Ecology, Population Dynamics, and Translocation of the Endangered Laysan Teal Completed
The Laysan teal has the most restricted range of any duck species and is especially vulnerable to extinction because of its small population size and vulnerability to climate change. The species was believed to be endemic to one island until new sub-fossil evidence and ancient DNA-testing revealed Laysan teal were widespread across the Hawaiian archipelago. Despite its previously wide distribution, today the Laysan teal shows strong tenacity to Laysan Island in the Hawaiian Islands National Wildlife Refuge (NWR) that is a part of the Papahānaumokuākea Marine National Monument. Small isolated populations are extremely vulnerable to extinction from stochastic events, natural disturbance, alien species, emerging diseases, and sea-level rise. On Laysan Island, the endemic rail, honeycreeper, and millerbird all went extinct after the introduction of rabbits to this fragile ecosystem.
Overview:
The Laysan teal (Anas laysanensis) has the most restricted range of any duck species and is especially vulnerable to extinction because of its small population size and vulnerability to climate change. The species was believed to be endemic to one island until new sub-fossil evidence and ancient DNA-testing revealed Laysan teal were widespread across the Hawaiian archipelago. Despite its previously wide distribution, today the Laysan teal shows strong tenacity to Laysan Island in the Northwestern Hawaiian Islands (NWHI) that is part of the Papahānaumokuākea Marine National Monument. Small isolated populations are extremely vulnerable to extinction from stochastic events, natural disturbance, alien species, emerging diseases, and sea-level rise. On Laysan Island, the endemic rail, honeycreeper, and millerbird all went extinct after the introduction of rabbits to this fragile ecosystem. The last wild population of Laysan teal existed as a relict population with a limited carrying capacity and vulnerable to population crashes during drought and epizootics. Wild translocation or the movement of wild birds to establish additional populations is a high priority of the U.S. Fish and Wildlife Service to reduce the species high extinction risks and recover the species. Due to the remoteness of Laysan Island, few researchers or naturalists have studied the species and little was known of its ecology or population status. Refuge managers are interested in restoring ecosystems of the Northwestern Hawaiian Islands; however, little was known about the Laysan teal’s habitat use or requirements. This project examined aspects of the Laysan teal ecology including population dynamics and reintroduced biology, behavior, reproductive success, population genetics, and habitat use on Laysan Island and the reintroduced population on Midway Atoll NWR.
Application of USGS research to restore a second population of the species has been viewed as one of the most successful applied research/conservation projects in decades. This work has been a model for recent FWS efforts for other reintroductions in the Hawaiian Islands (i.e. Nihoa millerbird translocations) and demonstrated that additional populations can be created.
Additional studies were added to help the USFWS develop techniques monitor the birds reproduction and survival, identify population crashes, identify causes of population crashes, and predict the impacts of climate change on the species. Impacts from the 2011 Tohohu tsunami on the population were also examined for our USFWS partners. Additionally, analysis of genetic variability in the species was conducted to better understand the evolutionary potential of the species.
Project Objectives:
The objectives of this study were to investigate factors essential to conservation and management of the Laysan teal:
- Population Dynamics - Identify factors influencing reproduction and mortality on Laysan Island. Develop population models to estimate population size, age, and sex structure and population viability. Determine survival, reproductive status using appropriate models.
- Ecology - Examine behavioral ecology, foraging, wetland use in relation to invertebrate prey densities, prey and habitat availability, and environmental parameters influencing prey and habitat use by Laysan teal.
- Translocation - Apply data gathered on foraging ecology, population dynamics, habitat use, and behavior to make recommendation on best methods, timing, and ecosystem restoration required for the highest probability of a successful translocation and population persistence.
Highlights and Key Findings:
An experimental translocation of Laysan teal from Laysan Island to Midway Atoll NWR was conducted in 2004 and 2005 in collaboration with the USFWS. The 2004 and 2005 experimental reintroduction of 42 birds was successful and won a Recovery Leader Award from the USFWS. The methods and results have been published in books, journals, and reports and have been featured as models and examples for species recovery, adaptive management, and research.
