AHM Report is Out

Carl

Carl

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Staff member
Supporter
Check it out:
http://www.flyways.us/
The "new" pintail population/season model is very interesting, will provide a clear framework for a closed season, 1 bird limit or 2 bird limit on pintails.
 
Carl, you read that as "clear"? Wow, I just perused it and am not familiar with the history/protocol, but that is hard reading and I read and write specifications for work!

Dave
 
I guess I should say it is clear as far as statistical models are concerned!

Actually, I was thinking "clear", as in at least now they have a set framework to use each year to set the season & bag limit. That makes the decisions a little more "clear" when the biologist get together at the flyway meetings. Takes most of the politics out of it as well.
 
​
Not Hard to understand the new Pintail objective. Less than 1.75m Pintails season closed, 1.75m to 2.5m Pintails one per day, 2.5m and over two birds per day. This year they counted 3.5m.​
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Table 10​
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{ Northern pintail optimal regulatory strategya for all 4 Flyways for the 2010 hunting season. This​
strategy is based on current regulatory alternatives (including the closed-season constraint), northern pintail​
models and weights, and the objective of maximizing long-term cumulative harvest. The shaded cell indicates​
the regulatory prescription for 2010.​
Mean Latitude​
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​
​
c​
Bpop​
​
​
​
b 53.0 53.5 54.0 54.5 55.0 55.5 56.0 56.5 57.0​
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​
​
​
1.75 C C C C C C C C C​
1.75{2.5 L1 L1 L1 L1 L1 L1 L1 L1 L1​
​
​
​
​
2.5 L2 L2 L2 L2 L2 L2 L2 L2 L2​
a​
​
​
​
C = closed season, L1 = liberal season with 1 bird bag, L2 = liberal season with 2 bird bag.​
b​
​
​
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Observed northern pintail breeding population size (in millions) from the WBPHS (strata 1{50, 75{77)​
c​
​
​
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Mean Latitude (in degrees).​


 
Actually, it is very clear compared to years past. This breeding population estimate with a distribution mean latitude of ? with a mallard season of ? means the pintail limit is.... The AHM process is driven by May Ponds and mallard numbers. This gives a clear definitation of pintail limits assocaited with BPOP, where they are, and Mallard season limits. Just try to figure out scaup? Redheads? and you will see pintails are VERY clear.

Clint
 
Clint,
Are there similar models in the works for redheads & cans?
I thought one was drafted for cans a couple of years back, X no. of cans = season, X no. = no season, etc.., but havent heard much since.
Do you have a link to the scaup framework, cant find that one either.
 
Carl,

The background for the scaup models are in the lit cited with links to the documents by Boomer. They provide the basis for the models. There has been talk about cans, not sure about redheads. I seriously doubt you'll see much movement in that direction because there isn't as much concern for either species as there used to be. If things change, regarding their populations, that'll change, but until then, I doubt there'll be much effort.

Clint
 
Thanks, Will look up the Scaup documents, I may have them at work.

Is the high degree of egg dumping/nest parasitism considered when looking at redhead numbers?

Where you here last week for the meeting?
 
The canvasback model is older and needs to be revised but hasn't been updated since about 2000 but the harvest strategy was updated after the 2 bird bag limit was added a few years ago. I've heard the Mississippi Flyway is asking for it to be revised.

There has been informal discussion of building a redhead model but no progress to report. The flyways haven't really requested it yet because at some point the harvest strategies for all of the divers will have to be melded. I don't want to imagine a season in which the scaup season is moderate, the canvasback season is closed and the redhead season is only open for a partial season.
 
I was going to try to make it to the MS meeting here in Mobile but oil spill and family stuff got in the way.
 
I cuold see your example happening, though we havent had less than a full season and 2 bird limit on redheads in years, since 1997 at least I believe.
 
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