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Guo F, Buler JJ, Smolinsky JA, Wilcove DS. Seasonal patterns and protection status of stopover hotspots for migratory landbirds in the eastern United States. Curr Biol 2024; 34:235-244.e3. [PMID: 38091989 DOI: 10.1016/j.cub.2023.11.033] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2023] [Revised: 09/17/2023] [Accepted: 11/15/2023] [Indexed: 01/25/2024]
Abstract
Migratory landbirds in North America are experiencing dramatic population declines. Although considerable research and conservation attention have been directed toward these birds' breeding and wintering grounds, far less is known about the areas used as stopover sites during migration. To address this knowledge gap, we used 5 years of weather surveillance radar data to map seasonal stopover densities of landbirds across the eastern United States during spring and autumn migration. We identified stopover hotspots covering 2.47 million ha that consistently support high densities of migratory landbirds in spring or autumn. However, only 16.7% of these sites are hotspots in both seasons. The distribution of hotspots is shifted eastward in autumn compared with spring. Deciduous forest is the most important habitat type in both seasons, with deciduous forest fragments embedded in broadly deforested regions having the highest probability of being hotspots. The concentration of birds in these forest fragments is stronger in spring, especially in the agricultural Midwest. We found generally higher stopover densities in protected areas than in unprotected areas in both seasons. Nonetheless, only one-third of identified stopover hotspots have some sort of protected status, and more than half of these protected hotspots are subject to extractive uses. A well-distributed network of well-protected stopover areas, complementing conservation efforts on the breeding and wintering grounds, is essential to sustaining healthy populations of migratory landbirds in North America.
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Affiliation(s)
- Fengyi Guo
- Department of Ecology and Evolutionary Biology, Princeton University, Princeton, NJ 08544, USA.
| | - Jeffrey J Buler
- Department of Entomology and Wildlife Ecology, University of Delaware, Newark, DE 19716, USA
| | - Jaclyn A Smolinsky
- Department of Entomology and Wildlife Ecology, University of Delaware, Newark, DE 19716, USA
| | - David S Wilcove
- Department of Ecology and Evolutionary Biology, Princeton University, Princeton, NJ 08544, USA; Princeton School of Public and International Affairs, Princeton University, Princeton, NJ 08544, USA
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2
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Cohen EB, Buler JJ, Horton KG, Loss SR, Cabrera‐Cruz SA, Smolinsky JA, Marra PP. Using weather radar to help minimize wind energy impacts on nocturnally migrating birds. Conserv Lett 2022. [DOI: 10.1111/conl.12887] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Affiliation(s)
- Emily B. Cohen
- Migratory Bird Center Smithsonian Conservation Biology Institute, National Zoological Park Washington District of Columbia USA
| | - Jeffrey J. Buler
- Department of Entomology and Wildlife Ecology University of Delaware Newark Delaware USA
| | - Kyle G. Horton
- Fish, Wildlife, and Conservation Biology Colorado State University Fort Collins Colorado USA
| | - Scott R. Loss
- Department of Natural Resource Ecology and Management Oklahoma State University Stillwater Oklahoma USA
| | - Sergio A. Cabrera‐Cruz
- Department of Entomology and Wildlife Ecology University of Delaware Newark Delaware USA
| | - Jaclyn A. Smolinsky
- Department of Entomology and Wildlife Ecology University of Delaware Newark Delaware USA
| | - Peter P. Marra
- Migratory Bird Center Smithsonian Conservation Biology Institute, National Zoological Park Washington District of Columbia USA
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3
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Kim JY, Yoon J, Choi YS, Eo SH. The influencing factors for distribution patterns of resident and migrant bird species richness along elevational gradients. PeerJ 2022; 10:e13258. [PMID: 35509964 PMCID: PMC9059752 DOI: 10.7717/peerj.13258] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2021] [Accepted: 03/22/2022] [Indexed: 01/13/2023] Open
Abstract
The latitudinal and elevational patterns of species richness of resident and migrant birds have been of interest to researchers over the past few decades, and various hypotheses have been proposed to explain the factors that may affect these patterns. This study aimed to shed light on the elevational distribution patterns of resident and migrant bird species richness by examining biotic and abiotic factors such as climate, and habitat heterogeneity using a piecewise structural equation model (pSEM). The overall pattern of resident species richness showed a decreasing trend with increasing elevation, whereas that of migrant species richness showed an increasing trend. The mid-peak pattern of species richness was affected by a combination of resident and migrant species and not by either resident or migrant species. Our results showed that resident species were distributed in lower elevation regions with higher mean spring temperatures, whereas migrant species were found in higher elevation regions with lower mean spring temperatures and higher overstory vegetation coverage. Although high elevation conditions might adversely affect the reproduction of migrant birds, higher overstory vegetation coverage at high elevations seemed to compensate for this by providing a better nesting and roosting environment. Despite the significance of habitat diversity and understory vegetation coverage in univariate linear regression models, multiple regression models of the interconnection of ecological processes demonstrated that mean spring temperature and overstory vegetation coverage were more explanatory than other variables.
