Mercury (Hg) pollution remains a concern to Arctic ecosystems. The objective of this study was to... more Mercury (Hg) pollution remains a concern to Arctic ecosystems. The objective of this study was to identify factors influencing Hg concentrations in Arctic-breeding shorebirds and highlight regions and species at greatest risk of Hg exposure. We analyzed 2,478 blood and feather samples from 12 shorebird species breeding at nine sites across the North American Arctic during 2012 and 2013. Blood Hg concentrations, which reflect Hg exposure in the local area in individual shorebirds: 1) ranged from 0.01–3.52 µg/g, with an overall mean of 0.30 ± 0.27 µg/g; 2) were influenced by species and study site, but not sampling year, with birds sampled near Utqiaġvik, AK, having the highest concentrations; and 3) were influenced by foraging habitat at some sites. Feather Hg concentrations, which reflected Hg exposure from the wintering grounds, were generally higher than blood, ranging from 0.07–12.14 µg/g in individuals, with a mean of 1.14 ± 1.18 µg/g. Feather Hg concentrations were influenced b...
Thesis (M.S.) University of Alaska Fairbanks, 2012Accurate estimates of, and identifying factors ... more Thesis (M.S.) University of Alaska Fairbanks, 2012Accurate estimates of, and identifying factors affecting, survival and productivity can provide insight into population trends and help determine what management actions would most benefit a population. Only limited demographic data are available for many Arctic-breeding shorebird species. I estimated survival probabilities for Arctic-breeding Dunlin (Calidris alpina arcticola); for adults between 2003 and 2010, and for chicks in 2008 and 2009. Adult apparent survival probabilities were higher for males (0.60 ± 0.04) than females (0.41 ± 0.05), were higher for individuals initiating nests earlier in the season, and yearly variation was high. These apparent survival rates appear insufficient to maintain a stable population. Daily survival rates of chicks increased as insect biomass increased across all ages and hatch dates, but the relationship with age and hatch date depended on the values of the other variables. The probability of a...
Abstract. Although much of the Arctic Coastal Plain has remained undeveloped, oil and gas industr... more Abstract. Although much of the Arctic Coastal Plain has remained undeveloped, oil and gas industries, new and expanding villages, as well as tourism are likely to increase in the near future. One potential effect of increased human development is increased anthropogenic waste and the need to dispose of this waste in landfills. We investigated potential indirect effects of the North Slope Borough landfill on breeding shorebirds by examining changes in environmental conditions (predator densities and timing of snow melt) and measures of shorebird reproduction (nest-initiation dates, nest density, nest survival, and return rates) in relation to construction and deposition of waste in the landfill. This study included one year of pre-construction data (2004), three years when landfill roads and fences were being constructed (2005–2007), and five years when waste was being deposited (2008–2012). We monitored 364 shorebird nests within a 36-ha plot (approximately half of which was inside the landfill and half outside). Construction of a fence around the landfill reduced snow levels inside the landfill, leading to earlier snow melt and likely to shorebirds initiating nests earlier. Densities of avian predators increased following waste deposition, but nest densities, nest survival, and return rates were generally greater inside the landfill than outside in all years after landfill construction. Our results indicate that fences placed around landfills and procedures to reduce attraction of predators to landfills can minimize indirect negative effects of landfill construction and operation and even favor species breeding in the area.
Climate change in the Arctic is leading to earlier summers, creating a phenological mismatch betw... more Climate change in the Arctic is leading to earlier summers, creating a phenological mismatch between the hatching of insectivorous birds and the availability of their invertebrate prey. While phenological mismatch would presumably lower the survival of chicks, climate change is also leading to longer, warmer summers that may increase the annual productivity of birds by allowing adults to lay nests over a longer period of time, replace more nests that fail, and provide physiological relief to chicks (i.e., warmer temperatures that reduce thermoregulatory costs). However, there is little information on how these competing ecological processes will ultimately impact the demography of bird populations. In 2008 and 2009, we investigated the survival of chicks from initial and experimentally-induced replacement nests of arcticola Dunlin (Calidris alpina) breeding near Utqiaġvik, Alaska. We monitored survival of 66 broods from 41 initial and 25 replacement nests. Based on the average hatch...
