Gray-cheeked Thrush "Catharus minimus"

21 (81%) Treated in Appendix H: 2020, Hung et al. It lacks eye-catching, distinguishing features, and has plain, olive-brown upperparts and off-white underparts. The real problem is that the two species overlap in all visible features, including size and color. BBS data indicate that Northern Gray-cheeked Thrushes in Alaska and possibly mainland Canada are also declining, though estimated trends are much weaker than on Newfoundland (SSAC 2020, Environment Canada 2020, Sauer et al. )

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Marshall (2020) also noted the intermediate size and coloration of Gray-cheeked Thrushes breeding on Newfoundland and suggested that in the past they may have intergraded with Bicknell’s Thrushes along the north shore of the Gulf of St. Seasonal migration, speciation, and morphological convergence in the genus Catharus (Turdidae). John’s, Newfoundland, USA. Another example, showing even more pointed rectrices. Photo by Marcel Gahbauer, McGill Bird Observatory (QC), September 2020 AHY Gray-cheeked Thrushes have broad rectrices with relatively blunt tips, although there can be a slight point right at the tip of the shaft.

This medium-sized thrush has brownish-gray upperparts and tail, is pale below with heavier spotting on the breast than other thrushes, a plain gray face with some light streaks but no eye-ring. Synapomorphy of the Bilateria. Hylocichlid thrushes in captivity with notes on their behaviour. Oral thrush: overview, breastfeeding mothers should be alert to signs of thrush during a healthy newborn’s first two weeks—that is when the infection is quite common. Judy’s delicious sea food chowder, rhubarb cobbler ( yum) and stories of the Marlow’s early years in Alaska. Uncorrected nucleotide divergence was calculated using DNASP v. Spends winters in Central and South America. Round-headed thrush that lacks an eyering.

Rare along Pacific coast. Ground cover composition (quantified within eight 0. )Upper mandible is black with pale base, while lower mandible is yellow with black tip. Springer, The Hague, The Netherlands. From 5 June through 11 July of 2020 and 2020 we conducted field investigations across Newfoundland and the southern half of Labrador. Birders are more likely to hear this species’ nocturnal flight call during spring and fall migration than to observe migrants on the ground. Perched bird on breeding grounds. As a broad generalization Bicknell’s Thrush is smaller and more reddish than Gray-cheeked.

  • Rare but regular vagrant to Great Britain (45+ records).
  • It is difficult to say whether losses are restricted to these regions, as monitoring data are extremely limited elsewhere.
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  • The addition of mud makes the nest stronger.
  • Impact of non-native terrestrial mammals on the structure of the terrestrial mammal food web of Newfoundland, Canada.
  • Voice (and primarily song) is still the most reliable way to distinguish these species.

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A full occupancy model including all habitat variables did not converge, so we analyzed 23 separate univariate models, and ranked models according to AIC. Various lines of evidence support the split of Northern (C. )005) and higher local abundance of large broadleaf trees (U = 46, p = 0. Our results support previous designations of C. Blyškiaskruotis strazdas. Thrushes are most well known for their beautiful flute-like songs; an attribute shared by many North American thrush species. The female alone incubates the eggs for 12-14 days before hatching.

Given the decline of the Gray-cheeked Thrushes on the island of Newfoundland, understanding the taxonomic status and current distribution of this population could play a key role in protection, conservation, and recovery planning. It also feed on various small wild fruits, including cherries and raspberries. Ornithologists are also concerned about the future of some species, such as the Bicknell's Thrush, due to destruction and development of their small wintering habitat areas. 10 (Rozas et al. )

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We compared morphological traits of Gray-cheeked Thrushes between three regions: Song is a stuttering series of descending phrases with a notably wiry tone. Oral thrush: overview, the signs to look out for are white, raised areas in your mouth. Convergence was assessed with Tracer v.

  • Coupled with our observations supporting the existence of a substantial geographic gap between these populations, these findings suggest that the Newfoundland subspecies C.
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  • I can believe this is true but it needs confirmation and further study.
  • Pairwise comparisons of genetic variation among regional groupings (Table 1) using φ st values indicated that Northern Gray-cheeked Thrushes from western Labrador/Quebec and Alaska (C.)
  • A statement such as “When I see a Bicknell’s it just jumps out as redder and less robust” is a classic example of what psychologists call a “one-sided event”.
  • Fortieth supplement to the American Ornithologists’ Union check-list of North American birds.
  • The gray-cheeked thrush feeds primarily on insects, including ants, wasps, caterpillars, and beetles.

