MacGillivrays Warbler (Oporornis tolmiei)

MacGillivrays Warbler

[order] PASSERIFORMES | [family] Parulidae | [latin] Oporornis tolmiei | [UK] MacGillivrays Warbler | [FR] Sylvette des buissons | [DE] Dickicht-Waldsanger | [ES] Verdin de Tolmie | [NL] Rouwkopzanger


Genus Species subspecies Breeding Range Breeding Range 2 Non Breeding Range
Geothlypis tolmiei
Oporornis tolmiei NA w, also n Mexico MA
Oporornis tolmiei monticola
Oporornis tolmiei tolmiei

Physical charateristics

Male: Olive above, yellow below, with a slate gray hood (blackish on the throat) completely encircling the head and neck. Partial white eye-ring is broken fore
i and aft. Female: Similar, but the hood is much paler, washed out on the throat. Immature
may have only a suggestion of the hood and is difficult to separate from immature Mourning Warbler, which breeds in Canada east of the Rockies.

Listen to the sound of MacGillivrays Warbler

[audio: Warbler.mp3]

Copyright remark: Most sounds derived from xeno-canto

wingspan min.: 17 cm wingspan max.: 20 cm
size min.: 11 cm size max.: 15 cm
incubation min.: 11 days incubation max.: 13 days
fledging min.: 8 days fledging max.: 9 days
broods: 1   eggs min.: 2  
      eggs max.: 5  


North America : West, also North Mexico


Low dense undergrowth; shady thickets.
Breeds in thickets of willow and alder, near stream bottoms or at edge of coniferous or mixed forest. Favors new growth in logged or burned areas (especially with dead and fallen trees), brushy thickets near low moist ground, and thicketed mountain canyo
ns. In winter in the tropics, occurs in forest undergrowth in foothills and mountains.


Male sings frequently through breeding season to defend nesting territory.
Nest: Site is well hidden in dense shrubs, often placed in upright fork of fir saplings, scrub oaks, alders, salal, chokecherry or Spiraea. Usually 2-
3′ above the ground, sometimes lower or as high as 5′. Frequently in shady damp places or amid tall weeds and ferns. Nest i
s loosely constructed open cup made of weed stems, bark shreds, and dry grass; lined with fine grasses, rootlets, and hair. Both sexes probably help build nest.
Eggs: Usually 4, sometimes 3-5, rarely 6. Creamy white with brown spots, speckles, or blotches. Incubation is probably by female alone, about 11 days. Apparently cowbirds do not commonly parasitize this warbler’s nests.

Young: Both parents feed the nestlings. Young leave the nest about 8-9 days after hatching.

Feeding habits

Mostly insects. Details of diet are not well known; undoubtedly feeds mostly on insects. Known to eat click beetles, dung
beetles, alfalfa weevils, flea beetles, caterpillars, and other insects. Young birds in Colorado will take oozing sap from holes drilled in willows by sapsuckers.
Forages mostly close to ground in dense thickets, seeking insects on branches and among foliage. Hops when searching for insects on the ground. On the wintering grounds, individuals defend feeding territories and usually forage alone.


This species has an extremely large range, and hence does not approach the thresholds for Vulnerable under the range size criterion (Extent of Occurrence <20,000 km2 combined with a declining or fluctuating range size, habitat extent/quality, or population size and a small number of locations or severe fragmentation). Despite the fact that the population trend appears to be decreasing, the decline is not believed to be sufficiently rapid to approach the thresholds for Vulnerable under the population trend criterion (>30% decline over ten years or three generations). The population size is extremely large, and hence does not approach the thresholds for Vulnerable under the population size criterion (<10,000 mature individuals with a continuing decline estimated to be >10% in ten years or three generations, or with a specified population structure). For these reasons the species is evaluated as Least Concern.
MacGillivrays Warbler status Least Concern


Breeds western North America. Winters Sonora to western Panama. Migration: Probably migrates mostly at night. Migration is spread over a lengthy period in both spring and fall.

Distribution map

MacGillivrays Warbler distribution range map

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