We determined the effects of inbreeding, husbandry, age, and pair bond tenure on reproductive suc... more We determined the effects of inbreeding, husbandry, age, and pair bond tenure on reproductive success in captive populations of endangered Hawaiian Geese, or Nene Branta sandvicensis. We found evidence of inbreeding depressions among captive Nene from Hawaii. At the Hawaiian colony, fertility, hatchability, and total survivorship decreased as male inbreeding coefficient increased, and survivorship decreased as co-ancestry coefficient increased. Husbandry, age and pair bond tenure also influenced reproductive success. At the Hawaiian colony, fertility increased with pair bond tenure, hatchability decreased with incubation type, and total survivorship decreased with incubation type and female age. To maximize reproductive success within the colonies, inbreeding should be minimized, older females should not be allowed to breed, and pari bonds should be maintained.
On March 11, 2011, ocean surges caused by a 9.0 magnitude earthquake off of Honshu, Japan reached... more On March 11, 2011, ocean surges caused by a 9.0 magnitude earthquake off of Honshu, Japan reached the Hawaiian Islands and inundated extensive areas along Maui’s north shore, including large portions of Kanahā Pond Wildlife Sanctuary. The surges traveled one-third the sanctuary’s width at its greatest extent (water depth 1.37 m), filling normally dry areas with seawater, some unfortunate sea life, coral rubble, and other debris. Initial assessments suggested that certain native coastal plants including Scaevola taccada, Ipomoea pes-caprae, and Sesuvium portulacastrum fared better than introduced species. Twenty-six of 30 introduced species were moderately to heavily impacted by inundation, with 25 of 30 experiencing high levels of mortality in affected areas. Particularly vulnerable were introduced grasses and herbaceous taxa, as well as the invasive shrub Pluchea indica. After one year, however, the introduced grass, Cynodon dactylon, which initially dropped in cover from 62% to 51...
each to support the cost of compiling and publishing the data; there is no fee for children under... more each to support the cost of compiling and publishing the data; there is no fee for children under 18. Visit www.audubon.org/ bird/cbc for more information. This one-day annual event is a great opportunity to meet other local volunteers, hone your birding skills, and take part in a seasonal tradition. Come out this year and help to collect valuable data for Hawai'i; contact a coordinator today!
Female reproductive success in the unisexual perennial clonal moss Hylocomium splendens was exami... more Female reproductive success in the unisexual perennial clonal moss Hylocomium splendens was examined by recording, if the segment was reproductive [produced sporophyte(s)] or not, together with several distance-to-male and male density variables, and segment size. This was done for every female segment in a population over a 5 year study period. A high fraction of the population could be sexed because we monitored the population in situ for 5 years, and thereafter harvested the population for electrophoretic analysis from which the clonal identity and expressed sex could be deduced. Fertilization distances in H. splendens were short, indicated by the fact that as many as 85% of the female segments with sporophytes were situated within a distance of 5.0 cm from the nearest male. The longest distance measured between a sporophytic female and the closest male was 11.6 cm. However, analysed within a generalized linear modelling (GLM) framework, the year was the best single predictor for the presence of H. splendens sporophyte although female-segment size and distance to the closest situated male were also strongly significant. The two latter factors explained larger fractions of variation in sporophyte presence in a GLM model with three predictors than in single-predictor models. This is because (i) the large variation in sporophyte production among years partly obscures the strong general increase in sporophyte production with increasing female-segment size and vitality, and (ii) the between-year variation and the size obscure the effect of the distance to the most proximate male. To our knowledge, this study is the first to incorporate into one model the relative importance of several factors for bryophyte reproductive success. Our results demonstrate the value of multiple-predictor approaches in studies of reproductive success.
DNA fingerprinting was used to assess levels of genetic variation in 106 Hawaiian Geese, or Nene ... more DNA fingerprinting was used to assess levels of genetic variation in 106 Hawaiian Geese, or Nene (Branta sandvicensis), from two captive colonies in Hawaii and Slimbridge, England. Mantel tests were used to determine differences in mean similarity coefficients obtained from DNA fingerprints between unrelated and related Nene within and between captive colonies and to determine whetherpedigree-based estimates of relatedness correlated with DNA fingerprint-based estimates. Between colonies, mean similarity coefficients for unrelated and related Slimbridge Nene were higher than those for Hawaiian Nene. Within each colony, related Nene had higher mean similarity coefficients than did unrelated Nene. A positive relationship was found between coancestry coefficients and similarity coefficients. A
Foraging segregation may play an important role in the maintenance of animal diversity, and is a ... more Foraging segregation may play an important role in the maintenance of animal diversity, and is a proposed mechanism for promoting genetic divergence within seabird species. However, little information exists regarding its presence among seabird populations. We investigated genetic and foraging divergence between two colonies of endangered Hawaiian petrels (Pterodroma sandwichensis) nesting on the islands of Hawaii and Kauai using the mitochondrial Cytochrome b gene and carbon, nitrogen and hydrogen isotope values (d 13 C, d 15 N and dD, respectively) of feathers. Genetic analyses revealed strong differentiation between colonies on Hawaii and Kauai, with U ST = 0.50 (p \ 0.0001). Coalescent-based analyses gave estimates of \1 migration event per 1,000 generations. Hatch-year birds from Kauai had significantly lower d 13 C and d 15 N values than those from Hawaii. This is consistent with Kauai birds provisioning chicks with prey derived from near or north of the Hawaiian Islands, and Hawaii birds provisioning young with prey from regions of the equatorial Pacific characterized by elevated d 15 N values at Communicated by Markku Orell.
