Migratory Canada Geese Research Articles

Cree-driven community-partnered research on coastal ecosystem change in subarctic Canada: a multiple knowledge approach

Indigenous-driven and community-partnered research projects seeking to develop salient, legitimate, and credible knowledge bases for environmental decision-making require a multiple knowledge systems approach. When involving partners in addition to communities, diverging perspectives and priorities may arise, making the pathways to engaging in principled research while generating actionable knowledge unclear to disciplinarily-trained natural science researchers. Here, we share insights from the Eeyou Coastal Habitat Comprehensive Research Project (CHCRP), an interdisciplinary, Cree-driven community-academic partnership. This project brought together Cree community members, regional organizations, industry (Hydro-Québec), and academics from seven universities across Canada to address the unprecedented loss of seagrass Zostera marina (eelgrass), the concurrent decline in migratory Canada geese and its impact on fall goose harvest activities in Eeyou Istchee. After describing the history and context of the project, we discuss the challenges, complexities, and benefits of the collaborative approach balancing saliency, legitimacy and credibility of the knowledge produced. We suggest the paper may be of use to researchers and partners seeking to engage in principled and actionable research related to environmental change including impacts of past development.

Population trends of resident and migratory Canada geese in relation to strikes with civil aircraft

Canada geese (Branta canadensis) are of particular concern to aviation in the USA because of their large size, flocking behavior, attraction to airports for grazing, and, for the resident population, year-round presence in urban environments. We documented trends in resident and migrant Canada goose populations in North America from 1970 to 2012, and for 1990 to 2012 examined these trends in relation to trends in reported civil aircraft collisions (strikes) with Canada geese. The overall Canada goose population increased 4.5 fold from 1.26 million in 1970 to 5.69 million in 2012. Most of this overall increase was due to a 15.6-fold increase in the population of resident geese (from 0.25 to 3.85 million), especially during the 1990s when the population increased at a mean annual rate of 12.7%. From 2000 to 2012, the resident population has stabilized, fluctuating between 3.36 and 3.85 million birds. The migrant population has remained relatively stable since 1990, with the population in 2012 estimated at 1.84 million. Resident geese comprised 68% of the total Canada goose population in 2012 compared to 41% in 1990 and 20% in 1970. From 1990 to 2012, 1,403 Canada goose strikes with civil aircraft were reported in the USA, of which 704 (50%) caused damage. The strike rate and damaging strike rate for all geese and for resident geese only (strikes in May to September) increased in parallel with the increase in the total Canada goose population (resident and migratory combined) and resident population, respectively, from 1990 to 1999. From 1999 to 2012, the strike rate and especially the damage strike rate exhibited a downward trend, especially for strikes involving resident geese during May to September. We hypothesize that this decline is due to Canada goose management programs implemented at many airports and in other urban areas.

Migratory Canada geese cause crash of US Airways Flight 1549

In the United States alone, over 7400 bird–aircraft collisions (birdstrikes) were reported in 2007. Most of these strikes occurred during takeoff or landing of the flight, and it is during these flight phases that aircraft experience their highest risk of substantial damage after colliding with birds. Birdstrikes carry enormous potential costs in terms of lives and money. Using feather remains and other tissue samples collected from the engines of US Airways Flight 1549, which crash landed in the Hudson River in New York City on 15 January 2009 after a birdstrike, we apply molecular tools and stable hydrogen isotopes to demonstrate that migratory Canada geese were responsible for the crash. Determining whether the geese involved in this birdstrike event were resident or migratory is essential to the development of management techniques that could reduce the risk of future collisions. Currently, the US civil aviation industry is not required to report birdstrikes, yet information on frequency, timing, and species involved, as well as the geographic origin of the birds, is critical to reducing the number of birdstrikes. Integrating this information with bird migration patterns, bird‐detecting radar, and bird dispersal programs at airports can minimize the risk of such collisions in the future.