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Logistical and in-kind support was provided by the NL-Wildlife Division and Gros Morne National Park. South, editor. It’s best to distinguish the two by their voices. Recent concern over a dramatic decline in Gray-cheeked Thrush numbers on Newfoundland has increased the importance of clarifying the taxonomic status of individuals breeding on the island (SSAC 2020). Candidiasis infections: yeast infections, thrush, daiper rash, now that your foods are figured out, it’s important to look at supplements that may help you to get rid of the overgrowth. Checklist of North American birds. Consequently, during the 2020 field season we also recorded whether squirrels or physical evidence of squirrels were detected at survey points during bird surveys or vegetation sampling.

Gray-cheeked Thrush can generally be aged by a combination of molt limits and feather condition. During the winter, the Gray-cheeked Thrush migrates to the northern part of South America including Colombia , Venezuela, Peru and Brazil. Avifaunal inventory, Gros Morne National Park. All AMOVA calculations were significant (p < 0. )


Spruce forests near bog areas in subarctic Canada. Also, both landscape coverage of shrub habitat and local abundance of large broadleaf trees differed significantly between currently and historically occupied sites. In contrast, ecosystems on Newfoundland have been altered by the introduction of numerous species (e. )It stays along the east coast. Diurnal onward migration occurs in spring in the Gulf coast region and presumably in the far northern latitudes. However, following the description of “Bicknell’s Gray-cheeked Thrush” (Ridgway 1882), a consensus emerged that the species comprised two subspecies: Bicknell's Thrush, its taxonomy, distribution, and life history. (2020, Ralston and Kirchman 2020, Lait and Burg 2020), and is consistent with the hypothesis that a Pleistocene refugium for boreal species existed off of the coast of Newfoundland.

They have olive-brown upper parts, gray cheeks, and pink legs.

We also did not find Gray-cheeked Thrushes in the reported historical distributional gap from Mary’s Harbour north to Cartwright in Labrador. Even though the Grey-cheeked Thrushes have a much larger range across North America than their close relatives, the Bicknell's Thrushes are typically found closer to urban areas and are, therefore, more likely to be encountered. Right after hatching, the young chicks cannot feed themselves and depend on their parents for food. To quantify habitat at survey points we measured 19 attributes of vegetation composition and structure in 4 m x 20 m transects (80 m² sampling area; hereafter, local habitat variables). The breeding birds of Quebec:

Range Map

The female alone builds the nest, constructing an open cup shape of moss, twigs, bark, stems, and weeds lined with fine plant materials such as moss. Veery has a similar plain face, but more muted spotting on the breast, and is usually more reddish overall. COSEWIC status report on the Bicknell’s Thrush (Catharus bicknelli) in Canada. First, we used a single-visit occupancy model (Lele et al. )Consequently C. Similarly, Gray-cheeked Thrushes may have experienced a range contraction eastwards along the north shore of the Gulf of St. Although robins use this foraging strategy, bluebirds snatch insects by flying to the ground and solitaires sally into the air to catch insects. 05) but showed low to moderate differentiation from the Long Range Mountains (φ st 0.

Once decided, she searches for a good spot to build her nest, which usually ends up being in the crotch of the lower branches of a small spruce or tamarack, or sometimes on the ground next to a willow or alder. 05) and southern Labrador (φ st 0. Molecular genetics analyses have supported and enhanced our understanding of endemism on Newfoundland, indicating that both resident species such as Rock Ptarmigan (Lagopus mutus welchi; Holder et al. )An integrated software package for population genetics data analysis. Although endemism on Newfoundland is undoubtedly maintained by contemporary marine barriers, the population structure for many of these species may have originated through historical isolation in Pleistocene glacial refugia, including the putative Atlantic Shelf refugium on the now submerged continental shelf south and east of Newfoundland (Rogerson 1983, Pielou 1991, Jaramillo-Correa et al. )The sexes are similar and have a distinctive song which is very high pitched with quick chippers. 0182), and negatively associated with local abundance of large broadleaf trees (slope = -2.

