WHERE HAVE ALL THE MUSKRATS GONE?????????????????

[Bogmaster]

 I wrote an article on this subject a year ago in The Trapper and Predator Caller.Letters to the editor on this subject,ran month after month. We will discuss this subject now,for Mike and the other curious trappers.
 The ones I blame the most are raptors--no rat is safe day or night.Eagles and hawks patrol the ponds and sloughs during the day ,and the Great Gorned owl at night.Remember--there is no greater killer than the Great Horned.
 I am also coming to believe more and more,that the raccoon takes another big toll.
 Isn't it odd,as the raptor population and coon populations continue to climb--rat numbers decline.
 Many blame otters--I can't and won't--we have always had an otter population in my trapping grounds.Steve presented us with his take on otters and rats--we do agree--It AIN"T them.
 I am saving some of my goodies on this subject for future arguements--LOL.
 Tom

[Hairtrigger]

In my area I believe chemicals that run off farm fields are ending up in the creeks and destroying the wild animal population

[Bogmaster]

 Trigger,where are you from?
 The lifespan of a muskrat,isn't long enough for the buildup of chemicals to kill it--I posed that question to our furbearer specialist too.
 Think back for a moment--when was the greatest amount of pollution and chemical dumping into our water???THE 60's and 70's---When were our rat populations soaring??--The 60's and 70's.
 Tom

[Hairtrigger]

I live in NW Ohio.... flat farmlands.
Do you think the chemicals could affect the reproductive systems?

[Bogmaster]

 I have my doubts on that,there again,they have short lifespans and chemicals don,t have the length of time to build up in their bodies.
 The decline in rats is nation wide,while certain small areas may be affected by local conditions---for instance a chemical spill---how do we account for the decline in other areas?
 Tom

[MChewk]

Thanks Tom good info...good thoughts. I am no otter expert just was pondering ...again. Something to think about again maybe...your thoughts on chemicals NOT EFFECTING rat pop....My info tells me that some 'rats CAN breed several times thoughout the year. If chemicals were reducing reproduction rates to say only one time a year...wouldn't that negatively effect pop.? Throw all the predators you previously mentioned into the puzzle and there might be a possibility that there might be some effect??

[Macthediver]

Tom
As you know I've never been much of a rat trapper. However growing up along the Mississippi river, trapping, hunting, fishing and diving the river. I have to say over the years I've seen many changes. I can't say that the big birds are totally responsable for the rat decline. I do know that as you have said there is defenitly more of the birds of pray. I have to agree with you about the chemicals.The chemicals everyone believes is the decline of the rats now. They were to blame for the birds being gone in the 60 and 70s. There are birds coming through the area here now like we never seen in the 60 and 70s. Hawks, owl, eagles and huge flocks of none preditor birds, Swans, Pellicans commerants. As for the birds taking muskrats I believe you left out the gulls. Which at times here turn things white.
When I sold my rats to Groeny back in December. His buyer said they were seeing a high rate of scaring and damage to the rats. Like I said I'm no big time rat trapper. But I did notice this myself while putting the rats up. I have to believe that some of if not all of this scarring is from raptor. It surely can't all be rat fighting rat and mink bites.
I can also say that with this years higher rat price our local rats are taking a pounding. It's going to be interesting to see what happens next year. The other day I took a drive and seen a trapper looking for rats. I know for sure that the area he was poking through had been trapped by someone at least twice before. For all I know it may have been the same guy just coming back to mope up stragglers.
I know the area I trapped this year had less rats in it then last season just by my lower catch. I have trapped the same general area for the same number of days, same amount of traps, for the last five or six years now. I always caught roughly the same number of rats give or take a few.  Couple weeks back I talked to another trapper at the boat landing. He told me that last season after rat prices went up he went back through the same area I had trapped. So for some part here on the river (public ground) we trappers are our own worst enemies.
I hate to knock anyone who's out there trying to string a line and make a buck. But when guys go back over day after day the same ground they know has been trapped. To me that starts to run a fine line between need and greed.
Well now that I'm off track that is enough from me.

