Karen (Fischer) Courtot has worked as a biologist at PIERC since 2011. Karen coordinates 'ōpe'ape'a (Hawaiian hoary bat) projects and center-wide project and data management. Her previous work at PIERC focused on investigations of potential impacts of sea-level rise on wildlife in the Northwestern Hawaiian Islands and studies of the ecology and population dynamics of Laysan ducks.
Education and Certifications
M.S. Wildlife Science, Oregon State University, Corvallis, Oregon
B.A. Ecology and Evolutionary Biology, University of Colorado, Boulder, Colorado
Science and Products
Filter Total Items: 16
Hawaiian hoary bat acoustic surveys on Marine Corps Base Hawaii, 2019–2021
The endangered Hawaiian hoary bat (Lasiurus semotus, Vespertilionidae, also known as Aeorestes semotus and ‘ōpe‘ape‘a) occurs on all the principal volcanic islands in Hawai‘i. Advances in acoustic bat monitoring techniques have contributed to the body of knowledge of bat activity and behavior in many areas of the State of Hawai‘i; however, there is still much that is unknown about the population a
Survival of Laysan Teal Anas laysanensis differs among island populations: Role of chronic avian botulism
Monitoring demographic response over time is valuable for understanding population dynamics of endangered species. We quantified the variation in survival patterns for three small isolated island populations of endangered waterfowl in the Hawaiian Archipelago. Laysan Teal Anas laysanensis were individually marked and the fate of 1,150 individuals were followed from different cohorts among the two
How 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 after
Lessons from the Tōhoku tsunami: A model for island avifauna conservation prioritization
Earthquake-generated tsunamis threaten coastal areas and low-lying islands with sudden flooding. Although human hazards and infrastructure damage have been well documented for tsunamis in recent decades, the effects on wildlife communities rarely have been quantified. We describe a tsunami that hit the world's largest remaining tropical seabird rookery and estimate the effects of sudden flooding o
A low-disturbance capture technique for ground-nesting Double-crested Cormorants (Phalacrocorax auritus)
Capturing breeding adults of colonially nesting species can entail risks of nest failure and even colony abandonment, especially in species that react strongly to human disturbance. A low-disturbance technique for capturing specific adult Double-crested Cormorants (Phalacrocorax auritus) at a ground-nesting colony was developed to reduce these risks and is described here. Nesting habitat enhanceme
Will the effects of sea-level rise create ecological traps for Pacific Island seabirds?
More than 18 million seabirds nest on 58 Pacific islands protected within vast U.S. Marine National Monuments (1.9 million km2). However, most of these seabird colonies are on low-elevation islands and sea-level rise (SLR) and accompanying high-water perturbations are predicted to escalate with climate change. To understand how SLR may impact protected islands and insular biodiversity, we modeled
Developing nondestructive techniques for managing conflicts between fisheries and double-crested cormorant colonies
Double-crested cormorants (Phalacrocorax auritus) have been identified as the source of significant mortality to juvenile salmonids (Oncorhynchus spp.) in the Columbia River Basin. Management plans for reducing the size of a large colony on East Sand Island (OR, USA) in the Columbia River estuary are currently being developed. We evaluated habitat enhancement and social attraction as nondestructiv
Long-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 accur
Peregrine 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 (
Microsatellite 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. transloc
Recent population size, trends, and limiting factors for the double-crested Cormorant in Western North America
The status of the double-crested cormorant (Phalacrocorax auritus) in western North America was last evaluated during 1987–2003. In the interim, concern has grown over the potential impact of predation by double-crested cormorants on juvenile salmonids (Oncorhynchusspp.), particularly in the Columbia Basin and along the Pacific coast where some salmonids are listed for protection under the United
Evidence 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 var
Conservation Genetics of the Hawaiian Hoary Bat
The Hawaiian Hoary Bat (Lasiurus semotus) or ʻōpeʻapeʻa is the only extant land mammal native to the Hawaiian archipelago and is listed as endangered due to apparent population declines, and a lack of knowledge concerning its distribution, abundance, and habitat needs. This study is designed to apply molecular techniques to document demographic information, assess genetic variability, describe...
