Adaptive Management Report

So having looked only at the Ex. Summary, this paragraph caught my eye, as someone who for whom black ducks are the majority of what I see once the teal and woodies mostly head south:

"For black ducks, the optimal country-specific regulatory strategies for the 2026 hunting season were calculated using:(1) an objective to achieve 98% of the maximum, long-term cumulative harvest; (2) current country-specific black duckregulatory alternatives; and (3) updated model parameters and weights. Based on a liberal regulatory alternativeselected by Canada and a moderate regulatory alternative selected by the U.S. for the 2025 hunting season, and 0.79million breeding black ducks estimated in eastern Canada, the optimal regulatory choices for the 2026 hunting seasonare the liberal regulatory alternative in Canada and the moderate regulatory alternative in the United States."


I know the history of allowing a higher bag limit in Canada because they have so many fewer hunters and kill so many fewer black ducks and don't disagree with it. But how can Canada and the US, assessing the same data set on a single migratory population, justify a liberal framework in Canada and a moderate one in the US?

I'm fine with the 2 black duck limit-just think that description risks undermining confidence in a rational, data-driven process to set limits.
 
Jeff Reardon said:
So having looked only at the Ex. Summary, this paragraph caught my eye, as someone who for whom black ducks are the majority of what I see once the teal and woodies mostly head south:

"For black ducks, the optimal country-specific regulatory strategies for the 2026 hunting season were calculated using:(1) an objective to achieve 98% of the maximum, long-term cumulative harvest; (2) current country-specific black duckregulatory alternatives; and (3) updated model parameters and weights. Based on a liberal regulatory alternativeselected by Canada and a moderate regulatory alternative selected by the U.S. for the 2025 hunting season, and 0.79million breeding black ducks estimated in eastern Canada, the optimal regulatory choices for the 2026 hunting seasonare the liberal regulatory alternative in Canada and the moderate regulatory alternative in the United States."


I know the history of allowing a higher bag limit in Canada because they have so many fewer hunters and kill so many fewer black ducks and don't disagree with it. But how can Canada and the US, assessing the same data set on a single migratory population, justify a liberal framework in Canada and a moderate one in the US?

I'm fine with the 2 black duck limit-just think that description risks undermining confidence in a rational, data-driven process to set limits.
Click to expand...
Jeff, you answered your own question. More black ducks in Canada and far fewer hunters and realized harvest. US has fewer black ducks, more hunters and higher harvest. There are 2 countries with separate regulatory processes equitably sharing the resource.

Here is the description of the rationale from the AHM report.


9.1 American Black Duck

Federal, state, and provincial agencies in the U.S. and Canada agreed that an international harvest strategy for black
ducks is needed because the resource is valued by both countries and both countries have the ability to influence
the resource through harvest. The partners also agreed a harvest strategy should be developed with an AHM approach
based on the integrated breeding-ground survey data (Zimmerman et al. 2012, U.S. Fish and Wildlife Service
2019). Finally, the strategy should also provide a formal approach to determining appropriate harvest levels and fair
allocation of the harvest between countries (Conroy 2010).

The overall goals of the Black Duck International Harvest strategy include:

(1) maintain a black duck population that meets legal mandates and provides consumptive and non-consumptive
use commensurate with habitat carrying capacity;

(2) maintain societal values associated with the hunting tradition; and

(3) maintain equitable access to the black duck resource in Canada and the U.S.

The objectives of the harvest strategy are to achieve 98% of the long-term cumulative harvest and to share the allocated
harvest equitably between countries (i.e., parity). Historically, the realized allocation of harvest between Canada and
the U.S. has ranged from 40% to 60% in either country. Recognizing the historical allocation and acknowledging
incomplete control over harvest, parity is achieved through a constraint which discounts combinations of country-
specific harvest rates that are expected to result in allocation of harvest that is >50% in one country. The constraint
applies a mild penalty on country-specific harvest options that result in one country receiving >50% but <60% of the
harvest allocation and a stronger discount on combinations resulting in one country receiving >60% of the harvest
allocation (Figure 9). The goals and objectives of the black duck AHM framework were developed through a formal
consultation process with representatives from the CWS, USFWS, Atlantic Flyway Council and Mississippi Flyway
Council.

Country-specific harvest opportunities were determined from a set of expected harvest rate distributions defined as
regulatory alternatives. Canada has developed 4 regulatory alternatives (liberal, moderate, restrictive and closed);
and the U.S. has developed 3 (moderate, restrictive, closed). We fit a generalized linear model to direct recoveries
of black ducks banded in eastern Canada (Ontario, Quebec, New Brunswick, Nova Scotia, Prince Edward Island,
Newfoundland, and Labrador) from 1990–2023 to predict harvest rate distributions. Annual harvest rates were derived
by adjusting band recoveries by country- and band inscription-specific reporting rates, and reporting rates were
treated as known. In both Canada and the U.S., reporting rate estimates for bands inscribed with 1-800 numbers or
web addresses have changed over time (2002–2004: Garrettson et al. 2013, 2017–2019: Garrettson unpubl. report).
We imputed reporting rates for 1-800 bands and web-address bands for interim years using a simple linear trend.
 