Mac   

[Newt]

The Ideas I have about the declining Muskrat poplation. These may or may not be listed in order that they effect the poplation.
                                                                     



                                                                                   In "NEWT'S WORLD"
1- Raptors
2- The Clean water acts of the 60's and 70's
3-Spraying of DDT in the 60's
4- The Atlantic Ocean has risen 2 inches in the last 20 years
5- Phragmites chok'n out native plants
6- Modern Farming practices
7- What ever the desiese is that Muskrats have that puts white spots on their liver

[tundragriz]

Where I live in NE Pa. the muskrat is literally all but extinct.  There is not a single one along the creek for miles.  25 years ago there were nice trappable amounts.  2 years ago I watched a couple raise a couple litters.  I never bothered them and no one else traps in this area.  About a year ago every one disappeared.  I picked up the only mink that was running the creek back around Christmas.  I know he has been patrolling for at least 2 years.  Maybe some will return.  There are 3 Great Horned owls I see regulary.  A few weeks ago they were really hootin up a storm for mating.

[NONYA]

we have more rats here than i have ever seen,the rivers,lakes and canals are full of em.

[Wackyquacker]

The central dogma of predator prey relationships through out nature states: prey regulate predator s not the reverse.  This holds true for species that have a very narrow prey or preferred prey base and more loosely for the "generalist" type predator.  However, predation can significantly impact on recruitment rates of already strained populations.

Another fairly well established theory states population densities are a function of habitat.  Newts list above includes a long list of issue that dramatically affected the habitat of the muskrats. 

Raptors are more generalist types of predators.  I can see how many would think that the Owls and such have increased and the rats declined as a cause and effect relationship but I doubt it is that simple.  The increase in Owls and such may be significantly impeding the return of muskrats but they didn't cause the population shrinkage...I'll put my money on habitat destruction, whatever that encompasses.

[skidway]

Well, I'll say it. In my area I believe they've been over harvested. Add in predators, loss of habitat, etc. and they are gone- along with the beaver. You can get a few but not many; not enough for me to bother with.

[Asa Lenon]

There is a lot of habitat decline here in upper Michigan due to low water levels in recent years.  Ace

[bblwi]

In my home trapping area of East-Central WI I noticed our decline on my wadable rivers about the mid 1990s. I was catching almost the same numbers on this 5 mile stretch every year for about 10 years. The population dropped by over 50% and has not yet returned to pre 1995 levels. There are isolated spots that were good this year and I see more houses on our large Collins Marsh again this year. Not like the early 80s but more than the last decade.
My two marshes are down but not as much as the streams.
This area is heavily farmed and mostly dairy farms with alfalfa, corn, soybeans and small grains. I believe habitat loss, faster movement of water off after rain events. ( higher highs and lower lows.) wetland filling, cleaner farming, wide use of chemicals with very similar carbon links, predation.  All is due to human influence. We have many farms so when farmers could not kill birds of prey they are all over the place. We have more raccoons than ever as very few were here 50 years ago.
I like Tom feel the raccoon is a big influence here as I see more rats in the large expansive open marshes with fiew trees for raptors and too much "edge" for coons, mink, ferrel cats, dogs etc. like on a narrow river or stream.

I contrast that with this year's fall muskrat trapping in the national forest of northern WI. These areas flowages were created in the 30s by the CCC crews. The habitat has basically been unchanged in 70 plus years. There is only about 400 acres of ag land in the watershed. The coon numbers are low and there were never a ton of raptors as there were fewer open lands and spotting trees etc. These areas I found to have very good rat populations. In fact very good.  I am an average rat trapper and in a canoe with two days of ice and one all day rain I caugt 171 rats in 5 days with about 90 traps.

I can remember years ago driving along the Mississippi River when the snow was on the marshes in the pools and one could litterly see 100s of houses from just one bridge going over the river.  As a wildlife Ecology student I can remember being on Horicon assisting in goose banding and seeing so many rat houses in the late 60s that you could almost walk across the marsh.
As with most wildlife and or biological issues the outcomes are simple and the reasons for the outcomes are complex.