Ecology and Distribution of the Endangered Hawaiian Hoary Bat
The Hawaiian Hoary Bat (Lasiurus cinereus semotus) is the only extant land mammal native to the Hawaiian archipelago. It is listed as endangered due to apparent population declines, and a lack of knowledge concerning its distribution, abundance, and habitat needs. Agencies and landowners in Hawai‘i seek to assist in the creation of sustainable uses for managed lands while also protecting bat...
Sea-Level Rise and Tsunami Vulnerability of Habitat and Wildlife of the Northwestern Hawaiian Islands
Low-elevation Pacific islands are vulnerable to inundation from sea-level rise and sudden flooding events. The largely low-lying islands of Northwestern Hawaiian Islands (NWHI), that extend 1,930 km beyond the main Hawaiian Islands, are a World Heritage Site and part of the Papahānaumokuākea Marine National Monument. The NWHI support the largest tropical seabird rookery in the world, provide...
Movements and Demographic Factors Limiting Recovery of Endangered Koloa Maoli (Hawaiian Duck)
USGS and Oregon State University (OSU) have joined forces to support USFWS with research needed help manage and recover the endangered Hawaiian duck, locally known as koloa maoli. Hybridization of koloa with feral Mallards on O‘ahu and Maui is believed to have resulted in complete introgression in those populations (Engilis et al. 2002), and Kaua‘i is the only island that likely supports a viable...
Predicting the Risk of Species Extinctions Due to Sea-Level Rise in the Northwestern Hawaiian Islands
If current climate change trends continue, rising sea levels could inundate low-lying islands across the globe. The Northwestern Hawaiian Islands (NWHI) is a group of islands of great conservation importance that is threatened by sea-level rise. Stretching 2,000 km beyond the main Hawaiian Islands, the NWHI are a World Heritage Site and part of the Papahānaumokuākea Marine National Monument. The i...
Hawaii Island bird activity from 2014 through 2019
We used an automated radio telemetry network to document the activity of radio telemetered Hawaiian forest birds in two study sites, one a continuous forest and the other a fragmented forest. Four bird species were studied: the nectarivorous 'i'iwi (Drepanis coccinea) and 'apapane (Himatione sanguinea), the frugivorous 'oma'o (Myadestes obscurus), and the generalist Hawai'i 'amakihi (Chlorodrepani
Northwestern Hawaiian Islands Laysan duck survival 1998-2018
Monitoring demographic response over time is valuable for understanding population dynamics of endangered species. We quantified the variation in survival patterns for three small isolated island populations of endangered Laysan ducks (Anas laysanensis; also called Laysan teal) in the Hawaiian Archipelago using data from individually marked birds. Using the median or maximum resight intervals of i
Hawaii Island, Hawaiian hoary bat roosting ecology and detection 2018-2019
The Hawaiian hoary bat (Lasiurus cinereus semotus), a federally and state listed endangered subspecies, is the only extant native terrestrial mammal in the Hawaiian archipelago. It is an insectivorous, solitary and foliage-roosting species that generally roosts alone or in mother-pup family groups. A total of 58 bats (17 female; 41 male; 56 adult; 2 juvenile) were captured at multiple locations on
Northwestern Hawaiian Islands Sea-level Rise Scenarios and Models 2010-2015
This data release consists of two ESRI geodatabases that store inundation areas for various future scenarios of sea-level rise (SLR), groundwater rise, and storm waves for Laysan Island and Midway Atoll in the Northwestern Hawaiian Islands. Five types of inundation scenarios are considered: (1) passive SLR, (2) passive SLR including groundwater rise, (3) wave-driven inundation during storm events,
Northwestern Hawaiian Islands: Impacts to Avifauna from the Tohoku Tsunami 2011
This collection of nine datasets covers Midway Atoll and Laysan Island in the Northwestern Hawaiian Islands, and was created to help estimate the impacts of the March 11, 2011 tsunami event on avifauna in the Northwestern Hawaiian Islands. For each island, we generated a coastline dataset and a land cover dataset based on satellite imagery taken the year before the tsuanmi event. We also created d
