Moose Research Articles

Weekend warriors: contrasting temporal patterns in the harvest of three species of boreal ungulates

Understanding the drivers that shape hunter behaviour and success can help guide management decisions regarding hunting. Although there has been work on the socioeconomic and environmental drivers of hunter effort, less quantitative analysis of the temporal patterns of wildlife harvest has been available. Yet, knowing when hunters are most active may be useful for distributing the spatiotemporal allotment of hunting opportunities where real or perceived issues of hunt quality (e.g. hunter congestion) or negative impacts to local people or target and non‐target wildlife species are of concern. As a case study, we used generalized linear models to examine the effect of season, day of week (i.e. weekday versus weekends), and holidays on 26–28 years of harvest data for bison Bison bison, thinhorn sheep Ovis dalli, and moose Alces americanus in Yukon, Canada. These species are important in regional socioecological systems and highly prized by local hunters. For all three species, harvest was significantly greater on weekends than weekdays. Most of the harvest for thinhorn sheep occurred early in the season, consistent with an ‘opening day' phenomenon, whereas that for moose and bison started slowly and increased throughout the season. For all three species harvest was not significantly influenced by holidays. Bison harvest, however, was influenced in relation to public school holidays, with harvest decreasing over the winter (Christmas) break and increasing over spring break in March. Differences between these three species are likely due to species‐specific hunting strategies, the behaviour of each species, hunter competition, and seasonal climate. Identifying patterns in hunter effort and harvest can inform wildlife management decisions on permit allocation. However, our data indicate that species‐specific patterns vary substantially, even in the same region, and need to be understood for proposed changes to the timing of hunting opportunities to be effective.

Application of artificial neural network for description of the Earth remote sensing data to identify natural habitats used by European elk, Alces alces (Linnaeus, 1758), in autumn-winter period 2023

The paper presents the results of using neural networks of pixel-by-pixel image classification to decipher multichannel space images obtained by the Landsat 8 satellite. Natural habitats were identified based on differences in phytocenotic characteristics of land areas. The level of use of areas by elk was determined by the occurrence of elk presence indicators, which were the density of winter excrement piles (in spring) and the abundance of winged forms of the monoxenous ectoparasite of elk, Lipoptena cervi (Linnaeus, 1758), as measured by the number of individuals attacking the census taker (in the summer-autumn period). The material that forms the basis for deciphering was obtained by the route census method in different areas of the Leningrad Province. High values of the measured parameters were recorded in reforestation areas, in wet pine and birch forests, in aspen forests, on the edges of raised bogs and in overgrown fields – typical elk winter feeding habitats. Based on the data on the maximum values of the measured parameters, a positive correlation was established for the first time between the abundance of winged forms of L. cervi and the physiological activity of the host (the density of the piles of “winter” excrement). The paper also provides a valid reference to the material of schematic maps developed for a part of the territory of the Leningrad Province and Saint Petersburg. The scheme of the use of areas by elk is compiled on the basis of the relative index calculated from the measured parameters of the survey. Field observation areas and territories close to them were most reliably identified (90–95% accuracy). For areas not covered by field observations, the paper provides comments on the main inaccuracies of the schemes and the reasons for the identified discrepancies, based on an analysis of literary sources devoted to similar research topics. The results of the study indicate that the frequency of attacks of winged forms of L. cervi can be used as an additional criterion for assessing the stationary preferences of elk in the winter period using information on the period of active flight, and the decoding method mentioned in the paper can be used in limited areas of specific territories, including reserves, areas of hunting farms and district forestries.

Nucleation and growth behavior of primary Al11Ce3 intermetallic compounds during solidification in a hypereutectic Al–Ce alloy

In this study, the nucleation and growth mechanisms of Al11Ce3 intermetallic compounds (IMCs) in a hypereutectic Al–Ce alloy during solidification were investigated through synchrotron radiation X-ray real-time imaging. The results showed that Al11Ce3 IMCs nucleate and grow from the melt as the primary phase at the initial stage of solidification. Growth preferred orientations were observed in two opposite directions, resulting in an I-shaped growth pattern. Based on the minimum energy criterion, the morphology of Al11Ce3 IMCs displayed either hollow cubic tubes or grooves. The nucleation and growth rates of Al11Ce3 IMCs gradually decreased over time, owing to the variations in the Ce concentration in the melt and the undercooling. The nucleation and growth characteristics of Al11Ce3 IMCs can provide the theoretical basis for optimization on the performance of Al–Ce alloys.

