Biology subjects

Auger-Methe, M.

Publications and source records attributed to Auger-Methe, M..

12 recordsLinked to original sources

bioRxiv2026

Seabird diet and transmission routes mediate the increase in pathogen prevalence with human disturbance

Human disturbances can alter patterns of wildlife infection, but their effects are likely to differ between terrestrial and marine environments. Seabirds range across land and sea and are therefore exposed to diverse human pressures such as urbanization, agriculture, and landfills, as well as fisheries, shipping, and marine pollution. However, most literature on wildlife infection has focused on terrestrial hosts or single type of disturbance (e.g., urbanization). Studying seabirds, which exploit diverse diets and habitats, offers a unique opportunity to disentangle how disturbances at sea and on land, as well as diets, and transmission routes, can change pathogen prevalence at a global scale. We conducted a global literature review and extracted datasets on seabird infection status for a range of pathogens, seabirds diets (piscivore, invertivore, generalist), and pathogen transmission routes (contact-based, vector-borne, intermediate host) to link pathogen prevalence to human disturbances at sea and on land. Our results showed that the association between human disturbances and pathogen prevalence was mediated by species diets and differed across transmission routes. Across gradients of human disturbance at sea, pathogen prevalence in piscivorous seabirds increased from near zero to over 0.7, particularly for contact-based pathogens. Land-based disturbance was also associated with higher pathogen prevalence in generalists across transmission routes, whereas invertivores showed a negative association with terrestrial disturbance. These results indicate that piscivores are most vulnerable in heavily disturbed marine environments, while generalists face greater risk on highly disturbed lands, suggesting that effective disease mitigation will require targeted management actions in both environments.

ecology↗

bioRxiv2025

Including fitness and health proxies can alter our understanding of habitat selection

Habitat selection analyses, which discern the environmental conditions individuals select, often inform conservation planning. Through a literature review, we demonstrate that recent habitat selection studies rarely include fitness and health information. With a simulation study, we show that ignoring such information could support the protection of sink habitats. Our case studies demonstrate how health and fitness proxies can modify our understanding of habitat selection: (1) incorporating mass gain of thick-billed murres shows the energetic benefit of areas deemed secondary by a naive resource selection function; (2) including number of chicks in a step selection function (SSF) exposes the complex relationships glaucous-winged gulls have with landscapes impacted by humans; and (3) including external signs of trauma in the movement kernel of SSFs demonstrate others ways in which narwhal distribution can be altered. We urge movement ecologists to collect and use health and fitness data to improve ecological inference and conservation action.

ecology↗

bioRxiv2025

Using wingbeat frequency to estimate mass gained by seabirds

1. Energy intake is a fundamental currency in ecology that is critical to reproductive success, survival and lifetime fitness. Measuring foraging success in wild animals via biologgers has been a long-standing challenge. 2. Flying animals gain mass during foraging, and they must counteract the associated increased gravitational force by creating additional lift. Pennycuick (1996) proposed that wingbeat frequency (w) should vary with the square root of body mass [Formula], when other variables influencing wingbeat frequency are held constant. 3. We present a state-space model that estimates instantaneous changes in body mass by modelling this relationship with wingbeat frequency using animal-borne accelerometer and depth data. To demonstrate the usefulness of our proposed method, we applied it to biologging data from 55 thick-billed murres (Uria lomvia) during the incubation period. 4. Our mass estimates allowed us to identify areas associated with higher gains, and to demonstrate that foraging success was generally higher farther from the colony. However, 79% of foraging trips were associated with mass deficits. We performed simulation studies to assess the sensitivity of our method to parameter misspecification and the increase in accuracy gained from including the known mass at recapture. As estimates of energy intake allow for testing of long-standing hypotheses in foraging ecology, our method provides a new tool to help answer these questions with any animal that engages in flapping flight.

ecology↗

bioRxiv2025

A Bayesian approach to include Indigenous Knowledge in habitat selection functions

Indigenous Knowledge (IK) of species-habitat relationships provides in-depth understanding of species presence. While IK and Western scientific data are rarely combined in the same model, Bayesian statistics provides a method to include IK as prior knowledge (priors) and combine it with Western data. In partnership with Inupiat hunters, we developed a method to include IK in Bayesian habitat selection functions as priors and show how habitat variables mapped by IK holders can be included as covariates. We explain how to include IK and show the effects of IK in a case study for ringed seals (natchiq in Inupiaq; Pusa hispida). We show that influence of IK can vary depending on the covariate, and how IK provides information at scales not available in Western data. Our work points to the importance of both Western science and IK data sources in models that may be used for conservation and management decisions.