Lawrence or on islands around Nova Scotia and in the gulf, as suggested by Marshall (2020). The grey-cheeked thrush is a long-distance migrant species with a migration on average of 300 km. Written and continually updated by acknowledged experts on each species, Birds of North America accounts include a comprehensive bibliography of published research on the species. Conversely, birds from the highlands of the Long Range Mountains of western Newfoundland showed low to moderate differentiation from other C.

The median age of the node uniting all Gray-cheeked Thrushes ranged from 235–238 ky in both constrained and unconstrained runs (95% CI = 10 - 1280 ky).


We amplified and sequenced the entire 1041 base pairs (bp) mitochondrial NADH dehydrogenase 2 (ND2) gene from all individuals and two nuclear loci from subsets of individuals: We then used a Chi-squared test to evaluate the association between detections of thrushes and squirrels. We compared each habitat variable present in the top occupancy model between current and historically occupied sites. In other words, Central and South America. Consequently this shy skulker of the underbrush is not well known and is rather infrequently seen. 2020, Rae et al. Thank you for taking time to point out places of interest and helping some fly fishing folks find their private oasis (Fish Lake) Looking forward to returning soon. Avifaunal survey of Gros Morne National Park.


HY/SY individuals are often easily recognized by retained juvenile greater coverts with pale shafts or tips, but since these can fade over time, some intermediates may be difficult to assess by spring. As a result, we suspect that the level of gene flow is greater across the 15–60 km wide Strait of Belle Isle than across the 150–350 km wide apparent distributional gap between southeastern Labrador and central Labrador (see Fig. )Nearly identical to Bicknell's Thrush, which shows slight reddish wash to plumage. 2020, Marshall 2020), Gray-cheeked Thrushes on Newfoundland appear to make more limited use of deciduous thickets, and instead are characteristically associated with windswept coastal conifer thickets, conifer scrub, regenerating clearcuts dominated by young balsam fir (Abies balsamea), and high elevation, old-growth balsam fir forests (Lamberton 1976, Vassallo and Rice 1981, Thompson et al. A reticent bird, the Gray-cheeked Thrush keeps mostly under cover, searching for food on the ground. Gray-cheeked Thrushes breeding on Newfoundland are purported to be a distinct subspecies (Catharus minimus minimus) and have declined precipitously since the 1980s. In areas where they are expected, it may be reasonable to identify small and reddish birds as Bicknell’s Thrush after careful and lengthy study, even without hearing them sing, but I don’t think sight observations or photos alone would ever be acceptable evidence of a bird out of range, for example, in Ohio, or Alaska, or the UK.

Uncommon in spring; occasional in fall. Survey sites encompassed the full suite of breeding habitat types reported in the literature, including low and high elevation conifer scrub, willow and alder thickets, regenerating clearcuts and montane old-growth fir forest. We observed 53 individual thrushes at 13 of the sites sampled, and 13 of these thrushes were not detected until the broadcast portion of the survey. “Great Hosts, Great accommodations, Great time. Analysis of mitochondrial (ND2) and nuclear intron (ADAM-TS 6, FIB7) sequences from these and additional samples from Nova Scotia, Newfoundland, Labrador, Quebec, Alaska, and Siberia showed low genetic variation at both nuclear loci, and shallow mitochondrial divergence between subspecies; there were no shared haplotypes between thrushes from Newfoundland/Nova Scotia (n = 41) and those from western Labrador and further west (n = 24). The southern Labrador group showed low to moderate levels of differentiation from all Newfoundland regional groups (φ st range: )


Despite a large sample size, however, birds from the Avalon Peninsula were not significantly different from the Burgeo or Northern Peninsula groupings, and showed low differentiation from southern Labrador; this lack of significant differentiation may be due to the fact that 15 of 17 individuals from the Avalon group had identical ND2 sequences despite being sampled from four sites (Appendix 1). (2020) using the Earth Observation for Sustainable Development of Forests (EOSD) satellite data (25-m resolution; Wulder and Nelson 2020). Bayesian evolutionary analysis with BEAST 2.


