Richard Camp - Academia.edu (original) (raw)

Papers by Richard Camp


Science Advances, Sep 2, 2016


CTIT technical reports series, Sep 15, 2017


CTIT technical reports series, Oct 1, 2012

CTIT technical reports series, Nov 1, 2009


The Great Basin naturalist, 1998

CTIT technical reports series, 2009

Hakalau Forest National Wildlife Refuge, on the Island of Hawai'i, was established in 1985 to pro... more Hakalau Forest National Wildlife Refuge, on the Island of Hawai'i, was established in 1985 to protect native forest birds, particularly endangered species. Management actions on the 15,400 ha refuge include removing feral ungulates from the forest and pastures, controlling invasive alien plants, reforesting pastures, and supplementing endangered plant populations. To assess effects of this habitat improvement for birds, we calculated annual density estimates from point transect surveys and examined population trends for eight native and four alien passerine bird species over the 21 years since the refuge was established (1987-2007). We examined trends using a Bayesian approach to log-linear regression. We tested for changes in bird density in three study areas: (1) a middle elevation forest that had been heavily grazed, (2) an upper elevation pasture that was reforested during the study, and (3) a lower area of relatively intact forest that was formerly lightly grazed. In the middle study area, we found that densities of Hawai'i 'Elepaio (Chasiempis s. sandwichensis), and the endangered 'Akiapōlā'au (Hemignathus munroi) and Hawai'i Creeper (Oreomystis mana) increased, and that all other native birds showed stable trends and exhibited no evidence of declining trends as has been seen elsewhere in much of Hawai'i. Trends for all alien birds were also stable, except that House Finch (Carpodacus mexicanus) density has declined. In the lower study area, Hawai'i Creeper and Hawai'i 'Ākepa (Loxops c. coccineus) showed increasing trajectories, and densities have declined for the other native species. Within the reforested upper study area, densities increased for three common native species-Hawai'i 'Amakihi (Hemignathus virens), 'I'iwi (Vestiaria coccinea), and 'Apapane (Himatione sanguinea)-and two alien species-Japanese White-eye (Zosterops japonicus) and House Finch. Bird trends at the Hakalau refuge provide some of the first results of habitat improvement for forest birds in Hawai'i. Restoring tree cover in open pasture and assisting recovery of high-quality habitat benefits both endangered and abundant native birds.

CTIT technical reports series, Jul 1, 2011

Journal of Fish and Wildlife Management

Endemic Hawaiian forest birds have experienced dramatic population declines. The Big Island Natio... more Endemic Hawaiian forest birds have experienced dramatic population declines. The Big Island National Wildlife Refuge Complex (Refuge Complex) was established for the conservation of endangered forest birds and their habitats. Surveys have been conducted at two units of the Refuge Complex to monitor forest bird populations and their response to management actions. We analyzed survey data from 1987 to 2019 at the Hakalau Forest Unit (HFU) and from 1995 to 2019 at the Kona Forest Unit (KFU). We analyzed three strata at HFU: open-forest, closed-forest, and afforested-pasture, and two strata at KFU: upper (>1,524 m elevation) and lower (<1,524 m). In all years, ‘i‘iwi Drepanis coccinea, ‘apapane Himatione sanguinea, and Hawai‘i ‘amakihi Chlorodrepanis virens virens were the most abundant species at HFU. Three endangered forest bird species, Hawai‘i ‘ākepa Loxops coccineus, ‘alawī Loxops mana (also known as Hawai‘i creeper) and ‘akiapōlā‘au Hemignathus wilsoni, had much lower densit...

Wildlife Society Bulletin

Effective species management and conservation benefit from knowledge of species distribution and ... more Effective species management and conservation benefit from knowledge of species distribution and status. Surveys to obtain that information often involve replicate sampling, which increases survey effort and costs. We simultaneously modeled species distribution, abundance and spatial correlation, and compared the uncertainty in replicate abundance estimates of the endangered palila (Loxioides bailleui) using hierarchical generalized additive models with a soap film smoother that incorporated random effects for visit. Based on survey coverage and detections, we selected the 2017 point‐transect distance sampling survey on Mauna Kea, Hawai‘i Island, for our modeling. Our modeling approach allowed us to account for imperfect detections, control the effects of boundary features, and generate visit‐specific density surface maps. We found that visit‐specific smooths were nearly identical, indicating that little information was gained from a subsequent visit, and that most of the estimator ...