ENUMERATION AND ANTIBIOTIC RESISTANCE PATTERNS OF FECAL INDICATOR ORGANISMS ISOLATED FROM MIGRATORY CANADA GEESE (BRANTA CANADENSIS)

Thermotolerant fecal indicator organisms carried by migratory waterfowl may serve as reservoirs of antibiotic resistance. To determine the extent to which such antibiotic resistance markers were present in migratory Canada geese (Branta canadensis) on the Maryland Eastern Shore, we isolated Enterococcus spp. and Escherichia coli from fresh feces and examined the antibiotic resistance profiles of these bacteria. Samples were obtained in October 2002, January 2003, and March 2003. Thermotolerant E. coli counts ranged from 0 to 1.0x10(7) colony forming units (CFU)/0.1g (g-1) wet weight of feces, whereas Enterococcus spp. counts ranged from 1.0x10(2)-1.0x10(7) CFU g-1 wet weight of feces. Primary isolates of each indicator organism were tested against a panel of 10 antibiotics. Greater than 95% of E. coli isolates were resistant to penicillin G, ampicillin, cephalothin, and sulfathiazole; no E. coli were resistant to ciprofloxacin. Enterococcal isolates showed highest resistance to cephalothin, streptomycin, and sulfathiazole; no enterococci were resistant to chloramphenicol. The tetracyclines, streptomycin, and gentamycin provided the greatest discrimination among E. coli isolates; chlortetracycline, cephalothin, and gentamycin resistance patterns provided the greatest discrimination between enterococcal strains. Multiple antibiotic resistance (MAR) profiles were calculated: fall (E. coli=0.499; enterococci=0.234), winter (E. coli=0.487; enterococci=0.389), and spring (E. coli=0.489; enterococci=0.348). E. faecalis and E. faecium, which are recognized human nosocomial pathogens, were cultured from winter (44 and 56%, respectively) and spring (13 and 31%, respectively) fecal samples.

Genetic Methods for Determining Racial Composition of Canada Goose Harvests

We used molecular genetic markers and established statistical methods to estimate proportional contributions of subspecies and breeding populations to admixed wintering and migratory Canada goose (Branta canadensis) harvests. We compared harvest estimates across spatially and temporally explicit sampling intervals. We characterized 997 individuals from breeding populations in Canada representing interior Canada geese (B. c. interior; n = 4) and in Michigan representing giant Canada geese (B. c. maxima; n = 5) for 5 microsatellite loci. We determined that microsatellite loci coupled with maximum-likelihood methods provided accurate and precise proportional contribution estimates of samples from each subspecies and population. We first conducted simulation analyses and derived harvest estimates for unknown individuals representing a range of plausible harvest mixture scenarios using blind tests. Based on harvested individuals collected over a 4-year period (1993-1996), we found that the racial composition of Canada goose harvests varied significantly among years and across early, regular, and late seasons within a year. Harvest composition varied spatially between management areas in different regions and between managed and private lands in close (<40 km) geographic proximity. Higher proportions of resident giant Canada geese were harvested during early hunting seasons and on private lands relative to migratory interior Canada geese. Harvest estimates suggest that individuals from different subspecies and populations are differentially abundant or susceptible to harvest at different times of the fall season, during different years, and populations across different geographic locations. Given that baseline genetics data are available for subspecies of management interest, genetic methods can provide harvest composition estimates at many spatial and temporal scales, including enumeration of statistical confidence.

Seasonal changes in the concentration of plasma prolactin in the migratory Canada goose ( Branta canadensis interior)

1. 1. Seasonal changes in the plasma prolactin level of the migratory Canada goose breeding in the Canadian subarctic region (Fort Churchill, Manitoba) and wintering in the southern USA (Swan Lake Refuge, Missouri) were studied. 2. 2. Peak prolactin level was observed in geese collected at Missouri in October, immediately after Fall migration (Fall postmigratory period). This was significantly higher than that in September (Fall premigratory period), July (moulting period) and March (Spring premigratory period). 3. 3. Prolactin levels in May (Spring postmigratory period) and June (incubating period) did not differ significantly from that of any other period.

Seasonal changes in circulating levels of luteinizing hormone and growth hormone in the migratory Canada goose

Seasonal changes in plasma levels of LH and GH in the Canada goose ( Branta canadensis interior) have been studied. The population examined breeds in the Canadian subarctic region (Fort Churchill, Manitoba) and winters in the southern United States (Swan Lake Refuge, Missouri). Peak levels of LH were observed during spring postmigratory (nest-building, early May) and nesting (incubating, early June) periods, while no significant differences were observed during the other periods studied. The highest levels of GH were observed during molting (late July) and the immediately following fall premigratory (early September) period.

