Evidence for Toxoplasma gondii in migratory vs. nonmigratory herbivores in a terrestrial arctic ecosystem

It is currently unclear how Toxoplasma gondii (Nicolle and Manceaux, 1908) persists in arctic tundra ecosystems in the absence of felid definitive hosts. To investigate potential transmission routes of T. gondii in a terrestrial arctic food web, we collected samples from two migratory herbivores, Ross’s Geese (Chen rossi (Cassin, 1861)) and Lesser Snow Geese (Chen caerulescens (L., 1758)), and from two resident herbivores, Nearctic brown lemmings (Lemmus trimucronatus (Richardson, 1825)) and collared lemmings (Dicrostonyx groenlandicus (Traill, 1823)), trapped at Karrak Lake, Nunavut, Canada. Antibodies were detected in 76 of 234 (32.4%) serum samples from Ross’s Geese and 66 of 233 (28.3%) serum samples from Lesser Snow Geese. We did not detect T. gondii antibodies in filter-paper eluate tested from thoracic fluid samples collected from 84 lemmings. We did not detect T. gondii DNA in brain tissue from these lemmings. Although a small sample size, our findings suggest that lemmings in this terrestrial arctic ecosystem are not exposed to, or infected with, the parasite. This suggests that oocysts are not introduced into the terrestrial arctic ecosystem at Karrak Lake via freshwater runoff from temperate regions. This study demonstrated that live adult arctic-nesting geese are exposed to T. gondii and therefore migratory herbivorous hosts are potential sources of T. gondii infection for predators in terrestrial arctic ecosystems.

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Hybridization and Population Subdivision Within and Between Ross's Geese and Lesser Snow Geese: A Molecular Perspective

The Condor ◽

10.1093/condor/104.2.432 ◽

2002 ◽

Vol 104 (2) ◽

pp. 432-436 ◽

Cited By ~ 1

Author(s):

Jason D. Weckstein ◽

Alan D. Afton ◽

Robert M. Zink ◽

Ray T. Alisauskas

Keyword(s):

Control Region ◽

Mtdna Control Region ◽

Data Set ◽

Snow Goose ◽

Chen Caerulescens ◽

Snow Geese ◽

Lesser Snow Geese ◽

Lesser Snow Goose ◽

Chen Caerulescens Caerulescens ◽

Ross's Geese

AbstractWe reanalyzed Quinn's (1992) mtDNA control region data set including new sequences from nine Lesser Snow Geese (Chen caerulescens caerulescens) and 10 Ross's Geese (Chen rossi) and found the same divergent lineages that Quinn (1992) attributed to vicariant separation of Lesser Snow Goose populations during the Pleistocene. However, peculiar patterns of mtDNA control region sequence variation, including a multimodal mismatch distribution of mtDNA sequences with two levels of population structuring and the sharing of two divergent haplotype lineages, are consistent with two hybridization episodes in Chen geese. Comparisons of mtDNA variation with historical and allozyme data sets compiled by Cooke et al. (1988) are consistent with the hypothesis that sharing of two mtDNA haplotype lineages between Ross's Goose and Lesser Snow Goose resulted from hybridization (Avise et al. 1992). Furthermore, population structure found within one haplotype cluster is consistent with Cooke et al.‘s (1988) hypothesis of past allopatry between blue and white Lesser Snow Geese.Hibridización y Subdivisión dentro y entre Poblaciones de Chen rossi y Chen caerulescens caerulescens: Una Perspectiva MolecularResumen. Reanalizamos los datos de la región de control del ADN mitocondrial (ADNmt) de Quinn (1992), junto con nuevas secuencias de nueve individuos de la especie Chen caerulescens caerulescens y 10 de Chen rossi. Encontramos los mismos linajes divergentes que Quinn (1992) atribuyó a la separación vicariante de las poblaciones de C. c. caerulescens durante el Pleistoceno. Sin embargo, encontramos que las dos especies comparten dos linajes de haplotipos divergentes, y la distribución de “mismatch” en secuencias del ADNmt mostró multimodalidad con dos niveles de estructuración de la población. Estos patrones peculiares están de acuerdo con la hipótesis de que hubo dos episodios de hibridización en gansos del género Chen. Los datos históricos y de aloenzimas compilados por Cooke et al. (1988) también apoyan esta hipótesis (Avise et al. 1992). Además, la estructura de la población dentro de un grupo de haplotipos es consistente con la hipótesis de Cooke et al. (1988) acerca de la pasada alopatría entre los morfos azul y blanco de C. c. caerulescens.

