scholarly journals Glaucous Gull Predation of Goslings on the Yukon-Kuskokwim Delta, Alaska

The Condor ◽  
2004 ◽  
Vol 106 (2) ◽  
pp. 288-298
Author(s):  
Timothy D. Bowman ◽  
Robert A. Stehn ◽  
Kim T. Scribner
Keyword(s):  
Aerial Survey ◽  
Branta Canadensis ◽  
Canada Goose ◽  
Canada Geese ◽  
Brood Rearing ◽  
Anser Albifrons ◽  
Stratified Sample ◽  
Larus Hyperboreus ◽  
Survey Estimates ◽  
Species Specific

Abstract Glaucous Gulls (Larus hyperboreus) nesting on the Yukon-Kuskokwim (Y-K) Delta frequently prey on juvenile waterfowl. We collected 434 Glaucous Gulls from late June to early August 1994 to examine diet. Identification of undigested prey tissue, based on DNA microsatellite loci, showed three species of goslings in gull stomachs: Emperor Goose (Chen canagica), White-fronted Goose (Anser albifrons), and Cackling Canada Goose (Branta canadensis minima). Gulls that nested inland and were collected >1.6 km from the coast accounted for approximately 70% of the total gull predation on Emperor and Canada Geese, and 96% on White-fronted Geese. Our stratified sample of gull stomachs and aerial survey estimates of population size and distribution of gulls and juvenile geese enabled extrapolation of species-specific predation rates to the entire Y-K Delta. We estimated that a minimum of 21 000 Emperor Goose, 34 000 Canada Goose, and 16 000 White- fronted Goose goslings were consumed by 12 600 Glaucous Gulls during the brood-rearing period on the Y-K Delta in 1994. Minimum estimated take by gulls represented 33% of Cackling Canada Goose, 47% of Emperor Goose, and 39% of White-fronted Goose eggs estimated to have hatched in the same area as gull collections. Gulls selected the three species of geese approximately in proportion to their abundance. Although gull predation caused significant gosling mortality, its role in regulating goose populations on Y-K Delta remains unresolved. Depredación de Pichones de Gansos por Gaviotas Larus hyperboreus en el Delta del Yukon-Kuskokwim, Alaska Resumen. Las gaviotas Larus hyperboreus que nidifican en el delta del Yukon-Kuskokwim (Y-K) depredan aves acuáticas juveniles con frecuencia. Para examinar su dieta, colectamos 434 gaviotas de esta especie entre finales de junio y principios de agosto de 1994. Identificamos los tejidos de presas no digeridos con base en loci de ADN microsatelital y encontramos pichones de tres especies de gansos (Chen canagica, Anser albifrons y Branta canadensis minima) en los estómagos de las gaviotas. Las gaviotas que estaban nidificando tierra adentro y que fueron colectadas a más de 1.6 km de la costa representaron aproximadamente el 70% del total de las depredaciones de C. canagica y B. canadensis y el 96% de las de A. albifrons. Nuestra muestra estratificada de estómagos de gaviotas, junto con estimaciones del tamaño poblacional de las gaviotas y gansos juveniles hechas mediante censos desde el aire, permitieron hacer extrapolaciones de tasas de depredación especie- específicas para todo el delta Y-K. Los números estimados mínimos de pichones depredados por 12 600 gaviotas en el delta durante el período de cría de 1994 fueron 21 000 C. canagica, 34 000 B. canadensis y 16 000 A. albifrons. Estimamos que en lás áreas en que fueron colectadas, las gaviotas consumieron como mínimo el 33%, 47% y 39% del número estimado de huevos allí eclosionados de B. canadensis, C. canagica y A. albifrons, respectivamente. Las gaviotas seleccionaron a las tres especies de gansos aproximadamente en proporción a su abundancia. Aunque la depredación por gaviotas causó una mortalidad significativa de los pichones, aún debe determinarse su papel en la regulación de las poblaciones de gansos en el delta Y-K.

scholarly journals Distribution and use of brood-rearing and moulting sites of the Atlantic population of Canada Geese (Branta canadensis) in Nunavik, Quebec

2015 ◽  
Vol 129 (3) ◽  
pp. 229
Author(s):  
Richard C. Cotter
Keyword(s):  
Branta Canadensis ◽  
Hudson Bay ◽  
Canada Geese ◽  
Nesting Ecology ◽  
Brood Rearing ◽  
Atlantic Population ◽  
The Mean ◽  
Shallow Bay ◽  
Over Time ◽  
Coastal Lowlands