ecology↗

bioRxiv2025

Linking acoustic telemetry data to spatial covariates in river networks with spatially explicit capture-recapture models

O_LISpatially explicit capture-recapture (SECR) models extend classical capture-recapture models to include spatially-explicit animal locations and environmental covariates. SECR models have been widely employed in terrestrial studies to predict the population size and densities of animals assuming a closed population over a defined area. In this work, we extend and apply SECR models to a novel use-case that both uses a relative density formulation and accounts for biased tagging distributions to estimate parameters of habitat use from acoustic telemetry data in a branching river network. C_LIO_LIUsing SECR models, we predict how temperature distributions during the summer feeding season influenced how tagged Arctic grayling (Thymallus arcticus) distributed themselves through the Parsnip watershed in northcentral British Columbia, Canada. We found that the relative density of tagged Arctic grayling peaked at water temperatures of 12.4 {degrees}C. In warm years, relative densities were constricted as parts of the watershed became unfavorably warm. In cool years, fish were distributed widely throughout the watershed. C_LIO_LIIn acoustic telemetry, only the tagged population is available for detection. We highlight several specific considerations and assumptions for using this approach: i.e. (a) activity centres are assumed to remain in the same location throughout the study period, thus the time window of the study should be selected accordingly (e.g., exclude migratory periods); (b) inferences from acoustic telemetry data depict relative (not absolute) densities; and (c) spatial tagging effort must be defined in the model to ensure that predictions are not merely an artefact of tagging effort across space and time. When applied following these assumptions, this method is broadly useful for ecologists as it presents a quantitative way to merge automated telemetry datasets with discrete habitat parameters that drive population distributions through time and are relevant to managers and conservation professionals. Further, this method can be applied to branching river networks in which topological challenges have hindered other statistical approaches. C_LI

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bioRxiv2023

Disrupting traditions of science: Indigenous Knowledge to model species habitat use

While Indigenous Knowledge (IK) contains a wealth of information on the behaviour and habitat use of species, it is rarely included in the species-habitat models frequently used by Western species management authorities. As decisions from these authorities can limit access to species that are important culturally and for subsistence, exclusion of IK in conservation and management frameworks can negatively impact both species and Indigenous communities. In partnership with Inupiat hunters, we developed methods to statistically characterize IK of species-habitat relationships and developed models that rely solely on IK to identify species habitat use and important areas. We provide methods for different types of IK documentation and for dynamic habitat types (e.g., ice concentration). We apply the method to ringed seals (natchiq in Inupiaq) in Alaskan waters, a stock for which the designated critical habitat has been debated in part due to minimal inclusion of IK. Our work demonstrates how IK of species-habitat relationships, with the inclusion of dynamic habitat types, expands on existing mapping approaches and provides another method to identify species habitat use and important areas. The results of this work provide a straightforward and meaningful approach to include IK in species management, especially through co-management processes. "Agencies have a traditional way they do science and including Indigenous Knowledge is less traditional." - Taqulik Hepa, subsistence hunter and Director, North Slope Borough Department of Wildlife Management Statement of PositionalityThis study and the conversion and application of Indigenous Knowledge (IK) for habitat use models was initiated through discussions with the North Slope Borough Department of Wildlife Management (DWM). The DWM is an agency of the regional municipal government representing eight primarily Inupiat subsistence communities in Northern Alaska. One of the goals of the DWM is to "assure participation by Borough residents in the management of wildlife and fish... so that residents can continue to practice traditional methods of subsistence harvest of wildlife resources in perpetuity" (1). Additionally, this project was presented to the Ice Seal Committee (ISC) for review, input, and approval. The ISC is an Alaskan Native organization with representatives from five regions that cover ice-associated seal ranges and "was established to help preserve and enhance ice seal habitat; protect and enhance Alaska Native culture, traditions-particularly activities associated with the subsistence use of ice seals" (2). Both the DWM and the ISC have mandates to manage ice-associated seals considering both IK and Western scientific knowledge (1, 2), and this study was developed to meet those mandates. Inupiat hunters from Utqia[g]vik, Alaska (Figure 1) were collaborators on this project, five of whom are co-authors (B. Adams, B. Frantz, J. Gatten, Q. Harcharek, and R. Sarren), while the other hunter chose to remain anonymous for this publication. The other authors are not Indigenous: R. Gryba was a PhD candidate at the University of British Columbia, M. Auger-Methe and G. Henry are professors at the University of British Columbia, A. Von Duyke is a researcher at the DWM, and H. Huntington is an independent social scientist. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=78 SRC="FIGDIR/small/556613v2_fig1.gif" ALT="Figure 1"> View larger version (13K): org.highwire.dtl.DTLVardef@bf6ec5org.highwire.dtl.DTLVardef@149f2org.highwire.dtl.DTLVardef@9dc98aorg.highwire.dtl.DTLVardef@11aa42a_HPS_FORMAT_FIGEXP M_FIG O_FLOATNOFig. 1.C_FLOATNO Study area around Utqia[g]vik, Alaska (shown in the yellow triangle). C_FIG Significance StatementIndigenous Knowledge (IK) is an extensive source of information of species habitat use and behavior, but is still rarely included in statistical methods used for species conservation and management. Because current conservation practices are frequently still rooted in Western practices many Indigenous organizations are looking for ways for IK to be better included and considered. We worked with Inupiat hunters to develop a new statistical approach to characterize IK and use it as a sole data source in habitat models. This work expands on mapping approaches, that are valuable, but cannot be applied to dynamic habitat types (e.g., ice concentration). This work shows how IK can be meaningfully included in modelling and be considered in current approaches for species management.

