Territory occupancy by breeding yellow‐billed loons near oil development

• Published in: The Journal of Wildlife Management
• Main Authors: Johnson, Charles B., Wildman, Ann M., Prichard, Alexander K., Rea, Caryn L.
• Other Authors: ConocoPhillips Alaska, Inc.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wiley 2018
• Subjects: Gavia adamsii; yellow-billed loon; Alaska
• Online Access: http://dx.doi.org/10.1002/jwmg.21592; https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1002%2Fjwmg.21592; https://onlinelibrary.wiley.com/doi/pdf/10.1002/jwmg.21592; https://onlinelibrary.wiley.com/doi/full-xml/10.1002/jwmg.21592

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 ...