The Atlantic population of Canada Geese (Branta canadensis) nests in the coastal lowlands of eastern Hudson Bay and southwestern Ungava Bay in Nunavik, Quebec. Although many aspects of the nesting ecology of this and other northern populations of Canada Geese have been studied and published, there is a paucity of information on the use of brood-rearing and moulting sites. Based on 18 years of band and recapture data from an ongoing banding program, this paper presents the distribution of brood-rearing and moulting sites and the use of these sites over time. Along Hudson Bay and Ungava Bay, the most important brood-rearing and moulting areas are the stretch of coastal lowlands between the Mariet River and Shallow Bay and between Rivière aux Feuilles and Virgin Lake, respectively. Of all adult geese captured during the banding program (n = 41 924), 7.5% (standard error [SE] 0.13%) were recaptures, that is, birds that had previously been caught and banded; annual recapture rates ranged from 5.1% to 11.4%. The mean and median distances between the site of first recapture and the original site of capture were 4.3 km (SE 0.22 km) and 1.5 km, respectively. Juveniles moved, on average, 5.4 km farther than adults and males moved 1.4 km farther than females. Among geese banded as juveniles, males moved twice as far as females: 11.5 km versus 5.7 km.

A study of Canada geese, Branta canadensis, nesting on islands in southeastern Alberta

1970 ◽  
Vol 48 (2) ◽  
pp. 235-240 ◽  
Author(s):  
Kees Vermeer
Keyword(s):  
Egg Laying ◽  
Water Levels ◽  
Branta Canadensis ◽  
Canada Goose ◽  
Canada Geese ◽  
Uniform Spacing ◽  
Incubation Periods

Canada goose clutches situated on islands in Dowling Lake and Lake Newell, Alberta, were checked from laying to hatching. Egg-laying intervals averaged 1.87 days and incubation periods 26.8 days. The distribution of nests showed a significant deviation from randomness in the direction of uniform spacing. Causes of extensive hatching failure at Dowling Lake were predation and desertion. Predation by coyotes was facilitated by low water levels. A preference for nesting on islands appears to be a mechanism to counteract mammalian predation.

scholarly journals A white feathered area on the forehead is more common in hybrids of Greylag Goose Anser anser and Greater Canada Goose Branta canadensis than in the parent species

Ornis Svecica ◽  
2011 ◽  
Vol 21 (1) ◽  
pp. 37-44
Author(s):  
C G Gustavsson
Keyword(s):  
Quantitative Comparison ◽  
Branta Canadensis ◽  
Canada Goose ◽  
Canada Geese ◽  
Parent Species ◽  
Anser Anser ◽  
White Area ◽  
Greylag Goose ◽  
Greylag Geese

This study evaluated prevalence and extent of white areas on heads of Greylag Goose × Greater Canada Goose hybrids. A white area which bordered the bill and then to various degrees extended over the forehead was found in 17 out of 20 hybrids. This was significantly more common in the hybrids than in the parent species. The white areas in the hybrids were also significantly larger than in those 82 out of 191 adult Greylag Geese which had some amount of white area. There were too few Greater Canada Geese with a white area outside the normal pale cheek patch to make a meaningful similar quantitative comparison also with them. No white area was seen in the three presumed 1st Calendar Year (CY) hybrids but when two of them were seen again in September of the 2nd CY there were some pale feathers that were interpreted as the beginning of white areas. The white areas in hybrids are therefore regarded to be adult features which like in several pure Anser species begin to develop during the 2nd CY.

Assessment of bias in US waterfowl harvest estimates

2012 ◽  
Vol 39 (4) ◽  
pp. 336 ◽  
Author(s):  
Paul I. Padding ◽  
J. Andrew Royle
Keyword(s):  
Survey Methodology ◽  
Management Policy ◽  
Canada Goose ◽  
Canada Geese ◽  
Correction Factors ◽  
Harvest Management ◽  
The Usa ◽  
Survey Estimates ◽  
Negative Impacts ◽  
Band Recovery

