Alces (A Journal Devoted to the Biology and Management of Moose)
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THE IMPACT OF MOOSE BROWSING ON TREE SPECIES COMPOSITION IN FINLAND
No full textThe attitude usually adopted in Finnish forestry regarding the moose (Alces alces) has traditionally been that it influences Scots pine in young mixed stands and therefore intensiv treatments have been recommended to favor monocultures. The need to maintain diversity across the landscape is, however, changing attitudes. We tested the hypothesis that selective browsing can influence the composition of tree species in young stands, both in managed and natural forests. Moose browsing effect on sapling heights was compared in exclosures and adjacent open areas in the south- and mid-boreal forest zones of Central and North Finland at the end of the 1990s. Moose appeared to impact young trees by reducing height growth, thereby reducing the possibility of selected broadleaved species to reach maturity. The number of aspen trees can obviously be expected to greatly decrease as a result of regenerating suckers being browsed by moose. Rowan considerably declined under browsing pressure. On the other hand, the results also suggest that moose browsing may be beneficial by releasing conifers from competition among tree species in managed forests. In this sense, the relationship between browsed birches and the condition of conifers is crucial. Browsing obviously reduces tree species diversity in areas of high moose density. However, some trees sheltered by neighboring ones are not browsed, and more information is needed about optimal treatment of young stands. In Finland’s relatively small nature conservation areas, repeated browsing can quickly retard the height of slowly-regenerating broadleaf species. This browsing impact may lead to ecosystem changes without significantly impacting moose populations, the management of which by hunting is restricted in the set-aside natural forests and conservation areas
THE ROLE OF MAMMALS AS ECOSYSTEM LANDSCAPERS
No full textThe role of mammals in ecosystems is to modify vegetation structure, alter pathways of nutrients, and thereby change species composition. Their large-scale structuring effects make large mammals ‘ecological landscapers’. Through this they influence ecosystem function and biodiversity. Landscaping effects occur when mammals are regulated by food, rather than by predators. This condition is constrained by four factors: when (1) body size is large enough to avoid predators; (2) populations adopt large scale migration behaviour because predators are unable to follow them; (3) in multispecies communities (savanna, grasslands) with a range of predator and prey sizes, only the largest species can avoid predation because they subsidize predators that regulate smaller prey species; and (4) in single predator-prey systems (tundra, desert, boreal, and temperate forests), ecological conditions determine whether or not predators regulate prey. The structuring role of mammals in maintaining species diversity is evident not just in vegetation, but also in birds, other mammals, and invertebrates. This role makes them prime candidates as ‘umbrella species’ for conservation. Protection of large mammal species and their habitats also conserves a large part of the remaining community. It also means that such mammals become the ‘indicator species’ for the health of the ecosystem
SEASONAL AND HABITAT DIFFERENCES IN VISIBILITY OF MOOSE PELLETS
No full textCounts of faecal pellet groups have been widely used to estimate population densities and trends of large ungulates like moose (Alces alces). The visibility of pellet groups affects the accuracy of estimates, decreases with time, and varies among habitat types. I investigated the impact of season and habitat type on how, over time, visibility of moose pellets decreased along a forest productivity gradient in boreal forests of northeastern Sweden. Visibility decreased at the fastest rate during the transition from spring to summer due to concealment by new vegetation. Visibility also varied significantly among habitat types and was correlated with vegetative litter production. After one winter of exposure, more than 95% of all pellet groups were visible independent of habitat type, but thereafter visibility decreased fast in more productive habitats. The results demonstrated that if study plots are cleared in late autumn after the vegetation period and then visited as soon as possible after snowmelt, pellet counts can be used to estimate population trends and habitat use of moose in winter without bias caused by differences in visibility within different habitat types. Also, the correlation with litter production suggests that if a sightability correction factor is developed, pellet counts could be used to estimate habitat use and population distribution during the vegetation period and with longer periods between plot visits
