Avian movements in a modern world - cognitive challenges

Different movement patterns have evolved as a response to predictable and unpredictable variation in the environment with migration being an adaptation to predictable environments, nomadism to unpredictable environments and partial migration to a mixture of predictable and unpredictable conditions. Along different movement patterns different cognitive abilities have evolved which are reviewed and discussed in relation to an organism’s ability to respond to largely unpredictable environmental change due to climate and human-induced change and linked to population trends. In brief, migrants have a combination of reliance on memory, low propensity to explore and high avoidance of environmental change that in combination with overall small brain sizes results in low flexibility to respond to unpredictable environmental change. In line with this, many migrants have negative population trends. In contrast, while nomads may use their memory to find suitable habitats they can counteract negative effects of finding such habitats disturbed by large-scale exploratory movements and paying attention to environmental cues. They are also little avoidant of environmental change. Population trends are largely stable or increasing indicating their ability to cope with climate and human-induced change. Cognitive abilities in partial migrants are little investigated but indicate attention to environmental cues coupled with high exploratory tendencies that allow them a flexible response to unpredictable environmental change. Indeed, their population trends are mainly stable or increasing. In conclusion, cognitive abilities have evolved in conjunction with different movement patterns and affect an organism’s ability to adapt to rapidly human-induced changes in the environment

Oil Vulnerability Index, Impact on Arctic Bird Populations (Proposing a Method for Calculating an Oil Vulnerability Index for the Arctic Seabirds)

In recent decades, political and commercial interest in the Arctic’s resources has increased dramatically. With the projected increase in shipping activity and hydrocarbon extraction, there is an increased risk to marine habitats and organisms. This comes with concomitant threats to the fragile Arctic environment especially from oil, whether from shipping accidents, pipeline leaks, or sub-surface well blowouts. Seabirds are among the most threatened group of birds, and the main threats to these species at-sea are commercial fishing and pollution. Seabirds are vulnerable to oil pollution, which can result in mass mortality events. Species are affected to a differing extent, therefore it is important to objectively predict which species are most at risk from oil spills and where. Assessing the vulnerability of seabirds to oil is achieved through establishing an index for the sensitivity of seabirds to oil – Oil Vulnerability Index (OVI). This incorporates spatial information on the distribution and density of birds as well as on species specific behaviours and other life history characteristics. This chapter focuses on the threat of oil to seabirds, especially in the Arctic, and how an OVI can be used to highlight which species are most at risk and where within the Arctic region.© Springer Nature Switzerland AG 2020. The attached file is the final accepted manuscript version

Polycyclic Aromatic Hydrocarbon Baselines in Gulf of Mexico Fishes

The lack of baseline data has hindered the assessment of impacts from large-scale oil spills throughout their history. Baseline data collected before an adverse event such as an oil spill are critical for quantifying impacts and understanding recovery rates to pre-spill levels. In the case of the two largest oil spills in the Gulf of Mexico (GoM), Deepwater Horizon and Ixtoc 1, the lack of comprehensive contaminant baselines limits our ability to project when the ecosystem will return to pre-spill conditions and assess the short- and long-term impacts of contamination on ecosystems. Beginning in 2011, we initiated comprehensive sampling in the GoM to develop broad-scale and Gulf-wide hydrocarbon contaminant baselines primarily targeting continental shelf fishes in the USA, Mexico, and Cuba. We also developed a time series of collections over 7 years from the region in which DWH occurred. In the event there is another oil spill in the GoM, the samples from these baselines will provide broad-scale but not installation-specific baseline information for the assessment of impact and recovery. This chapter provides a summary of historical sampling and current baseline data for pelagic, mesopelagic, and demersal fish in the GoM. Further, we outline the importance of ongoing and more specific collection of monitoring data for hydrocarbon pollution

Hepatobiliary Analyses Suggest Chronic PAH Exposurein Hakes (\u3cem\u3eUrophycis\u3c/em\u3e spp.) Following the \u3cem\u3eDeepwater Horizon\u3c/em\u3e Oil Spill

Prior to theDeepwater Horizon oil spill, we lacked a comprehensive baseline of oil contamination in the Gulf of Mexico’s sediments, water column, and biota. Gaps in prespill knowledge limit our ability to determine the aftereffects of the Deepwater Horizon blowout or prepare to mitigate similar impacts during future oil spill disasters. We examined spatio temporal differences in exposure to and metabolism of polycyclic aromatic hydrocarbons (PAHs) in 2 hake species (Urophycis spp.)to establish a current baseline for these ecologically important, abundant, and at‐risk demersal fishes. Gulf hake (Urophycis cirrata) and southern hake (Urophycis floridana) were collected throughout the Gulf of Mexico during extensive longline surveys from2012 to 2015. Analyses of biliary PAH metabolites and liver PAH concentrations provided evidence of exposures to di‐and tricyclic compounds, with the highest concentrations measured in the northern Gulf of Mexico. Species‐specific differences were not detected, but temporal trends observed in biliary PAHs suggest a decrease in acute exposures, whereas increasing liver PAHs suggest chronic exposures marked by greater assimilation than metabolism rates. To our knowledge, the present study provides the first multitissue contaminant analyses, as well as the most exhaustive biometric analyses, for both gulf and southern hakes.Though sources of exposure are complex because of multiple natural and anthropogenic PAH inputs, these results will facilitate the development of much needed health metrics for Gulf of Mexico benthos. Environ Toxicol Chem 2019;38:2740–2749.© 2019 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals, Inc. on behalf of SETAC

International migration patterns of Red-throated Loons (<i>Gavia stellata</i>) from four breeding populations in Alaska

<div><p>Identifying post-breeding migration and wintering distributions of migratory birds is important for understanding factors that may drive population dynamics. Red-throated Loons (<i>Gavia stellata</i>) are widely distributed across Alaska and currently have varying population trends, including some populations with recent periods of decline. To investigate population differentiation and the location of migration pathways and wintering areas, which may inform population trend patterns, we used satellite transmitters (n = 32) to describe migration patterns of four geographically separate breeding populations of Red-throated Loons in Alaska. On average (± SD) Red-throated Loons underwent long (6,288 ± 1,825 km) fall and spring migrations predominantly along coastlines. The most northern population (Arctic Coastal Plain) migrated westward to East Asia and traveled approximately 2,000 km farther to wintering sites than the three more southerly populations (Seward Peninsula, Yukon-Kuskokwim Delta, and Copper River Delta) which migrated south along the Pacific coast of North America. These migration paths are consistent with the hypothesis that Red-throated Loons from the Arctic Coastal Plain are exposed to contaminants in East Asia. The three more southerly breeding populations demonstrated a chain migration pattern in which the more northerly breeding populations generally wintered in more northerly latitudes. Collectively, the migration paths observed in this study demonstrate that some geographically distinct breeding populations overlap in wintering distribution while others use highly different wintering areas. Red-throated Loon population trends in Alaska may therefore be driven by a wide range of effects throughout the annual cycle.</p></div