Age class dynamics of Canada geese in the Central Flyway (original) (raw)
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The Journal of Wildlife Management, 2014
The abundance of Canada geese (Branta canadensis) nesting in temperate regions of North America has increased dramatically during the past half century. Numbers have reached nuisance levels in many areas and supplementary hunting seasons, which are timed to occur before and after traditional waterfowl hunting periods, are widely employed to limit population growth. We evaluated how changes in hunting regulations have affected population growth, the seasonal age distribution of harvest, and survival rates of temperate-breeding Canada geese banded in Ontario. We found that although the number of geese harvested in the province has increased, population growth has not abated. Annual survival rates ð SÞ of locally nesting adults (i.e., after-hatch-year geese captured in brood flocks) have declined in association with harvest liberalization (pre-liberalization:
Harvest demographics of temperate-breeding Canada geese in South Dakota, 1967–1995
In South Dakota, breeding giant Canada geese (Branta canadensis maxima) have increased substantially, and harvest management strategies have been implemented to maximize hunting opportunity (e.g., special early-September seasons) on local, as well as molt-migrant giant Canada geese (B. c. interior) while still protecting lesser abundant Arctic breeding Canada geese and cackling geese (e.g., B. hutchinsii, B. minima). Information on important parameters, such as survival and recovery rates, are generally lacking for giant Canada geese in the northern Great Plains. Patterns in Canada goose band recoveries can provide insight into the distribution, chronology, and harvest pressures to which a given goose population segment is exposed. We studied spatial and temporal recovery patterns of molting Canada geese during annual banding efforts in South Dakota between 1967 and 1995. Recovery rates (% ± SE) for Canada geese increased over time in both western South Dakota (0.034 ± 0.005 [1967 t...
SURVIVAL RATES AND RECOVERY DISTRIBUTIONS OF CANADA GEESE BANDED IN NEBRASKA
We analyzed banding and recovery data for Canada geese (Branta canadensis) banded in Nebraska during 1990-2000. Survival rates were lower during 1996-2000 (adult: 0.688, SE = 0.016; juvenile: 0.611, SE = 0.029), than 1990-1995 (adult: 0.727, SE = 0.011; juvenile: 0.639, SE = 0.024). Average juvenile-to-adult ratio from banding data was 0.834 (SD = 0.485), resulting in an annual population growth rate (λ) estimate for 1990-1995 of 0.995 (95% CI = 0.021), and 0.922 (0.018) for 1996-2000. Our recovery analysis suggests that 67% of geese banded in Nebraska are shot in Nebraska. Over 30% of both juvenile and adult recoveries are obtained in December, and geese banded in Lancaster County are recovered in higher numbers during October than geese banded in the Panhandle and Sandhills regions. Sixty to 70% of geese banded in Lan- caster County and the Panhandle region are recovered in their respective region, while less than 20% of geese banded in the Sandhills are recovered in the Sandhills...
The Journal of Wildlife Management, 2015
In the last few decades, non-migratory populations of Canada geese (Branta canadensis) have become established in metropolitan areas throughout North America. We banded 1,845 Canada geese in New Haven County, Connecticut, and studied goose survival of geese from 1984 through 2001, a period when local goose numbers increased several fold. Males outnumbered females among adults but not among juveniles. The hunter-recovery proportion (probability that a goose was harvested by a hunter and its band reported to the U.S. Banding Lab) was 0.17 for all banded geese and was higher for males (0.19) than females (0.15). We used the Seber band-recovery model in Program MARK to estimate the annual recovery rate and annual survival rate. The annual recovery rate was 0.22 for all geese and varied by year. The annual survival rate was 0.72 for all geese; survival was higher for females than males and higher for juveniles than adults. Survival rates varied among years and decreased in years with higher winter temperatures or more geese observed during Audubon's Christmas Bird Count. During our study, special hunting seasons in Connecticut targeted non-migratory geese. Despite this, we found survival rates to be at the high end of values reported elsewhere, and the number of geese killed by hunters in Connecticut did not influence survival. Our results suggest that it will be difficult for wildlife agencies to rely solely on hunting to reduce the size of nonmigratory goose populations. Ó 2015 The Wildlife Society.
