February 22, 2018

Recolonizing Gray Wolves Increase Parasite Infection Risk in Their Prey

Abstract

The recent recolonization of Central Europe by the European gray wolf (Canis lupus) provides an opportunity to study the dynamics of parasite transmission for cases when a definitive host returns after a phase of local extinction. We investigated whether a newly established wolf population increased the prevalence of those parasites in ungulate intermediate hosts representing wolf prey, whether some parasite species are particularly well adapted to wolves, and the potential basis for such adaptations. We recorded Sarcocystis species richness in wolves and Sarcocystis prevalence in ungulates harvested in study sites with and without permanent wolf presence in Germany using microscopy and DNA metabarcoding. Sarcocystis prevalence in red deer (Cervus elaphus) was significantly higher in wolf areas (79.7%) than in control areas (26.3%) but not in roe deer (Capreolus capreolus) (97.2% vs. 90.4%) or wild boar (Sus scrofa) (82.8% vs. 64.9%). Of 11 Sarcocystis species, Sarcocystis taeniata and Sarcocystis grueneri occurred more often in wolves than expected from the Sarcocystis infection patterns of ungulate prey. Both Sarcocystis species showed a higher increase in prevalence in ungulates in wolf areas than other Sarcocystis species, suggesting that they are particularly well adapted to wolves, and are examples of “wolf specialists”. Sarcocystis species richness in wolves was significantly higher in pups than in adults. “Wolf specialists” persisted during wolf maturation. The results of this study demonstrate that (1) predator–prey interactions influence parasite prevalence, if both predator and prey are part of the parasite life cycle, (2) mesopredators do not necessarily replace the apex predator in parasite transmission dynamics for particular parasites of which the apex predator is the definitive host, even if meso- and apex predators were from the same taxonomic family (here: Canidae, e.g., red foxes Vulpes vulpes), and (3) age-dependent immune maturation contributes to the control of protozoan infection in wolves.<<<Read More>>>

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Coywolves in Maine Using Wolf Tactics To Bring Down Healthy Buck

The below photograph was sent to me from people I know in Maine. It was taken with a game camera from a location in Eastern Maine.

We know that genetically the wild dogs in Maine are a hybrid mixture of coyote, wolf, feral dog and domestic dog. It appears from this photo and others similar to it that I have seen, that Maine’s “coywolves” certainly have inherited more size and hunting tactics employed by wolves to bring down large prey such as the nice mature, healthy buck shown in the picture.

The myths of predator/prey relationships perpetuated by the ignorant believe that wolves/coyotes only kill sick prey and have no idea that this is simply not true or how the wild dogs go about eating and killing their prey while the prey is still alive, as is depicted in this photograph. For this kind of hunting, there is no such thing as an instant or “humane” kill.

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Photography: Buck Out-swims a Hungry Wolf

Please follow this link to view some photographs of a wolf swimming after a buck across a lake. The wolf takes a bite but is unsuccessful in bringing down the buck.

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It Happens Every Spring

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Bears are Bigger Killers Than Thought

*Editor’s Note* – When media crafts these headlines, it would be nice if they were a bit more accurate and explicit in whom they are referring when they write: “Bears are Bigger Killers Than Thought.” Thought by whom? I didn’t think they were sparse eaters of such things as moose, caribou and even cannibalism. Perhaps maybe, scientists are catching on a little bit instead of relying on Bambi and Yogi Bear to determine who kills and eats what.  

Overall, the bears [just seven of them] killed an average of 34.4 moose and caribou calves over 45 days. That’s far higher than average kill rates from previous studies using other methods, including aerial observation. Compared with one 1988 study in which scientists counted an average of 5.4 moose calf kills from the air in a different part of Alaska, the new study found an average of 13.3 moose calf kills. The new study also found wide variation in the number of calves killed by any one bear, with one killing 44 calves in 25 days and another killing just seven in 27 days.<<<Read More>>>

I wonder what cameras on wolves would reveal?

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And People Think Little Red Riding Hood is a Fairy Tale

This not only is a fairy tale, but it’s the biggest lie of the century.

“Phillips described the benefits of wolf recovery in terms of a “trophic cascade.” Essentially, that the reintroduction of wolves in Western Colorado will have a widespread effect resulting from the predation of elk. Most directly, it has the potential to cleanse the herd and mitigate the prevalence of chronic wasting disease. If wolves have a “big enough effect on prey, it can benefit willows and Aspens for example. They can grow more robust and many species can benefit from that,” he said.”<<<Read More Nonsense>>>

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Can coyote predation risk induce reproduction suppression in white-tailed deer?