USGS provided technical support and design for the 2014 translocation of Laysan teal from Midway Atoll NWR to Kure Atoll in partnership with the US Coast Guard and the State of Hawai‘i Division of Land and Natural Resources.
Below are publications associated with this project.
How many Laysan Teal Anas laysanensis are on Midway Atoll? Methods for monitoring abundance after reintroduction
Long-term monitoring of endangered Laysan ducks: Index validation and population estimates 1998–2012
Peregrine falcon predation of endangered Laysan teal and Laysan Finches on remote Hawaiian atolls
Microsatellite variation and rare alleles in a bottlenecked Hawaiian Islands endemic: implications for reintroductions
Evidence of low genetic variation and rare alleles in a bottlenecked endangered island endemic, the Lasan Teal (Anas laysanensis)
Experimental reintroduction reveals novel life-history variation in Laysan Ducks (Anas laysanensis)
Subfossil remains indicate that the Laysan Duck (Anas laysanensis) formerly occurred throughout the Hawaiian archipelago, but for more than 150 years it has been confined to a single, small atoll in the northwestern chain, Laysan Island. In 2004–2005, 42 ducks were reintroduced from Laysan to Midway Atoll, where they exhibited variation in life history never observed on Laysan. On Laysan, females
Demographic variation, reintroduction, and persistence of an island duck (Anas laysanensis)
Influence of space use on fitness and the reintroduction success of the Laysan teal
Modelling reintroduced populations: The state of the art and future directions
Population estimates and monitoring guidelines for endangered Laysan Teal, Anas Laysanensis, at Midway Atoll: Pilot study results 2008-2010.
Avian botulism: a case study in translocated endangered Laysan ducks (Anas laysanensis) on Midway Atoll
Trading off short-term and long-term risk: minimizing the threat of Laysan duck extinction from catastrophes and sea-level rise
Below are partners associated with this project.
- Overview
The Laysan teal has the most restricted range of any duck species and is especially vulnerable to extinction because of its small population size and vulnerability to climate change. The species was believed to be endemic to one island until new sub-fossil evidence and ancient DNA-testing revealed Laysan teal were widespread across the Hawaiian archipelago. Despite its previously wide distribution, today the Laysan teal shows strong tenacity to Laysan Island in the Hawaiian Islands National Wildlife Refuge (NWR) that is a part of the Papahānaumokuākea Marine National Monument. Small isolated populations are extremely vulnerable to extinction from stochastic events, natural disturbance, alien species, emerging diseases, and sea-level rise. On Laysan Island, the endemic rail, honeycreeper, and millerbird all went extinct after the introduction of rabbits to this fragile ecosystem.
Overview:
The Laysan teal (Anas laysanensis) has the most restricted range of any duck species and is especially vulnerable to extinction because of its small population size and vulnerability to climate change. The species was believed to be endemic to one island until new sub-fossil evidence and ancient DNA-testing revealed Laysan teal were widespread across the Hawaiian archipelago. Despite its previously wide distribution, today the Laysan teal shows strong tenacity to Laysan Island in the Northwestern Hawaiian Islands (NWHI) that is part of the Papahānaumokuākea Marine National Monument. Small isolated populations are extremely vulnerable to extinction from stochastic events, natural disturbance, alien species, emerging diseases, and sea-level rise. On Laysan Island, the endemic rail, honeycreeper, and millerbird all went extinct after the introduction of rabbits to this fragile ecosystem. The last wild population of Laysan teal existed as a relict population with a limited carrying capacity and vulnerable to population crashes during drought and epizootics. Wild translocation or the movement of wild birds to establish additional populations is a high priority of the U.S. Fish and Wildlife Service to reduce the species high extinction risks and recover the species. Due to the remoteness of Laysan Island, few researchers or naturalists have studied the species and little was known of its ecology or population status. Refuge managers are interested in restoring ecosystems of the Northwestern Hawaiian Islands; however, little was known about the Laysan teal’s habitat use or requirements. This project examined aspects of the Laysan teal ecology including population dynamics and reintroduced biology, behavior, reproductive success, population genetics, and habitat use on Laysan Island and the reintroduced population on Midway Atoll NWR.
