Role of brown bears (Ursus arctos) in the flow of marine nitrogen into a terrestrial ecosystem

  title={Role of brown bears (Ursus arctos) in the flow of marine nitrogen into a terrestrial ecosystem},
  author={Grant V. Hilderbrand and Thomas A. Hanley and Charles T. Robbins and Charles C. Schwartz},
Abstract We quantified the amount, spatial distribution, and importance of salmon (Oncorhynchus spp.)-derived nitrogen (N) by brown bears (Ursus arctos) on the Kenai Peninsula, Alaska. We tested and confirmed the hypothesis that the stable isotope signature (δ15N) of N in foliage of white spruce (Picea glauca) was inversely proportional to the distance from salmon-spawning streams (r=–0.99 and P<0.05 in two separate watersheds). Locations of radio-collared brown bears, relative to their… 
Major decline in marine and terrestrial animal consumption by brown bears (Ursus arctos)
The results suggest that human activities have caused an alteration in the trophic structure of brown bears in the Hokkaido islands, which includes a major decline in the marine-terrestrial linkage in eastern region, and a loss of indirect-interactions between bears and wolves, because the interactions potentially enhanced deer predation by brown bears.
Use of salmon (Oncorhynchus spp.) by Brown Bears (Ursus arctos) in an Arctic, interior, montane environment
Salmon (Oncorhynchus spp.) is a key dietary item for temperate coastal Brown Bears (Ursus arctos) across much of their circumpolar range. Brown Bears living in Arctic, interior, and montane
Diverse Ecological Pathways of Salmon Nutrients Through an Intact Marine-terrestrial Interface
This is the first study to integrate estuarine to riparian ecological processes in the cycling of salmonid nutrients and identifies a range of ecological baselines that can inform the multiple restoration programs underway in degraded watersheds in the North Pacific.
Using stable isotopes to understand the feeding ecology of the Hokkaido brown bear (Ursus arctos) in Japan
Diet of brown bears on Hokkaido Island, Japan was assessed using carbon and nitrogen stable isotopes to determine the effect of demographic (age and sex) and environmental (developed and undeveloped area) factors on salmon consumption, suggesting that human activities restrict brown bears' salmon consumption.
Tracing salmon nutrients in riparian food webs : isotopic evidence in a ground-foraging passerine
Positive relationships between δ15N and δ13C in fall-grown feathers and fecal samples below the falls but not above the falls are observed, and large positive shifts (as high as...
Nitrogen uptake in riparian plant communities across a sharp ecological boundary of salmon density
The additional N source that salmon provide to nitrogen-limited habitats appears to have significant impacts on the N budget of riparian vegetation, which may increase primary productivity, and result in community shifts between sites with and without salmon access.
Large predators and biogeochemical hotspots: brown bear (Ursus arctos) predation on salmon alters nitrogen cycling in riparian soils
Two important themes in ecology include the understanding of how interactions among species control ecosystem processes, and how habitats can be connected through transfers of nutrients and energy by
Salmon consumption by Kodiak brown bears (Ursus arctos middendorffi) with ecosystem management implications
Stable isotopes and mercury accumulated in hair were used to estimate intake of salmon by Kodiak brown bears and salmon intake increased as salmon escapement increased from ∼1 500 to ∼14 000 kg·bear−1·year−1.
Variation in Maize Consumption by Brown Bears (Ursus arctos) in Two Coastal Areas of Hokkaido, Japan
It is found that a stable-isotope ratio analysis of individual Hokkaido brown bears can serve as a tool to review the effectiveness of control killing and to monitor trends in maize consumption by local populations of bears.
Marine nitrogen in central Idaho riparian forests: evidence from stable isotopes
Terrestrial and marine ecosystems are linked by the annual migration of salmonids. We examined the contribution of anadromous fish to foliar nitrogen (N) in central Idaho riparian forests where


Trophic relations of brown and black bears in several western North American Ecosystems
Adult male brown bears were more carnivorous than any other age or sex class within these ecosystems, and long-dead bears can be compared to living bears to evaluate historical changes in ecosystems.
Fertilization of terrestrial vegetation by spawning Pacific salmon : the role of flooding and predator activity
Spawning Pacific salmon (Onchorhynchus) transport marine-derived nutrients into streams and rivers. Subsequently, these marine-derived nutrients are incorporated into freshwater and terrestrial food
The potential use of stable-isotope analyses (δ13C and δ15N) to estimate bear diets was assessed in 40-day feeding trials using American black bears (Ursus americanus) and brown bears of Chichagof and Admiralty islands, Alaska.
E very year, millions upon millions of anadromous fish come from the oceans to spawn in freshwater streams, and these teeming hordes of fish fall prey not only to marine hunters, such as other fish, whales, and sea lions, but also to numerous terrestrial predators and scavengers.
Recycling of elements transported upstream by runs of Pacific Salmon. I: δ15N and δ13C evidence in Sashin Creek, southeastern Alaska
Values of δ15N and δ13C (the per mil deviation from the recognized isotope standard) from biota of a southeastern Alaska stream (Sashin Creek) that receives an annual run of 30 000 anadromous pink ...
Development of two methods to estimate body composition of bears
The measurement of body composition in black bears, brown bears, and polar bears was investigated by means of isotopic water dilution and bioelectrical impedance analysis (BIA), and the basic relationships between body lipid, water, protein, and ash were determined.
There is much interest in biogeochemical processes that occur at the interface between soils and streams since, at the scale of landscapes, these habitats may function as control points for fluxes of
Stable isotopes in ecology and environmental science
Contributors. Abbreviations. Introduction. 1. Stable isotope chemistry and measurement: a primer. Elizabeth W. Sulzman. Introduction. What isotopes are, what makes them distinct. Properties of
Effect of seasonal differences in dietary meat intake on changes in body mass and composition in wild and captive brown bears
Daily intake by captive brown bears fed meat ad libitum during 12-day trials was positively related to body mass, but the composition of the gain varied by season, with spring gains primarily lean body weight, while ...