Journal ArticleDOI
Diet shifts in moose due to predator avoidance.
Reads0
Chats0
TLDR
This study suggests that in order to avoid predators, cows with calves sacrifice the high quality diet available on the main island and move to the small outlying islands where plant phenology is delayed by the cold water of Lake Superior.Abstract:
On Isle Royale, Michigan, moose cows which have calves show a different distribution and diet from solitary adults and yearling moose. Solitary adults and yearlings follow a feeding pattern predicted from the location of high nutrient plant growth. In the presence of wolves, they feed on the ridges of the main island, where they take advantage of plants that leaf early; only later in the season do they move to the small outlying islands where plant phenology is delayed by the cold water of Lake Superior. Cows with calves deviate sharply from this pattern. They remain on the wolf-free small islands throughout the growing season. While on the islands, cows with calves eat a poorer quality diet than other moose. They switch to eating high quality spring and summer foods later than other moose and they eat significantly fewer high preference shrubs and significantly more herbs and low preference shrubs than other moose. This study suggests that in order to avoid predators, cows with calves sacrifice the high quality diet available on the main island. These data also suggest that the wolves not only affect prey numbers by direct kills but may also indirectly influence prey numbers by altering the diet of their prey. In this case, the reproductive cows, those individuals that contribute most directly to growth of the population, avoid predators but frequent poor feeding areas.read more
Citations
More filters
Citation classic - optimal foraging - a selective review of theory and tests
TL;DR: A review of the literature on optimal foraging can be found in this article, with a focus on the theoretical developments and the data that permit tests of the predictions, and the authors conclude that the simple models so far formulated are supported by available data and that they are optimistic about the value both now and in the future.
Journal ArticleDOI
Human-caused Disturbance Stimuli as a Form of Predation Risk
Alejandro Frid,Lawrence M. Dill +1 more
TL;DR: A growing number of studies quantify the impact of non-lethal human disturbance on the behavior and reproductive success of animals as mentioned in this paper, and many of these studies are well designed and analytically sophisticated, but most lack a theoretical framework for making predictions and for understanding why particular responses occur.
Journal ArticleDOI
Wolves influence elk movements: behavior shapes a trophic cascade in yellowstone national park
Daniel Fortin,Hawthorne L. Beyer,Mark S. Boyce,Douglas W. Smith,Thierry Duchesne,Julie S. Mao +5 more
TL;DR: In this article, the authors investigated whether the observed trophic cascade might have a behavioral basis by exploring environmental factors influencing the movements of 13 female elk equipped with GPS radio collars and found that elk movements were influenced by multiple factors, such as the distance from roads, the presence of a steep slope along the step, and the cover type in which they ended.
Journal ArticleDOI
Predator vigilance and group size in mammals and birds: a critical review of the empirical evidence
TL;DR: Most of the studies fail to adequately demonstrate an unambiguous relationship between vigilance behaviour and group size, but many studies reveal interesting features of the relationship between Vigilance and Group size that should provide fruitful avenues for future research.
Journal ArticleDOI
Trophic cascades : the primacy of trait-mediated indirect interactions
TL;DR: It is shown that simple trade-off behaviour can lead to both positive and negative indirect effects of predators on plant resources and hence can explain considerable contingency on the nature and strength of cascading effects among systems.
References
More filters
Journal ArticleDOI
Theory of Feeding Strategies
TL;DR: Throughout, emphasis will be placed on strategic aspects of feeding rather than on what Holling (75) has called "tactics," and possible answers to the first problem may be given to the second problem.
Journal ArticleDOI
Optimal foraging: A selective review of theory and tests
TL;DR: The general conclusion is that the simple models so far formulated are supported are supported reasonably well by available data and that the author is optimistic about the value both now and in the future of optimal foraging theory.
Citation classic - optimal foraging - a selective review of theory and tests
TL;DR: A review of the literature on optimal foraging can be found in this article, with a focus on the theoretical developments and the data that permit tests of the predictions, and the authors conclude that the simple models so far formulated are supported by available data and that they are optimistic about the value both now and in the future.
Journal ArticleDOI
Optimal Foraging and the Size Selection of Prey by the Bluegill Sunfish (Lepomis Macrochirus)
Earl E. Werner,Donald J. Hall +1 more
TL;DR: Evidence is presented that changes in diet maximize return with respect to time spent foraging in the bluegill sunfish, Lepomis macrochirus, that is known to select prey on the basis of size.
Journal ArticleDOI
Diet optimization in a generalist herbivore: the moose.
TL;DR: The general conclusion arrived at is that the foraging of a generalist herbivore can be predicted in a quantitative manner, at least in this case, as has been shown for other types of consumers (carnivores and granivores).
Related Papers (5)
Behavioral decisions made under the risk of predation: a review and prospectus
Steven L. Lima,Lawrence M. Dill +1 more