Oil and gas exploration and development is expanding across the Arctic Coastal Plain (ACP) of Alaska, USA. To examine the effects of industrial development on greater white-fronted geese (Anser albifrons), we monitored nests and nesting behavior within a 4-km2 study area within 4 km of gravel roads and pads during pre-development, construction, and operation activities at a new oil development in the National Petroleum Reserve-Alaska in 2013-2019. We examined distribution, incubation constancy, and nest survival in relation to distance to gravel roads or pads, year and status of development, presence of an ice road the previous winter, and land cover type. Nest density increased throughout the study period, which was consistent with surveys of this species in other regions of the ACP. There was no direct evidence that oil extraction infrastructure and the associated human activity adversely influenced the abundance, distribution, or daily nest survival of greater white-fronted goose nests. Geese avoided nesting in the alignments of ice roads from the previous winter, and land cover type influenced their nest distribution. Nest age and incubation constancy were important predictors of daily nest survival. The incubation constancy of successful nesters (98.5 +/- 0.1% [SE]) was significantly greater than for failed nesters (94.7 +/- 0.6%) for all years combined and tended to be greater during the pre-construction and construction years of 2014 and 2015, compared to when oilfield operations began in 2017 and 2019. Greater-white fronted geese appear to be tolerant of some levels of industrial activities and the presence of gravel roads did not have a significant effect on nest distribution, incubation constancy, or nest survival. We recommend, however, that indirect effects from ice roads should be explicitly considered in impact assessments because white-fronted geese avoid nesting in the footprints of the previous winter's ice roads and pads. We monitored nests and nesting behavior of greater white-fronted geese (Anser albifrons) within 4 km of gravel roads and pads during pre-development, construction, and operation activities at a new oil development in the National Petroleum Reserve-Alaska, 2013-2019, to examine the effects of industrial development. We found no evidence that oil extraction infrastructure and the associated human activity adversely influenced the abundance, distribution, or daily nest survival of greater white-fronted goose nests; however, we suggest that indirect effects from ice roads should be explicitly considered in impact assessments because white-fronted geese avoid nesting in the footprints of the previous winter's ice roads and pads. image

The Coastal Plain of northern Alaska is an important nesting area for a variety of avian species, where the productivity of ground-nesting species can be strongly influenced by nest predators. Recently, the density of red foxes (Vulpes vulpes) has increased in many areas of the Arctic, likely because of climate warming as well as the availability of anthropogenic food sources during winter. In areas where they occur sympatrically, red foxes can outcompete and kill the smaller Arctic fox (Vulpes lagopus). There is considerable dietary overlap between the fox species, but if the red fox is a more successful nest predator, this ongoing shift in canid species could have important implications for ground-nesting species like the Yellow-billed Loon (Gavia adamsii). We examined time-lapse photographs from 186 nests of Yellow-billed Loons in northern Alaska during the years 2008 – 15 and 2019 for the presence of foxes and other nest predators and quantified nest predation by species. Although both Arctic and red foxes were photographed near nests, we found that all successful predation of Yellow-billed Loon nests by foxes was attributable to red foxes, which were the second most frequent predator of Yellow-billed Loon nests after Glaucous Gulls (Larus hyperboreus). Arctic foxes photographed at Yellow-billed Loon nests were unsuccessful at displacing incubating loons. Several data sources suggest that the prevalence of red foxes has increased in Arctic Alaska over the last three decades, a change that is likely to have negative impacts on the nesting success of Yellow-billed Loons and possibly other large waterbirds.