Mercury (Hg) pollution remains a concern to Arctic ecosystems. The objective of this study was to... more Mercury (Hg) pollution remains a concern to Arctic ecosystems. The objective of this study was to identify factors influencing Hg concentrations in Arctic-breeding shorebirds and highlight regions and species at greatest risk of Hg exposure. We analyzed 2,478 blood and feather samples from 12 shorebird species breeding at nine sites across the North American Arctic during 2012 and 2013. Blood Hg concentrations, which reflect Hg exposure in the local area in individual shorebirds: 1) ranged from 0.01–3.52 µg/g, with an overall mean of 0.30 ± 0.27 µg/g; 2) were influenced by species and study site, but not sampling year, with birds sampled near Utqiaġvik, AK, having the highest concentrations; and 3) were influenced by foraging habitat at some sites. Feather Hg concentrations, which reflected Hg exposure from the wintering grounds, were generally higher than blood, ranging from 0.07–12.14 µg/g in individuals, with a mean of 1.14 ± 1.18 µg/g. Feather Hg concentrations were influenced b...
Thesis (M.S.) University of Alaska Fairbanks, 2012Accurate estimates of, and identifying factors ... more Thesis (M.S.) University of Alaska Fairbanks, 2012Accurate estimates of, and identifying factors affecting, survival and productivity can provide insight into population trends and help determine what management actions would most benefit a population. Only limited demographic data are available for many Arctic-breeding shorebird species. I estimated survival probabilities for Arctic-breeding Dunlin (Calidris alpina arcticola); for adults between 2003 and 2010, and for chicks in 2008 and 2009. Adult apparent survival probabilities were higher for males (0.60 ± 0.04) than females (0.41 ± 0.05), were higher for individuals initiating nests earlier in the season, and yearly variation was high. These apparent survival rates appear insufficient to maintain a stable population. Daily survival rates of chicks increased as insect biomass increased across all ages and hatch dates, but the relationship with age and hatch date depended on the values of the other variables. The probability of a...
Abstract. Although much of the Arctic Coastal Plain has remained undeveloped, oil and gas industr... more Abstract. Although much of the Arctic Coastal Plain has remained undeveloped, oil and gas industries, new and expanding villages, as well as tourism are likely to increase in the near future. One potential effect of increased human development is increased anthropogenic waste and the need to dispose of this waste in landfills. We investigated potential indirect effects of the North Slope Borough landfill on breeding shorebirds by examining changes in environmental conditions (predator densities and timing of snow melt) and measures of shorebird reproduction (nest-initiation dates, nest density, nest survival, and return rates) in relation to construction and deposition of waste in the landfill. This study included one year of pre-construction data (2004), three years when landfill roads and fences were being constructed (2005–2007), and five years when waste was being deposited (2008–2012). We monitored 364 shorebird nests within a 36-ha plot (approximately half of which was inside the landfill and half outside). Construction of a fence around the landfill reduced snow levels inside the landfill, leading to earlier snow melt and likely to shorebirds initiating nests earlier. Densities of avian predators increased following waste deposition, but nest densities, nest survival, and return rates were generally greater inside the landfill than outside in all years after landfill construction. Our results indicate that fences placed around landfills and procedures to reduce attraction of predators to landfills can minimize indirect negative effects of landfill construction and operation and even favor species breeding in the area.
Climate change in the Arctic is leading to earlier summers, creating a phenological mismatch betw... more Climate change in the Arctic is leading to earlier summers, creating a phenological mismatch between the hatching of insectivorous birds and the availability of their invertebrate prey. While phenological mismatch would presumably lower the survival of chicks, climate change is also leading to longer, warmer summers that may increase the annual productivity of birds by allowing adults to lay nests over a longer period of time, replace more nests that fail, and provide physiological relief to chicks (i.e., warmer temperatures that reduce thermoregulatory costs). However, there is little information on how these competing ecological processes will ultimately impact the demography of bird populations. In 2008 and 2009, we investigated the survival of chicks from initial and experimentally-induced replacement nests of arcticola Dunlin (Calidris alpina) breeding near Utqiaġvik, Alaska. We monitored survival of 66 broods from 41 initial and 25 replacement nests. Based on the average hatch...
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Papers by Brooke Hill