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Filter Total Items: 16
Hawaiian hoary bat acoustic surveys on Marine Corps Base Hawaii, 2019–2021
The endangered Hawaiian hoary bat (Lasiurus semotus, Vespertilionidae, also known as Aeorestes semotus and ‘ōpe‘ape‘a) occurs on all the principal volcanic islands in Hawai‘i. Advances in acoustic bat monitoring techniques have contributed to the body of knowledge of bat activity and behavior in many areas of the State of Hawai‘i; however, there is still much that is unknown about the population aSurvival of Laysan Teal Anas laysanensis differs among island populations: Role of chronic avian botulism
Monitoring demographic response over time is valuable for understanding population dynamics of endangered species. We quantified the variation in survival patterns for three small isolated island populations of endangered waterfowl in the Hawaiian Archipelago. Laysan Teal Anas laysanensis were individually marked and the fate of 1,150 individuals were followed from different cohorts among the twoHow 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 afterLessons from the Tōhoku tsunami: A model for island avifauna conservation prioritization
Earthquake-generated tsunamis threaten coastal areas and low-lying islands with sudden flooding. Although human hazards and infrastructure damage have been well documented for tsunamis in recent decades, the effects on wildlife communities rarely have been quantified. We describe a tsunami that hit the world's largest remaining tropical seabird rookery and estimate the effects of sudden flooding oA low-disturbance capture technique for ground-nesting Double-crested Cormorants (Phalacrocorax auritus)
Capturing breeding adults of colonially nesting species can entail risks of nest failure and even colony abandonment, especially in species that react strongly to human disturbance. A low-disturbance technique for capturing specific adult Double-crested Cormorants (Phalacrocorax auritus) at a ground-nesting colony was developed to reduce these risks and is described here. Nesting habitat enhancemeWill the effects of sea-level rise create ecological traps for Pacific Island seabirds?
More than 18 million seabirds nest on 58 Pacific islands protected within vast U.S. Marine National Monuments (1.9 million km2). However, most of these seabird colonies are on low-elevation islands and sea-level rise (SLR) and accompanying high-water perturbations are predicted to escalate with climate change. To understand how SLR may impact protected islands and insular biodiversity, we modeledDeveloping nondestructive techniques for managing conflicts between fisheries and double-crested cormorant colonies
Double-crested cormorants (Phalacrocorax auritus) have been identified as the source of significant mortality to juvenile salmonids (Oncorhynchus spp.) in the Columbia River Basin. Management plans for reducing the size of a large colony on East Sand Island (OR, USA) in the Columbia River estuary are currently being developed. We evaluated habitat enhancement and social attraction as nondestructivLong-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 accurPeregrine 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 (Microsatellite 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. translocRecent population size, trends, and limiting factors for the double-crested Cormorant in Western North America
The status of the double-crested cormorant (Phalacrocorax auritus) in western North America was last evaluated during 1987–2003. In the interim, concern has grown over the potential impact of predation by double-crested cormorants on juvenile salmonids (Oncorhynchusspp.), particularly in the Columbia Basin and along the Pacific coast where some salmonids are listed for protection under the UnitedEvidence 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 var - Science
Conservation Genetics of the Hawaiian Hoary Bat
The Hawaiian Hoary Bat (Lasiurus semotus) or ʻōpeʻapeʻa is the only extant land mammal native to the Hawaiian archipelago and is listed as endangered due to apparent population declines, and a lack of knowledge concerning its distribution, abundance, and habitat needs. This study is designed to apply molecular techniques to document demographic information, assess genetic variability, describe...Ecology and Distribution of the Endangered Hawaiian Hoary Bat