Reductions in nest attendance can increase predation risk and, therefore, reduce nesting success of ground-nesting birds. We recorded the incubation behavior, nest predators, and nesting success of yellow-billed loons (Gavia adamsii) at 2 adjacent study areas with differing amounts of industrial activity on the Arctic Coastal Plain of Alaska, USA, during 2008-2015 and 2019. Successful pairs had higher incubation constancies (97.3 +/- 1.7% [SE], n = 96 nests) than failed pairs (91.6 +/- 3.1%, n = 79 nests) and took fewer and shorter recesses than failed pairs. The intrusion of conspecifics into territories significantly lowered the daily incubation constancy of nesting pairs. Daily incubation constancy also declined as the daily maximum temperature increased, especially during periods with little wind. Both conditions contributed to nest failure. Predation was the primary cause of nest failure, with glaucous gulls (Larus hyperboreus) and parasitic jaegers (Stercorarius parasiticus) accounting for 41% of the nest failures. These avian predators took advantage of unattended nests, underscoring the consequence of disrupting incubation behavior. In both study areas, nest survival decreased as recess frequency increased. In the Colville Delta study area, loons with territories composed of separate nesting and brood-rearing lakes had lower nest survival than loons that used 1 lake for both activities. In the National Petroleum Reserve-Alaska study area (NPR-A), loons nesting on shorelines and peninsulas had lower nest survival than those nesting on islands and nest survival decreased as the proportion of days with intruders increased. The overall probability of a nest hatching >= 1 egg in the Colville Delta study area was 0.40 (95% CI = 0.26-0.54) and was 0.68 (95% CI = 0.40-0.91) in the NPR-A study area. Our results demonstrate the importance of nest attendance by yellow-billed loons in warding off nest predators on the Arctic Coastal Plain of Alaska and provide a mechanism that shows how a warming Arctic climate could negatively affect yellow-billed loons.

ABSTRACT Less than 4,000 yellow‐billed loons ( Gavia adamsii ) breed in remote and disjunct locations in northern Alaska, USA. Over 75% of the United States population of yellow‐billed loons nests in the National Petroleum Reserve–Alaska (NPRA), where impending oil and gas development will intersect their breeding range. We investigated the relationship of recent oilfield development to occupancy of yellow‐billed loon territories by breeding pairs (indicated by active nests) and broods using 14 years of aerial surveys on the Colville River delta. We also evaluated the survey requirements prescribed by the Bureau of Land Management (BLM) for NPRA. We began aerial surveys for yellow‐billed loons in 1993, prior to construction of the Alpine oilfield in 1998, and followed territories through 2008, after construction of 2 additional satellite drill sites. We used records from 37 breeding territories on 36 lakes in model selection analyses to examine how habitat and disturbance factors (proximity to facilities and construction time period) influenced occupancy by breeding pairs and broods. Annually, 13 ± 2.5 (SE)% ( n = 14 yr) of broods ( n = 19) moved from nesting lakes to adjacent brood‐rearing lakes, and the remainder stayed in nesting lakes ( n = 128). Lakes used for nesting and brood‐rearing were almost 25 times larger ( = 95.9 ± 25 ha, n = 23 lakes) than nesting lakes from which broods left ( = 4.0 ± 1.1 ha, n = 7 lakes, P < 0.001). Thirty‐eight percent of territories ( n = 14 territories) were on lakes shared by >1 breeding pair. Lake type (deep open lakes with islands or polygonized margins, deep open lakes without islands or polygonized margins, and tapped lakes with high‐water connections) was the most influential covariate on occupancy by breeding pairs, and lake area was most influential on occupancy by broods. Time period and distance to facilities (as discrete zones at 1.6 km and 3.2 km and as linear distance) were factors in the highest‐ranked models for 5 of the 6 model sets that included disturbance parameters. Interaction terms for time period and distance to oilfield facilities were factors in 3 of 6 model sets. The pattern of occupancy of breeding territories, however, was not consistent with disturbance‐related effects. Occupancy of territories by breeding pairs was lower in the pre‐development period (lowest human activity) than in the latest development period (highest human activity) and higher in the zones near oilfield facilities than far from facilities. Occupancy of territories by broods was highest in the latest development period and similarly high in zones near and far from facilities. Application of BLM minimum survey requirements (3 yr with 2 surveys/yr) to the initial 3 years of surveys in this study resulted in detecting 81% of the known territories on the Colville River delta. The BLM restrictions on development were judged conservative in maintaining breeding territories around oilfield developments. Our results did not demonstrate displacement of nests or broods from long‐standing territories by oil development. Our findings suggest that territory occupancy by breeding pairs and broods of yellow‐billed loons on the Colville River delta was resilient to levels of human activity at recently constructed oilfield facilities. © 2018 The Authors. Journal of Wildlife Management published by Wiley Periodicals, Inc. on behalf of The Wildlife Society.