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Affiliation(s)
- Jin-Yong Kim
- Research Center for Endangered Species, National Institute of Ecology, Yeongyang, South Korea
| | - Jongmin Yoon
- Research Center for Endangered Species, National Institute of Ecology, Yeongyang, South Korea
| | - Yu-Seong Choi
- National Migratory Birds Center, National Institute of Biological Resources, Ongjin, South Korea
| | - Soo Hyung Eo
- Department of Forest Science, Kongju National University, Chungnam, South Korea
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4
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Long-term dynamics of the network structures in seed dispersal associated with fluctuations in bird migration and fruit abundance patterns. Oecologia 2022; 198:457-470. [PMID: 35112172 DOI: 10.1007/s00442-021-05102-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2021] [Accepted: 12/21/2021] [Indexed: 10/19/2022]
Abstract
In temperate zones, seed-dispersal networks by migratory birds are formed on long time scale. In mid-October from 2005 to 2016, to explore the dynamics of the network structures, we examined interannual variability of fruit abundance, bird migration, and seed-dispersal networks in central Japan. For 12 years, the fruit abundance exhibited a remarkable fluctuation across years, with the number of fruiting plants and matured fruits fluctuating repeatedly every other year, leading to the periodic fluctuations. The abundance of migratory birds was also fluctuated. According to the abundance of fruits and migratory birds, the 12 years was classified into three types: frugivores and fruits were abundant, frugivores were abundant but fruits were scarce, and frugivores were scarce. The seed-dispersal networks were investigated by collecting faeces and vomits of migrants. Of the 6652 samples collected from 15 bird species, 1671 (25.1%) included seeds from 60 plant species. Main dispersers were composed of Turdus pallidus, T. obscurus, and Zosterops japonicus. The network structures were almost nested for 12 years. Specifically, the nested structure was developed in years when fruit abundance was low. GLM analyses showed the abundance of migrants, particularly T. pallidus and T. obscurus, had strong positive effects on nested structure. It may be caused by the fact the two Turdus species were more frequently functioning as generalist dispersers when fruit abundance was lower. Our study suggested fruit abundance and foraging behaviour of frugivores determine the network structures of seed dispersal on long time scale.
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5
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A Gaussian Mixture Model to Separate Birds and Insects in Single-Polarization Weather Radar Data. REMOTE SENSING 2021. [DOI: 10.3390/rs13101989] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Recent and archived data from weather radar networks are extensively used for the quantification of continent-wide bird migration patterns. While the process of discriminating birds from weather signals is well established, insect contamination is still a problem. We present a simple method combining two Doppler radar products within a Gaussian mixture model to estimate the proportions of birds and insects within a single measurement volume, as well as the density and speed of birds and insects. This method can be applied to any existing archives of vertical bird profiles, such as the European Network for the Radar surveillance of Animal Movement repository, with no need to recalculate the huge amount of original polar volume data, which often are not available.
