you will learn more than most PhDs by trapping and observing.....oh the line - correlation does not equal causation brings me back to horrid memories of biometry

Enjoy being outdoors and watching the Lords creation adapt and change. We definitely impact nature in mighty ways and I personally have issues with top former herbicide companies running our USDA. Worked too long for agencies to trust them when money is involved - money is always involved. Most corn crops are pounded with fertilizers, herbicides, insecticides and often fungicides. If only manure is being used - it would surprise me.

Around here about the only place you find muskrats in any numbers is in neighborhood ponds that all the big number neighborhoods are built around and all those fancy houses and lawns are treated heavily with everything under the sun to make them green and lush

I always assumed the same as Eric's findings. The creeks I trapped as a kid had loads of rats in them in the late 70's to the mid 80's. After that, populations went in the crapper. The only thing that made sense was chemicals used on crop ground. Hardly a rat anywhere on the creeks I trapped as a kid today.

I reckon, those urbanites aren't using much Roundup on their lawns.

We have as much agricultural spray up here as anywhere. When we have water we have rats, its that simple. Probably several factors leading to their decline.

interesting . . thanks for sharing

52Carl, which is specifically why I said linked and not caused by. I doubt anyone has scientifically studied or funded research into ALL the possible contributing factors beyond NOT being AG chems. Most of the research done to “ prove” safety are funded by the chem corps so they needs to be reviewed very judiciously. The current Neonics have been incidentally found in over 2/3 of MN deer being tested for CWD around the whole state. The effects are yet to be learned. But how wide spread might a buildup be? State bee keepers have won a lawsuit over it here. I am opened to true unbiased facts

My area stays pretty constant-slim to none. They are only by products of a mink and coon line here. You would be considered crazy to try to target them. What I always wondered is what happened when an area only giving up 0-3 rats for years gives up 3-6? Maybe we should ask whats bringing them back?

I'm not sure I buy the "chemicals used in farming" conclusion.

Reason being, in the Dakotas, which is essentially all farm ground, all you need is water and there will be rats galore.

That is some interesting info I commend you for taking your time to document some info and see what might happen over time I was a volunteer for a local Pheasants Forever chapter in south east PA for about 25 years from the1990's to 2018 The pheasant and the muskrat has been on the same population decline during that time As a 12 year old beginning bird hunter and rat trapper I could not have foreseen what has become of both of them But on the other hand coyotes are numerous throughout PA and in many places the white tail deer are regarded as pest Mother Nature is always changing

I own some of the same ground now that I trapped when a boy, a ditch creek runs to the river through it. Not one rat in it all winter, and mink droppings were in a pile on the culverts as a boy, now none. Did I kill mink when I put mouse poison in my deer blind 12 foot off the ground, probably, because it was completely eaten and my cushions were still all chewed up. I will try some dryer sheets from now on, don't want the dead mice to be killing other critters. But the lack of mink is not just in the field by me, lots less than the 70s.

Who do you suppose originally "linked" frog mutations to pesticides? Likely not friends of ours, to say the least.

Here I think chemicals too. Plus the creeks act different now than they did before all of the fields were tiled. Less water in the creeks, the fields all drain off faster. Plus there is less habitat as far as brush on the creek banks.

Spray fields, less water, less debris... not good for rats. I wonder if the minnow and crawfish population fluctuated with the rats? That would be an interesting line graph.

Has the resurgence of birds of prey and predators like otter had an effect on the rats?

Mr. Space and what do you think the cause of the decline in your mink population is? YOu mentioned this a few weeks ago and I was wondering if this would spread to here......jk

I think the mink decline is due to guinea worms. The last ones I caught had literally 100's under their skin. The mink were extremely thin. This summer I have seen a few roadkills so I hope they are making a comeback.
As to the muskrats that were the point of this thread: We had so much snow and cold last winter (March of 2026) that I was unable to trap the swamp. Hope to get in there in March of 2027.

Thank you Eric ,this is good stuff for Trapperman .

You might be surprised, I’ve seen the various lawn services using those hand held sprayers spraying round up but it’s probably not as much as it n farm fields true

Back in the 60/70 my cousins who farmed sprayed tons of herbicides and pesticides on their farm and the creek running through it still supported a good rat population, but sometimes a lot of people do t take into account is that farming practices have also changed, where there used to be a border of vegetation around farm fields nowadays most fields are plowed border to border and many of the shelter belts have been torn out to make plowing easier so there’s no longer that to filter or slow down chemicals from entering the waterways

Frankly I don’t know what the answer is but I will say I have seen an upswing in rat populations in many areas where a few years ago there were little or none and many of those areas farming has slowed or stopped or shifted from row crops to things like hay or pasture for livestock

I suspect you are on to something. I may be a card-carrying biologist, but I have far more faith in the observations of trappers on the ground they are infinitely familiar with, than most the studies done by educated idiots!

I hadn't thought about it for many years, but in the 50's and 60's there in Sussex County, I was responsible for many the .45 cent 'rat going to Rat Heaven!

Pete

sure wish they would make a come back here, only real place that has any is one golf coarse and they want them gone I have live trap a few and relocated them