Geographic Distribution and Neuropathology of Elaeophora schneideri in Shiras Moose (Alces alces shirasi) in Idaho, USA.

Elaeophorosis, infection by the filarial worm Elaeophora schneideri, is a parasitic disease of wild ungulates in North America; however, our understanding of the relevance of E. schneideri to moose (Alces alces) morbidity and mortality is incomplete. Between March 2020 and July 2022, necropsy and histopathology were performed on 61 Shiras moose (Alces alces shirasi) in Idaho, US. Among the 41 adults (greater than 1 yr old), 21 moose were from northern Idaho, and 20 were from southeastern Idaho. Elaeophorosis was diagnosed in 24% (10 of 41). All 10 infected moose were from southeastern Idaho; none of the 21 moose from northern Idaho were infected. No juvenile moose (nine from northern and 11 from southeastern Idaho) were infected. Microfilariae were detected histologically in 9 of 10 infected moose, most consistently in brain tissue associated with lesions indicative of ischemic injury to the neuroparenchyma attributed to occlusion of arterioles and capillaries by microfilariae or fibrin thrombi, including edema, necrosis, and glial nodules. Microfilariae found in other tissues of the head, including the eye, tongue, and pinnae of some animals, as well as in lung, heart, liver, and kidney, typically were associated with inflammation. Three of the 10 infected moose had cropped ears attributed to elaeophorosis, and four exhibited abnormal behavior, which may have been due to neuropathology associated with E. schneideri microfilariae in the brain.

Structure and Mechanical Properties of Al–Ce–Fe Alloy Synthesized by LPBF Method

Structure and Mechanical Properties of Al–Ce–Fe Alloy Synthesized by LPBF Method

Behaviours of moose at roadside mineral licks in British Columbia: Implications for moose-vehicle collisions

Moose (Alces americanus) visit roadside mineral licks (RMLs; areas of roadside ditches where de-icing salts accumulate in spring) to obtain minerals that may be otherwise lacking in their diet. When moose use road corridors to access salts, they become hazards to motorists. Moose use of RMLs is dependent on season and time of day, but specific patterns of use and associated behaviours that may influence moose-vehicle collision risk are unknown. We used video-enabled camera traps, analysis of variance, and generalized additive mixed models to record, review, interpret, classify, and analyze the behaviours of adult moose between July 2012—July 2020 at five RMLs in north-central British Columbia. Monthly visitation rates to RMLs peaked in mid-summer which corresponds with the summer peak in moose-vehicle collisions in the study area. Bi-hourly visitation rates peaked at night. Vigilance and licking were the most common of many behaviours recorded. Cows with young spent the most time at RMLs, followed by bulls, then solitary cows. Proportion of time spent being vigilant peaked in May, licking peaked in June. Time spent licking was highest for bulls, followed by cows with young, then solitary cows. Research into complex and interacting factors such as traffic volume and flow, driver visibility and awareness of moose, and various methods for de-icing roads is further required to determine robust means of mitigating the risk of moose-vehicle collisions associated with RMLs.

Ungulate niche partitioning and behavioural plasticity of aurochs in Early Holocene southern Scandinavia revealed by stable isotope analysis of bone collagen

This study examines the impact of the extensive climatic and environmental changes associated with the Early Holocene on the feeding ecology of aurochs, European bison, red deer, and Eurasian elk in southern Scandinavia from radiocarbon dates and analysis of stable carbon and nitrogen isotopes. Molecular sex information is utilised in the study of aurochs to understand the underlying reasons behind observed intraspecific differences. Asynchronous diachronic changes in dietary palaeoecology were observed between the included taxa. The observed trends in foraging and habitat use among herbivores in our dataset can be attributed to the directional vegetation change from open landscape to forest. Our findings imply that environmental changes and/or interspecific competition contributed to the local extinction of European bison and impacted the niches of remaining species through niche overlap (cervids) and partitioning (between cervids and aurochs). Thus, our observations are consistent with the influence of multiple mechanisms that acted concurrently.

