Spatial variation in predation pressure is a fundamental feature of predation ecology. Landscape patterns emerging from prey life history dynamics and habitat heterogeneity have been observed in the predation ecology of fish and insects, but this is the first mammalian system for which such observations have been made. These differences can be attributed, at least in part, to senescent moose being more vulnerable to predation and making different risk-sensitive habitat decisions than prime moose. Moreover, the probability of kill occurrence for senescent moose, in comparison to prime moose, increased in high elevation habitat with patches of dense coniferous trees.
ARE WOLVES MOOSE PREDATORS FULL
Predation on senescent moose was clustered in one kill zone in the northeast portion of the island, whereas predation on prime moose was clustered in 13 separate kill zones distributed throughout the full extent of the island. We use pattern analysis and kernel density estimates of moose kill sites to demonstrate that moose in senescent condition and moose in prime condition tend to be wolf-killed in different regions of Isle Royale in winter. We demonstrate how life history dynamics of moose ( Alces alces) contribute to landscape patterns in predation by wolves ( Canis lupus) in Isle Royale National Park, Lake Superior, USA.
Little attention has been given to how the influence of habitat heterogeneity on the landscape ecology of predation might be modulated by life history dynamics of prey in mammalian systems. The recovery of wild forest reindeer in eastern Finland probably requires ecosystem management involving both habitat restoration and control of species abundances.The landscape ecology of predation is well studied and known to be influenced by habitat heterogeneity. However, these two hypotheses are not mutually exclusive and the primary mechanism is difficult to distinguish as the system is heavily managed by moose hunting. Because reindeer and moose populations were positively associated, our results seemed to support the alternative prey hypothesis more than the apparent competition hypothesis. The wolf population was not related to moose abundance even though it is likely to consist the majority of the prey biomass. The calf/female ratio was negatively related to wolf population size, but the reindeer population size was related to the wolf population only when moose abundance was entered as another independent variable. Wolf population size in turn did not show long-term trends. Change in reindeer population size between consecutive winters was related positively to the calf/female ratio. The trends in reindeer population size and moose abundance were almost identical: an increase during the first years and then a decrease until the last years of our study period. We performed linear and general linear models for the calf/female ratio of reindeer. We used least squares regression (GLS) models (for handling autocorrelated error structures and resulting pseudo-R 2s) and generalized linear mixed (GLMs) models (for avoidance of negative predictions) to determine the relationships between abundances. Summer predation of wolves on reindeer focuses on calves. Only moose population size was regulated by hunting.
ARE WOLVES MOOSE PREDATORS SERIES
We examined a 22-year time series (1996 - 2017) to determine how the population size and the calf/female ratio of wild forest reindeer in Eastern Finland were related to the abundances of wolf and moose. Here, we examined whether alternative prey and/or apparent competition hypothesis can explain the population dynamics and reproductive output of the secondary prey, wild forest reindeer ( Rangifer tarandus fennicus) in Finland, in a predator-prey community in which moose ( Alces alces) is the primary prey and the wolf ( Canis lupus) is the generalist predator. Apparent competition is a process where the abundance of two co-existing prey species are negatively associated because they share a mutual predator, which negatively affects the abundance of both prey. The alternative prey hypothesis describes the mechanism for apparent competition whereby the mortality of the secondary prey species increases (and population size decreases) by the increased predation by the shared predator if the population size of the primary prey decreases.
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