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6
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Weisshaupt N, Lehikoinen A, Mäkinen T, Koistinen J. Challenges and benefits of using unstructured citizen science data to estimate seasonal timing of bird migration across large scales. PLoS One 2021; 16:e0246572. [PMID: 33539480 PMCID: PMC7861542 DOI: 10.1371/journal.pone.0246572] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2020] [Accepted: 01/21/2021] [Indexed: 11/20/2022] Open
Abstract
Millions of bird observations have been entered on online portals in the past 20 years either as checklists or arbitrary individual entries. While several hundred publications have been written on a variety of topics based on bird checklists worldwide, unstructured non-checklist observations have received little attention and praise by academia. In the present study we tested the suitability of non-checklist data to estimate key figures of large-scale migration phenology in four zones covering the whole of Finland. For that purpose, we analysed 10 years of ornithological non-checklist data including over 400 million. individuals of 115 bird species. We discuss bird- and human-induced effects to be considered in handling non-checklist data in this context and describe applied methodologies to address these effects. We calculated 5%, 50% and 95% percentile dates of spring and autumn migration period for all species in all four zones. For validation purposes we compared the temporal distributions of 43 bird species with migration phenology from standardized long-term ringing data in autumn of which 24 species (56%) showed similar medians. In a model approach, non-checklist data successfully revealed latitudinal migration progression in spring and autumn. Overall, non-checklist data proved to be well suited to determine descriptors of migration phenology in Northern Europe which are challenging to attain by any other currently available means. The effort-to-yield ratio of data processing was commensurate to the outcomes. The unprecedented spatiotemporal coverage makes non-checklist data a valuable complement to current migration databases from bird observatories. The basic concept of the present methodology is applicable to data from other bird portals, if combined with local field ornithological knowledge and literature. Species-specific descriptors of migration phenology can be potentially used in climate change studies and to support echo interpretation in radar ornithology.
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Affiliation(s)
| | - Aleksi Lehikoinen
- Finnish Museum of Natural History, University of Helsinki, Helsinki, Finland
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7
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Lin T, Winner K, Bernstein G, Mittal A, Dokter AM, Horton KG, Nilsson C, Van Doren BM, Farnsworth A, La Sorte FA, Maji S, Sheldon D. M
ist
N
et
: Measuring historical bird migration in the US using archived weather radar data and convolutional neural networks. Methods Ecol Evol 2019. [DOI: 10.1111/2041-210x.13280] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Tsung‐Yu Lin
- College of Information and Computer Sciences University of Massachusetts Amherst Amherst MA USA
| | - Kevin Winner
- College of Information and Computer Sciences University of Massachusetts Amherst Amherst MA USA
| | - Garrett Bernstein
- College of Information and Computer Sciences University of Massachusetts Amherst Amherst MA USA
| | - Abhay Mittal
- College of Information and Computer Sciences University of Massachusetts Amherst Amherst MA USA
| | | | - Kyle G. Horton
- Cornell Lab of Ornithology Cornell University Ithaca NY USA
- Department o f Fish Wildlife, and Conservation Biology Colorado State University Fort Collins CO USA
| | | | | | | | | | - Subhransu Maji
- College of Information and Computer Sciences University of Massachusetts Amherst Amherst MA USA
| | - Daniel Sheldon
- College of Information and Computer Sciences University of Massachusetts Amherst Amherst MA USA
- Department of Computer Science Mount Holyoke College South Hadley MA USA
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8
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Anderson AM, Duijns S, Smith PA, Friis C, Nol E. Migration Distance and Body Condition Influence Shorebird Migration Strategies and Stopover Decisions During Southbound Migration. Front Ecol Evol 2019. [DOI: 10.3389/fevo.2019.00251] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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9
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Horton KG, Van Doren BM, La Sorte FA, Cohen EB, Clipp HL, Buler JJ, Fink D, Kelly JF, Farnsworth A. Holding steady: Little change in intensity or timing of bird migration over the Gulf of Mexico. GLOBAL CHANGE BIOLOGY 2019; 25:1106-1118. [PMID: 30623528 DOI: 10.1111/gcb.14540] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/17/2018] [Revised: 10/05/2018] [Accepted: 11/02/2018] [Indexed: 06/09/2023]
Abstract
Quantifying the timing and intensity of migratory movements is imperative for understanding impacts of changing landscapes and climates on migratory bird populations. Billions of birds migrate in the Western Hemisphere, but accurately estimating the population size of one migratory species, let alone hundreds, presents numerous obstacles. Here, we quantify the timing, intensity, and distribution of bird migration through one of the largest migration corridors in the Western Hemisphere, the Gulf of Mexico (the Gulf). We further assess whether there have been changes in migration timing or intensity through the Gulf. To achieve this, we integrate citizen science (eBird) observations with 21 years of weather surveillance radar data (1995-2015). We predicted no change in migration timing and a decline in migration intensity across the time series. We estimate that an average of 2.1 billion birds pass through this region each spring en route to Nearctic breeding grounds. Annually, half of these individuals pass through the region in just 18 days, between April 19 and May 7. The western region of the Gulf showed a mean rate of passage 5.4 times higher than the central and eastern regions. We did not detect an overall change in the annual numbers of migrants (2007-2015) or the annual timing of peak migration (1995-2015). However, we found that the earliest seasonal movements through the region occurred significantly earlier over time (1.6 days decade-1 ). Additionally, body mass and migration distance explained the magnitude of phenological changes, with the most rapid advances occurring with an assemblage of larger-bodied shorter-distance migrants. Our results provide baseline information that can be used to advance our understanding of the developing implications of climate change, urbanization, and energy development for migratory bird populations in North America.