Achieving enhanced strength retention at elevated temperatures in ultrafine-fibrous interconnected Al–Ce–Ni eutectic alloy solidified under super-gravity field

Super-gravity field was reported to strongly intensify the buoyancy-driven flow of liquid during solidification, affecting the solute convection and morphology of eutectic structure in binary alloys. In ternary eutectic alloys, certain two-phase regions with a coarse structure can usually be detected concurrently along with three-phase eutectics, leading to the formation of heterogeneous structure with limited ductility. Currently, Al–Ce–Ni ternary eutectic alloy was chosen as a modal system, which was reported for the first time to be solidified under super-gravity field with high volume fraction of three-phase eutectics. Meanwhile, the formation of ultrafine-fibrous interconnected Al11Ce3–Al3Ni eutectic clusters with more “chains” and higher spatial connectivity was detected mainly due to the relatively higher nucleation rate. The high volume fraction and refinement of interconnected Al11Ce3–Al3Ni eutectic clusters with excellent thermal stability could contribute to enhancement of ductility and tensile strength at elevated-temperature. Interestingly, the strength retention at 300 °C and 400 °C were able to reach up to ∼68.1 % and ∼33.2 %, respectively.

Enhanced high-temperature strength and ductility of wire arc additive manufactured Al–Ce–Mg alloys with fine α-Al/Al11Ce3 eutectics

Here, wire-arc additive manufacturing (WAAM) is employed to fabricate Al–Ce–Mg heat-resistant aluminum alloy, considering its capability to manufacture large complex structures more efficiently. Large-sized faceted Al11Ce3 intermetallic compounds are formed in the as-cast alloy with a hypereutectic microstructure. The microstructure is transformed to a eutectic microstructure by non-equilibrium solidification of WAAM, consisting lamellar α-Al/A111Ce3 eutectics. The WAAM alloy shows enhanced mechanical strength and ductility at 200 °C, compared with the as-cast alloy. The significant improvements of ultimate tensile strength and elongation for the WAAM alloy are correlated with its higher strain hardening rate, along with the transition from cleavage fracture to dimple fracture. The cracking of All1Ce3 particles occurs preferentially during the elastic deformation stage, as revealed by in-situ testing, and the strain hardening capability of the as-cast alloy is reduced. Pore defects, 0.15 % in volume fraction, are produced via WAAM processing, and the plastic deformation promotes the pore growth and mergence, increases the pore volume fraction, and decreases the pore sphericity. Our results demonstrate that WAAM is strongly attractive for the fabrication of Al–Ce–Mg alloys, due to the enhanced high-temperature strength-ductility synergy.

Effect of Ti microalloying and laser remelting on the microstructure and mechanical properties of laser powder bed fusion Al–12Si alloy

This study explores the impact of micron-Ti microalloying and laser remelting on the microstructure and mechanical properties of laser powder bed fusion (LPBF) Al–12Si alloy, analyzing the underlying reasons. The findings show that the tensile strength and elongation at 300 °C (184 ± 13 MPa and 7.4 ± 1.4 %) are on par with other LPBF heat-resistant Al alloys, such as near-eutectic Al–Ce and Al–Ni. Introducing micron Ti (1 wt%) to AlSi12 effectively eliminates the α-Al <100> texture and refines the grain structure, thanks to the strong nucleation effect from the formed D022-(Al, Si)3Ti, leading to enhanced tensile strength in both as-built and heat-treated (300 °C for 2 h) samples, while maintaining ductility within the typical range for LPBF near-eutectic Al–Si alloys. Laser remelting further decreases the presence of unmelted Ti powder in AlSi12Ti and encourages the formation of D022-(Al, Si)3Ti, offering insights into LPBF Al alloy composition design through promoting the melt of the modified powder and improving material homogeneity, especially for incorporating micron powders with high melting points. Additionally, the superior mid-high temperature properties (300 °C) of AlSi12+1 wt% micron-Ti contribute to expanding the database of LPBF Al alloys.

