference and not just adult visitation preference. © 2013 The Royal Entomological Society.


Reedy A.M.,University of Virginia | Edwards A.,University of Virginia | Pendlebury C.,University of Virginia | Murdaugh L.,Mountain Lake Biological Station | And 7 more authors.
General and Comparative Endocrinology | Year: 2014

Hormones play key, functional roles in mediating the tradeoff between survival and reproduction. Glucocorticoid hormones can inhibit reproduction and improve chances of survival during periods of stress. However, glucocorticoid hormones are, at times, also associated with successfully engaging in energetically costly courtship and mating behaviors. Corticosterone (CORT), a primary glucocorticoid hormone in amphibians, reptiles and birds, may be important in activating or sustaining energetically costly mating behaviors. We used a non-invasive, water-borne hormone assay to measure CORT release rates of male and female red-spotted newts (. Notophthalmus viridescens) collected when either engaged in amplexus or when not engaged in amplexus. Because amplexus is energetically costly for males, we predicted that males would have higher CORT release rates than females. We also predicted that females in amplexus would have elevated CORT release rates because the restraint of amplexus prevents foraging and breathing and may be costly. Here we show that an acute increase in CORT is associated with amplexus behavior in both male and female red-spotted newts. Additionally we demonstrate that males have higher overall CORT release rates both in and out of amplexus than do females. Our results support the hypothesis that glucocorticoid hormones are associated with energetically costly courtship and mating behaviors for both sexes. © 2014 Elsevier Inc.


Fenster C.B.,University of Maryland University College | Reynolds R.J.,University of Maryland University College | Reynolds R.J.,University of Alabama at Birmingham | Williams C.W.,Mountain Lake Biological Station | And 4 more authors.
Evolution | Year: 2015

Darwin recognized the flower's importance for the study of adaptation and emphasized that the flower's functionality reflects the coordinated action of multiple traits. Here we use a multitrait manipulative approach to quantify the potential role of selection acting on floral trait combinations underlying the divergence and maintenance of three related North American species of Silene (Caryophyllaceae). We artificially generated 48 plant phenotypes corresponding to all combinations of key attractive traits differing among the three Silene species (color, height, inflorescence architecture, flower orientation, and corolla-tube width). We quantified main and interaction effects of trait manipulation on hummingbird visitation preference using experimental arrays. The main effects of floral display height and floral orientation strongly influenced hummingbird visitation, with hummingbirds preferring flowers held high above the ground and vertically to the sky. Hummingbirds also prefer traits in a nonadditive manner as multiple two-way and higher order interaction effects were important predictors of hummingbird visitation. Contemporary trait combinations found in hummingbird pollinated S. virginica are mostly preferred. Our study demonstrates the likelihood of pollination syndromes evolving due to selection on trait combinations and highlights the importance of trait interactions in understanding the evolution of complex adaptations. © 2015 The Author(s).


PubMed | University of Virginia, Texas State University, Indiana University of Pennsylvania and Mountain Lake Biological Station
Type: | Journal: General and comparative endocrinology | Year: 2014

Hormones play key, functional roles in mediating the tradeoff between survival and reproduction. Glucocorticoid hormones can inhibit reproduction and improve chances of survival during periods of stress. However, glucocorticoid hormones are, at times, also associated with successfully engaging in energetically costly courtship and mating behaviors. Corticosterone (CORT), a primary glucocorticoid hormone in amphibians, reptiles and birds, may be important in activating or sustaining energetically costly mating behaviors. We used a non-invasive, water-borne hormone assay to measure CORT release rates of male and female red-spotted newts (Notophthalmus viridescens) collected when either engaged in amplexus or when not engaged in amplexus. Because amplexus is energetically costly for males, we predicted that males would have higher CORT release rates than females. We also predicted that females in amplexus would have elevated CORT release rates because the restraint of amplexus prevents foraging and breathing and may be costly. Here we show that an acute increase in CORT is associated with amplexus behavior in both male and female red-spotted newts. Additionally we demonstrate that males have higher overall CORT release rates both in and out of amplexus than do females. Our results support the hypothesis that glucocorticoid hormones are associated with energetically costly courtship and mating behaviors for both sexes.


Castillo D.M.,Indiana University Bloomington | Kula A.A.R.,Mountain Lake Biological Station | Kula A.A.R.,University of Maryland University College | Dotterl S.,University of Bayreuth | And 5 more authors.
International Journal of Plant Sciences | Year: 2014

