Ducaholic wrote: but I won't discount their efforts or the impact that flooded unharvested crops are having on the migration as a whole and certainly on mallards. Imprinting is real.
Also don't discount the large increase in warmwater discharges and no till farming. The few flooded crops up here are froze solid, but we still have piles of mallards living on all the open water and eating corn in the harvested fields. The rich guys with frozen crops actually got our zone lines changed so they had an extra week before they froze out. They wouldn't have done that if the birds were hitting these fields after it freezes and we have a lot more birds in the area late, so I trust that these guys really don't have birds after it freezes.
Last year in January, the field next to the one we were hunting in, looking through the binoculars, it was acres of wall to wall ducks. We had tons of ducks in north east part of the central zone of Illinois all the way through the end of the January goose season. And that's just one cooling lake. Even when we had the polar vortex with low temps in the -20's the ducks didn't move south. They are getting like the geese where it takes a lot of snow to move them south.
What I don't understand is that their surveys seem to show less ducks than the total number that I see. There is a survey from the 11/14. I hunted 11/30 and saw thousands of ducks, but the survey said only 3,000. That's two weeks, so it could have changed. However, they did a survey on the 1/11 and said there were only 1,300 mallards. The 18th I saw tons of mallards. And pretty much the entire month people were seeing tons of mallards. They just never left the area because we never got enough snow to move them on. I don't know how they do the surveys in the area, but it seems like they are missing most of the ducks in the area. Maybe a large fraction are just spending all day in the fields and fly from field to field. They also survey much less frequently than I remember a decade ago.
These were all built in the 70's or maybe late 60's.
There were also a lot of big coal plants built at the same time.
If we are holding ducks at the end of January, they simply don't NEED to migrate further south, flooded crops or not.
There has also been big environmental changes over that time. The forcing of building retention ponds and restoring of wetlands. They built an interstate extension near me a few years ago. It is lined with retention ponds which are some of the best waterfowl habitat in the area. They also rehabbed a large marsh near me which is now the area that holds the most waterfowl during much of the season.
There have been a lot of dramatic changes and it is not surprising that this has impacted waterfowl behavior for those species like Canada Geese and mallards that simply don't have a biological need to migrate and have always had large subsets that did not migrate further than necessary. Simple Darwinian math would favor these birds over those that migrate further south. The mallards that stop where I live are hunted for over 30 days less than the populations of mallards that migrate far south. On top of that, they face far less hunting pressure as well. Hunter mortality has got to be a lot lower so over time the populations would be expected to grow faster.
Why would the populations not be expected to shift away from the places where the most hunters are killing the most birds to the places where the least hunters are killing the least birds?
I think to bring things back to the good old days, we need to extend seasons up north until the end of January
Last year if we could have hunted ducks in January it would have been freaking awesome. We'll keep the pressure on them for you all