BONE MARROW FAT CONTENT FROM MOOSE IN NORTHEASTERN MINNESOTA, 1972-2000
No full textPercent fat in femur bone marrow has been used as an indicator of animal condition at time of death. However, femur bone marrow is not always available for collection. We used linear regression to examine relationships among marrow fat values for long bones (i.e., femur, tibia, mandible, humerus, radius, tarsal and carpal bones) of moose (Alces alces) from northeastern Minnesota during 1972-2000. Linear regressions for bone marrow fat in each set of bones (paired with femur) in calves and adults were significant and highly correlated (r2 = 0.83-0.99). Linear regressions for femur bone marrow fat for yearling moose were significant and highly correlated for tibia, humerus and radius bones (r2 = 0.86-0.93), and less so for tarsal bones (r2 = 0.63). Bone marrow fat deposition appeared first in proximal and distal bones and was mobilized last in distal bones. Calves had higher femur fat in fall and early winter than late winter and spring. Month, season, and year had no significant effect on femur marrow fat percent for yearlings or adults. Percent femur marrow fat was lower in accidentally killed calves than accidentally killed yearlings or adults. Adults killed by disease had lower percent femur fat than those killed by accident or wolves (Canis lupus). Amount of adult male femur fat was loosely correlated to a winter severity index for the previous winter. Our results suggest that fat deposition and mobilization were similar to that found in other studies and that bone marrow fat content may be a good indicator of relative moose health within a population
OF MOOSE AND MAN: THE PAST, THE PRESENT, AND THE FUTURE OF HUMAN DIMENSIONS IN MOOSE RESEARCH
No full textThere is a gap between a growing interest to study the moose/human interface (MHI) and the actual effort made to understand this human dimension (HD) component in moose research. A content analysis of Alces 1974-2001 showed that the relative contribution of HD-papers increased until 1991 but decreased thereafter. Of 66 HD-articles published, 68% of the papers covered how “man affects moose” with hunting and collisions the single most important topics, and 15% were about “values” (economic and attitudes). Outside Alces, articles appeared that were underrepresented in Alces or in the Proceedings of the North American Moose Conference and Workshop. I identify four priority HD-areas for future studies: (1) how do people react to changing moose densities and distributions?; (2) which management alternatives are acceptable for managing the urban and suburban MHI and what makes them acceptable?; (3) how important are moose to non-consumptive users?; and (4) what are the population dynamics and attributes of the consumptive moose user and what makes moose important to consumptive users? A scientific challenge is to further merge ecological and social science to integrate this in management strategies
CHEMICAL IMMOBILIZATION OF FREE-RANGING MOOSE
No full textA wide range of drugs and drug combinations have been used to capture free-ranging moose (Alces alces). Currently, potent opioids are considered the drugs of choice for capture of free-ranging moose. Recommended doses are carfentanil at 0.01 mg/kg or etorphine at 7.5 mg/adult. Combining an opioid with a sedative drug like xylazine will increase the risk of bloat, regurgitation, and aspiration of rumen contents. Extreme toxicity for humans and lost darts are major concerns when using potent opioids under field conditions. The best non-opioid alternative is medetomidine at 40-50 mg/adult combined with ketamine at 600 mg/adult. Carfentanil, etorphine, and medetomidineketamine have wide safety margins in moose and the risk of severe anesthetic side effects in healthy animals is minimal. Chemical immobilization from a helicopter in winter is considered the best capture method for moose. Due to animal welfare considerations and a low therapeutic index, neuromuscular blocking agents should not be used in moose. A mortality rate greater than 2% during immobilization and a one month post capture period is not acceptable for routine moose captures
EFFECTS OF BROWSING HISTORY BY ALASKAN MOOSE ON REGROWTH AND QUALITY OF FELTLEAF WILLOW