ecology↗

bioRxiv2023

Diving efficiency at depth and pre-breeding foraging effort increase with hemoglobin levels in gentoo penguins

Individual differences in oxygen storage and carrying capacity have been associated with fitness-related traits and, for air-breathing aquatic animals, to diving ability and foraging success. In winter, many seabirds must replenish the energy reserves they have depleted during the breeding period. Thus, winter foraging efficiency can influence their upcoming breeding behaviour. Using gentoo penguins (Pygoscelis papua), we investigate (1) if inter-individual variation in diving efficiency (proportion of time spent at the bottom) is associated with indices of oxygen storage and carrying capacity (haemoglobin, haematocrit, body mass), and (2) if measures of pre-breeding foraging effort (mean trip duration, total time at sea, and vertical distance travelled) are associated with these oxygen indices and breeding status. Haemoglobin was positively correlated with diving efficiency, particularly for deeper dives, and only penguins with high haemoglobin levels frequently dove at depth [≥] 140 m. Such differences could affect resource access. However, potentially because reaching deep offshore waters requires travelling more than foraging nearshore, vertical distance travelled pre-breeding increased with haemoglobin levels. The relationship with haematocrit was non-linear, suggesting that commonly-used analyses may be inappropriate for this index. We found that early-laying penguins spent less time at sea prior to nesting than non-breeding penguins, suggesting that more efficient foragers lay earlier. Given that diving efficiency at depth is linked to aerobic capacity, anthropogenic activities taking place in either nearshore or offshore waters (e.g., shallow water fisheries, offshore oil rigs) may have differing impacts on individuals. Further understanding these links could help the conservation of diving species.

ecology↗

bioRxiv2023

The dynamic interaction between predator and prey drives mesopredator movement and foraging ecology

Prey availability and predation risk drive animal distribution, movement, and foraging ecology, yet studies rarely analyze multiple predator-prey levels together. Understanding how predators optimize risk-reward tradeoffs is important for species conservation and management, especially in systems facing extreme ecosystem change. We examined how top-down (modelled polar bear habitat selection) and bottom-up (modeled fish diversity) processes influence the habitat selection, movement, and foraging behavior of 26 ringed seals (greater than 70,000 dives and 10,000 locations over 877 seal days). Our results suggest that polar bears spatially restrict seal movements and reduce the time seals spend foraging, potentially decreasing foraging success. Seals were more likely to be present and dive longer in high-predation risk areas when prey diversity was high. Further, seal habitat selection models excluding polar bears overestimated core space use. These findings illustrate the dynamic tradeoffs that mesopredators make when balancing predation risk and resource acquisition.

ecology↗

bioRxiv2022

Linking movement and dive data to prey distribution models: new insights in foraging behaviour and potential pitfalls of movement analyses

