Postby Steel 3's » Thu Dec 13, 2001 9:04 am
Hey Travis,
I don't know the proportion of hens that would be effected by the later season. Some harvest data collected by the state of Mississippi seemed to show a rather constant kill from 12/12 through the end of Jan. in 1998/99 .... about 30,000 mallards killed 12/12-12/21 and about 34,000 killed from 1/21-1/31, but didn't include data from say 12/1 through 12/11 which would likely have been the open days for a traditional (non-extended) framework season. Also important is the fact that the 3 5-day periods with the highest mallard kill were BEFORE the extended framework days. So just guessing, I would say that increase in hen mallard kill would not be more than 10%, which if the harvest rate is indeed 10%, then we are talking about the later season affecting 1% of the mallard hen population.
The counter to that argument is the additive nature of late harvest (rather than compensatory). In this case we have good data from 2 studies on radio-collared hen mallards: 1 right in y'all's backyard done by a guy named Bruce Dugger and another done in the panhandle of Texas (OK, Southern High Plains of Texas) by Loren Smith. Both studies were published 5-10 years ago in the Journal of Wildlife Management, and what both of them showed was that if hen mallards survived until Jan. 15th, then NOTHING killed them except hunters. Throughout the earlier part of the season, there were deaths due to other causes (I'd have to look them up specifically but probably include predation, exposure, disease/poisoning, etc.). But once they survived until mid-January, they did not die of anything else but shooting. That suggests very strongly that hunting mortality after that date is totally additive.
Does that matter at high population levels? I don't know. I don't know how sensitive the AHM models are to changes in harvest rates. The USFWS has put out at least one report that estimates the effect of later seasons if ALL states accept them, and shows that resulting AHM simulations reduce the number of years that we will be offered liberal or moderate harvest regulations because of that impact. However, a report from the state of Mississippi suggests that because of the high variability in harvest due to things other than regulations, the USFWS has no good evidence to make that argument. (I've still not closely read that report, so I can't really spell out details). AHM has only been in effect since 1995, a period of increasing and high duck populations, and there has already been some concern about 1) the importance of pond numbers in determining harvest regulations even though the correlation between pond numbers and imm/adult ratio in the harvest has been getting weaker, and 2) we have seen maticies that would recommend closed seasons at mallard populations higher than what we saw during the 30-day, 3-duck days. We have a lot to learn about AHM and how it functions during a down-cycle.
Biologically, there simply isn't very strong evidence for or against the extended framework. There are certainly indications that the effect will be negative, but nobody knows if that effect will have population implications.
Xpress - I didn't mean it judgementally, but I do believe that as most waterfowlers mature, they just naturally become more selective and are not satisfied with just killing whatever comes in until their legal limit is filled. It may be as simple as drakes look better in a photograph. I don't know about "higher" or "lower" levels, but I do feel some disrespect for a hunter when offered a decoying group of birds, shoots a hen ... of any species. Just my personal opinion. And I believe that behavior evolves with age and/or waterfowling experience, thus my use of the word mature. I just think so much of the sport is missed when that isn't considered.