No full textWe studied effects of browsing history by Alaskan moose (Alces alces gigas) on regrowth and quality of feltleaf willow (Salix alaxensis) during late winter 2002 in interior Alaska, USA. We recorded extensive browsing on willows, with 55.6% of leaders on 43 plants browsed by moose and 3.9% browsed by snowshoe hares (Lepus americanus). Foraging moose removed, on average, 15.1 mm of current annual growth from willow twigs, which averaged 24.1 mm in length (62.3% removed). Twigs re-growing from 2-year-old stems that were browsed previously had larger diameters at their bud scale scar than those re-growing from stems that were not browsed in the previous year. Browsing history by moose, however, had no effect on nitrogen content, in vitro dry matter digestibility, or tannin content of willow twigs. Willows did not respond to browsing on individual twigs with an inducible defense system that involved tannins. Diameter at point of browsing (bite size) was larger on twigs that had been browsed previously than for twigs re-growing from second-year growth that had not been browsed. Moose did not exhibit an optimal bite size, but took larger-diameter bites from larger compared with smaller leaders of current annual growth. Forage selection by moose for previously browsed twigs likely relates to greater forage biomass on those twigs rather than to forage quality. We caution, however, that foraging behavior by moosecannot be understood fully without considering additional factors, including predation risk in relation to forage availability
APPLICATION OF POPULATION VIABILITY THEORY TO MOOSE IN MAINLAND NOVA SCOTIA
No full textPopulations of moose (Alces alces americana) in mainland Nova Scotia, Canada, have been reduced to approximately 1,000 individuals fragmented into a number of isolated populations. Although the data required for a comprehensive population viability assessment (PVA) are not currently available, there are some general rules concerning minimum viable population (MVP) size that may be applied for a preliminary assessment. Genetic evidence suggests that, in general, a genetically effective population (Ne) of 50 individuals is required for short-term persistence and 500 to 5,000 individuals are required for long-term survival. Census population size (N) is generally larger than Ne, and a 10:1 relationship between N and Ne has been roughly established in moose populations elsewhere. Given this relationship, N = 5,000 individuals may be required for long-term viability. Based on current home range size (30-55 km2) and population density (0.05/km2), the minimum critical area required by a population of this size is estimated to be approximately 100,000-200,000 km2. Strategies for moose conservation and forest management should concentrate on (1) conducting genetic, population, and habitat analyses to increase understanding of population viability and limiting factors; (2) reestablishing connectedness among discrete populations to form a viable metapopulation; (3) protecting/enhancing habitat to meet the critical requirements of a viable population; and (4) increasing carrying capacity of available habitat to support a greater population density
EFFECTS OF MOOSE POPULATION DENSITY ON DEVELOPMENT OF FOREST STANDS IN CENTRAL EUROPEAN RUSSIA
No full textWhen moose population density is high (3–5 individuals per 1,000 hectares), deciduous trees, in particular aspen, are depressed, and cutovers are rapidly overgrown with spruce. Higher moose densities can result in the depression of spruce and degradation of the tree stands. In the near future, preservation of a high population of moose may cause the aspen to disappear and prevent regeneration of pine, oak, and mountain ash. When moose density is 2–3 individuals per 1,000 hectares, the development of stands follows its usual pattern. The composition and structure of modern forests is a function of the pattern of tree stand development on cutovers. According to modern theory, following the removal of coniferous trees on cutovers, deciduous stands are formed, and regeneration of the main coniferous forests is extended over a period of more than 100 years. As a result, coniferous forests are ubiquitously replaced by deciduous
HISTOPATHOLOGICAL CHANGES IN THE CENTRAL NERVOUS SYSTEM OF MOOSE (ALCES ALCES) IN THE IVANOVO REGION OF RUSSIA
No full textThis work describes histopathological changes in the central nervous system of moose (Alces alces) of different ages from various regions of the Ivanovo District. Moose are affected in certain parts of the world by a variety of infectious agents, such as anthrax, rinderpest, necrobacillosis, and foot and mouth disease, which is contracted by coming into contact with reindeer. All of these agents are capable of causing serious disease. Our present work attempted to detect less conspicuous forms of disease in moose that might reflect disturbances or degradation of ecological systems comprising their habitat. We particularly noted lesions in the central system of moose that were characterized by nonpurulent meningo–encephalitis, edema, perivasculitis in extracellular spaces, and focal ischaemic necrosis because of thrombosis of small vessels. Such changes presumably resulted from neuro–dynamical, vascular, physical–chemical, and fluid disturbances and were pronounced in the central nervous system of moose inhabiting regions with unfavorable environmental conditions. We observed the most serious changes in regions where chemical weed–killers, pesticides, and mineral fertilizers were irrationally applied