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Do geese fully develop brood patches? A histological analysis of lesser snow geese (Chen caerulescens caerulescens) and Ross’s geese (C. rossii)

Journal of Comparative Physiology B ◽

10.1007/s00360-006-0066-y ◽

2006 ◽

Vol 176 (5) ◽

pp. 453-462 ◽

Cited By ~ 4

Author(s):

Jón Einar Jónsson ◽

Alan D. Afton ◽

Dominique G. Homberger ◽

William G. Henk ◽

Ray T. Alisauskas

Keyword(s):

Histological Analysis ◽

Chen Caerulescens ◽

Snow Geese ◽

Lesser Snow Geese ◽

Chen Caerulescens Caerulescens ◽

Ross's Geese

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Lesser Snow Geese, Chen caerulescens caerulescens, and Ross's Geese, Chen rossii, of Jenny Lind Island, Nunavut

The Canadian Field-Naturalist ◽

10.22621/cfn.v122i1.540 ◽

2008 ◽

Vol 122 (1) ◽

pp. 34

Author(s):

Richard H. Kerbes ◽

Katherine M. Meeres ◽

James E. Hines ◽

David G. Kay

Keyword(s):

Habitat Degradation ◽

Population Decline ◽

Snow Goose ◽

Chen Caerulescens ◽

Snow Geese ◽

Lesser Snow Geese ◽

Limited Food ◽

Chen Caerulescens Caerulescens ◽

Chen Rossii ◽

Ross's Geese

We surveyed the Lesser Snow (Chen caerulescens caerulescens) and Ross’s geese (Chen rossii) of Jenny Lind Island, Nunavut, using aerial photography in June 1988, 1998, and 2006, and a visual helicopter transect survey in July 1990. The estimated number of nesting geese was 39 154 ± SE 2238 in 1988, 19 253 ± 2323 in 1998, and 21 572 ± 1898 in 2006. In 1988 an estimated 2.7% of the nesting geese were Ross’s. The July 1990 population of adult-plumaged birds was 25 020 ± 3114. The estimated percentage blue morph among Snow and Ross’s geese was 19.0% in 1988, 25.1% in 1989, 23.0% in 1990 and 21.1% in 2006. Estimated pre-fledged Snow Goose productivity was 47% young in 1989 and 46% in 1990. Combined numbers of Snow and Ross’s geese on Jenny Lind Island grew over 250 fold, from 210 adults in 1962-1966 to 54 100 adults in 1985. Numbers subsequently declined, to 42 200 in 1988, 25 000 in 1990, 20 300 in 1998, and 26 400 in 2006. Population decline between 1985 and 1990 was consistent with anecdotal reports by others that die-offs of Snow Geese occurred in 1984, 1985 and 1989, and with our August 1989 fieldwork which found evidence of habitat degradation and malnourishment of young geese. In spite of limited food resources on Jenny Lind Island, the colony continued to exist in 2006 at near its 1990 and 1998 levels. Further studies there could provide insights for management of the overabundant mid-continent Snow Goose population and its arctic habitats.

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Some problems in identification of origins of lesser snow geese by chemical profiles

Canadian Journal of Zoology ◽

10.1139/z79-298 ◽

1979 ◽

Vol 57 (12) ◽

pp. 2292-2302 ◽

Cited By ~ 7

Author(s):

John P. Kelsall ◽

Roland Burton

Keyword(s):

Great Accuracy ◽

Small Sample ◽

Sample Sizes ◽

X Ray ◽

Chen Caerulescens ◽

Snow Geese ◽

Lesser Snow Geese ◽

Chemical Profiles ◽

Small Sample Sizes ◽

Work Done

Results are reported of experimental work done to clarify problems and unknowns involved in identifying origins of lesser snow geese through computer-controlled, X-ray spectrometric analyses of primary flight feathers. Materials from wild and captive populations of lesser snow geese (Chen caerulescens caerulescens) were used. The use of an X-ray tube source of irradiation was successfully introduced to previously described techniques. Practical investigation of sample size for the generation of discriminant functions suggests that 30 samples per population are a barely adequate minimum and that 40 or more should be used.Given adequate sample sizes, and suitably different populations, the classification process overrides differences attributable to sex, age, and "Feather year" with great accuracy. With small sample sizes, however, those differences will dampen the accuracy of discrimination and classification, as will increasing numbers of populations. Examination of feathers from a captive flock, maintained for 4 years, shows statistically insignificant sexual differences, significant "within-year" changes in feather chemistry between October and May, and moderately consistent discrimination between year classes. Some of the chemical variables involved in the observed differences are examined.