BackgroundAnimal movement data are regularly used to infer foraging behaviour and relationships to environmental characteristics, often to help identify critical habitat. To characterize foraging, movement models make a set of assumptions rooted in theory, for example, time spent foraging in an area increases with higher prey density. MethodsWe assessed the validity of these assumptions by associating horizontal movement and diving of satellite-telemetered ringed seals (Pusa hispida) - an opportunistic predator - in Hudson Bay, Canada, to modelled prey data and environmental proxies. ResultsModelled prey biomass data performed better than their environmental proxies (e.g., sea surface temperature) for explaining seal movement, however movement was not related to foraging effort. Counter to theory, seals appeared to forage more in areas with relatively lower prey diversity and biomass, potentially due to reduced foraging efficiency in those areas. ConclusionsOur study highlights the need to validate movement analyses with prey data to effectively estimate the relationship between prey availability and foraging behaviour.

ecology↗

bioRxiv2022

A statistical censoring approach accounts for hook competition in abundance indices from longline surveys

Fishery-independent longline surveys provide valuable data to monitor fish populations. However, competition for bait on the finite number of hooks leads to biased estimates of relative abundance when using simple catch-per-unit-effort methods. Numerous bias-correcting instantaneous-catch-rate methods have been proposed, modelling the bait removal times as independent random variables. However, experiments have cast doubts on the many assumptions required for these to accurately infer relative abundance. We develop a new approach by treating some observations as right-censored, acknowledging that observed catch counts are lower bounds of what they would have been in the absence of hook competition. Through simulation experiments we confirm that our approach consistently outperforms previous methods. We demonstrate performance of all methods on longline survey data of eleven species. Accounting for hook competition leads to large differences in relative indices (often -50% to +100%), with effects of hook competition varying between species (unlike other methods). Our method can be applied using existing statistical packages and can include environmental influences, making it a general and reliable method for analyzing longline survey data.

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bioRxiv2018

Complex stopover and migratory behavior revealed using mechanistic movement models with environmentally driven dynamic parameters

AstractLong distance migration can increase lifetime fitness, but can be costly, incurring increased energetic expenses and higher mortality risks. Stopover and other en route behaviors allow animals to rest and replenish energy stores and avoid or mitigate other hazards during migration. Some animals, such as soaring birds, can subsidize the energetic costs of migration by extracting energy from flowing air. However, it is unclear how these energy sources affect or interact with behavioral processes and stopover in long-distance soaring migrants. To understand these behaviors and the effects of processes that might enhance use of flight subsidies, we developed a flexible mechanistic model to predict how flight subsidies drive migrant behavior and movement processes. The novel modelling framework incorporated time-varying parameters informed by environmental covariates to characterize a continuous range of behaviors during migration. This model framework was fit to GPS satellite telemetry data collected from a large soaring and opportunist foraging bird, the golden eagle (Aquila chrysaetos), during migration in western North America. Fitted dynamic model parameters revealed a clear circadian rhythm in eagle movement and behavior, which was directly related to thermal uplift. Behavioral budgets were complex, however, with evidence for a joint migrating/foraging behavior, resembling a slower paced fly-and-forage migration, which could facilitate efficient refueling while still ensuring migration progress. In previous work, ecological and foraging conditions are normally considered to be the key aspects of stopover location quality, but taxa that can tap energy sources from moving fluids to drive migratory locomotion, such as the golden eagle, may pace migration based on both foraging opportunities and available flight subsidies.

ecology↗

bioRxiv2018

Movement behaviour responses to environment: fast inference of individual variation with a mixed effects model

Like many species, movement patterns of southern elephant seals (Mirounga leonina) are being influenced by long-term environmental change. These seals migrate up to 4000 km from their breeding colonies, foraging for months in a variety of Southern Ocean habitats. Understanding how movement patterns vary with environmental features and how these relationships differ among individuals employing different foraging strategies can provide insight into foraging performance at a population level. We apply new fast-estimation tools to fit mixed effects within a random walk movement model, rapidly inferring among-individual variability in southern elephant seal environment-movement relationships. We found that seals making foraging trips to the sea-ice on or near the Antarctic continental shelf consistently reduced speed and directionality (move persistence) with increasing sea ice coverage and had variable responses to chlorophyll a concentration, whereas seals that foraged pelagically reduced move persistence in regions where circumpolar deep water shoaled. Given future climate scenarios, pelagic foragers may encounter more productive habitat but sea-ice foragers may see reduced habitat availability. Our approach is scalable to large telemetry data sets and allows flexible combinations of mixed effects to be evaluated via model selection, thereby illuminating the ecological context of animal movements that underlie habitat use.

ecology↗