Application of USGS research to restore a second population of the species has been viewed as one of the most successful applied research/conservation projects in decades. This work has been a model for recent FWS efforts for other reintroductions in the Hawaiian Islands (i.e. Nihoa millerbird translocations) and demonstrated that additional populations can be created.
Additional studies were added to help the USFWS develop techniques monitor the birds reproduction and survival, identify population crashes, identify causes of population crashes, and predict the impacts of climate change on the species. Impacts from the 2011 Tohohu tsunami on the population were also examined for our USFWS partners. Additionally, analysis of genetic variability in the species was conducted to better understand the evolutionary potential of the species.
Project Objectives:
The objectives of this study were to investigate factors essential to conservation and management of the Laysan teal:
- Population Dynamics - Identify factors influencing reproduction and mortality on Laysan Island. Develop population models to estimate population size, age, and sex structure and population viability. Determine survival, reproductive status using appropriate models.
- Ecology - Examine behavioral ecology, foraging, wetland use in relation to invertebrate prey densities, prey and habitat availability, and environmental parameters influencing prey and habitat use by Laysan teal.
- Translocation - Apply data gathered on foraging ecology, population dynamics, habitat use, and behavior to make recommendation on best methods, timing, and ecosystem restoration required for the highest probability of a successful translocation and population persistence.
Highlights and Key Findings:
An experimental translocation of Laysan teal from Laysan Island to Midway Atoll NWR was conducted in 2004 and 2005 in collaboration with the USFWS. The 2004 and 2005 experimental reintroduction of 42 birds was successful and won a Recovery Leader Award from the USFWS. The methods and results have been published in books, journals, and reports and have been featured as models and examples for species recovery, adaptive management, and research.
USGS provided technical support and design for the 2014 translocation of Laysan teal from Midway Atoll NWR to Kure Atoll in partnership with the US Coast Guard and the State of Hawai‘i Division of Land and Natural Resources.
- Publications
Below are publications associated with this project.
Filter Total Items: 21How many Laysan Teal Anas laysanensis are on Midway Atoll? Methods for monitoring abundance after reintroduction
Wildlife managers often request a simple approach to monitor the status of species of concern. In response to that need, we used eight years of monitoring data to estimate population size and test the validity of an index for monitoring accurately the abundance of reintroduced, endangered Laysan Teal Anas laysanensis. The population was established at Midway Atoll in the Hawaiian archipelago afterAuthorsMichelle H. Reynolds, Karen Courtot, Jeffrey HatfieldLong-term monitoring of endangered Laysan ducks: Index validation and population estimates 1998–2012
Monitoring endangered wildlife is essential to assessing management or recovery objectives and learning about population status. We tested assumptions of a population index for endangered Laysan duck (or teal; Anas laysanensis) monitored using mark–resight methods on Laysan Island, Hawai’i. We marked 723 Laysan ducks between 1998 and 2009 and identified seasonal surveys through 2012 that met accurAuthorsMichelle H. Reynolds, Karen Courtot, Kevin W. Brinck, Cynthia Rehkemper, Jeffrey HatfieldPeregrine falcon predation of endangered Laysan teal and Laysan Finches on remote Hawaiian atolls
We report the first records of Peregrine falcon (Falco peregrinus) predation on endangered Laysan teal (or duck; Anas laysanensis) and predation on endangered Laysan finches (Telespiza cantans). At Midway Atoll, vagrant Peregrine falcons killed ≥4% of a newly translocated Laysan teal population in 2006 and ≥2% in 2008. On Laysan Island during 2008–2009, remains of >76 Laysan finches (<1% of the poAuthorsMichelle H. Reynolds, Sarah A.B. Nash, Karen CourtotMicrosatellite variation and rare alleles in a bottlenecked Hawaiian Islands endemic: implications for reintroductions