Foraging segregation may play an important role in the maintenance of animal diversity, and is a ... more Foraging segregation may play an important role in the maintenance of animal diversity, and is a proposed mechanism for promoting genetic divergence within seabird species. However, little information exists regarding its presence among seabird populations. We investigated genetic and foraging divergence between two colonies of endangered Hawaiian petrels (Pterodroma sandwichensis) nesting on the islands of Hawaii and Kauai using the mitochondrial Cytochrome b gene and carbon, nitrogen and hydrogen isotope values (d 13 C, d 15 N and dD, respectively) of feathers. Genetic analyses revealed strong differentiation between colonies on Hawaii and Kauai, with U ST = 0.50 (p \ 0.0001). Coalescent-based analyses gave estimates of \1 migration event per 1,000 generations.
Foraging segregation may play an important role in the maintenance of animal diversity, and is a ... more Foraging segregation may play an important role in the maintenance of animal diversity, and is a proposed mechanism for promoting genetic divergence within seabird species. However, little information exists regarding its presence among seabird populations. We investigated genetic and foraging divergence between two colonies of endangered Hawaiian petrels (Pterodroma sandwichensis) nesting on the islands of Hawaii and Kauai using the mitochondrial Cytochrome b gene and carbon, nitrogen and hydrogen isotope values (d 13 C, d 15 N and dD, respectively) of feathers. Genetic analyses revealed strong differentiation between colonies on Hawaii and Kauai, with U ST = 0.50 (p \ 0.0001). Coalescent-based analyses gave estimates of \1 migration event per 1,000 generations.
We determined the effects of inbreeding, husbandry, age, and pair bond tenure on reproductive suc... more We determined the effects of inbreeding, husbandry, age, and pair bond tenure on reproductive success in captive populations of endangered Hawaiian Geese, or Nene Branta sandvicensis. We found evidence of inbreeding depressions among captive Nene from Hawaii. At the Hawaiian colony, fertility, hatchability, and total survivorship decreased as male inbreeding coefficient increased, and survivorship decreased as co-ancestry coefficient increased. Husbandry, age and pair bond tenure also influenced reproductive success. At the Hawaiian colony, fertility increased with pair bond tenure, hatchability decreased with incubation type, and total survivorship decreased with incubation type and female age. To maximize reproductive success within the colonies, inbreeding should be minimized, older females should not be allowed to breed, and pari bonds should be maintained.
On March 11, 2011, ocean surges caused by a 9.0 magnitude earthquake off of Honshu, Japan reached... more On March 11, 2011, ocean surges caused by a 9.0 magnitude earthquake off of Honshu, Japan reached the Hawaiian Islands and inundated extensive areas along Maui’s north shore, including large portions of Kanahā Pond Wildlife Sanctuary. The surges traveled one-third the sanctuary’s width at its greatest extent (water depth 1.37 m), filling normally dry areas with seawater, some unfortunate sea life, coral rubble, and other debris. Initial assessments suggested that certain native coastal plants including Scaevola taccada, Ipomoea pes-caprae, and Sesuvium portulacastrum fared better than introduced species. Twenty-six of 30 introduced species were moderately to heavily impacted by inundation, with 25 of 30 experiencing high levels of mortality in affected areas. Particularly vulnerable were introduced grasses and herbaceous taxa, as well as the invasive shrub Pluchea indica. After one year, however, the introduced grass, Cynodon dactylon, which initially dropped in cover from 62% to 51...
each to support the cost of compiling and publishing the data; there is no fee for children under... more each to support the cost of compiling and publishing the data; there is no fee for children under 18. Visit www.audubon.org/ bird/cbc for more information. This one-day annual event is a great opportunity to meet other local volunteers, hone your birding skills, and take part in a seasonal tradition. Come out this year and help to collect valuable data for Hawai'i; contact a coordinator today!