The Hawaiian Hoary Bat (Lasiurus cinereus semotus) is the only extant land mammal native to the Hawaiian archipelago. It is listed as endangered due to apparent population declines, and a lack of knowledge concerning its distribution, abundance, and habitat needs. Agencies and landowners in Hawai‘i seek to assist in the creation of sustainable uses for managed lands while also protecting bat...Sea-Level Rise and Tsunami Vulnerability of Habitat and Wildlife of the Northwestern Hawaiian Islands
Low-elevation Pacific islands are vulnerable to inundation from sea-level rise and sudden flooding events. The largely low-lying islands of Northwestern Hawaiian Islands (NWHI), that extend 1,930 km beyond the main Hawaiian Islands, are a World Heritage Site and part of the Papahānaumokuākea Marine National Monument. The NWHI support the largest tropical seabird rookery in the world, provide...Movements and Demographic Factors Limiting Recovery of Endangered Koloa Maoli (Hawaiian Duck)
USGS and Oregon State University (OSU) have joined forces to support USFWS with research needed help manage and recover the endangered Hawaiian duck, locally known as koloa maoli. Hybridization of koloa with feral Mallards on O‘ahu and Maui is believed to have resulted in complete introgression in those populations (Engilis et al. 2002), and Kaua‘i is the only island that likely supports a viable...Predicting the Risk of Species Extinctions Due to Sea-Level Rise in the Northwestern Hawaiian Islands
If current climate change trends continue, rising sea levels could inundate low-lying islands across the globe. The Northwestern Hawaiian Islands (NWHI) is a group of islands of great conservation importance that is threatened by sea-level rise. Stretching 2,000 km beyond the main Hawaiian Islands, the NWHI are a World Heritage Site and part of the Papahānaumokuākea Marine National Monument. The i... - Data
Hawaii Island bird activity from 2014 through 2019
We used an automated radio telemetry network to document the activity of radio telemetered Hawaiian forest birds in two study sites, one a continuous forest and the other a fragmented forest. Four bird species were studied: the nectarivorous 'i'iwi (Drepanis coccinea) and 'apapane (Himatione sanguinea), the frugivorous 'oma'o (Myadestes obscurus), and the generalist Hawai'i 'amakihi (ChlorodrepaniNorthwestern Hawaiian Islands Laysan duck survival 1998-2018
Monitoring demographic response over time is valuable for understanding population dynamics of endangered species. We quantified the variation in survival patterns for three small isolated island populations of endangered Laysan ducks (Anas laysanensis; also called Laysan teal) in the Hawaiian Archipelago using data from individually marked birds. Using the median or maximum resight intervals of iHawaii Island, Hawaiian hoary bat roosting ecology and detection 2018-2019
The Hawaiian hoary bat (Lasiurus cinereus semotus), a federally and state listed endangered subspecies, is the only extant native terrestrial mammal in the Hawaiian archipelago. It is an insectivorous, solitary and foliage-roosting species that generally roosts alone or in mother-pup family groups. A total of 58 bats (17 female; 41 male; 56 adult; 2 juvenile) were captured at multiple locations onNorthwestern Hawaiian Islands Sea-level Rise Scenarios and Models 2010-2015
This data release consists of two ESRI geodatabases that store inundation areas for various future scenarios of sea-level rise (SLR), groundwater rise, and storm waves for Laysan Island and Midway Atoll in the Northwestern Hawaiian Islands. Five types of inundation scenarios are considered: (1) passive SLR, (2) passive SLR including groundwater rise, (3) wave-driven inundation during storm events,Northwestern Hawaiian Islands: Impacts to Avifauna from the Tohoku Tsunami 2011
This collection of nine datasets covers Midway Atoll and Laysan Island in the Northwestern Hawaiian Islands, and was created to help estimate the impacts of the March 11, 2011 tsunami event on avifauna in the Northwestern Hawaiian Islands. For each island, we generated a coastline dataset and a land cover dataset based on satellite imagery taken the year before the tsuanmi event. We also created d - News
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