Olivaceous Thornbill vs Allen's Hummingbird
Chalcostigma olivaceum compared with Selasphorus sasin
Side-by-Side Comparison
| Attribute | Olivaceous Thornbill | Allen's Hummingbird |
|---|---|---|
| Scientific Name | Chalcostigma olivaceum | Selasphorus sasin |
| Order | Caprimulgiformes | Caprimulgiformes |
| Family | Trochilidae | Trochilidae |
| Conservation Status | Least Concern | Least Concern |
| Length | — | — |
| Wingspan | 16.3 cm (6.4 in) | 8.1 cm (3.2 in) |
| Weight | 7.3999999999999995 g (0.26 oz) | 3.1500000000000004 g (0.11 oz) |
| Diet | Nectarivore of high Bolivian and Peruvian páramo; short bill accesses small open flowers. Gleans insects … | Feeds on nectar from coastal sage scrub and forest flowers in California. Supplements diet with … |
| Clutch Size | 2 | 2 |
| Population Trend | — | — |
Habitat Comparison
Song & Call Comparison
Olivaceous Thornbill
Buzzy, high-frequency trill with insect-like quality; sustained continuous vibration with rapid amplitude modulation.
Allen's Hummingbird
Deep, resonant churring trill; prolonged low buzzing sound carrying well across broad coastal mangroves.
Geographic Range & Migration
Olivaceous Thornbill
Widespread in high Andean puna grassland from Peru to Bolivia and northwestern Argentina. 3,200–4,800 m.
Allen's Hummingbird
Breeds along the Pacific coast from Oregon to southern California. Partial migrant; some Channel Islands populations resident year-round.
Conservation Status
Olivaceous Thornbill
Allen's Hummingbird
About These Birds
Olivaceous Thornbill
A small hummingbird (11-12 cm) found in Andean puna and páramo from Peru to Bolivia at 3,500-4,800 m. Olive-green plumage with subtle throat iridescence. Nectarivore of high-altitude flowering plants. One of the drabbest thornbills. Tolerates extreme cold.
Allen's Hummingbird
A small hummingbird (8-9 cm) breeding along the Pacific coast from Oregon to southern California. Males have an orange-red throat and rufous flanks. Closely related to Rufous Hummingbird. Partial migrant; some populations resident on Channel Islands. Named after Thomas Allen.