Science Advances, Sep 2, 2016


CTIT technical reports series, Sep 15, 2017


CTIT technical reports series, Oct 1, 2012

CTIT technical reports series, Nov 1, 2009


The Great Basin naturalist, 1998

CTIT technical reports series, 2009

Hakalau Forest National Wildlife Refuge, on the Island of Hawai'i, was established in 1985 to pro... more Hakalau Forest National Wildlife Refuge, on the Island of Hawai'i, was established in 1985 to protect native forest birds, particularly endangered species. Management actions on the 15,400 ha refuge include removing feral ungulates from the forest and pastures, controlling invasive alien plants, reforesting pastures, and supplementing endangered plant populations. To assess effects of this habitat improvement for birds, we calculated annual density estimates from point transect surveys and examined population trends for eight native and four alien passerine bird species over the 21 years since the refuge was established (1987-2007). We examined trends using a Bayesian approach to log-linear regression. We tested for changes in bird density in three study areas: (1) a middle elevation forest that had been heavily grazed, (2) an upper elevation pasture that was reforested during the study, and (3) a lower area of relatively intact forest that was formerly lightly grazed. In the middle study area, we found that densities of Hawai'i 'Elepaio (Chasiempis s. sandwichensis), and the endangered 'Akiapōlā'au (Hemignathus munroi) and Hawai'i Creeper (Oreomystis mana) increased, and that all other native birds showed stable trends and exhibited no evidence of declining trends as has been seen elsewhere in much of Hawai'i. Trends for all alien birds were also stable, except that House Finch (Carpodacus mexicanus) density has declined. In the lower study area, Hawai'i Creeper and Hawai'i 'Ākepa (Loxops c. coccineus) showed increasing trajectories, and densities have declined for the other native species. Within the reforested upper study area, densities increased for three common native species-Hawai'i 'Amakihi (Hemignathus virens), 'I'iwi (Vestiaria coccinea), and 'Apapane (Himatione sanguinea)-and two alien species-Japanese White-eye (Zosterops japonicus) and House Finch. Bird trends at the Hakalau refuge provide some of the first results of habitat improvement for forest birds in Hawai'i. Restoring tree cover in open pasture and assisting recovery of high-quality habitat benefits both endangered and abundant native birds.

CTIT technical reports series, Jul 1, 2011

Journal of Fish and Wildlife Management

Endemic Hawaiian forest birds have experienced dramatic population declines. The Big Island Natio... more Endemic Hawaiian forest birds have experienced dramatic population declines. The Big Island National Wildlife Refuge Complex (Refuge Complex) was established for the conservation of endangered forest birds and their habitats. Surveys have been conducted at two units of the Refuge Complex to monitor forest bird populations and their response to management actions. We analyzed survey data from 1987 to 2019 at the Hakalau Forest Unit (HFU) and from 1995 to 2019 at the Kona Forest Unit (KFU). We analyzed three strata at HFU: open-forest, closed-forest, and afforested-pasture, and two strata at KFU: upper (>1,524 m elevation) and lower (<1,524 m). In all years, ‘i‘iwi Drepanis coccinea, ‘apapane Himatione sanguinea, and Hawai‘i ‘amakihi Chlorodrepanis virens virens were the most abundant species at HFU. Three endangered forest bird species, Hawai‘i ‘ākepa Loxops coccineus, ‘alawī Loxops mana (also known as Hawai‘i creeper) and ‘akiapōlā‘au Hemignathus wilsoni, had much lower densit...

Wildlife Society Bulletin

Effective species management and conservation benefit from knowledge of species distribution and ... more Effective species management and conservation benefit from knowledge of species distribution and status. Surveys to obtain that information often involve replicate sampling, which increases survey effort and costs. We simultaneously modeled species distribution, abundance and spatial correlation, and compared the uncertainty in replicate abundance estimates of the endangered palila (Loxioides bailleui) using hierarchical generalized additive models with a soap film smoother that incorporated random effects for visit. Based on survey coverage and detections, we selected the 2017 point‐transect distance sampling survey on Mauna Kea, Hawai‘i Island, for our modeling. Our modeling approach allowed us to account for imperfect detections, control the effects of boundary features, and generate visit‐specific density surface maps. We found that visit‐specific smooths were nearly identical, indicating that little information was gained from a subsequent visit, and that most of the estimator ...