Context North American waterfowl managers have long suspected that waterfowl harvest estimates derived from national harvest surveys in the USA are biased high. Survey bias can be evaluated by comparing survey results with like estimates from independent sources. Aims We used band-recovery data to assess the magnitude of apparent bias in duck and goose harvest estimates, using mallards (Anas platyrhynchos) and Canada geese (Branta canadensis) as representatives of ducks and geese, respectively. Methods We compared the number of reported mallard and Canada goose band recoveries, adjusted for band reporting rates, with the estimated harvests of banded mallards and Canada geese from the national harvest surveys. We used the results of those comparisons to develop correction factors that can be applied to annual duck and goose harvest estimates of the national harvest survey. Key results National harvest survey estimates of banded mallards harvested annually averaged 1.37 times greater than those calculated from band-recovery data, whereas Canada goose harvest estimates averaged 1.50 or 1.63 times greater than comparable band-recovery estimates, depending on the harvest survey methodology used. Conclusions Duck harvest estimates produced by the national harvest survey from 1971 to 2010 should be reduced by a factor of 0.73 (95% CI = 0.71–0.75) to correct for apparent bias. Survey-specific correction factors of 0.67 (95% CI = 0.65–0.69) and 0.61 (95% CI = 0.59–0.64) should be applied to the goose harvest estimates for 1971–2001 (duck stamp-based survey) and 1999–2010 (HIP-based survey), respectively. Implications Although this apparent bias likely has not influenced waterfowl harvest management policy in the USA, it does have negative impacts on some applications of harvest estimates, such as indirect estimation of population size. For those types of analyses, we recommend applying the appropriate correction factor to harvest estimates.

The costs of raising nidifugous offspring: brood rearing by giant Canada geese (Branta canadensis maxima)

1994 ◽  
Vol 72 (3) ◽  
pp. 533-540 ◽  
Author(s):  
Laura M. Seddon ◽  
Thomas D. Nudds
Keyword(s):  
Brood Size ◽  
Time Budget ◽  
Branta Canadensis ◽  
Feeding Time ◽  
Canada Geese ◽  
Predator Detection ◽  
Brood Rearing ◽  
Competing Hypotheses ◽  
Branta Canadensis Maxima ◽  
Time Spent Feeding

Competing hypotheses that have been advanced to explain the phenomenon of posthatch brood mixing by waterfowl can be distinguished by whether they assume that adults experience costs in rearing nidifugous offspring. To test this, time budget data were collected for giant Canada geese (Branta canadensis maxima) at Cambridge, Ontario, in 1990. Breeding adults with broods devoted more time to vigilance (p = 0.001) and less time to feeding (p = 0.001) than adults that hatched clutches but were without broods, suggesting a cost to rearing nidifugous young. However, as goslings matured, parents allocated less time to vigilance (p < 0.001) and more time to locomotion (p = 0.005), and time spent feeding did not change (p = 0.336). In addition, brood size did not affect the time parents allocated to vigilance (p = 0.543) or feeding (p = 0.727), suggesting that caring for additional young has negligible effects on parents. Goslings were selective about the adult with which they associated (they were positioned closer to females than to males), but neither brood size nor brood age affected the feeding time of goslings (p = 0.94 and 0.76, respectively) or time spent vigilant (p = 0.22 and 0.69, respectively), suggesting that goslings gained no obvious advantage from greater foraging opportunities or better predator detection by congregating in larger broods.

scholarly journals Effects of liberalizing harvest regulations on Canada goose (Branta canadensis) demography in Nebraska.

2020 ◽  
Author(s):  
Timothy P Lyons ◽  
Larkin A Powell ◽  
Mark Vrtiska
Keyword(s):  
Growth Rate ◽  
Population Growth ◽  
Regional Growth ◽  
Branta Canadensis ◽  
Adult Survival ◽  
Canada Goose ◽  
Canada Geese ◽  
Data Set ◽  
Early Season ◽  
Capture Recapture

