mouthcallinmatt1
04-06-2005, 04:04 PM
Isn't this what we've been saying? Let's hope some weight is put on this and the commission adopts CWA's recommendation.
****USFWS EXPERIMENT IN RESTRICTIVE HARVEST REGULATIONS HAS NOT INCREASED PINTAIL POPULATIONS****
The U.S. Fish and Wildlife Service (USFWS) has required reduced pintail harvest in the United States since 1988 in response to the declining North American pintail population. However, these restrictions do not appear to have had any impact in helping pintails. A report prepared by Michael Runge of the U.S. Geological Survey and Scott Boomer of the USFWS in February 2005 (Population Dynamics and Harvest Management of the Continental Northern Pintail Population) shows long-term stability in annual survival of pintails despite variable harvest regulations over time. Average annual survival of adult pintails (74% in males and 64% in females) has not changed over the period from 1965 to the present, and first-year survival of young pintails increased slightly through the 1965 to 2003 period, which had both high and low bag limits; thus, these trends cannot be attributed to restrictive harvest. In addition, an upcoming paper in the July issue of the Journal of Wildlife Management by Chris Nicolai and his co-authors reports that 90% of surviving northern pintails banded on the important nesting area of the Yukon-Kuskokwim Delta returned there. Most of these pintails winter in California, suggesting a relatively discrete subpopulation, and these birds survived at very high rates that also have not changed over time despite changes in harvest regulations.
Several years of excellent production of young, as evidenced by high pintail harvest age ratios during wet years in Prairie Canada, suggest that “super production” events produced and sustained high pintail populations during the 1970s. The Runge-Boomer report states that pintails no longer have the reproductive potential they did in the 1970s because of various types of upland and wetland habitat losses and long-term drought.
During the prolonged prairie drought of the 1980s and early 1990s, pintails counted in the prairies decreased precipitously. Pintails are known to seek northern regions of Canada and Alaska when preferred prairie breeding grounds are dry (the prairie “over-flight” phenomenon). As shown in the Runge-Boomer report, such movements are to the north and west, and as this occurs, many pintails fly out of survey regions, so the numbers counted during the annual May Survey show exaggerated declines. Runge-Boomer corrected for these movements and found that the underestimation was in the range of a few percent to as much as 80% (typically 30 to 60%)! This disparity between the unadjusted and corrected counts has widened over time as the pintail population shifted away from traditional southern prairie breeding grounds.
The lack of evidence that harvest impacts pintail numbers and the present abundance and stability of pintails breeding in Alaska clearly support increased harvest opportunity. The USFWS data show that harvest has had no impact on pintail survival during the past 40 years. California hunters have been subjected to excessive pintail restrictions for more than a decade despite the fact that pintails are typically the most abundant wintering duck in California and the Pacific Flyway. The data indicate that some additional harvest, especially of drakes, will not harm the pintail population. The large populations experienced in the 1970s will only be achieved again if recruitment (production of young ducks that survive to join the breeding population) from the prairies increases and is sustained, especially in wet years.
Tradition in harvest regulation changes demands conservatism in the face of uncertainty, but given the data presented by the USFWS and current population size and distribution of pintail, CWA advocates adding two drakes to the bag limit after December 1st when drakes are clearly distinguishable from hens ( a three-pintail limit, of which only one may be a hen). In addition, CWA advocates that the USFWS quickly address the deficiencies in the Runge and Boomer report. The Pacific Flyway Council’s recommendations
follow:
1) The assumption that hunting mortality is completely additive to natural mortality in the current pintail harvest model is unsupported and should be modified,
2) Specific stock management of pintails must be addressed in light of the Nicolai et al. scientific paper, and
3) Sex-specific harvest regulations for pintails should be incorporated after December 1.
In concert with such changes, CWA will recommend and assist in increased pintail banding efforts to improve the precision of annual survival calculations. We will also lobby for funding for the USFWS and California Department of Fish and Game and offer our biological assistance to support appropriate population monitoring to assess impacts of our proposed changes, if implemented. We will encourage federal waterfowl population biologists through both traditional and political channels to seek these more reasonable pintail regulations for California hunters.