Female reproductive success in the unisexual perennial clonal moss Hylocomium splendens was exami... more Female reproductive success in the unisexual perennial clonal moss Hylocomium splendens was examined by recording, if the segment was reproductive [produced sporophyte(s)] or not, together with several distance-to-male and male density variables, and segment size. This was done for every female segment in a population over a 5 year study period. A high fraction of the population could be sexed because we monitored the population in situ for 5 years, and thereafter harvested the population for electrophoretic analysis from which the clonal identity and expressed sex could be deduced. Fertilization distances in H. splendens were short, indicated by the fact that as many as 85% of the female segments with sporophytes were situated within a distance of 5.0 cm from the nearest male. The longest distance measured between a sporophytic female and the closest male was 11.6 cm. However, analysed within a generalized linear modelling (GLM) framework, the year was the best single predictor for the presence of H. splendens sporophyte although female-segment size and distance to the closest situated male were also strongly significant. The two latter factors explained larger fractions of variation in sporophyte presence in a GLM model with three predictors than in single-predictor models. This is because (i) the large variation in sporophyte production among years partly obscures the strong general increase in sporophyte production with increasing female-segment size and vitality, and (ii) the between-year variation and the size obscure the effect of the distance to the most proximate male. To our knowledge, this study is the first to incorporate into one model the relative importance of several factors for bryophyte reproductive success. Our results demonstrate the value of multiple-predictor approaches in studies of reproductive success.
DNA fingerprinting was used to assess levels of genetic variation in 106 Hawaiian Geese, or Nene ... more DNA fingerprinting was used to assess levels of genetic variation in 106 Hawaiian Geese, or Nene (Branta sandvicensis), from two captive colonies in Hawaii and Slimbridge, England. Mantel tests were used to determine differences in mean similarity coefficients obtained from DNA fingerprints between unrelated and related Nene within and between captive colonies and to determine whetherpedigree-based estimates of relatedness correlated with DNA fingerprint-based estimates. Between colonies, mean similarity coefficients for unrelated and related Slimbridge Nene were higher than those for Hawaiian Nene. Within each colony, related Nene had higher mean similarity coefficients than did unrelated Nene. A positive relationship was found between coancestry coefficients and similarity coefficients. A
Foraging segregation may play an important role in the maintenance of animal diversity, and is a ... more Foraging segregation may play an important role in the maintenance of animal diversity, and is a proposed mechanism for promoting genetic divergence within seabird species. However, little information exists regarding its presence among seabird populations. We investigated genetic and foraging divergence between two colonies of endangered Hawaiian petrels (Pterodroma sandwichensis) nesting on the islands of Hawaii and Kauai using the mitochondrial Cytochrome b gene and carbon, nitrogen and hydrogen isotope values (d 13 C, d 15 N and dD, respectively) of feathers. Genetic analyses revealed strong differentiation between colonies on Hawaii and Kauai, with U ST = 0.50 (p \ 0.0001). Coalescent-based analyses gave estimates of \1 migration event per 1,000 generations. Hatch-year birds from Kauai had significantly lower d 13 C and d 15 N values than those from Hawaii. This is consistent with Kauai birds provisioning chicks with prey derived from near or north of the Hawaiian Islands, and Hawaii birds provisioning young with prey from regions of the equatorial Pacific characterized by elevated d 15 N values at Communicated by Markku Orell.
Foraging segregation may play an important role in the maintenance of animal diversity, and is a ... more Foraging segregation may play an important role in the maintenance of animal diversity, and is a proposed mechanism for promoting genetic divergence within seabird species. However, little information exists regarding its presence among seabird populations. We investigated genetic and foraging divergence between two colonies of endangered Hawaiian petrels (Pterodroma sandwichensis) nesting on the islands of Hawaii and Kauai using the mitochondrial Cytochrome b gene and carbon, nitrogen and hydrogen isotope values (d 13 C, d 15 N and dD, respectively) of feathers. Genetic analyses revealed strong differentiation between colonies on Hawaii and Kauai, with U ST = 0.50 (p \ 0.0001). Coalescent-based analyses gave estimates of \1 migration event per 1,000 generations.
Foraging segregation may play an important role in the maintenance of animal diversity, and is a ... more Foraging segregation may play an important role in the maintenance of animal diversity, and is a proposed mechanism for promoting genetic divergence within seabird species. However, little information exists regarding its presence among seabird populations. We investigated genetic and foraging divergence between two colonies of endangered Hawaiian petrels (Pterodroma sandwichensis) nesting on the islands of Hawaii and Kauai using the mitochondrial Cytochrome b gene and carbon, nitrogen and hydrogen isotope values (d 13 C, d 15 N and dD, respectively) of feathers. Genetic analyses revealed strong differentiation between colonies on Hawaii and Kauai, with U ST = 0.50 (p \ 0.0001). Coalescent-based analyses gave estimates of \1 migration event per 1,000 generations.
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Papers by Fern Duvall