Comparative Prevalence and Intensity of Endoparasites in a Dynamic Boreal Ungulate Community

Surveillance of endoparasites at the host community level is rarely reported for ungulates. Yet, changes in the composition and abundance of species in ungulate assemblages, coupled with environmental and climate change, bring into focus the need for baseline data on endoparasite occurrence in host species at the community level. We investigated the prevalence and intensity of eggs of endoparasites in feces of a dynamic boreal ungulate community in Yukon, Canada, that included reintroduced bison (Bison bison), as well as introduced elk (Cervus canadensis), naturally colonizing mule deer (Odocoileus hemionus), and resident populations of caribou (Rangifer tarandus), moose (Alces americanus), and thinhorn sheep (Ovis dalli). We also examined the change in endoparasite prevalence and intensity in bison fecal samples collected eight years apart. The prevalence of eggs detected in feces differed across species for most endoparasite groups. We also provide new records of several endoparasites in novel hosts or new geographic records. We detected a substantially greater prevalence and intensity of trichostrongyle-type eggs in bison feces between samples collected eight years apart. Our data emphasize the need for targeted pathogen surveillance programs to monitor the movement of various ungulate and associated endoparasites. This is particularly pertinent since our data potentially supports evidence for the continued northward expansion and host switching of protostrongylid species, which may have health implications for animals at a new interface.

Using camera traps and N‐mixture models to estimate population abundance: Model selection really matters

Abstract Estimating the abundance or density of wildlife populations is a critical part of species conservation and management, but estimates can vary greatly in precision and accuracy according to the sampling and statistical methods, sampling and ecological variation, and sample size. We used images of moose (Alces americanus) from camera traps to parameterize N‐mixture models and tested the effect of ecological conditions, the spatial scale of measurement, and the criteria used to define independent detections on estimates of population abundance. We compared the model estimates to those generated empirically with aerial survey data, the standard method for many species of ungulate. We explored the sensitivity of estimates to model choice based on the common statistical criterion of parsimony. The two most parsimonious N‐mixture models (i.e. AICc) were considerably biased, producing implausibly large and considerably imprecise estimates of abundance. Most of the other models produced estimates of moose abundance that were ecologically realistic and relatively accurate. The accuracy of population estimates produced by N‐mixture models was not overly sensitive to the formulation of models, the scale at which ecological conditions were measured, or the criteria used to define independent detection and by extension sample size. Our results suggested that parsimony was a poor measure of the predictive accuracy of the population estimates produced with the N‐mixture model. We recommend using a suite of models to generate predictions of abundance instead of the single top‐ranked model. Collecting and processing data from the aerial survey was less expensive and took less time, but data from camera traps provided a broader set of insights into the behaviour of moose and the co‐occurrence of competitors and predators.

Cut vs. fire: a comparative study of the temporal effects of timber harvest and wildfire on ecological indicators of the boreal forest

ContextLarge-scale natural disturbances are crucial drivers of ecosystem function and composition for many forested ecosystems. In the last century, the prevalence of anthropogenic disturbances has increased across Canada’s boreal forest. Habitat disturbance from timber harvest and wildfire is linked to declines of boreal species, including woodland caribou (Rangifer tarandus caribou).ObjectivesWe tested how disturbances influenced the recovery trajectory of ecological indicators of timber, biodiversity, and wildlife habitat through time following timber harvest and wildfire across the boreal forest of Alberta, Canada.MethodsDuring 2021 and 2022, we collected field data from 251 timber harvested and 264 burned stands (0–40 years since disturbance), as well as 256 older forest stands used by caribou (> 40 years since disturbance). Field data included metrics of stand attributes (e.g., basal area, stems per hectare), coarse woody debris (CWD), and abundance of forage for caribou, moose (Alces americanus), and bears (black bear: Ursus americanus, grizzly bear: Ursus arctos).ResultsBasal area of trees and stems per hectare recovered more quickly in timber harvest sites when compared to wildfire sites, but as time since disturbance increased there were no differences in these attributes among timber harvest, wildfire, and caribou use sites. CWD was greatest in recently burned sites, but declined over time to be similar in quantity as in harvested stands and older forest stands. Terrestrial lichens, important forage for caribou, were most abundant in the older caribou use sites, whereas forage for moose and bears, including shrubs, was most abundant in younger timber harvest and wildfire sites.ConclusionsOur results demonstrate that timber harvesting may result in a quicker development of timber volume when compared to wildfire. However, this anthropogenic disturbance is less advantageous for the development of caribou habitat.