****USFWS EXPERIMENT IN RESTRICTIVE HARVEST REGULATIONS HAS NOT INCREASED PINTAIL POPULATIONS****
The U.S. Fish and Wildlife Service (USFWS) has required reduced pintail harvest in the United States since 1988 in response to the declining North American pintail population. However, these restrictions do not appear to have had any impact in helping pintails. A report prepared by Michael Runge of the U.S. Geological Survey and Scott Boomer of the USFWS in February 2005 (Population Dynamics and Harvest Management of the Continental Northern Pintail Population) shows long-term stability in annual survival of pintails despite variable harvest regulations over time. Average annual survival of adult pintails (74% in males and 64% in females) has not changed over the period from 1965 to the present, and first-year survival of young pintails increased slightly through the 1965 to 2003 period, which had both high and low bag limits; thus, these trends cannot be attributed to restrictive harvest. In addition, an upcoming paper in the July issue of the Journal of Wildlife Management by Chris Nicolai and his co-authors reports that 90% of surviving northern pintails banded on the important nesting area of the Yukon-Kuskokwim Delta returned there. Most of these pintails winter in California, suggesting a relatively discrete subpopulation, and these birds survived at very high rates that also have not changed over time despite changes in harvest regulations.
Several years of excellent production of young, as evidenced by high pintail harvest age ratios during wet years in Prairie Canada, suggest that “super production” events produced and sustained high pintail populations during the 1970s. The Runge-Boomer report states that pintails no longer have the reproductive potential they did in the 1970s because of various types of upland and wetland habitat losses and long-term drought.
During the prolonged prairie drought of the 1980s and early 1990s, pintails counted in the prairies decreased precipitously. Pintails are known to seek northern regions of Canada and Alaska when preferred prairie breeding grounds are dry (the prairie “over-flight” phenomenon). As shown in the Runge-Boomer report, such movements are to the north and west, and as this occurs, many pintails fly out of survey regions, so the numbers counted during the annual May Survey show exaggerated declines. Runge-Boomer corrected for these movements and found that the underestimation was in the range of a few percent to as much as 80% (typically 30 to 60%)! This disparity between the unadjusted and corrected counts has widened over time as the pintail population shifted away from traditional southern prairie breeding grounds.
The lack of evidence that harvest impacts pintail numbers and the present abundance and stability of pintails breeding in Alaska clearly support increased harvest opportunity. The USFWS data show that harvest has had no impact on pintail survival during the past 40 years. California hunters have been subjected to excessive pintail restrictions for more than a decade despite the fact that pintails are typically the most abundant wintering duck in California and the Pacific Flyway. The data indicate that some additional harvest, especially of drakes, will not harm the pintail population. The large populations experienced in the 1970s will only be achieved again if recruitment (production of young ducks that survive to join the breeding population) from the prairies increases and is sustained, especially in wet years.
Tradition in harvest regulation changes demands conservatism in the face of uncertainty, but given the data presented by the USFWS and current population size and distribution of pintail, CWA advocates adding two drakes to the bag limit after December 1st when drakes are clearly distinguishable from hens ( a three-pintail limit, of which only one may be a hen). In addition, CWA advocates that the USFWS quickly address the deficiencies in the Runge and Boomer report. The Pacific Flyway Council’s recommendations
follow:
1) The assumption that hunting mortality is completely additive to natural mortality in the current pintail harvest model is unsupported and should be modified,
2) Specific stock management of pintails must be addressed in light of the Nicolai et al. scientific paper, and
3) Sex-specific harvest regulations for pintails should be incorporated after December 1.
In concert with such changes, CWA will recommend and assist in increased pintail banding efforts to improve the precision of annual survival calculations. We will also lobby for funding for the USFWS and California Department of Fish and Game and offer our biological assistance to support appropriate population monitoring to assess impacts of our proposed changes, if implemented. We will encourage federal waterfowl population biologists through both traditional and political channels to seek these more reasonable pintail regulations for California hunters.