June 17, 2019

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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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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Predator-Prey Study: Wolves not threat to deer you may think

*Editor’s Note* – I have not read the entire report referenced in the below link. Most of the information presented is sensible and seems to substantiate most all other real scientific studies on predator prey relationships.

However, it still amazes me that Mr. Beyer, one of the DNR researchers makes some puzzling and seemingly contradictory statements. First he is quoted as saying that wolves will NOT decimate a deer herd. This is followed by: “What we know from the scientific literature is there are only two reports where wolves are believed to have contributed to a substantial reduction of deer … winter weather is still the driving factor, even in the low-snow zone,”

Even though the article begins by stating that there are several factors involved with trying to determine predator prey relationships, all of a sudden it now appears that none of that matters because “only two reports” suggest that wolves are believed to decimate deer herds.

I don’t know those reports but I’m willing to wager they are pro wolf, fake science reports.

I will not dispute that winter weather is a driving force of great influence on deer survival. Perhaps Beyer believes that 100 years from now there will be wolves, coyotes and deer sharing habit – and there may well be. But what happens in the interim? We cannot control the weather. We can only mitigate disease with good sound wildlife management. The possibility exists that wild swings in deer populations will be a reality. We also know through scientific studies that with the right combination of circumstances, uncontrolled large predators can easily destroy a deer herd and keep it at levels that are unsustainable. If this is the conditions in which the DNR believes will not decimate a deer herd, then one has to believe their goals will be the elimination of hunting as a management tool.

All this being said, the data being shared in this article reinforces what many of us have always known about the relationship of deer with weather and predators.

“We’ve been surprised by a few things in Phase I (low-snow study),” notes Dean Beyer, a researcher with the DNR. “We learned that adult does were avoiding core wolf areas and that coyotes were avoiding them, too. That put coyotes and does in the same area, which probably resulted in a greater mortality by coyotes. And we were all surprised by the rate at which bobcats killed fawns. The rate is much higher than other species.”

Source: Predator-Prey Study: Wolves not threat to deer you may think | MLive.com

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Relationships With Fish and Game Departments at All-Time Low

Yesterday in the Missoulian, republican gubernatorial candidate Rick Hill stated, “One of the things I’ve heard everywhere that I go is that the relationship today between Fish, Wildlife and Parks and landowners and sportsmen is at an all-time low.”

Should this come as a surprise to anyone? Do people think that this is something that has happened overnight? No and no! And this seemingly newly discovered phenomenon isn’t relegated to Montana. It’s an epidemic that reaches every state in this Union. Sportsmen and landowners have almost as bad an opinion of their fish and game departments as Americans do of their Congress or the presidency. And why is that?

There once was a day when fish and game departments were constructed with the idea to devise plans that would perpetuate game species so that everyone had a chance to stock up on food and/or sell animal furs to supplement or provide income. These fish and game departments originally were a direct extension of the outdoor sportsmen.

Not anymore! Fish and game departments have become giant government agencies with too many powers and a focus that caters to environmentalism and animal rights and animal protection. Along with this demented change in direction and overreaching power grab, landowners are not only losing rights to use their land as is necessary but in some cases they lose their land altogether. And with this do we really need to doubt what Hill says, that this relationship between sportsmen/landowners and fish and game is at an all-time low?

When fish and game departments functioned as a supporting entity of the sportsmen, there was also a certain degree of ownership and pride in that ownership. Are any readers old enough to remember the day when you could actually talk with a representative from a fish and game department and be treated as an equal, one with respect and an understanding of who paid whose salary? That pride of ownership kept sportsmen involved in the process. They knew their voice would be heard and when it wasn’t, fish and game personnel were out of a job.

Today, fish and game departments pretend they are interested in the sportsmen. Some even masquerade as humans who understand their role and function as that of serving the public. But don’t be fooled. They are a government organization. Governments are not any friend of the people and they certainly are not friends of sportsmen or landowners. This is because sportsmen and landowners are what stand in their way to fulfill their agendas of protecting wildlife, ridding human presence from the forests and fields, relegating us all to concrete jungles and levying control over us all. Get rid of us and they get what they want, or at least think they do.

But the problem that perpetuates this insanity is that government attempts to fix government with more government. It’s what keeps them collecting a salary. Talk is cheap. Words in this case are nothing more than campaign rhetoric, meaningless drivel to placate the masses in order to steal your vote.

Until states regain control over their environmentalism-strangled fish and game departments and change the direction and goals back to game management combined with an understanding and respect for landowners, nothing will change. Actually look for it to get worse.

The people are lazy, brainwashed robots who want government to do their bidding. Why do you think we are where we are now? Government is not the answer to government.

Tom Remington

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