Survival and harvest of Atlantic Flyway resident population Canada Geese
Wildlife Society Bulletin, 2015
Resident Population Canada geese (Branta canadensis) are a valuable natural resource, but at high densities they create problems by colliding with vehicles, damaging crops, and fouling parks with feces. Effective management of these geese could be improved with knowledge of demographic rates, especially survival. We used band recovery data from 2005 to 2012 to estimate temporally and spatially explicit survival and recovery rates of Atlantic Flyway Resident Population Canada geese. We analyzed the data in Program MARK and found evidence that survival and recovery varied by age, state of banding, and year. We present state-age-year survival, recovery, and harvest rates from all states. Model-averaged estimates of adult survival ranged from 0.62 to 0.87 and had high precision for most states. Estimates of survival of juvenile geese were generally higher than those for adult geese, but they were less precise and more variable among states. Based on estimates of survival and recovery rates, the average annual harvest rate of adult geese was 13.5% and ranged from 3.1% in North Carolina to 20.1% in Pennsylvania, USA. Harvest rates of juvenile geese were not significantly different from those of adult geese and averaged 15.3%. The estimated survival and harvest rates can be incorporated into population models to assess potential effectiveness of various management strategies for Resident Population Canada geese.
Factors influencing survival of Canada geese breeding in Southern Quebec
The Journal of Wildlife Management, 2014
Temperate nesting Canada geese are considered a nuisance in many regions of eastern North America. In southern Quebec, a breeding population became established 20 years ago and has grown steadily since that time. Because of the long-lived nature of geese, understanding the factors that influence annual survival is critical to the management of these populations. Our objectives were to describe the spatiotemporal distribution of the harvest of Canada geese that breed in southern Quebec, determine how year, sex, and age affect survival rates, and to evaluate the effects of hatch date and body condition near fledging on juvenile survival. We conducted mixed live recapture and dead recovery capture-mark-recapture analyses using data from birds banded as pre-fledged juveniles between 2003 and 2009 (n ¼ 3,972). Recoveries were distributed near the breeding area and along the east coast of the United States. Juveniles were mainly recovered in Quebec and yearlings in the United States. Harvest during the special early hunting season in Quebec represented only 9% of the total harvest. Annual survival rates were similar for both males and females, but varied among years for each age class. Survival averaged 0.82 (95% CI 0.76-0.87) for juveniles, 0.76 (0.69-0.82) for yearlings, and 0.82 (0.75-0.87) for adults. We observed a negative relationship between hatch date and juvenile survival but did not find significant effects of body condition and age at banding on survival. In addition to a short migration, a possible explanation for the high survival of juveniles includes the use by family groups predominantly of areas that are not open to hunting. The use of rural habitats where susceptibility to hunting is high, combined with the behavior of molt migration could explain the lower survival rates of yearlings than juveniles. We argue that high survival rates for all age classes contribute significantly to the growth of this population. Ó
Wildlife Monographs, 2011
We assessed the effectiveness of an extensive and unprecedented wildlife reduction effort directed at a wide-ranging migratory population of geese. Population reduction efforts that targeted several populations of light geese (greater snow geese [Chen caerulescens atlantica], lesser snow geese [C. c. caerulescens], and Ross's geese [C. rossii]) began in 1999 in central and eastern North America. Such efforts were motivated by a broad consensus that abundance of these geese was causing serious ecological damage to terrestrial and salt marsh ecosystems in central and eastern parts of the Canadian Arctic and subarctic regions along Hudson Bay. Starting in February 1999, special conservation measures (or, in the U.S., a conservation order) were added to the respective federal regulations that permitted hunters to take snow geese (in parts of Canada and the U.S.) and Ross's geese (in parts of the U.S.) during specified harvest periods outside of the hunting season. These measures were accompanied by increase or removal of daily kill and possession limits and by permissions to