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Affiliation(s)
- Kyle G Horton
- Cornell Lab of Ornithology, Cornell University, Ithaca, New York
| | | | - Frank A La Sorte
- Cornell Lab of Ornithology, Cornell University, Ithaca, New York
| | - Emily B Cohen
- Migratory Bird Center, Smithsonian Conservation Biology Institute, National Zoological Park, Washington, District of Columbia
| | - Hannah L Clipp
- Department of Entomology and Wildlife Ecology, University of Delaware, Newark, Delaware
| | - Jeffrey J Buler
- Department of Entomology and Wildlife Ecology, University of Delaware, Newark, Delaware
| | - Daniel Fink
- Cornell Lab of Ornithology, Cornell University, Ithaca, New York
| | - Jeffrey F Kelly
- Department of Biology, University of Oklahoma, Norman, Oklahoma
- Corix Plains Institute, University of Oklahoma, Norman, Oklahoma
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10
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La Sorte FA, Horton KG, Nilsson C, Dokter AM. Projected changes in wind assistance under climate change for nocturnally migrating bird populations. GLOBAL CHANGE BIOLOGY 2019; 25:589-601. [PMID: 30537359 DOI: 10.1111/gcb.14531] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/28/2018] [Revised: 10/12/2018] [Accepted: 11/12/2018] [Indexed: 06/09/2023]
Abstract
Current climate models and observations indicate that atmospheric circulation is being affected by global climate change. To assess how these changes may affect nocturnally migrating bird populations, we need to determine how current patterns of wind assistance at migration altitudes will be enhanced or reduced under future atmospheric conditions. Here, we use information compiled from 143 weather surveillance radars stations within the contiguous United States to estimate the daily altitude, density, and direction of nocturnal migration during the spring and autumn. We intersected this information with wind projections to estimate how wind assistance is expected to change during this century at current migration altitudes. The prevailing westerlies at midlatitudes are projected to increase in strength during spring migration and decrease in strength to a lesser degree during autumn migration. Southerly winds will increase in strength across the continent during both spring and autumn migration, with the strongest gains occurring in the center of the continent. Wind assistance is projected to increase across the central (0.44 m/s; 10.1%) and eastern portions of the continent (0.32 m/s; 9.6%) during spring migration, and wind assistance is projected to decrease within the central (0.32 m/s; 19.3%) and eastern portions of the continent (0.17 m/s; 6.6%) during autumn migration. Thus, across a broad portion of the continent where migration intensity is greatest, the efficiency of nocturnal migration is projected to increase in the spring and decrease in the autumn, potentially affecting time and energy expenditures for many migratory bird species. These findings highlight the importance of placing climate change projections within a relevant ecological context informed through empirical observations, and the need to consider the possibility that climate change may generate both positive and negative implications for natural systems.
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Affiliation(s)
- Frank A La Sorte
- Cornell Laboratory of Ornithology, Cornell University, Ithaca, New York
| | - Kyle G Horton
- Cornell Laboratory of Ornithology, Cornell University, Ithaca, New York
| | - Cecilia Nilsson
- Cornell Laboratory of Ornithology, Cornell University, Ithaca, New York
| | - Adriaan M Dokter
- Cornell Laboratory of Ornithology, Cornell University, Ithaca, New York
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11
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Ward MP, Benson TJ, Deppe J, Zenzal TJ, Diehl RH, Celis-Murillo A, Bolus R, Moore FR. Estimating apparent survival of songbirds crossing the Gulf of Mexico during autumn migration. Proc Biol Sci 2018; 285:rspb.2018.1747. [PMID: 30355710 DOI: 10.1098/rspb.2018.1747] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2018] [Accepted: 09/27/2018] [Indexed: 11/12/2022] Open
Abstract
Many migratory bird species are declining, and the migratory period may limit populations because of the risk in traversing large geographical features during passage. Using automated radio-telemetry, we tracked 139 Swainson's thrushes (Catharus ustulatus) departing coastal Alabama, USA and crossing the Gulf of Mexico to arrive in the Yucatan Peninsula, Mexico during autumn. We estimated apparent survival and examined how extrinsic (weather variables and day of year) and intrinsic (fat load, sex and age) factors influenced survival using a mark-recapture approach. We also examined how favourability of winds for crossing the Gulf varied over the past 25 years. Fat load, day of year and wind profit were important factors in predicting which individuals survived crossing the Gulf. Survival estimates varied with wind profit and fat, but generally, fat birds departing on days with favourable wind profits had an apparent survival probability of greater than 0.90, while lean individuals with no or negative wind profits had less than 0.33. The proportion of favourable nights varied within and among years, but has increased over the last 25 years. While conservation strategies cannot improve extrinsic factors, they can provide opportunities for birds to refuel before crossing large geographical features through protecting and creating high-quality stopover sites.
