No abstract

We synthesized an expert review of climate change implications for hydroecological and terrestrial ecological systems in the northern coastal temperate rainforest of North America. Our synthesis is based on an analysis of projected temperature, precipitation, and snowfall stratified by eight biogeoclimatic provinces and three vegetation zones. Five IPCC CMIP5 global climate models (GCMs) and two representative concentration pathways (RCPs) are the basis for projections of mean annual temperature increasing from a current average (1961-Climatic Change (2015 1990) of 3.2°C to 4.9-6.9°C (5 GCM range; RCP4.5 scenario) or 6.4-8.7°C (RCP8.5), mean annual precipitation increasing from 3130 mm to 3210-3400 mm (3-9 % increase) or 3320-3690 mm (6-18 % increase), and total precipitation as snow decreasing from 1200 mm to 940-720 mm (22-40 % decrease) or 720-500 mm (40-58 % decrease) by the 2080s (2071-2100; 30-year normal period). These projected changes are anticipated to result in a cascade of ecosystem-level effects including: increased frequency of flooding and rain-on-snow events; an elevated snowline and reduced snowpack; changes in the timing and magnitude of stream flow, freshwater thermal regimes, and riverine nutrient exports; shrinking alpine habitats; altitudinal and latitudinal expansion of lowland and subalpine forest types; shifts in suitable habitat boundaries for vegetation and wildlife communities; adverse effects on species with rare ecological niches or limited dispersibility; and shifts in anadromous salmon distribution and productivity. Our collaborative synthesis of potential impacts highlights the coupling of social and ecological systems that characterize the region as well as a number of major information gaps to help guide assessments of future conditions and adaptive capacity.

Abstract-Ecotoxicology has focused almost exclusively on countries and ecosystems in temperate zones. Tropical ecosystems, which combined contain as much as 75% of the global biodiversity, have been neglected. Tropical ecosystems are under increasing threat of development and habitat degradation from population growth and urbanization, agricultural expansion, deforestation, and mining. Some of these activities also lead to the release of toxic substances into the environment. Little research in ecotoxicology has been carried out in tropical environments. Techniques and procedures developed for temperate environments are often applied, even though physical and chemical environmental parameters in the tropics can be very different. Most research has focused on water quality and aquatic toxicology. The regulatory environment also varies among countries. We present a review of the literature on tropical ecotoxicology, with an emphasis on Latin America and the Caribbean. We also address priority areas for immediate research in the tropics. These include large-scale agricultural activities, especially banana, pineapple, and soybean farming, and gold mining with the associated heavy use of mercury. We outline the special issues that must be addressed as the field of tropical ecotoxicology progresses.

The number of helicopter flights used to gain access to backcountry has increased in recent years. Biologists, land managers, and the public have expressed concern about disturbance impacts to mountain goats (Oreamnos americanus) resulting from helicopter activity. We recorded behavioral responses of 122 groups of mountain goats from 347 helicopter overflights at 4 geographic areas in Alaska and analyzed responses in relation to distance and angle from helicopters to mountain goats, reproductive class, season, and area of study. We used multinomial logistic regression modeling combined with a bootstrap randomization procedure to identify factors associated with increased probability of mountain goats being in 1 of the 4 behavioral response categories during helicopter overflights. The probability of a goat group being disturbed was inversely related to distance of the helicopter from the group. Odds of disturbance increased by a factor of 1.25 for every 100‐m reduction in approach distance. Approach distances resulting in >90% probability of maintenance were significantly larger where mountain goats had received less prior exposure to helicopters. When mountain goats were disturbed during overflights, a second analysis (i.e., gamma regression model with inverse link function) estimated elapsed time until mountain goats returned to maintenance behavior. The length of time that a goat remained in a disturbed state following overflight did not depend upon any of the covariates; mountain goats remained in a disturbed state for an average of 30.7 seconds (95% C***I, 25.7–35.9 seconds). The results offer land managers an opportunity to evaluate risk for permitting helicopter activity.

The behavioural rhythms of organisms are thought to be under strong selection, influenced by the rhythmicity of the environment1–4. Such behavioural rhythms are well studied in isolated individuals under laboratory conditions1,5, but free-living individuals have to temporally synchronize their activities with those of others, including potential mates, competitors, prey and predators6–10. Individuals can temporally segregate their daily activities (e.g. prey avoiding predators, subordinates avoiding dominants) or synchronize their activities (e.g. group foraging, communal defence, pairs reproducing or caring for offspring)6–9,11. The behavioural rhythms that emerge from such social synchronization and the underlying evolutionary and ecological drivers that shape them remain poorly understood5–7,9. Here, we address this in the context of biparental care, a particularly sensitive phase of social synchronization12 where pair members potentially compromise their individual rhythms. Using data from 729 nests of 91 populations of 32 biparentally-incubating shorebird species, where parents synchronize to achieve continuous coverage of developing eggs, we report remarkable within– and between-species diversity in incubation rhythms. Between species, the median length of one parent’s incubation bout varied from 1 – 19 hours, while period length–the time in which a parent’s probability to incubate cycles once between its highest and lowest value – varied from 6 – 43 hours. The length of incubation bouts was unrelated to variables reflecting energetic demands, but species relying on crypsis (the ability to avoid detection by other animals) had longer incubation bouts than those that are readily visible or actively protect their nest against predators. Rhythms entrainable to the 24-h light-dark cycle were less prevalent at high latitudes and absent in 18 species. Our results indicate that even under similar environmental conditions and despite 24-h environmental cues, social synchronization can generate far more diverse behavioural rhythms than expected from studies of individuals in captivity5–7,9. The risk of predation, not the risk of starvation, may be a key factor underlying the diversity in these rhythms.

Increasing demand for backcountry recreation opportunities during winter (e.g., snowshoeing, helicopter-assisted skiing, snowmobiling) in steep, high-elevation terrain has elevated concern about disturbance to brown bears (Ursus arctos) denning on the Kenai Peninsula, Alaska, USA. To help identify areas where such conflicts might occur, we developed a spatially explicit model to predict potential den habitat. The model indicated brown bears selected locations for den sites with steep slopes, away from roads and trails. Den sites were associated with habitat high in elevation and away from potential human contact. We then compared areas with the highest probability of providing den habitat with patterns of snowmobile and nonmotorized recreation on a portion of the Kenai Peninsula. We found limited overlap between the 2 recreation activities and potential den habitat for brown bears. At the landscape scale, however, backcountry skiing overlapped more high-quality den habitat than did snowmobile riding. Our results may be used by land management agencies to identify potential conflict sites and to minimize the potential effects of recreation activities on brown bears in dens.

No abstract

Abstract-Ecotoxicology has focused almost exclusively on countries and ecosystems in temperate zones. Tropical ecosystems, which combined contain as much as 75% of the global biodiversity, have been neglected. Tropical ecosystems are under increasing threat of development and habitat degradation from population growth and urbanization, agricultural expansion, deforestation, and mining. Some of these activities also lead to the release of toxic substances into the environment. Little research in ecotoxicology has been carried out in tropical environments. Techniques and procedures developed for temperate environments are often applied, even though physical and chemical environmental parameters in the tropics can be very different. Most research has focused on water quality and aquatic toxicology. The regulatory environment also varies among countries. We present a review of the literature on tropical ecotoxicology, with an emphasis on Latin America and the Caribbean. We also address priority areas for immediate research in the tropics. These include large-scale agricultural activities, especially banana, pineapple, and soybean farming, and gold mining with the associated heavy use of mercury. We outline the special issues that must be addressed as the field of tropical ecotoxicology progresses.