Timing and Location of Wing Molt in Horned, Red-necked and Western Grebes in North America

Stout, Bonnie E.; Cooke, Fred

doi:10.1675/1524-4695(2003)026[0088:talowm]2.0.co;2

Cited by 11 publications

(8 citation statements)

References 16 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Western grebes initiate moult after nesting and tend not to fly once they are established on a lake during their breeding season [29], [30], [31]. Therefore, it was assumed that resource units (lakes) were closed to movement during the time of surveying (May-August).…”

Section: Methodsmentioning

confidence: 99%

“…Four assumptions proposed by MacKenzie et al [3] were necessary for this presence/absence/detectability study: 1) Survey units were closed to changes in presence on a lake, i.e., no immigration/emigration during the survey season. Western grebes initiate moult after nesting and tend not to fly once they are established on a lake during their breeding season [29] , [30] , [31] . Therefore, it was assumed that resource units (lakes) were closed to movement during the time of surveying (May-August).…”

Section: Methodsmentioning

confidence: 99%

See 1 more Smart Citation

Using Latent Selection Difference to Model Persistence in a Declining Population

2014

View full text Add to dashboard Cite

Population persistence is a direct measure of the viability of a population. Monitoring the distribution of declining populations or subpopulations over time can yield estimates of persistence, which we show can be modeled as a latent selection difference (LSD) contrasting attributes of sites where populations have persisted versus those that have not. Predicted persistence can be modeled with predictor covariates to identify factors correlated with species persistence. We demonstrate how to model persistence based on changes in occupancy that can include adjustments for detection probability. Using a known historical distribution of the western grebe (Aechmophorus occidentalis), we adapted methods originally developed for occupancy modeling to evaluate how environmental covariates including emergent vegetation and human developments have affected western grebe persistence in Alberta. The relative probability of persistence was correlated with the extent of shoreline bulrush (Scirpus lacustris), which is important vegetation for nesting cover. We also documented that western grebe populations were less likely to persist on lakes in the boreal forest, primarily located on the northern boundary of the species' range. Factors influencing occupancy were different than those determining persistence by western grebes; persistence and occupancy were not correlated. Persistence was more likely on lakes with recreational development, reflecting reliance by grebes on the larger, fish-bearing waterbodies that also are attractive for lakeshore development. Unfortunately, the correlation with recreational development on Alberta's lakes puts grebes at risk for loss of brood-rearing habitats—primary threats to altricial birds—if steps are not taken to prevent disturbance to bulrush stands. Identifying factors related to the persistence of a species—especially one in decline—is a fundamental step in conservation management.

show abstract

Section: Methodsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

Using Latent Selection Difference to Model Persistence in a Declining Population

2014

View full text Add to dashboard Cite

show abstract

“…Prior reports of molt peaking in late summer (Storer and Nuechterlein 1985) or at fall staging areas (Stout and Cooke 2003) may represent regional variation or sampling biases. We found the greatest proportion of molting grebes at the Oregon/Washington border in fall (35%); it is unknown if these individuals were staging or would have overwintered there.…”

Section: Discussionmentioning

confidence: 99%

“…It has been suggested that adult grebes undergo molt in late summer and immatures in winter (Storer and Nuechterlein 1985;Pyle 2008). Although grebes do not need flight during breeding, competition with their young for food resources or the use of their remiges for back-brooding chicks may preclude molt from occurring then (Stout and Cooke 2003;Howell 2010), and nutritional or other constraints may influence whether molt and breeding can take place simultaneously (Stiles and Wolf 1974;Howell 2000). Timing of molt in non-breeding grebes may relate to breeding phenology (Howell 2010), which can vary substantially among regions and years.…”

Section: Discussionmentioning

confidence: 99%

“…commun. ), and in fall in coastal British Columbia and Washington (Henny et al 1990;Stout and Cooke 2003). There is limited evidence of remigial molt in grebes during winter: it was reported in approximately 10% of grebes from the January/February 1969 Santa Barbara oil spill (Sibley 1970), in a single grebe from southern California in February (Storer and Nuechterlein 1985), in a single grebe in midwinter from an unknown location (Palmer 1962), and in Pyle (2008).…”

Section: Western Grebes (Aechmophorus Occidentalis)mentioning

confidence: 99%

See 1 more Smart Citation

Revisiting Winter Wing Molt in Western Grebes (Aechmophorus occidentalis) and Clark's Grebes (A. clarkii)

2013

View full text Add to dashboard Cite

Inorganic Contaminants, Nutrient Reserves and Molt Intensity in Autumn Migrant Red-Necked Grebes (Podiceps grisegena) at Georgian Bay

Holman

Schummer

Petrie

et al. 2015

Arch Environ Contam Toxicol

View full text Add to dashboard Cite

Red-necked grebes (Podiceps grisegena) are piscivorous waterbirds that breed on freshwater lakes in northwestern Canada and stop-over at the Great Lakes during autumn migration to molt feathers and replenish lipid and protein reserves. The objectives of this study were to (1) describe concentrations of, and correlations among, inorganic contaminants in a sample of autumn migrant red-necked grebes from the Great Lakes, (2) compare concentrations of inorganic contaminants to those in autumn migrant common loons from Schummer et al. (Arch Environ Contam Toxicol 62:704, 2011a), (3) evaluate if the inorganic elements are negatively associated with lipid and protein reserves, and (4) determine if nutrient reserves and molt intensity were correlated. None of the 14 contaminants analyzed were above threshold levels known to cause acute health problems in piscivorous birds. Body masses of plucked birds were within the normal reported range. Lipid reserves varied positively with hepatic concentrations of arsenic, copper, iron, nickel, lead, and selenium and negatively with mercury and magnesium. Protein reserves variety negatively with hepatic concentrations of arsenic, calcium, nickel, lead, and zinc and positively with aluminum, cadmium, and iron. A negative correlation was observed between chest molt and lipid reserves but not between nutrient reserves and other feather tracts. The relationships between lipid reserves and both mercury and selenium were consistent with current research on other piscivorous waterbirds at the Great Lakes and justify continued work to determine interactions of these contaminants in waterbirds that breed, stage, and winter in the region.

show abstract

Timing and Location of Wing Molt in Horned, Red-necked and Western Grebes in North America

Cited by 11 publications

References 16 publications

Using Latent Selection Difference to Model Persistence in a Declining Population

Using Latent Selection Difference to Model Persistence in a Declining Population

Revisiting Winter Wing Molt in Western Grebes (Aechmophorus occidentalis) and Clark's Grebes (A. clarkii)

Inorganic Contaminants, Nutrient Reserves and Molt Intensity in Autumn Migrant Red-Necked Grebes (Podiceps grisegena) at Georgian Bay

Contact Info

Product

Resources

About