Two things, virus! you will usually see red nose and lips and of course the virus needs flys to move it around and down here it's probably to late.
The other is weather! long grass and wet weather! IF there hasn't been a poison drop.
Wet cold weather, nocks them for a six with flu, there are studies in England that prove the point.
I have seen it reduce the population before winter, it's common and of course winter they stay tucked up in their warren system so numbers are lower, until spring.
I've heard another report on that line, but difficult to say just want without inspection.
KH
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