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Author
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Topic: Coyote population fluctuation
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2dogs
Knows what it's all about
Member # 649
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posted August 06, 2005 01:22 PM
I've noticed over the years. Their numbers in my area, change [greater or less] around the 3-yr mark. Regardless, of long wet springs or harsh winters. For the most part, they [increase].
Anyone else, noticed a similiar pattern, in their area? Or any weather pattern/time on populations?
[ August 06, 2005, 10:35 PM: Message edited by: Leonard ]
Posts: 1034 | From: central Iowa | Registered: Apr 2005
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Cdog911
"There are some ideas so absurd only an intellectual could believe them."--George Orwell.
Member # 7
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posted August 06, 2005 01:45 PM
I don't have a copy of it, but T&PC published a bit from a guy in one of the Dakotas several years ago who had been collecting data and found that the coyotes in his area ran on a 12-year cycle. I sat down with my dad and grandfather and as best as we could recall, his deductions were pretty close to what we have seen here for years.
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I am only one. But still, I am one. I cannot do everything, but still, I can do something; and, because I cannot do everything, I will not refuse to do something that I can do.
Posts: 5440 | From: The gun-lovin', gun-friendly wild, wild west | Registered: Jan 2003
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2dogs
Knows what it's all about
Member # 649
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posted August 06, 2005 01:50 PM
Interesting, hope others chime in.
Posts: 1034 | From: central Iowa | Registered: Apr 2005
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Leonard
HMFIC
Member # 2
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posted August 06, 2005 03:32 PM
The oldest theory I have heard is that predators, in general, follow the seven year rabbit cycle, one year behind. Always dependent on regional climatic variations.
Good hunting. LB
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EL BEE Knows It All and Done It All.
Don't piss me off!
Posts: 32371 | From: Upland, CA | Registered: Jan 2003
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2dogs
Knows what it's all about
Member # 649
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posted August 06, 2005 03:46 PM
Leonard,
Do you recall, where you heard that from? I wonder if this is a [focal], regional or perhaps national thing. I've thought about this on & off for many years.
I followed a pattern [weather]...for awhile, yrs ago. At one point, I thought I had nailed it. Then of course, the coyotes threw me a curve.
Then, I started to NOT pay attention to these hard, long weather cycles...[prey population flux's]. As being directive of their populations.
I came up with this 3-yr cycle, some yrs back. I couldn't see it at first, duh..[the forest for the trees]. It so far has held pretty accurate for me.
[ August 06, 2005, 03:47 PM: Message edited by: 2dogs ]
Posts: 1034 | From: central Iowa | Registered: Apr 2005
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Leonard
HMFIC
Member # 2
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posted August 06, 2005 06:07 PM
Yeah, might help? Thanks, Melvin. I'm not sure which graph I would hang my hat on, but, of course, there is a relationship.
I think coyotes are a lot more adaptable, they can get by on poodles when the rabbit cycle is low.
Good hunting. LB
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EL BEE Knows It All and Done It All.
Don't piss me off!
Posts: 32371 | From: Upland, CA | Registered: Jan 2003
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Melvin
Knows what it's all about
Member # 634
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posted August 06, 2005 06:12 PM
This might be better to explain.
Predatory Relationships and Population Fluctuation
It is an open question whether predators and prey commonly regulate each other's numbers in nature. There are many examples of cyclic changes in abundance over time, in which an increase in prey density is followed by an increase in the numbers of predators, and then the availability of prey decreases, also followed by a decrease in predators. Are predators causing their prey to fluctuate, or are prey responding to some other environmental factor, such as food supply? In the second case, prey may be regulated by food, and in turn, may be regulating predators, but not the reverse.
Predators can sometimes determine the number of prey species that can coexist in a habitat. If a predator feeds on a prey species that could outcompete (competitively exclude) other prey species in a habitat, it may free more resources for those other species. This relationship is known as the keystone effect. Empirical studies have indicated that the number of prey species in some communities is directly related to the intensity of predation (numerical and functional responses of predators) such that at low intensity, few species coexist because of competitive exclusion; at intermediate intensity, the diversity of the prey community is greatest; and at high intensity, diversity decreases because overgrazing begins to eliminate species. This intermediate predation hypothesis depends upon competition among prey species, which is not always the case.