Gents~

This argument has smoldered since my earliest days as a waterfowl biologist - when my task was to explain the science and reasoning behind the 1-bird/day Black Duck limit to Long Island gunners. (It had been 4/day when I started shooting in 1965). I hunted under the 1-bird restriction for decades - and would consistently see far more Blacks than any other puddlers on the tidal waters around Long Island. I imagine Jeff and other Mainers have the same experience. So, I was both thrilled and content when it rose to 2/day several years ago.

I especially enjoyed my first Black Duck double upstate - and then another on Long Island later in the season. Two Blacks is enough for me - especially when they are those late-season "Red-Leggers"....

All the best,

SJS
 
I agree with you both, and thought my OP made that clear. I don't begrudge Canada a higher bag limit than we get in the US. And like Steve, I am thrilled with the current 2 bird limit for blacks. What I question is the conclusion that based on evaluation of habitat conditions and populations, the data justify a liberal option in Canada and a moderate one in the US. It may be that due to the differences in hunter numbers, there will never be a season that justifies anything other than the bag limit associated with liberal option in Canada, because anything else would not equitably share the harvest. If that's the case, let's just say that. Or let's tweak the formula and/or language so the report does not give the impression that the duck population in Canada is in better shape than in the US. It can't be, as it's a single population with breeders in both countries. As for those Red-Leggers, Maine lore says those are 100% Canadian birds from the far north.
 
Steve Sanford said:
Gents~

This argument has smoldered since my earliest days as a waterfowl biologist - when my task was to explain the science and reasoning behind the 1-bird/day Black Duck limit to Long Island gunners. (It had been 4/day when I started shooting in 1965). I hunted under the 1-bird restriction for decades - and would consistently see far more Blacks than any other puddlers on the tidal waters around Long Island. I imagine Jeff and other Mainers have the same experience. So, I was both thrilled and content when it rose to 2/day several years ago.

I especially enjoyed my first Black Duck double upstate - and then another on Long Island later in the season. Two Blacks is enough for me - especially when they are those late-season "Red-Leggers"....

All the best,

SJS
Click to expand...
I recall you late season double on Long Island, a double with a double barrel! wish I had a camera !
 
My other AHM question is one I know nothing about--and entirely hypothetical for us in Maine as I don't know anyone who has ever shot more than one pintail in a day. I've shot 2 in the last 15 years--we just don't see them. But I am seeing a lot of chatter, including social media posts today from Delta Waterfowl, about the increased pintail bag limit of 3 birds. It seems that this--like our increase to the 2 bird limit on black ducks a few seasons ago--has more to do with tweaking the model and how it is used to inform decisions than by better conditions for/populations of each species. It's still hard to wrap my mind around increasing bag limits on pintail when the population is near the lowest point it's been in 40 years, and has not been at or above the population objective for the species in the last decade.
 
My 2 cents: the pintail populations level we see is probably the new normal. Given agricultural practices in their primary breeding areas, it’s doubtful we will see significant increases in population. Unless the extreme changes we are seeing in arctic temperatures and habitat migration north opens up significant new breeding areas.
Most likely the same situation for scaup populations
 
Carl said:
My 2 cents: the pintail populations level we see is probably the new normal. Given agricultural practices in their primary breeding areas, it’s doubtful we will see significant increases in population. Unless the extreme changes we are seeing in arctic temperatures and habitat migration north opens up significant new breeding areas.
Most likely the same situation for scaup populations
Click to expand...
I suspect you are correct. But I worry about accepting a shifting baseline as "normal".
 
Unfortunately shifting baselines seems to the reality we live in these days.
 
A Canadian Perspective. I think Brad has explained I well, but as a Canadian, and a waterfowl biologist I'm not sold on the current version ofd AHM. There are a few species of waterfowl that historical harvests were about equivalent between Canada and the USA. For most species/populations the US takes 75-95% of the North American harvest. The exceptions are Black Ducks, Common Eiders and White Fronts (there maybe a couple of others), and a large chunk of the Canadian harvest of White Fronts are probably taken by non-Canadian's. When the Black Duck Adaptive Harvest Management model (AHM) was in development there was a constraint built into the model that tries to enforce parity in the harvest between Canada and the USA. The idea was based on results of the country specific harvest surveys, but when implemented in the AHM model they used harvest rates instead of total harvest. Form my perspective this was an error that biases harvest to Canada (most opening day banded ducks shot in Canada are shot on the marshes where they were banded).

I've not updated this analysis in a few years, but the trends have not changed. Historically, The harvest estimates in Canada were larger than in the USA. There have been declines in the country specific harvests and the rate of decline has been steeper In Canada than in the USA. The overall harvest reached parity around the turn of the Century. Despite the parity function in the AHM model, the overall harvest in Canada is now less than the US despite the differences in the regulatory packages between the two countries. There are just way more waterfowl hunters in the USA.

As I mentioned, I'm not. huge fan of the current AHM model. But it is better than no model. With AHM we use data to make regulatory decisions which is the wait should be. My feeling is the current version of AHM is a bit simple as it treats black ducks as a single population. Makes sense to managed black ducks this way if your from the US, but not in Canada. Well, I would not like to be hunting blacks in the Mississippi Flyway...

Anyway, you could get me ranting for hours on this subject. It all comes down to total harvest and there are now many more black ducks harvested in the USA than in Canada.



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