This blog has over the recent months examined various evidences and hypotheses regarding whether Eastern Coyotes(Coywolves)--C.lycaon(x)latrans--are capable of filling the Eastern Wolf''s (C.lupus(x)lycaon or C.lycaon) biological role of preying on Moose , Elk, Caribou, Beaver as well as Deer. Most of the available literature suggests that while Eastern Coyotes will opportunistically take out Moose calves and scavenge Moose kills, they are not a primary predator of adult Moose at this time.
Trent University grad student Karen Loveless updates and reinforces this viewpoint in her thorough and in-depth analysis of Algonquin Park Wolves............. those whose genetics are more closely associated with Coyotes tend to score most of their food base from deer....................those whose genetics are more closely associated with lycaon and Lupus(Eastern and Gray Wolves) are more likely to extract a higher share of their calorie intake from Moose(while also enjoying many deer meals).
I have extracted what impacted me most as to this line-of-thought below. Thank you Karen for this teriffic updating on a main focus of this blog.....the re-wilding of North America with our full suite of native predator and prey species(and whether hybridized species, in this case wolves and coyotes interconnecting in Eastern North America ,can fulfill historical ecological ecosystem functions.
Genetic Admixture and Predation -(Karen Loveless analysis)
C. lupus influenced packs to specialize on moose, and for C. latrans influenced packs to specialize on deer, which became more distinct with higher levels of admixture. Strongly C. latrans influenced packs (defined here as >0.5 average admixture) were unlikely to prey on moose. There was one moose kill that may have been made by a strongly C. latrans pack, however it occurred at an intersection of territories with 2 C. lupus influenced packs that regularly killed moose, and we could not be sure which pack had made the kill. Conversely, deer were a minor prey item for strongly C. lupus influenced packs, comprising only 10-15% of diet. C. lycaon tendency to be more generalist than either the strongly C. lupus or C. latrans influenced packs could simply represent their intermediate morphological position between coyote and gray wolf-like animals. This could ultimately be an advantage in a system with high variability in the vulnerability and accessibility of prey, and may explain the persistence of eastern wolves in spite of genetic introgression from other canid types.Prey distribution was the most important factor driving prey use; however admixture was significant in the overall prey use model, and the mid-winter model. There was an overall, significant trend for
C. lycaon population utilized both deer and moose, some C. lycaon packs subsisted primarily on moose, and others relied heavily on deer, indicating that this genotype is not limited to one or the other prey species. C. latrans influence to utilize moose, we could not confirm any moose kills made by strongly C. latrans packs. If C. latrans influence limits a packs ability to exploit moose, then this would likely limit the establishment of strongly of C. latrans packs to the areas where deer are accessible. It is not clear whether C. lupus packs have any competitive advantage over C. packs, or vice versa. Large-scale patterns of hybridization in Ontario indicate higher gene flow between the C. lupus dominated population to the north than the C. latrans population to the south, so the differences between C. lycaon animals and the C. lycaon x C. lupus animals may be less distinct than the differences brought on by hybridization with coyotes. Further study is warranted to determine the trend of hybridization in Algonquin, and how this could influence the ongoing development of this predator-prey system.
It was determined that 70% of moose consumed by wolves were scavenged winter-killed moose, with low rates of actual predation on moose. Although moose were found to be an important resource, Forbes and Theberge (1996) concluded that wolves in Algonquin were deer specialists, on the basis of predation on deer versus scavenging on moose, and the high incidence of off-territory movements to forage in the deer yards in spite of moose availability on territories. Theberge and Theberge (2004) later suggested that moose predation may be increasing, or perhaps was more prevalent than previously thought. There has clearly been an increase in moose predation since the 1960s, and possibly increased predation on moose since the early 1990s, the degree of which is difficult to determine in the face of major differences in protocol and technology. Results of this study indicate that specialization on moose has developed among some packs, with less selective predation occurring among the moose specialist packs, and in milder winters.
If variation in prey use is influenced by hybridization in Algonquin, the plausible mechanisms could be 1) behavioral predisposition affecting hunting or social patterns, or 2) morphological differences which influence the cost:benefit of prey use. Both coyotes and gray wolves are social, though wolves tend to have more cohesive pack structure than coyotes, which often hunt singly or in small groups when foraging for small prey or deer (Bekoff et al. 1981, Geffen et al. 1996, Patterson and Messier 2001). Coyote-type canids would benefit from pack cohesiveness when large prey are available, however they may hunt individually and sustain themselves on small prey if necessary, whereas wolves are too large to effectively sustain themselves on small prey and are thus obligated to hunt in packs.
click below to read Karen's full thesis:Foraging strategies of Eastern Wolves in relation to migratory prey and hybridization
http://www.scribd.com/full/31700778?access_key=key-13prqnq807t4eerejayf
The availability of White-tailed Deer and Moose as prey has changed. The late 1950's populations in Algonquin were tracked by Ontario Lands and Forests Personnel and Ontario Research Foundation parasitologists. Moose were rare along the Highway section of the Park and Deer were common. This sityation has changed. The explanation for the populations at that time involved a brain parasite which both species carried but was mortal to Moose. George Francis, Prof. at U.Waterloo would know what happened to the Deer census records. Dr Audrey Fyfie,for many years Veterinarian for the Ministry of Natural Resources, ON will know the history of the brain parasite. John Theberge started to sleep in the bush in contact with a wolf pack at the endof the fifties. Roger.
ReplyDeleteRoger........accurate you are on all counts........The Theberge's(husband and wife wolf biologists of mid 20th century Algonquin National Park did some of the most detailed studies on eastern wolf/deer/moose interactions finding that wolves first sought the smaller deer, but would take on moose when opportune
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