The acquisition of new mutualists and escape from enemies are often essential for the establishment of invasive species. With its introduction to North America, Silene latifolia successfully escaped a number of generalist and specialist enemies, including the seed predator/specialist pollinator Hadena bicruris, but information regarding the acquisition of new mutualists in a community context has not been examined. We used field observations of mixed species arrays and laboratory feeding trials and compared floral scent and plant/ pollinator morphological match to explore the interaction in North America of the invasive S. latifolia with the native pollinating seed predator, Hadena ectypa, in order to understand mechanisms of enemy release and mutualist facilitation underlying the successful invasion of S. latifolia. In mixed arrays, H. ectypa visited S. latifolia at a low frequency similar to the combined visitation of other non-Hadena nocturnal moth species. Differences in the floral scent profiles of S. latifolia and Silene stellata, a native coflowering congener and natural host of H. ectypa, combined with the lack of morphological match between H. ectypa and S. latifolia, likely contribute to these results. In the field study, only one H. ectypa egg was oviposited on S. latifolia, and this did not result in a successful fruit attack. Larvae feeding trials in the lab showed no initial feeding preference for pistils of either Silene species. Therefore, our study suggests that S. latifolia has escaped the cost of seed predation typically associated with visitation and oviposition by Hadena pollinators, a potential natural enemy, while taking advantage of pollination services provided by both H. ectypa and other native North American nocturnal moth pollinators. © 2013 by The University of Chicago. All rights reserved.


PubMed | Mountain Lake Biological Station, Phoenix and University of Maryland College Park
Type: Journal Article | Journal: Evolution; international journal of organic evolution | Year: 2015

Darwin recognized the flowers importance for the study of adaptation and emphasized that the flowers functionality reflects the coordinated action of multiple traits. Here we use a multitrait manipulative approach to quantify the potential role of selection acting on floral trait combinations underlying the divergence and maintenance of three related North American species of Silene (Caryophyllaceae). We artificially generated 48 plant phenotypes corresponding to all combinations of key attractive traits differing among the three Silene species (color, height, inflorescence architecture, flower orientation, and corolla-tube width). We quantified main and interaction effects of trait manipulation on hummingbird visitation preference using experimental arrays. The main effects of floral display height and floral orientation strongly influenced hummingbird visitation, with hummingbirds preferring flowers held high above the ground and vertically to the sky. Hummingbirds also prefer traits in a nonadditive manner as multiple two-way and higher order interaction effects were important predictors of hummingbird visitation. Contemporary trait combinations found in hummingbird pollinated S. virginica are mostly preferred. Our study demonstrates the likelihood of pollination syndromes evolving due to selection on trait combinations and highlights the importance of trait interactions in understanding the evolution of complex adaptations.


News Article | October 29, 2016
Site: motherboard.vice.com

When scientists set up camera traps for North American wildlife, large primates aren't usually their main target. But recently, student biologists at Virginia Tech captured a rare species on film—a very wild, very naked Homo sapiens. Every couple of weeks, two dozen camera trap stations near Virginia's Mountain Lake Biological Station are checked by the students of Marcella J. Kelly, a professor at Virginia Tech who focuses on carnivore population ecology. "The student who does the downloading gave the cards to me and said, 'There's some really weird ones on there,'" Kelly told me. "'I think there's some naked people,'" the student added. According to Kelly, an anonymous man discovered two of their camera stations, proceeded to remove all of his clothes, and ran around on all fours like an animal. Each station captured approximately 20 photos of the man, many of which she deemed too graphic to share on Twitter. "In areas where people are hiking, we'll usually get photos of them making funny faces or waving or whatever. But it's pretty unusual that someone will take off all of their clothes," she said. When Kelly tweeted a couple of the photos, several other scientists chimed in to share their own flasher field reports. Take heed, future biologists, apparently this is par for the course. Most of the stations are located on hiking trails, logging roads, and game trails. Each of the traps set up by Virginia Tech students is between one and two kilometers apart, and utilizes two cameras per station. Since most of them are around knee-height, Kelly said, most human bystanders can only be identified from the waist down (which, depending on your point of view, is either a good or bad thing). When they're not grimacing at photos of buck-naked humans, members of The Wildlife Society's student chapter are monitoring the distribution of elusive species in Virginia's Appalachian Mountains. Generally, they're hoping to target deer, bears, coyotes, and bobcats. The Lake Biological Station overlaps with Jefferson National Forest, and contains a mix of deciduous forests, mountain streams, successional meadows, ponds, and bogs, making it abundant in research opportunities. Recently, the group noticed that gray foxes, a species considered widespread throughout parts of North America, had all but disappeared in the region. According to Kelly, the reason for this remains unclear, but it's possible that competition with bobcats or coyotes is affecting their population numbers. Camera traps have become especially helpful to scientists who study hard-to-spot species. For example, Ecuador's dark tree rat, which was filmed for the first time thanks to a camera station. Technology like motion detectors and infrared triggers provides researchers with unparalleled access and freedom. Not to mention, they're much more convenient than holing up in a blind. "A lot of these species are really hard to monitor. We've been monitoring them up in these areas since 2004," Kelly said. "They're a great way to monitor the distribution of elusive species, and keep tabs on what changes are happening through time." As for the Appalachian hominid, he'll get logged in a database along with the rest of the group's findings, Kelly told me. "I'm still not sure what we'll put in the notes section." Get six of our favorite Motherboard stories every day by signing up for our newsletter.

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