Bicknell’s Thrush was long-considered a subspecies of Gray-cheeked Thrush, but when the AOU split Gray-cheeked Thrush and gave Bicknell’s full species status in 1998 it created one of the most challenging field identification problems in eastern North America. At each site we surveyed 3–10 points for 10 minutes each between 04: R Core Development Team.

The species winters east of the Andes from Venezuela and Colombia to northwest Brazil and is an uncommon migrant across Montana with fewer than five observations reported in the typical year (Whitaker et al. )Each captured bird was marked with a uniquely numbered federal leg band and then measured (relaxed [unflattened] wing chord, tail, exposed culmen), weighed, photographed, and sampled for ~25–50 μL of blood drawn from the brachial vein. (3 - 649 ky), and the median age of C. Epiphytes and climbing plants are also abundant.

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We used a Welch’s two-sample t test for this comparison when the data were normal according to a Shapiro-Wilk test, or a Mann-Whitney U test when they were not. For our mitochondrial data we used Network v. Our findings agree with Topp et al. Call a high-pitched, piercing "pzeeer. "(15), indicating that thrushes were in excess of three times more likely to be detected at points where squirrels were not observed.

Found in wooded areas with thick undergrowth. Close 3, Dilger, W. Hot, muggy (80+F), calm. Close 1) and Dilger ( Dilger, W. Does coconut oil for vaginal yeast infections work? (2020) according to Bayesian information criterion (BIC).

Note that these models were fit using data from the subset of sites surveyed for squirrels in 2020. Not only do color and size overlap, but these two variables are not entirely linked. Tail and rump have rust-brown wash. Similarly, we calculated the odds ratio to estimate the relative likelihood of detecting thrushes at points where squirrels were or were not detected. Considering that this thrush breeds extensively in western Canada, Alaska, and extreme northeastern Siberia and migrates long distances to the neotropics, its extreme rarity in California is surprising (see the preceding account).


The willows had been defoliated by some type of caterpillars which I'd been seeing off and on along much of the River. Thrush mass did not vary across regional groupings. Wallace (1939) was the first to describe the subtle differences in coloration that distinguish the Newfoundland birds, which he found to be similar in size to the continental form Hylocichla minima aliciae but with distinctly browner backs like those of H. These latter elements suggest habitat affinities similar to those of Bicknell’s Thrushes (Rimmer et al. )

  • In spring, birds begin to arrive in mid- to late May and most have begun fall migration by the start of September.
  • At the first of these two variable sites 10 Bicknell’s Thrushes and one Gray-cheeked Thrush from southern Labrador (NYSM zt-1278) were heterozygous with the same two alleles.
  • In summary, our morphological and genetic data indicate that Gray-cheeked Thrushes of Newfoundland and southeastern Labrador are weakly differentiated from those found further west in the species’ breeding range.
  • The gray-cheeked thrush builds its nest on or near, the ground, usually no higher that 15 feet up.

Literature Cited

These variables were (1) conifers (combined proportion of EOSD rasters within 1250 m classified as Coniferous, Coniferous-dense, Coniferous-open, or Coniferous-sparse); (2) dense conifers (proportion of rasters classified as Coniferous-dense); (3) shrubs (combined proportion of rasters classified as Shrubland, Shrubs-tall, or Shrubs-short); and (4) mixed deciduous and coniferous forests (combined proportion of rasters classified as Mixedwoods, Mixedwoods-dense, Mixedwoods-open, or Mixedwoods-sparse). Oxygen-isotope and paleomagnetic stratigraphy of Pacific core V28-239: Further, as has been reported previously, we found that Gray-cheeked Thrushes on Newfoundland had shorter wings and had less black in the lower mandible than those from the range of C. 33% nucleotide divergence (range 2. )

The female incubates the eggs for 13 to 14 days. Bicknell's Thrush: 2020, van Els et al. This terrestrial biome also occurs at high elevations. During the breeding period the species shows considerable geographic overlap with four other thrushes, including two congeners—Swainson's Thrush (C. )Pages 163-206 in R. However had it been retained the mean wing chord of males from Newfoundland would still have been significantly shorter than that of males from western Labrador and Quebec.