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Affiliation(s)
- Michael P Ward
- Department of Natural Resources and Environmental Sciences, University of Illinois, Urbana-Champaign, IL, USA .,Illinois Natural History Survey, Prairie Research Institute, University of Illinois, Urbana-Champaign, IL, USA
| | - Thomas J Benson
- Illinois Natural History Survey, Prairie Research Institute, University of Illinois, Urbana-Champaign, IL, USA
| | - Jill Deppe
- Department of Biological Sciences, Eastern Illinois University, Charleston, IL, USA.,National Audubon Society, Washington, DC, USA
| | - Theodore J Zenzal
- Department of Natural Resources and Environmental Sciences, University of Illinois, Urbana-Champaign, IL, USA.,School of Biological, Environmental, and Earth Sciences, University of Southern Mississippi, Hattiesburg, MI, USA
| | - Robert H Diehl
- U.S. Geological Survey, Northern Rocky Mountain Science Center, Bozeman, MT, USA
| | - Antonio Celis-Murillo
- Illinois Natural History Survey, Prairie Research Institute, University of Illinois, Urbana-Champaign, IL, USA.,U.S. Geological Survey, Patuxent Wildlife Research Center, Laurel, MD, USA
| | - Rachel Bolus
- Department of Biology, Southern Utah University, Cedar City, UT, USA
| | - Frank R Moore
- School of Biological, Environmental, and Earth Sciences, University of Southern Mississippi, Hattiesburg, MI, USA
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12
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Horton KG, Van Doren BM, La Sorte FA, Fink D, Sheldon D, Farnsworth A, Kelly JF. Navigating north: how body mass and winds shape avian flight behaviours across a North American migratory flyway. Ecol Lett 2018; 21:1055-1064. [DOI: 10.1111/ele.12971] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2018] [Accepted: 03/26/2018] [Indexed: 02/03/2023]
Affiliation(s)
- Kyle G. Horton
- Department of Biology University of Oklahoma Norman OK USA
- Oklahoma Biological Survey University of Oklahoma Norman OK USA
- Advanced Radar Research Center University of Oklahoma Norman OK USA
- Cornell Lab of Ornithology Cornell University Ithaca New York USA
| | | | | | - Daniel Fink
- Cornell Lab of Ornithology Cornell University Ithaca New York USA
| | - Daniel Sheldon
- College of Information and Computer Sciences University of Massachusetts Amherst MA USA
- Department of Computer Science Mount Holyoke College South Hadley MA USA
| | | | - Jeffrey F. Kelly
- Department of Biology University of Oklahoma Norman OK USA
- Oklahoma Biological Survey University of Oklahoma Norman OK USA
- Corix Plains Institute University of Oklahoma Norman Oklahoma USA
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13
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La Sorte FA, Fink D, Johnston A. Seasonal associations with novel climates for North American migratory bird populations. Ecol Lett 2018; 21:845-856. [PMID: 29618169 DOI: 10.1111/ele.12951] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2018] [Accepted: 02/23/2018] [Indexed: 01/19/2023]
Abstract
Determining the implications of global climate change for highly mobile taxa such as migratory birds requires a perspective that is spatiotemporally comprehensive and ecologically relevant. Here, we document how passerine bird species that migrate within the Western Hemisphere (n = 77) are associated with projected novel climates across the full annual cycle. Following expectations, highly novel climates occurred on tropical non-breeding grounds and the least novel climates occurred on temperate breeding grounds. Contrary to expectations, highly novel climates also occurred within temperate regions during the transition from breeding to autumn migration. This outcome was caused by lower inter-annual climatic variability occurring in combination with stronger warming projections. Thus, migrants are projected to encounter novel climates across the majority of their annual cycle, with a pronounced peak occurring when juveniles are leaving the nest and preparing to embark on their first migratory journey, which may adversely affect their chances of survival.