Abstract

Predators can have powerful nonconsumptive effects on their prey by inducing behavioral, physiological, and morphological responses. These nonconsumptive effects may influence prey demography if they decrease birthrates or increase susceptibility to other sources of mortality. The Reproductive Suppression Model suggests that iteroparous species may maximize their lifetime reproductive success by suppressing their reproduction until a future time, when conditions may be more favorable. Coyote (Canis latrans) range expansion in the United States has exposed white-tailed deer (Odocoileus virginianus) populations to increased predation risk, and coyote predation can have profound effects on white-tailed deer reproductive success. We evaluated effects of temporal variation in predation risk (i.e., coyote–deer ratios) on fecundity and reproductive success of white-tailed deer on the Joseph W. Jones Ecological Research Center in southwestern Georgia, United States, by exploiting a rapid decline in coyote abundance to establish a natural experiment. We measured fecundity by examining ovaries for evidence of ovulation, and measured reproductive success using evidence of lactation from deer harvested before and after the decline in coyote abundance. We found that incidence of ovulation and lactation increased following the decline in predation risk. Our results suggest coyotes may be able to influence deer recruitment, independent of direct predation, through interactions that result in reduced fecundity. More broadly, our study suggests that in order to understand the totality of the effect of predators on prey population dynamics, studies should incorporate measures of direct and indirect predator effects.<<<Read More>>>

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Armed Prey

PreyArmed

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Understanding Coyote Behavior Can Contribute to Better Study Results

Below I emboldened part of a statement found in the article I linked to. Anyone who has maybe just slightly more than a basic understanding of how and when coyotes prey on fawn deer, would know that this killing occurs within moments of birth. Coyotes are bright animals and territorial. They know their habitat. They learn where deer, a creature of habit, often fawn. They will, at times, lay and wait. Coyotes have a keen sense of smell and can often “smell” when a fawn is born and move in for the kill. These same senses can be attributed to other predators that prey on deer, especially fawns – bear, bobcat, lynx, etc.

I have a camp in Maine. Around that camp, for many, many years I have been witness to a female deer that has given birth to a fawn(s). I’m quite certain the current resident doe is a descendant of the first mother deer I saw years ago.

It is on more occasions than not, that I see her in the early summer, “fawnless,” but is a treat to spot her with little ones.

When I first built the camp, shortly after spending some time there, I learned where this particular doe would go to drop her fawn. So did the coyotes. Over time, the deer have made several attempts to find a place to fawn that is safer. What may surprise some people is that the doe moves to within feet of my camp and hides her fawn there. After a week or two, when the fawn is quite capable of getting around, they disappear into the deeper forest, seldom to be seen again.

In association with this event, I am now seeing coyotes around my camp lot where I never did before. This is not a coincidence.

“These studies used a method that allowed fawns to be captured and collared at birth. Researchers did this by capturing adult does in the summer or fall and implanting a vaginal transmitter. When she gives birth to the fawn, she also gives birth to this implant and it signals the researchers to run in and mark the newborn fawn. With this approach, researchers discovered a lot of predation takes place that first week. In fact, the first week is the worst for fawn mortality from predators, especially coyotes. They concluded that all studies done with captured fawns that missed the first week underestimated the total fawn mortality due to coyotes.”<<<Read More>>>

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Reproduction and Nutrition of Desert Mule Deer With and Without Predation

Abstract

Desert mule deer (Odocoileus hemionus eremicus) in central Arizona declined from 11 deer/km2in the early 1960s to 2 deer/km2 in 2006. We had the opportunity to examine the causes of desert mule deer population fluctuations in Arizona from 1960 to 2006 by contrasting deer density, body condition, productivity, and diet quality inside and outside of the 259-ha Walnut Canyon Predator Proof Enclosure (WCPPE) on the Three Bar Wildlife Area (TBWA) in central Arizona. Mule deer inside the enclosure increased from 11/km2 in 1997 to 32 deer/km2 in 2004 while mule deer outside the enclosure in the TBWA remained between 1 and 5 deer/km2 during the same time. There was no difference in body mass and number of fetuses (in utero) between mule deer inside and outside the enclosure. However, there was evidence of mule deer in better body condition inside the enclosure compared to mule deer outside the enclosure. Mule deer inside the enclosure consumed a diet higher in energy than mule deer outside the enclosure. There were no differences in plant species diversity or composition inside and outside the enclosure. Current mule deer densities in the study area are below what the environment is capable of maintaining, and a history of higher mule deer densities inside WCPPE over 40 y has not resulted in measurable impacts on the highly diverse plant communities of TBWA. Observed differences in diet quality of mule deer may be related to trade-offs incurred through predation risk, where mule deer inside the enclosure are maximizing their energy intake without the burden of predator avoidance and vigilance. Our study provided evidence that current mule deer densities in central Arizona are below what the environment is capable of sustaining.<<<Read Entire Report>>>

Some very valuable information here.

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