use previously prohibited equipment for hunting these species in certain regions of the continent. The intent was to reduce adult survival through increased hunting mortality, which was judged to be the most cost-effective approach to reversing population growth. Our principal goal was to assess the effectiveness of reduction efforts directed at the midcontinent population of lesser snow geese, which was thought to be the most serious threat to arctic and subarctic ecosystems of the 3 light goose populations. Our multiple objectives included the estimation and detection of change in the response measures of total annual harvest, harvest rate, survival rate, and abundance, using the 1998 hunting period (defined as 1 Aug 1998 to 31 Jul 1999) as a point of reference. We used information about hunter recoveries of legbanded snow geese and estimates of regular-season harvest to estimate 1) conservation-order harvest and total annual harvest, 2) geographic and temporal distribution of recoveries by age class, 3) survival and recovery probability, and 4) abundance of snow geese each August using Lincoln's (1930) method. We also modeled population growth to infer the form of population response to management efforts. Toward that end, we also proposed a method of estimating conservation-order harvest and tested for differences in band-reporting rate between Canada and the United States. Overall, the balance of evidence favored the conclusion that the midcontinent population has continued to grow during the conservation order, although perhaps at a reduced rate. We suggest that annual rate of population growth ðlÞ, derived from estimates of annual population size in August, likely provides the most reliable inference about change in the midcontinent population. There was a decline in annual survival probability between these 2 periods from about 0.89 to about 0.83 among snow geese from the southern-nesting stratum (south of 608N latitude), thought to compose about 10% of the midcontinent population. However, we detected no change in the much larger northern-nesting stratum (north of 608N latitude), where annual survival remained at about 0.87 from 1989 to 2006. Thus, the conclusion that this population continued to increase during the conservation order was largely consistent with the finding that a weighted-survival probability for midcontinent snow geese essentially did not change between the period preceding (1989-1997) and during (1998-2006) the conservation order. Consistent with high survival rates were low harvest rates, which increased from 0.024 during 1989-1997 for northern geese to only 0.027 during 1998-2006 and from 0.031 to only 0.037 for southern geese. Despite the initial increase associated with the conservation order, harvest rates declined during the conservation order for geese from both strata. We suggest that the higher harvest rate evident for
Evaluation of the effects of September hunting seasons on resident Canada geese in Nebraska
Populations of temperate-nesting Canada geese (Branta canadensis) have increased in Nebraska, USA, resulting in an increased number of nuisance and damage complaints. September hunting seasons were initiated in southeastern Nebraska in 2004 to reduce populations of Canada geese. We analyzed band recoveries from Canada geese banded in southeastern Nebraska during their hatch-year (HY) or afterhatch-year (AHY) to determine whether September hunting seasons affected survival, harvest, and recovery rates. Survival analyses revealed that HY geese had higher survival than AHY geese (S AHY ¼ 0.696, 95% CI ¼ 0.679-0.713; S HY ¼ 0.896, 95% CI ¼ 0.786-0.953) and September seasons did not affect survival of geese in southeastern Nebraska. Geese banded in the geographic zone with the September seasons (southeastern Nebraska) had the same survival as did geese outside the hunt zone (northeastern Nebraska; S ¼ 0.711, 95% CI ¼ 0.666-0.752). September hunting seasons affected timing of band recovery; 23-49% of annual band recoveries occurred during the month of September. Prior to the initiation of the September seasons, the highest percent of recoveries occurred during November. The September seasons appeared to temporally redistribute harvest but did not reduce survival for populations of Canada geese in southeastern Nebraska. Continuation of the season may not be warranted, because management does not appear to be affecting AHY survival, which is needed to reduce the population. Additional or new methods are likely needed to control populations of temperate-nesting Canada geese in Nebraska and managers should evaluate the effectiveness of these methods as they are implemented. ß 2012 The Wildlife Society.