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Affiliation(s)
- Frank A La Sorte
- Cornell Laboratory of Ornithology, Cornell University, Ithaca, NY, 14850, USA
| | - Daniel Fink
- Cornell Laboratory of Ornithology, Cornell University, Ithaca, NY, 14850, USA
| | - Alison Johnston
- Cornell Laboratory of Ornithology, Cornell University, Ithaca, NY, 14850, USA.,Department of Zoology, Conservation Science Group, University of Cambridge, Cambridge, UK
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14
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Swainson's Thrushes do not show strong wind selectivity prior to crossing the Gulf of Mexico. Sci Rep 2017; 7:14280. [PMID: 29079749 PMCID: PMC5660249 DOI: 10.1038/s41598-017-14668-3] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2017] [Accepted: 10/05/2017] [Indexed: 11/09/2022] Open
Abstract
During long-distance fall migrations, nocturnally migrating Swainson’s Thrushes often stop on the northern Gulf of Mexico coast before flying across the Gulf. To minimize energetic costs, trans-Gulf migrants should stop over when they encounter crosswinds or headwinds, and depart with supportive tailwinds. However, time constrained migrants should be less selective, balancing costs of headwinds with benefits of continuing their migrations. To test the hypotheses that birds select supportive winds and that selectivity is mediated by seasonal time constraints, we examined whether local winds affected Swainson’s Thrushes’ arrival and departure at Ft. Morgan, Alabama, USA at annual, seasonal, and nightly time scales. Additionally, migrants could benefit from forecasting future wind conditions, crossing on nights when winds are consistently supportive across the Gulf, thereby avoiding the potentially lethal consequences of depleting their energetic reserves over water. To test whether birds forecast, we developed a movement model, calculated to what extent departure winds were predictive of future Gulf winds, and tested whether birds responded to predictability. Swainson’s Thrushes were only slightly selective and did not appear to forecast. By following the simple rule of avoiding only the strongest headwinds at departure, Swainson’s Thrushes could survive the 1500 km flight between Alabama and Veracruz, Mexico.
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15
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Van Doren BM, Horton KG, Dokter AM, Klinck H, Elbin SB, Farnsworth A. High-intensity urban light installation dramatically alters nocturnal bird migration. Proc Natl Acad Sci U S A 2017; 114:11175-11180. [PMID: 28973942 PMCID: PMC5651764 DOI: 10.1073/pnas.1708574114] [Citation(s) in RCA: 111] [Impact Index Per Article: 15.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Billions of nocturnally migrating birds move through increasingly photopolluted skies, relying on cues for navigation and orientation that artificial light at night (ALAN) can impair. However, no studies have quantified avian responses to powerful ground-based light sources in urban areas. We studied effects of ALAN on migrating birds by monitoring the beams of the National September 11 Memorial & Museum's "Tribute in Light" in New York, quantifying behavioral responses with radar and acoustic sensors and modeling disorientation and attraction with simulations. This single light source induced significant behavioral alterations in birds, even in good visibility conditions, in this heavily photopolluted environment, and to altitudes up to 4 km. We estimate that the installation influenced ≈1.1 million birds during our study period of 7 d over 7 y. When the installation was illuminated, birds aggregated in high densities, decreased flight speeds, followed circular flight paths, and vocalized frequently. Simulations revealed a high probability of disorientation and subsequent attraction for nearby birds, and bird densities near the installation exceeded magnitudes 20 times greater than surrounding baseline densities during each year's observations. However, behavioral disruptions disappeared when lights were extinguished, suggesting that selective removal of light during nights with substantial bird migration is a viable strategy for minimizing potentially fatal interactions among ALAN, structures, and birds. Our results also highlight the value of additional studies describing behavioral patterns of nocturnally migrating birds in powerful lights in urban areas as well as conservation implications for such lighting installations.