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Ecological and Physiological Factors Affecting Brood Patch Area and Prolactin Levels in Arctic-Nesting Geese

The Auk ◽

10.1093/auk/123.2.405 ◽

2006 ◽

Vol 123 (2) ◽

pp. 405-418 ◽

Cited By ~ 3

Author(s):

Jón Einar Jónsson ◽

Alan D. Afton ◽

Ray T. Alisauskas ◽

Cynthia K. Bluhm ◽

Mohamed E. El Halawani

Keyword(s):

Body Condition ◽

The Body ◽

Nest Size ◽

Patch Area ◽

Physiological Factors ◽

Factors Affecting ◽

Chen Caerulescens ◽

Brood Patch ◽

Snow Geese ◽

Ross's Geese

AbstractWe investigated effects of ecological and physiological factors on brood patch area and prolactin levels in free-ranging Lesser Snow Geese (Chen caerulescens caerulescens; hereafter “Snow Geese”) and Ross's Geese (C. rossii). On the basis of the body-size hypothesis, we predicted that the relationships between prolactin levels, brood patch area, and body condition would be stronger in Ross's Geese than in the larger Snow Geese. We found that brood patch area was positively related to clutch volume and inversely related to prolactin levels in Ross's Geese, but not in Snow Geese. Nest size, nest habitat, and first egg date did not affect brood patch area in either species. Prolactin levels increased as incubation progressed in female Snow Geese, but this relationship was not significant in Ross's Geese. Prolactin levels and body condition (as indexed by size-adjusted body mass) were inversely related in Ross's Geese, but not in Snow Geese. Our findings are consistent with the prediction that relationships between prolactin levels, brood patch area, and body condition are relatively stronger in Ross's Geese, because they mobilize endogenous reserves at faster rates than Snow Geese.Factores Ecológicos y Fisiológicos que Afectan el Área del Parche de Incubación y los Niveles de Prolactina en Gansos Nidificantes del Ártico

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Use of Supplemental Food by Breeding Ross's Geese and Lesser Snow Geese: Evidence for Variable Anorexia

The Auk ◽

10.2307/4089457 ◽

1999 ◽

Vol 116 (1) ◽

pp. 97-108 ◽

Cited By ~ 18

Author(s):

Mark L. Gloutney ◽

Ray T. Alisauskas ◽

Keith A. Hobson ◽

Alan D. Afton

Keyword(s):

Supplemental Food ◽

Snow Geese ◽

Lesser Snow Geese ◽

Ross's Geese

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Serum Adsorption Study to Validate the Specificity of a Rapid Test to Detect Strongyloides stercoralis Infection

American Journal of Tropical Medicine and Hygiene ◽

10.4269/ajtmh.21-0674 ◽

2021 ◽

Author(s):

Rahmah Noordin ◽

Emelia Osman ◽

Nor Suhada Anuar ◽

Nor Mustaiqazah Juri ◽

Anizah Rahumatullah ◽

...

Keyword(s):

Small Sample Size ◽

Rapid Test ◽

High Specificity ◽

Strongyloides Stercoralis ◽

Cross Reactivity ◽

Small Sample ◽

Polystyrene Microspheres ◽

Diagnostic Specificity ◽

Serum Samples ◽

Rapid Tests

A lateral flow rapid test for strongyloidiasis will greatly facilitate the control and elimination of the disease. Previously SsRapid™ prototype rapid test showed high diagnostic specificity to detect Strongyloides infection, determined using non-Strongyloides sera negative by IgG-ELISAs. Since high specificity is crucial before a test is used for public health control activities, further validation of its specificity is needed. Also, it needs to be ascertained whether non-Strongyloides sera positive by IgG-ELISAs and SsRapid are truly positive for Strongyloides or are cases of cross-reactivity. We performed 84 rapid tests (two types of dipsticks and cassettes) using 34 serum samples. They were divided into four groups based on Strongyloides infection and coinfection with other parasites and the availability of recombinant proteins and rapid tests for the latter. Sera was adsorbed using polystyrene microspheres beads separately coated with four recombinant parasite proteins. The small sample size is a limitation of this study; however, the overall results showed that the sera adsorption procedure was successful, and the SsRapid test is specific.

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