2011
We assessed the effectiveness of an extensive and unprecedented wildlife reduction effort directed at a wide-ranging migratory population of geese. Population reduction efforts that targeted several populations of light geese (greater snow geese [Chen caerulescens atlantica], lesser snow geese [C. c. caerulescens], and Ross's geese [C. rossii]) began in 1999 in central and eastern North America. Such efforts were motivated by a broad consensus that abundance of these geese was causing serious ecological damage to terrestrial and salt marsh ecosystems in central and eastern parts of the Canadian Arctic and subarctic regions along Hudson Bay. Starting in February 1999, special conservation measures (or, in the U.S., a conservation order) were added to the respective federal regulations that permitted hunters to take snow geese (in parts of Canada and the U.S.) and Ross's geese (in parts of the U.S.) during specified harvest periods outside of the hunting season. These measures were accompanied by increase or removal of daily kill and possession limits and by permissions to use previously prohibited equipment for hunting these species in certain regions of the continent. The intent was to reduce adult survival through increased hunting mortality, which was judged to be the most cost-effective approach to reversing population growth. Our principal goal was to assess the effectiveness of reduction efforts directed at the midcontinent population of lesser snow geese, which was thought to be the most serious threat to arctic and subarctic ecosystems of the 3 light goose populations. Our multiple objectives included the estimation and detection of change in the response measures of total annual harvest, harvest rate, survival rate, and abundance, using the 1998 hunting period (defined as 1 Aug 1998 to 31 Jul 1999) as a point of reference. We used information about hunter recoveries of legbanded snow geese and estimates of regular-season harvest to estimate 1) conservation-order harvest and total annual harvest, 2) geographic and temporal distribution of recoveries by age class, 3) survival and recovery probability, and 4) abundance of snow geese each August using Lincoln's (1930) method. We also modeled population growth to infer the form of population response to management efforts. Toward that end, we also proposed a method of estimating conservation-order harvest and tested for differences in band-reporting rate between Canada and the United States. Overall, the balance of evidence favored the conclusion that the midcontinent population has continued to grow during the conservation order, although perhaps at a reduced rate. We suggest that annual rate of population growth ðlÞ, derived from estimates of annual population size in August, likely provides the most reliable inference about change in the midcontinent population. There was a decline in annual survival probability between these 2 periods from about 0.89 to about 0.83 among snow geese from the southern-nesting stratum (south of 608N latitude), thought to compose about 10% of the midcontinent population. However, we detected no change in the much larger northern-nesting stratum (north of 608N latitude), where annual survival remained at about 0.87 from 1989 to 2006. Thus, the conclusion that this population continued to increase during the conservation order was largely consistent with the finding that a weighted-survival probability for midcontinent snow geese essentially did not change between the period preceding (1989-1997) and during (1998-2006) the conservation order. Consistent with high survival rates were low harvest rates, which increased from 0.024 during 1989-1997 for northern geese to only 0.027 during 1998-2006 and from 0.031 to only 0.037 for southern geese. Despite the initial increase associated with the conservation order, harvest rates declined during the conservation order for geese from both strata. We suggest that the higher harvest rate evident for
Evaluation of the effects of september hunting seasons on Canada geese in Nebraska
Wildlife Society Bulletin, 2012
Populations of temperate-nesting Canada geese (Branta canadensis) have increased in Nebraska, USA, resulting in an increased number of nuisance and damage complaints. September hunting seasons were initiated in southeastern Nebraska in 2004 to reduce populations of Canada geese. We analyzed band recoveries from Canada geese banded in southeastern Nebraska during their hatch-year (HY) or afterhatch-year (AHY) to determine whether September hunting seasons affected survival, harvest, and recovery rates. Survival analyses revealed that HY geese had higher survival than AHY geese (S AHY ¼ 0.696, 95% CI ¼ 0.679-0.713; S HY ¼ 0.896, 95% CI ¼ 0.786-0.953) and September seasons did not affect survival of geese in southeastern Nebraska. Geese banded in the geographic zone with the September seasons (southeastern Nebraska) had the same survival as did geese outside the hunt zone (northeastern Nebraska; S ¼ 0.711, 95% CI ¼ 0.666-0.752). September hunting seasons affected timing of band recovery; 23-49% of annual band recoveries occurred during the month of September. Prior to the initiation of the September seasons, the highest percent of recoveries occurred during November. The September seasons appeared to temporally redistribute harvest but did not reduce survival for populations of Canada geese in southeastern Nebraska. Continuation of the season may not be warranted, because management does not appear to be affecting AHY survival, which is needed to reduce the population. Additional or new methods are likely needed to control populations of temperate-nesting Canada geese in Nebraska and managers should evaluate the effectiveness of these methods as they are implemented. ß 2012 The Wildlife Society.