Conservation of genetic biodiversity in endangered wildlife populations is an important challenge to address since the loss of alleles and genetic drift may influence future adaptability. Reintroduction aims to re-establish species to restored or protected ecosystems; however, moving a subset of individuals may result in loss of gene variants during the management-induced bottleneck (i.e. translocAuthorsMichelle H. Reynolds, John M. Pearce, Philip Lavretsky, Pedro P. Seixas, Karen CourtotEvidence of low genetic variation and rare alleles in a bottlenecked endangered island endemic, the Lasan Teal (Anas laysanensis)
Genetic diversity is assumed to reflect the evolutionary potential and adaptability of populations, and thus quantifying the genetic diversity of endangered species is useful for recovery programs. In particular, if conservation strategies include reintroductions, periodic genetic assessments are useful to evaluate whether management efforts have resulted in the maximization or loss of genetic varAuthorsMichelle H. Reynolds, John M. Pearce, Philip Lavretsky, Peters Jeffrey L, Karen Courtot, Pedro P. SeixasExperimental reintroduction reveals novel life-history variation in Laysan Ducks (Anas laysanensis)
Subfossil remains indicate that the Laysan Duck (Anas laysanensis) formerly occurred throughout the Hawaiian archipelago, but for more than 150 years it has been confined to a single, small atoll in the northwestern chain, Laysan Island. In 2004–2005, 42 ducks were reintroduced from Laysan to Midway Atoll, where they exhibited variation in life history never observed on Laysan. On Laysan, females
AuthorsJeffrey R. Walters, Michelle H. ReynoldsDemographic variation, reintroduction, and persistence of an island duck (Anas laysanensis)
Population variation in life history can be important for predicting successful establishment and persistence of reintroduced populations of endangered species. The Laysan duck (Anas laysanensis) is an endangered bird native to the Hawaiian Archipelago that was extirpated from most islands after the introduction of mammalian predators. Laysan ducks were restricted to a single remote island, LaysanAuthorsMichelle H. Reynolds, Emily Weiser, Ian Jamieson, Jeffrey S. HatfieldInfluence of space use on fitness and the reintroduction success of the Laysan teal
Translocation is an important tool for wildlife conservation and biodiversity restoration, but an inefficient one because of the unpredictability of success. Predictors of success such as habitat quality of the release site and number of individuals released have been identified, but the dynamics of successful translocations remain poorly understood. In particular, little is known about the relatiAuthorsM.H. Reynolds, J. S. Hatfield, L.P. Laniawe, M.S. Vekasy, J.L. Klavitter, P. Berkowitz, L.H. Crampton, J. R. WaltersModelling reintroduced populations: The state of the art and future directions
No abstract available.AuthorsDoug P. Armstrong, Michelle H. ReynoldsPopulation estimates and monitoring guidelines for endangered Laysan Teal, Anas Laysanensis, at Midway Atoll: Pilot study results 2008-2010.
Accurate estimates of population size are often crucial to determining status and planning recovery of endangered species. The ability to detect trends in survival and population size over time enables conservation managers to make effective decisions for species and refuge management. During 2004–2007, the translocated population of endangered Laysan Teal (Anas laysanensis; also Laysan Duck) wasAuthorsMichelle H. Reynolds, Kevin W. Brinck, Leona LaniaweAvian botulism: a case study in translocated endangered Laysan ducks (Anas laysanensis) on Midway Atoll
Laysan Ducks are endemic to the Hawaiian archipelago and are one of the world’s most endangered waterfowl. For 150 yr, Laysan Ducks were restricted to an estimated 4 km2 of land on Laysan Island in the northwestern Hawaiian Islands. In 2004 and 2005, 42 Laysan Ducks were translocated to Midway Atoll, and the population increased to approximately 200 by 2007. In August 2008, mortality due to botuliAuthorsThierry M. Work, John L. Klavitter, Michelle H. Reynolds, David S. BlehertTrading off short-term and long-term risk: minimizing the threat of Laysan duck extinction from catastrophes and sea-level rise
Conservation of oceanic island species presents many ecological and logistical challenges. The Northwestern Hawaiian Islands (NWHI) include 300,000 km2 of ocean waters and 10 groups of sub-tropical islands and atolls of high conservation value. Designated as Papahanaumokuakea Marine National Monument, the islands provide habitat for four endangered species of terrestrial birds. Despite their proteAuthorsMichelle Reynolds, Conor P. McGowan, Sarah J. Converse, Brady Mattsson, Jeffrey S. Hatfield, Andrew McClung, Loyal Mehrhoff, Jeffrey R. Walters, Kim Uyehara - Partners
Below are partners associated with this project.