Circulating Levels of Thyroxine (T₄) and Triiodothyronine (T₃) in the Migratory Canada Goose

Changes in circulating levels of thyroxine (T₄) and triiodothyronine (T₃) in the migratory Canada goose (Branta canadensis interior) during the different periods of its yearly life cycle in both its breeding and wintering grounds were investigated. Total plasma T₄ level ranged from a minimal value of 1.156 μg/dl in the fall postmigratory period to a maximal value of 1.737 μg/dl in the spring postmigratory period. The T₄ values during spring postmigratory period and breeding (1.700 μg/dl) were significantly higher than those in the spring premigratory (1.175 μg/dl), fall premigratory (1.327 μg/dl), and the fall postmigratory periods. The T₄ level during molt was significantly higher than that during the spring premigratory period and the fall postmigratory period but was not significantly different from that in the other periods. The peak level in plasma T₃ (330.62 ng/dl) observed in the spring premigratory phase was significantly higher than that in all other periods, and the trough T₃ level (71.72 ng/dl) noted in the fall premigratory period was significantly lower than that in all the other periods. No significant variations in T₃ levels were noted during the spring postmigratory, breeding, molt, and the fall postmigratory periods. The T₃ level was at its peak in the spring premigratory period when the ambient temperature was 20-25 C and daily photoperiod 11.5 h. However, the T₄ levels were highest in the spring postmigratory and breeding periods when the ambient temperatures were from -12 to -3 C and from -3 to 0 C and the photoperiods 16 h and 18 h, respectively. It is concluded that the high T₄ levels during these periods are indicative of the influence of the lower ambient temperatures and greater day lengths on the activity of the thyroid and the activity of the animal. The hypertrophy of the pectoral muscles in the spring pre- and postmigratory periods may be attributed to increased thyroidal activity. No definite relationship of thyroidal activity to molt was discernible, however.

Seasonal changes in serum levels of certain metabolites, uric acid and calcium in the migratory Canada goose ( Branta canadensis interior)

1. 1. Changes in serum levels of total protein, albumin, uric acid, glucose, triglycerides, total cholesterol and calcium in the Canada goose were studied during six periods of its yearly life cycle: (1) Spring pre-migratory phase (March) at Swan Lake Refuge (MO, U.S.A.); (2) Spring post-migratory phase (May) at Fort Churchill (Manitoba, Canada); (3) Breeding (June); (4) Moult (August); (5) Fall pre-migratory phase (September); and (6) Fall post-migratory phase (October) (MO, U.S.A.). 2. 2. Low levels of total protein and albumin, and concurrently high levels of uric acid were observed during the breeding, moult and fall pre-migratory phases. 3. 3. Serum glucose and total cholesterol were highest in the fall post-migratory phase while triglycerides were lowest during breeding and moult. Highest triglyceride level was seen in females during the spring post-migratory phase prior to egg-laying. 4. 4. Serum calcium remained constant in both the sexes, except in females during the spring postmigratory phase prior to egg-laying.

Seasonal changes in serum free fatty acid level in the migratory Canada goose.

The changes in the serum level of free fatty acids (FFA) in the migratory Canada goose (Branta canadensis interior) breeding in Ft. Churchill (Manitoba, Canada) and wintering in Swan Lake (Missouri, U.S.A.), were studied during the different periods of its yearly life cycle. The lowest serum FFA level was noted during the spring premigratory phase (early March) at Swan Lake, and the highest during moult (early August) at Ft. Churchill. Serum FFA level during the spring postmigratory period (early May at Ft. Churchill) was significantly higher than that during the spring premigratory period and the breeding period (early at Ft. Churchill). No signigicant difference in FFA levels was noted between the fall premigratory (early September at Ft. Churchill) and the fall postmigratory (mid-October at Swan Lake) periods. The significance of the seasonal variations in serum FFA level is discussed in relation to the cyclic physiological events taking place in the bird.