Studying Predation
[ August 06, 2005, 06:17 PM: Message edited by: Melvin ]
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Melvin
Knows what it's all about
Member # 634
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posted August 06, 2005 06:35 PM
My personal opinion on fluctuating coyote numbers,has to do with five factors.
1.Food
2.Mange
3.rabies
4.hunting
5.trapping
Did i miss any others?..Weather?
Posts: 661 | From: PA. | Registered: Apr 2005
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2dogs
Knows what it's all about
Member # 649
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posted August 06, 2005 06:46 PM
Here's an example of the cycle, I use to follow. It was pretty accurate, well...for awhile anyway.
1st yr.
Long wet spring-long harsh winter.
Coyote pop= medium
2nd yr [regardless of season harshness or length].
Coyote pop= medium
3rd yr [regardless of season harshness or length].
Coyote pop= low.
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This is an example, of what I'm saying now;
1st yr.
Long, wet spring. Harsh long winter.
Coyote pop= medium
2nd yr.
Regardless of spring or winter
Coyote pop= medium-low
3rd yr.
Regardless of spring or winter.
Coyote pop= medium-low
4th yr. [Winter] [3 completed cycle's]
Coyote pop= Med-high
All this [stuff], hurts my head ![[Frown]](frown.gif) .
Ought to just go hunting, & forget about it.
[ August 06, 2005, 06:47 PM: Message edited by: 2dogs ]
Posts: 1034 | From: central Iowa | Registered: Apr 2005
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Cdog911
"There are some ideas so absurd only an intellectual could believe them."--George Orwell.
Member # 7
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posted August 06, 2005 06:57 PM
Along the lines of what Leonard said, it was once believed that predators were the primary influencing factor on prey species densities. After some long term studies were conducted, it was found that the reverse was true. Without digging thru a bunch of college text books in boxes in the basement, I'd have to guess that the studies involved Canada lynx and snowshoe hares, but I may be wrong.
In any event, certain species have been found to cycle independently of environmental factors. Cottontail bunnies run on a 7 year cycle in most areas. Skunks run on a 15-year cycle. Certain ambient conditions can exacerbate those sways, but they aren't generally the primary cause of a decrease or increase in overall numbers. It seems that most species run on one of either 7-, 11-, or 15-year cycles. Personally, I cannot believe that nature would be so orderly as to have everything running on one of only three specific intervals. And this is what made the 12-year pattern in northern coyotes so remarkable to me. Kinda stood out as an oddity.
Mange and rabies would both be listed under disease processes which would be density-dependent variables. Food availablility in many cases would be density-independent. Weather would have very little effect, except in very localized instances and would not be density dependent except in instances of prolonged cold or drought and its impact on excessive depredation tolls on conventional prey species. As for trapping and hunting, I personally don't think either of those parameters has nearly the degree of influence we would like people to believe. It helps, but the professional ADC ppl will tell you that recreational hunting has little impact on specific problem coyotes, unless one of us just gets lucky. And just when you think you've hunted an area so hard and gotten so many, you go there at night and it sounds like you didn't even scratch the surface.
I would say that Leonard is right in his offering that rabbit numbers may have some temporary downrange influence on coyote numbers and fluctuations, but because of their adaptability and omniverous tastes, they are better equipped to handle environmental crises better than just about any other species out there.
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I am only one. But still, I am one. I cannot do everything, but still, I can do something; and, because I cannot do everything, I will not refuse to do something that I can do.
Posts: 5440 | From: The gun-lovin', gun-friendly wild, wild west | Registered: Jan 2003
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Bryan J
Cap and Trade Weenie
Member # 106
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posted August 06, 2005 07:16 PM
http://edis.ifas.ufl.edu/images/200890386
Here is a graph that goes along with what Leonard said. I assume this is from the Curlew study...
Posts: 599 | From: Utah | Registered: Feb 2003
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2dogs
Knows what it's all about
Member # 649
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posted August 06, 2005 07:16 PM
I read in grade school[I was addicted on Red fox by then]. Read where the average adult coyote will eat up to 150lbs of grasshoppers a summer.
As I contually get educated by the perfect [survialists] they[coyotes] are. I just can't seem to get enough.
I don't put a lot of [water] in these weather cycles. But seeing how, I don't have copious numbers of coyotes radio-collared. Or DNA their scat. I'll have to just make do.