Harvest regulations are used to manage populations of game species. Across their range, Canada goose Branta canadensis populations have recovered from near extirpation and are now perceived as overabundant and even a nuisance or a threat to human safety in many regions. Like many states, Nebraska has liberalized harvest regulations to increase recreation opportunities for consumptive users and to control increasing numbers of Canada geese. However, the efficacy of harvest regulations to control populations of geese is unclear. We used a live capture-recapture and dead recovery data set of more than 19,000 Canada geese banded in Nebraska 2006-2017 to determine the effect of liberalized harvest regulations on goose survival and overall growth rate. Our goals were to 1) estimate demographic parameters for Canada geese in five different regions in Nebraska 2) estimate the effect of increasing daily bag limits during the early September season and regular season on survival of hatch-year, juvenile, and adult Canada geese and 3) relate the effect of estimated changes in survival to population growth rate. We found survival (0.54-0.87), fidelity (0.14-0.99), and productivity (number of young per adult, 0.17-2.08) varied substantially among regions within Nebraska. We found increasing early season bag limits, but not regular season bag limits, reduced survival in Canada geese. However, this effect was most pronounced when comparing years without an early season to years with the highest daily bag limits used in Nebraska (eight). Survival of juvenile geese (2-3 years post-hatch) were unaffected by changes in daily bag limits during any season, though the probability of reporting was greatest for this age-class. The observed reductions in survival probability of hatch-year and adult geese due to increased daily bag limits during the early season (&lt;10%) had only weak effects on regional growth rates. Regional growth rate estimates appeared more responsive to changes in adult survival, but only decreased ~5% between years with the most liberal early-season daily bag limits to years without an early season. Our results suggest increased bag limits during the early season may reduce Canada goose survival, but has a weak impact on population growth in Nebraska.

scholarly journals Feeding Ecology of Canada Geese (Branta Canadensis Interior) in Sub-Arctic Inland Tundra During Brood-Rearing

The Auk ◽  
2005 ◽  
Vol 122 (1) ◽  
pp. 144-157 ◽  
Author(s):  
Marie-Christine Cadieux ◽  
Gilles Gauthier ◽  
R. John Hughes
Keyword(s):  
Plant Species ◽  
Aboveground Biomass ◽  
Short Form ◽  
Nitrogen Concentration ◽  
Branta Canadensis ◽  
Canada Geese ◽  
Adult Males ◽  
Brood Rearing ◽  
Branta Canadensis Interior ◽  
Sedge Meadows

AbstractThe diet of adult Canada Geese (Branta canadensis interior) and their goslings was determined during the brood-rearing season in a freshwater tundra habitat using esophageal contents from 25 adult females, 27 adult males, and 59 goslings. Habitat use by geese and the availability and quality of aboveground biomass in wet sedge meadows and around ponds in lichen-heath tundra were also evaluated throughout the summer. During the first four weeks of brood-rearing, adult Canada Geese ate primarily graminoids (>65%), especially leaves of the short form of Carex aquatilis and Eriophorum spp., which had the highest nitrogen concentration (2.5–3.5%). Although graminoids were also important for goslings, they consumed a greater variety of other plant species (68%) than adults, especially in the first two weeks, possibly because of their inexperience. Late in the brood-rearing period, as the nitrogen concentration of graminoid plants declined, adults shifted to a diet composed mainly of berries (>40%, mostly Empetrum nigrum). At that time, goslings consumed fewer berries (24%) and maintained a higher proportion of nitrogen-rich plants in their diet (53% leaves, mostly graminoids) than adults, presumably to complete their growth. Plant species consumed by geese over the summer indicated a preference for high-quality plants (i.e. those with a high nitrogen concentration). Consequently, wet sedge meadow, the habitat that offered plant species of highest quality, was the habitat most heavily used throughout the summer, particularly around peak hatch. Goose grazing had no effect on seasonal production of aboveground biomass of graminoids, probably because of the relatively low density of the goose population.Écologie alimentaire de Branta canadensis interior pendant la période d’élevage des jeunes dans un milieu d’eau douce sub-arctique

scholarly journals Cooperative hunting of Canada Geese (Branta canadensis) by Gray Wolves (Canis lupus) in northern Quebec

2015 ◽  
Vol 129 (3) ◽  
pp. 290 ◽  
Author(s):  
Theodore C. Nichols
Keyword(s):  
Canis Lupus ◽  
Prey Species ◽  
Branta Canadensis ◽  
Canada Goose ◽  
Canada Geese ◽  
Gray Wolves ◽  
Cooperative Hunting ◽  
Short Period

Gray Wolves (Canis lupus) are opportunistic predators that feed mainly on ungulates across their range. Incidental to a Canada Goose (Branta canadensis) leg banding program in northern Quebec, I observed what appeared to be a predation attempt by three wolves on a flock of 28 Canada Geese at a time when geese were just regaining their flight capability following their annual remige moult (4 August 2003). Although I was able to observe only a short period of this presumed predation attempt, it seemed apparent from the position of the wolves and geese that this was ambushing behaviour described by other authors with other prey species.

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