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Affiliation(s)
- Benjamin M Van Doren
- Information Science Program, Cornell Lab of Ornithology, Ithaca, NY 14850
- Edward Grey Institute, Department of Zoology, University of Oxford, Oxford, OX1 3PS, United Kingdom
| | - Kyle G Horton
- Information Science Program, Cornell Lab of Ornithology, Ithaca, NY 14850
- Department of Biology, University of Oklahoma, Norman, OK 73019
- Oklahoma Biological Survey, University of Oklahoma, Norman, OK 73019
| | - Adriaan M Dokter
- Information Science Program, Cornell Lab of Ornithology, Ithaca, NY 14850
| | - Holger Klinck
- Bioacoustics Research Program, Cornell Lab of Ornithology, Ithaca, NY 14850
| | | | - Andrew Farnsworth
- Information Science Program, Cornell Lab of Ornithology, Ithaca, NY 14850;
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16
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Shamoun-Baranes J, Liechti F, Vansteelant WMG. Atmospheric conditions create freeways, detours and tailbacks for migrating birds. J Comp Physiol A Neuroethol Sens Neural Behav Physiol 2017; 203:509-529. [PMID: 28508130 PMCID: PMC5522504 DOI: 10.1007/s00359-017-1181-9] [Citation(s) in RCA: 63] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2016] [Revised: 05/04/2017] [Accepted: 05/05/2017] [Indexed: 11/17/2022]
Abstract
The extraordinary adaptations of birds to contend with atmospheric conditions during their migratory flights have captivated ecologists for decades. During the 21st century technological advances have sparked a revival of research into the influence of weather on migrating birds. Using biologging technology, flight behaviour is measured across entire flyways, weather radar networks quantify large-scale migratory fluxes, citizen scientists gather observations of migrant birds and mechanistic models are used to simulate migration in dynamic aerial environments. In this review, we first introduce the most relevant microscale, mesoscale and synoptic scale atmospheric phenomena from the point of view of a migrating bird. We then provide an overview of the individual responses of migrant birds (when, where and how to fly) in relation to these phenomena. We explore the cumulative impact of individual responses to weather during migration, and the consequences thereof for populations and migratory systems. In general, individual birds seem to have a much more flexible response to weather than previously thought, but we also note similarities in migratory behaviour across taxa. We propose various avenues for future research through which we expect to derive more fundamental insights into the influence of weather on the evolution of migratory behaviour and the life-history, population dynamics and species distributions of migrant birds.
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Affiliation(s)
- Judy Shamoun-Baranes
- Theoretical and Computational Ecology, Institute for Biodiversity and Ecosystem Dynamics, University of Amsterdam, P.O. Box 94248, 1090 GE, Amsterdam, The Netherlands.
| | - Felix Liechti
- Department of Bird Migration, Swiss Ornithological Institute, Seerose 1, 6204, Sempach, Switzerland
| | - Wouter M G Vansteelant
- Theoretical and Computational Ecology, Institute for Biodiversity and Ecosystem Dynamics, University of Amsterdam, P.O. Box 94248, 1090 GE, Amsterdam, The Netherlands
- Vansteelant Eco Research, Dijkgraaf 35, 6721 NJ, Bennekom, The Netherlands
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17
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La Sorte FA, Fink D. Projected changes in prevailing winds for transatlantic migratory birds under global warming. J Anim Ecol 2017; 86:273-284. [PMID: 27973732 DOI: 10.1111/1365-2656.12624] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2016] [Accepted: 12/02/2016] [Indexed: 11/26/2022]
Abstract
A number of terrestrial bird species that breed in North America cross the Atlantic Ocean during autumn migration when travelling to their non-breeding grounds in the Caribbean or South America. When conducting oceanic crossings, migratory birds tend to associate with mild or supportive winds, whose speed and direction may change under global warming. The implications of these changes for transoceanic migratory bird populations have not been addressed. We used occurrence information from eBird (1950-2015) to estimate the geographical location of population centres at a daily temporal resolution across the annual cycle for 10 transatlantic migratory bird species. We used this information to estimate the location and timing of autumn migration within the transatlantic flyway. We estimated how prevailing winds are projected to change within the transatlantic flyway during this time using daily wind speed anomalies (1996-2005 and 2091-2100) from 29 Atmosphere-Ocean General Circulation Models implemented under CMIP5. Autumn transatlantic migrants have the potential to encounter strong westerly crosswinds early in their transatlantic journey at intermediate and especially high migration altitudes, strong headwinds at low and intermediate migration altitudes within the Caribbean that increase in strength as the season progresses, and weak tailwinds at intermediate and high migration altitudes east of the Caribbean. The CMIP5 simulations suggest that, during this century, the likelihood of autumn transatlantic migrants encountering strong westerly crosswinds will diminish. As global warming progresses, the need for species to compensate or drift under the influence of strong westerly crosswinds during the initial phase of their autumn transatlantic journey may be diminished. Existing strategies that promote headwind avoidance and tailwind assistance will likely remain valid. Thus, climate change may reduce time and energy requirements and the chance of mortality or vagrancy during a specific but likely critical portion of these species' autumn migration journey.