[ August 06, 2005, 07:17 PM: Message edited by: 2dogs ]
Posts: 1034 | From: central Iowa | Registered: Apr 2005
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Leonard
HMFIC
Member # 2
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posted August 06, 2005 08:41 PM
I will tell you one thing that cannot be discounted, at least on the short term. Some of our western drought conditions can keep the grass from growing and the bunnies from hatching and the coyotes do need water, so whole areas can be completely void of any of those things, for as much as ten years? (as a wild ass guess)
One of my bellweather indicators is an obvious excess of rabbits and a corresponding absence of coyotes. The following year, things seem to reach an equilibrium, but I'm not following it close enough to predict anything?
Maybe the reason why the studies were done with Lynx and snowshoes is that they are a lot more specificly related to each other? As mentioned, coyotes can and do switch to whatever is available, including watermelons and grasshoppers.
Good hunting. LB
edit: also, looking at Melvins list. Rabies is not a significant factor out west here. Mange is not a significant factor here either.
[ August 06, 2005, 08:44 PM: Message edited by: Leonard ]
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EL BEE Knows It All and Done It All.
Don't piss me off!
Posts: 32371 | From: Upland, CA | Registered: Jan 2003
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2dogs
Knows what it's all about
Member # 649
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posted August 07, 2005 03:51 AM
I spoke of this before. A couple of winters ago. I noticed a [very large] increase in population in my "primary" area.
It was unreal, the amount of coyotes, I spotted that winter. Never before or since, has this occured. 75 coyotes spotted, 63 or 64 in one small [focal] area, roughly 4x15 miles sq.
I can't help but think/wonder. That there was somewhat of a "mass" migration that occured on a "mini" scale. Just a theory anyway...They were pretty thick ![[Cool]](cool.gif) . I Don't know why, this occured.
My area, has a steady abundance of field mice, voles & cottintail rabbit. With [greatly] flucuating pheasant populations[dependant on a long wet spring].
Mange;
It is very rare around here. I've only seen a handful of coyotes, over the yrs. That were infested. I've never seen a Red Fox, that had it ![[Confused]](confused.gif) . Hmmmm, why?
Hunting pressure;
There are a handful of C-hunters as well in my county. I hunt almost every day, I'm not at work in winter time. A good 90% of the time. I don't run across another coyote hunter.
[ August 07, 2005, 03:53 AM: Message edited by: 2dogs ]
Posts: 1034 | From: central Iowa | Registered: Apr 2005
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222shooter
PAKMAN
Member # 695
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posted August 22, 2005 12:02 PM
I read a study on ruffed grouse populations in the upper mid west(Minn., Mich.and Wisc.) and there was a clear direct relationship with their predators(Coopers hawk and owls)But,since predators live longer than grouse, they didn't just die when the food got scarce, they moved to other areas. They knew this by the increase in hawks and owls in Indiana and Illinois.
Grouse populations in the appalacian region were more dependent on the availability of quality food(i.e. aspen buds)and cover(deep snow).
So, the migration theory with coyotes, that 2dogs mentioned, may be valid. It makes sense to me too.
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"Coyote hunting has pretty much taken over my life".
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Leonard
HMFIC
Member # 2
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posted August 22, 2005 12:24 PM
Welcome to the New Huntmasters, 222shooter. Glad to have you on board.
Good hunting. LB
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EL BEE Knows It All and Done It All.
Don't piss me off!
Posts: 32371 | From: Upland, CA | Registered: Jan 2003
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keekee
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Member # 465
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posted August 23, 2005 12:18 AM
Ya Welcome! Were are you at in Southern Ohio?
Brent
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222shooter
PAKMAN
Member # 695
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posted August 23, 2005 04:45 PM
Hi Keekee, I live near Frankfort. Just west of Chillicothe. Have you done any yote hunting this summer? I haven't been hunting but I have been scouting and getting permission. I don't plan to hunt till fall, however, today a fella at work asked me to come out to his land and shoot the coyotes because they killed his old beagle. Guess I'll have to start early. ![[Big Grin]](biggrin.gif)
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"Coyote hunting has pretty much taken over my life".
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2dogs
Knows what it's all about
Member # 649
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posted August 24, 2005 05:50 AM
I recently brought this same [topic] up, on another site. The Adminstrator/coyote hunter, suggested. That I consider, this [3-yr/4-winter cyle] over a period of 5-complete cylces, in succession.
That seemed more logical & perhaps more accurate. To test the validity of my latest theory.
Posts: 1034 | From: central Iowa | Registered: Apr 2005
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