High latitudes and high genetic diversity:

Additional Information

Thrushes are well represented in North America with sixty species in thirteen genera (including the extinct Grand Cayman Thrush and Amahui of Hawaii). Broad and rounded rectrices; outermost primary (p10) narrow and pointed; wing uniformly brown. We attempted to add squirrels as an explanatory variable to our best occupancy model to see if it would improve performance, but the model did not converge. 1M Tris-HCl, 0. It’s range extends from northern Alaska and the Yukon and Northwest territories east to southern Hudson Bay, then astretching east to Newfoundland. Impressions of shape and size can be helpful, as the “classic” Bicknell’s is smaller, shorter-winged, more dumpy and Hermit-Thrush-like in shape compared to the “classic” Gray-cheeked. Yeast infections: medlineplus, genital warts is a sexually transmitted infection (STI, STD) caused by the human papillomavirus (HPV). The AMOVA with Bicknell’s Thrushes, Northern Gray-cheeked Thrushes, and Newfoundland Gray-cheeked Thrushes designated as groups showed that 84% of the genetic variance was partitioned among these groups (p < 0. )

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Boreal forests, tundra scrub; in migration other forests. Samples from Burgeo were not significantly different from any other Newfoundland group (p > 0. )Both of California’s inland records of the Gray-cheeked Thrush refer to fall vagrants at Galileo Hill in eastern Kern County. Hill III James Spruill James Wilson Jan Roberts Janet Bogue Janet Carter Jason Duncan Jason E. Vegetation is made up mostly of grasses, the height and species diversity of which depend largely on the amount of moisture available. Small thrush (minimus), with olive-brown upperparts, buff-brown breast with brown spots, and white or buff belly. We used hierarchical analysis of molecular variance (AMOVA) to assess whether a significant proportion of genetic variation could be attributed to species or subspecies divisions, based on 20,000 permutations of the data set. COSEWIC, Ottawa, Ontario, Canada.

The cup-shaped nest is built from grass and mud, placed in the low conifer. Colombia, Venezuela, Trinidad, Guyana and nw. Vagrants occur casually or accidentally in the Aleutian and Pribilof Islands and along the Pacific coast, with single records from southern British Columbia and Washington, two from Oregon, one from Isla Guadalupe (Quintana-Barrios et al. )To distinguish from other Catharus thrushes, note very faint eyering and plain gray face. Gray-cheeked Thrushes residing in the hypothesized Atlantic Shelf refugium may have diverged in allopatry from birds residing in one or more western refugia. Candida, how is Oral Thrush Diagnosed? SCIENTIFIC NAME: Few species of trees are present; these are primarily conifers that grow in dense stands with little undergrowth. Grey-cheeked Thrushes generally only produce one brood in a season; however, if the first one fails early in the season, they may have a second.

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Proceedings of the Boston Society of Natural History 41: 2020) and are now the dominant predator of songbird nests on Newfoundland (Lewis 2020), and recent field observations led to the hypothesis that squirrels have played a role in the decline of Gray-cheeked Thrushes (Whitaker et al. Is it okay to 'tough out' a yeast infection? self-diagnosing below the belt isn't always a smart decision. (2020) to test for the effects of each of our local and landscape habitat variables on occupancy, while accounting for detection probability.

Habitat use may also differ between Northern and Newfoundland Gray-cheeked Thrushes. All bird observations from our point count surveys and area searches have been entered into the eBird bird observation database. Small bill with yellow base. River, you are the sweetest and most stubborn doggie. Endothermy is a synapomorphy of the Mammalia, although it may have arisen in a (now extinct) synapsid ancestor; the fossil record does not distinguish these possibilities. Gray-cheeked Thrush migrates throughout eastern North America.

The hatchlings are helpless and both parents feed and protect them. You won’t see them very often during their migration, because they do so at night, although since the boreal north is bathed in sunshine for almost 24 hours in the summer, you have a better chance of seeing them here at that time. Although the disappearance of Gray-cheeked Thrushes throughout much of Newfoundland has been dramatic, little is known about the underlying causes. The grey-cheeked thrush is all but indistinguishable from Bicknell's thrush except by its slightly larger size and different song.