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Affiliation(s)
- Frank A La Sorte
- Cornell Laboratory of Ornithology, Cornell University, Ithaca, NY, 14850, USA
| | - Daniel Fink
- Cornell Laboratory of Ornithology, Cornell University, Ithaca, NY, 14850, USA
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18
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Horton KG, Van Doren BM, Stepanian PM, Farnsworth A, Kelly JF. Where in the air? Aerial habitat use of nocturnally migrating birds. Biol Lett 2016; 12:rsbl.2016.0591. [PMID: 27881761 DOI: 10.1098/rsbl.2016.0591] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
The lower atmosphere (i.e. aerosphere) is critical habitat for migrant birds. This habitat is vast and little is known about the spatio-temporal patterns of distribution and abundance of migrants in it. Increased human encroachment into the aerosphere makes understanding where and when migratory birds use this airspace a key to reducing human-wildlife conflicts. We use weather surveillance radar to describe large-scale height distributions of nocturnally migrating birds and interpret these distributions as aggregate habitat selection behaviours of individual birds. As such, we detail wind cues that influence selection of flight heights. Using six radars in the eastern USA during the spring (2013-2015) and autumn (2013 and 2014), we found migrants tended to adjust their heights according to favourable wind profit. We found that migrants' flight altitudes correlated most closely with the altitude of maximum wind profit; however, absolute differences in flight heights and height of maximum wind profit were large. Migrants tended to fly slightly higher at inland sites compared with coastal sites during spring, but not during autumn. Migration activity was greater at coastal sites during autumn, but not during spring. This characterization of bird migration represents a critical advance in our understanding of migrant distributions in flight and a new window into habitat selection behaviours.
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Affiliation(s)
- Kyle G Horton
- Department of Biology, University of Oklahoma, Norman, OK, USA .,Oklahoma Biological Survey, University of Oklahoma, Norman, OK, USA.,Advanced Radar Research Center, University of Oklahoma, Norman, OK, USA
| | - Benjamin M Van Doren
- Department of Ecology and Evolutionary Biology, Cornell University, Ithaca, NY, USA
| | - Phillip M Stepanian
- Advanced Radar Research Center, University of Oklahoma, Norman, OK, USA.,School of Meteorology, University of Oklahoma, Norman, OK, USA
| | | | - Jeffrey F Kelly
- Department of Biology, University of Oklahoma, Norman, OK, USA.,Oklahoma Biological Survey, University of Oklahoma, Norman, OK, USA
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19
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Stepanian PM, Horton KG, Melnikov VM, Zrnić DS, Gauthreaux SA. Dual‐polarization radar products for biological applications. Ecosphere 2016. [DOI: 10.1002/ecs2.1539] [Citation(s) in RCA: 52] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Affiliation(s)
- Phillip M. Stepanian
- Advanced Radar Research Center University of Oklahoma 120 David L. Boren Boulevard Norman Oklahoma 73072 USA
- School of Meteorology University of Oklahoma 120 David L. Boren Boulevard Norman Oklahoma 73072 USA
| | - Kyle G. Horton
- Advanced Radar Research Center University of Oklahoma 120 David L. Boren Boulevard Norman Oklahoma 73072 USA
- Oklahoma Biological Survey University of Oklahoma 120 David L. Boren Boulevard Norman Oklahoma 73072 USA
- Department of Biology University of Oklahoma 120 David L. Boren Boulevard Norman Oklahoma 73072 USA
| | - Valery M. Melnikov
- National Severe Storms Laboratory 120 David L. Boren Boulevard Norman Oklahoma 73072 USA
- Cooperative Institute for Mesoscale Meteorological Studies 120 David L. Boren Boulevard Norman Oklahoma 73072 USA
| | - Dušan S. Zrnić
- National Severe Storms Laboratory 120 David L. Boren Boulevard Norman Oklahoma 73072 USA
| | - Sidney A. Gauthreaux
- Civil and Environmental Engineering University of Illinois, Urbana–Champaign 205 North Mathews Avenue Urbana Illinois 61801 USA
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