Nest predation may influence population dynamics of birds on the Arctic Coastal Plain (ACP) of Alaska, USA. Anthropogenic development on the ACP is increasing, which may attract nest predators by providing artificial sources of food, perches, den sites, and nest sites. Enhanced populations or concentrations of human-subsidized predators may reduce nest survival for tundra-nesting birds. In this study, we tested the hypothesis that nest survival decreases in proximity to human infrastructure. We monitored 1257 nests of 13 shorebird species and 619 nests of four passerine species at seven sites on the ACP from 2002 to 2005. Study sites were chosen to represent a range of distances to infrastructure from 100 m to 80 km. We used Cox proportional hazards regression models to evaluate the effects of background (i.e., natural) factors and infrastructure on nest survival. We documented high spatial and temporal variability in nest survival, and site and year were both included in the best background model. We did not detect an effect of human infrastructure on nest survival for shorebirds as a group. In contrast, we found evidence that risk of predation for passerine nests increased within 5 km of infrastructure. This finding provides quantitative evidence of a relationship between infrastructure and nest survival for breeding passerines on the ACP. A posteriori finer-scale analyses (within oil field sites and individual species) suggested that Red and Red-necked Phalaropes combined (Phalaropus fulicarius, P. lobatus) had lower productivity closer to infrastructure and in areas with higher abundance of subsidized predators. However, we did not detect such a relationship between infrastructure and nest survival for Semipalmated and Pectoral Sandpipers (Calidris pusilla, C. melanotos), the two most abundant shorebirds. High variability in environmental conditions, nest survival, and predator numbers between sites and years may have contributed to these inconsistent results. We recommend targeted management actions to minimize anthropogenic effects and suggest new research needed on this issue as expanding development is planned for the ACP of Alaska. In particular, we recommend research on demography of key predators and their importance with respect to nest survival, and experimental studies that better address challenges posed by high natural variability.

A study was conducted in 2005 and 2006 to examine the hypothesis that sea otters (Enhydra lutris) continue to be exposed to residues of subsurface oil (SSO) while foraging on shorelines in the northern Knight Island (NKI) area of Prince William Sound, Alaska more than 17 years after the Exxon Valdez oil spill. Forty-three shoreline segments, whose oiling history has been documented by prior surveys, were surveyed. These included all shoreline segments reported by a 2003 NOAA random site survey to contain SSO residues in NKI. Sites were surveyed for the presence and location of otter foraging pits. Only one of 29 SSO sites surveyed was identified as an otter foraging site. Most buried SSO residues are confined to tide elevations above +0.8 m above mean lower low water (MLLW), above the range of intertidal clam habitat. More than 99% of documented intertidal otter pits at all sites surveyed are in the lower intertidal zone (-0.2 to +0.8 m above MLLW), the zone of highest clam abundance. The spatial separation of the otter pits from the locations of SSO residues, both with regard to tidal elevation and lateral separation on the study sites, coupled with the lack of evidence of intertidal otter foraging at SSO sites indicates a low likelihood of exposure of foraging otters to SSO on the shores of the NKI area.

Egg flotation was used to estimate incubation age and eggshell evidence was collected to determine nest fate at nests of 11 species of shorebirds on the Arctic Coastal Plain of Alaska during 2002-2004. We present egg-flotation schedules for nine species to facilitate the estimation of nest age. We evaluated the predictive ability of an egg-flotation schedule for Semipalmated Sandpipers (Calidris pusilla) and were able to estimate incubation age within similar to 1-3 d of the assumed age. Patterns of eggshell evidence were similar across species, with eggshell fragments (1-5 mm) present at most successful nests (96%) and eggshell tops or bottoms present only at successful nests. We determined nest fate independently of eggshell evidence and then used discriminant function analysis to predict the probability of correctly classifying a nest's fate using different types of eggshell evidence. The use of eggshell fragment evidence resulted in the correct classification of the fate of all 11 species of shorebirds in 92% of the cases. Both the egg-flotation technique and eggshell evidence can be used in future studies to calculate accurate measures of reproductive success needed for ecological investigations of shorebirds.

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