Bryce

[Seldom]

I’ve trapped here in Midland Co. MI all of my life and have to agree with what Newt, Wackyquacker, and what Asa stated.

In the 60’s a chemical company upstream of Midland made DDT and dumped it raw into the Pine River besides every farmer and gardener used it and Chlordane (? spelling).  I’ve lived the time period of no raptors to now where every kind of raptor is no longer a novelty.  As few as 10 years ago sighting a Bald Eagle in this county was something that could make the local paper.  That’s no longer true; eagles can be seen routinely any day of the week just by taking a drive along the rivers.

Wackerquacker mentions a theory referred to as Habitat Suitability Indexing (HSI).  The past three years I’ve worked for Michigan State University on a large dioxin study project that encompasses the animal food web chain all of our local rivers.  One of my key job responsibilities was to head up the trapping of mink throughout the entire watershed.  While doing this, one of the additional key components of the mink part of the project was to perform HSI readings as well.  I participated/worked with the students in this indexing and learned a heck of a lot about prey-habitat correlation.  Readings were taken every 500m along the river and extended inland for 100m in 25m increments.  Since the vast majority of the rivers frontage is private, we only took reading where we had access.

As Asa mentioned, we’ve had drought conditions here for several years previous to last year.  Many creeks and ditches with prime overhead cover were bone dry for 10+ months of the year.  In my opinion and I believe supported in several scientific publishing’s, this length of time with dry habitat is not conducive to supporting few rats or mink let alone a significant population.

Now with the increase of fur prices, specifically rats, I’ve seen as many as three waves of trappers running ditches, gleaning out every rat that can be found.  It’s going to be tough around here for a rat population that is already low, try to rebound.

[Buckskin]

Now how the heck does the rise of the Atlantic of 2" affect a musk rat in central US?
I would go on with Newts comments but this was this wildest.
I think the raptors have the biggest affect.   But rats seem to be making a come back around here. I saw more new rat houses this fall than I've seen in a decade.

[RdFx]

Buckskin, seeing the extra rat houses this year is a or was a good thing!  I bet if that land  was public the houses were on that three or more waves of trappers went over it at differant times.   I see places where people are trapping thru the ice  by rat huts that i KNOW  4 other differant trappers trapped during open water ... Not much left if any of breeding stock i would think.

[Wackyquacker]

  I'm certain that old Slimey can hold his own.  However, I'll chip in here on his behalf.  Firstly, the question, as I read it, was not how rats in the interior were effected but how rats in the US were effected.  The coastal salt marshes and estuary waters held some of the largest populations of Muskrats in the world.  Two inches in the Atlantic may not seem like much but it can and does have a profound effect on various ecosystems.

Blaming rat declines on Owls and other raptors is a kin to blaming the Mule deer decline on coyotes.  Predation will slow recruitment and there by slow recovery but it is not the cause of muskrat population drops.  In order to understand and possibly correct a problem it is critical to get the "cause and effect"  relationship correct.

[Bogmaster]

 Wack master,I will argue with you tomorrow.I never knew you had muskrats  lol--learn something every day.
 Till tomorrow.
 Tom

[Buckskin]

Well if thats the case, that 2" of water in the salt marshes kills off rats. Then there is a wonder that there are any rats at all on rivers systems.  The river behind my house will raise several feet in a day.  Marshes routinely are dry in the summers and in spring the rat houses can't be seen.

[tfyksen]

I believe much of the decline in central wis. is due to loss of habitat in combination with low water the last couple of years.  I am sure predation takes it's toll especialy in combintation with the above.

RdFx,

I know what you mean about the rats getting hammered by us.  I went to Mead 2 weeks and put out 90 traps out many of those in runs.  In a one week check I ended up with only 6 rats.  Hardly had any misses.  I pulled that day.  Place was trapped hard.

You ever get your cat???