Impacts of aluminum-cerium alloy deployment on different cerium commodities

An imbalance problem exists in the rare earth element (REE) market with cerium and lanthanum being more abundant and less valuable than REEs used in permanent magnets such as neodymium, praseodymium, and dysprosium. Research has been conducted on new applications for abundant REEs to improve mining economics. However, potential market impacts of these applications on individual REE commodities are unknown. A system dynamics model was built to investigate the impacts of a new aluminum-cerium (Al–Ce) alloy that can theoretically utilize three separate cerium forms: cerium carbonate, cerium oxide, or cerium metal. Cerium carbonate currently possesses the lowest price of the three available forms making it initially the most favorable choice. However, model results showed that cerium oxide could provide the best economics for future Al–Ce alloy deployment because its larger market size buffers major shocks to price.

The Beneficial Effect of Iron in Aluminum-Cerium-Based Cast Alloys

Iron (Fe) has been considered a major impurity since it is detrimental to the mechanical properties of many cast aluminum alloys due to the formation of Fe-containing brittle intermetallic phases. Fe is found naturally as an impurity in bauxite ore, resulting in Fe contamination of aluminum alloys with increasing contamination from current recycling practices. The Al–Ce–Fe system was investigated using CALPHAD (CALculation of PHAse Diagrams) modeling and experimental casting techniques. It was found that additions of Fe to the Al–Ce system are beneficial to the strength (slightly) and ductility (significantly) of the ternary alloys, which is attributed to the formation of fine metastable Al8CeFe2 phase with aggregate morphology and equilibrium Al10CeFe2 phase, suppressing coarse proeutectic Al11Ce3 phase in near-eutectic Al–Ce alloys. Heat treatment study showed that the metastable Al8CeFe2 phase transforms to predicted equilibrium Al10CeFe2 phase at 500 °C, with essentially no intermetallic or grain coarsening; thus, the alloy displayed excellent property retention. The Al–Ce–Fe alloy system offers opportunities for sustainable, recyclable alloy development using low-cost Fe and low-cost cerium (a byproduct of rare-earth extraction).

The Effect of Ca Pretreatment on the Characteristics of Rare‐Earth Nonmetallic Inclusions in Super‐Duplex Stainless Steel

Rare‐earth treatment enhances steel properties. Nevertheless, this beneficial effect can be counterbalanced by the formation of large‐sized rare‐earth inclusions. To refine and spheroidize these inclusions, Ca pretreatment is employed between Al deoxidation and Ce treatment stages for super‐duplex stainless steel 2507 at 1580 °C, using a vertical tube furnace. A systematic analysis is performed to compare the characteristics of nonmetallic inclusions between the Ca‐untreated and Ca‐treated tests. Prior to Ce addition, Ca pretreatment transforms irregular and clustered MgO–Al2O3 spinel inclusions into spherical CaO–MgO–Al2O3 inclusions. Additionally, Ca pretreatment significantly reduces mean diameter of the inclusions from 2.36 ± 0.54 to 1.27 ± 0.47 μm. After Ce addition, rare‐earth inclusions appear near‐spherical with few clustered inclusions in Ca pretreatment case. Conversely, the absence of Ca treatment results in numerous clustered inclusions, thereby yielding significantly larger rare‐earth inclusions, measuring 2.75 ± 1.66 μm compared to 1.99 ± 1.09 μm. CaO component in CaO–MgO–Al2O3 inclusions is largely reduced by Ce. Consequently, Ca pretreatment only yields slight alterations in chemical composition of rare‐earth inclusions. Ce in situ reduces parent inclusions, initiating from the periphery and progressing toward the center. Therefore, the size and morphology of final rare‐earth inclusions are largely inherited from parent inclusions.