[RdFx]

yeppers Teal, got three kittys!  When you come over sometime i will show you pics..

[trappnman]

I live near and grew up on some of the best muskrat marshes around- anywhere. While some consider the rat populations "good"- its not even a shadow of what it was like pre 1965.

Yet- the streams- streams that get the potent, direct runoff effect of chemicals- have never changed. The rats in them, have remained consisten over 45 years of trapping them. Why? Because of "stable" water- not months of flooding, because of more protection along streamsides than open marshes and because GRASSES are the stock in trade of stream rats- not various marsh broadleaves.

Raptors have a great deal to do with the decline of rats. Look at the the big marshes and the good creeks. Observe.

Owls sure- but I don't see any real evidence here of an owl explosion.

In fact- here- I'd argue that we have fewer owls now than at any time

My thoughts on the decline of rats isn't complex: (put in any order you like)

A) However- over the past 15 years- there has been a tremendous explosion in the other raptors such as red tails, northern harriers (marsh hawks) and esp Eagles. Bald eagles are a nuisance in many areas and Golden's are a common site.

B) Weather- on 2 ends. Here in my country- is has a lot to do with the series of 1000 year floods both spring and fall, that decimated the rats. Then throw drought in in between- and weather might be the most important factor

C) Vegetation. Chemicals matter but not for the rats directly. What the increased amounts do herbicides do, is change the makeup of the grasses in the marshes. So while they look nice and green, the vegetation you see isn't "muskrat" friendly.


Tularemia- those little white dots- really is self limiting and according to research has been much more prevalent in the past (overcrowding is a factor in its spread) and is said to not have much effect on population per se. (local outbreaks, not widespread)

[trappnman]

Blaming rat declines on Owls and other raptors is a kin to blaming the Mule deer decline on coyotes.

yes, it is.

if habitat was ideal, if man hadn't interrferred in the ecosystems, then neither coyotes or raptors would have much effect.

But they did..... and they do.

To think that neither coyotes or raptors have an affect on stressed populations, is silly.

[NONYA]

Maybe trapping should be factored into all those decline stats?

[Bogmaster]

 Prices on rats ,until this season have been in the dumpers.As a reult,few trappers were after rats.The decline has taken place ,without the assistance of trappers.
 Tom

[NONYA]

GUYS AROUND HERE TRAP THEM regardless OF PRICE.

[Newt]

Buckskin, Wake up!!!!!
 Your river out your back door rising in a rain storm .Is not the same at the Atlantic Rising. Matter of fact. The TIDE where I live rises and falls 4 and 1/2 feet twice a day.While were on the TIDES up in MAINE there is a 12 foot tide. That is not the problem. When the Ocean rises (or falls). . The whole ECO-SYSTOM changes.The Saltinity of the water can rise or fall. This will change EVERYTHING.When you add 2" to a coastal plane that is maybe only 1 foot above sea level. This is a major influx.

Let me put this so a LANDLUBBER can understand it. IF your standing in water that is ONE inch from the top of your boots. Now it rains and the water gets 2 inches higher.---------SEE the problem Stuff gets wat that did'nt before.

[NONYA]

LANDLUBBER.....lol priceless...

[trappnman]

NONYA- those that like trapping rats, do trap them- regardless of price.

I'm like that and so is Bogmaster.

But generally, most trappers aren't like that and if prices are way down, the harvest is also.

I agree with Tom- that trapping doesn't hurt overall populations (sure, a creek that has 2 can be trappedo ut iof you trap 2).

Research also bears this out- showing that rat populaitons do better in an area where there is a large turnover in populaiton (a big harvest)

Trouble is- due to lost habitat, due to veg, changes, due to increase predators (primarily raptors), and yes disease because stressed populations (drought, floods, etc) are more susceptible to disease- popuations have been gradually decreaseing on an overall scale.

one might also ask where are the greys? Where are the spotted skunks?

Both used to be very common in my area- but haven't seen a spotted skink in 30+ years or a grey in 4.