Motion‐sensitive cameras track population abundance changes in a boreal mammal community in southwestern Yukon, Canada

AbstractMotion‐sensitive cameras are commonly used to monitor wildlife occupancy rates; however, few studies have assessed whether data from cameras are correlated with density estimates obtained from more traditional labor‐intensive methods such as those based on capture‐mark‐recapture. We used data from a boreal forest community to test whether camera data were correlated with densities estimated from independent monitoring methods. We placed 72 covert cameras in the forest around Lhù'ààn Mân' (Kluane Lake), Yukon, Canada, for 7 years and tracked changes in population densities by camera hit rates. We independently estimated population densities of snowshoe hares (Lepus americanus) and red squirrels (Tamiasciurus hudsonicus) using capture‐mark‐recapture via live trapping, and Canada lynx (Lynx canadensis), coyotes (Canis latrans), and moose (Alces americanus) by snow track transects. Density estimates obtained from conventional aerial surveys were also periodically available for moose. Except for red squirrels, camera hit rates were highly correlated with population density estimates obtained by traditional methods, including across a large range of estimated densities corresponding to cyclic population dynamics in several species. Accordingly, we infer that motion‐sensitive cameras could supplement or replace traditional methods for monitoring key species in boreal forest food webs. Using cameras to monitor population change has several advantages; they require less effort in the field, are non‐invasive compared to live‐trapping, include multiple species at the same time, and rely less on weather than either aerial surveys or snow track transects. Tracking changes across the vast boreal forest is becoming increasingly necessary because of climate and landscape change and our data validate the use of motion‐sensitive cameras to provide a useful quantitative method for state‐of‐the‐environment reporting.

Linking weather conditions and winter tick abundance in moose

AbstractClimate change may modify species distribution to higher latitudes, resulting in potential changes of parasite diversity and transmission dynamics in areas where animals might not be locally adapted to these new parasite species. In addition, climate change may increase the frequency and severity of infestations of parasites that are already present in a region, by promoting the development and survival of infectious stages. Over the last decades, the number of moose (Alces americanus) infested by winter ticks (Dermacentor albipictus) has increased in eastern Canada, possibly because milder climatic conditions are increasing winter tick survival. Our main objective was to determine which meteorological variables are more likely to influence winter tick load on moose. We compiled several weather variables that may limit winter tick survival and explored which weather variables, or their interactions, influenced the winter tick load of 4,100 hunted moose from 2013 to 2019 in Québec, Canada along a latitudinal gradient. Winter tick load in fall decreased with the maximum number of consecutive days in spring with average daily temperatures below −15°C and with the number of consecutive days in summer with a relative humidity &lt;80% when snowmelt in spring was earlier. These results suggest that cold temperatures and prolonged periods of low humidity, amplified by early snowmelt, limit the survival of adult female ticks and eggs, thus limiting their subsequent load on moose during the following fall. With climate change, precipitation increases and warm temperatures occur earlier in spring and are more frequent in summer. Our results suggest that climate change may have a positive long‐term influence on winter tick abundance in the environment and thereby increase winter tick load on moose, which could lead to a significant decrease in moose body condition and survival.

The effect of minor Ti and Mn additions on the microstructure and mechanical properties of additive manufactured Al–Ce–Mg alloys

The effect of minor Ti and Mn additions on the microstructure and mechanical properties of additive manufactured Al–Ce–Mg alloys

High-Pressure Die Casting of Al–Ce–La–Ni–Fe Alloys

The effects on phase equilibria of La and Fe additions to the Al–Ce–Ni-based alloy system are explored under high-pressure die casting conditions. The addition of La to Al–Ce–Ni-based alloy system only reacts with Ce synergistically to promote the formation of the Al11(Ce,La)3 intermetallic phase as predicted by CALculation of PHAse Diagrams (CALPHAD) and verified experimentally. High Fe additions react with Ni to form the Al9FeNi intermetallic phase, which is an additional eutectic former. The targeted co-precipitation type eutectic morphology is achieved in the alloys studied. Additional coarse particles of Al11(Ce,La)3, present in the alloys studied and not predicted by CALPHAD, are attributed to possible inclusions of Ce and La oxide, present in the mischmetal feedstock used. Both alloys exhibit exceptional mechanical stability after 10 hours at 400 °C due to the stability of the phases formed during solidification. The alloy with high Fe additions possessed better mechanical properties after heat treatment based on the higher eutectic content and more substantial improvement to the morphology of secondary phases after treatment.