Species › Birds

Western Bonelli´s Warbler

Phylloscopus bonelli

Order: Passeriformes
Family: Phylloscopidae
Presence in the Strait: Seasonal
Abundance: abundant
Protection in Spain: Special protection (List)
In Spanish: Mosquitero papialbo

35% of its open observations in the area are from April.

Photograph: Codrin Bucur, CC BY, vía iNaturalist

Length: 11 cm
Weight: 8 g

Presence in the Strait

Abundant summer visitor to forests.

Identification

Greyishgreen back, yellowish rump and feather edges in wing, white underparts. Black legs. Its song resembles a Green Finch.

Movements

Peaks in 2nd hf. April and 1st hf. August.

Bioestrecho editorial text. Last revised: 8 September 2026.

Photographs from iNaturalist observations with the licence checked file by file. Those marked “Strait” were taken within the area; place and date are those of each observation.

Calendar in the Strait

35 %

Peak in April. Observations under CC0 or CC BY licences. The distribution also reflects observation effort.

Where it is seen

Open records from the atlas database, in cells of about 3.6 km. Opacity follows the square root of the count, and also reflects where people observe most.

See on the map

First open record: 29 April 1921
Latest record: 24 September 2024

The oldest and the most recent open observation in the extended area. A recent first observation does not mean the species is new: it means nobody had published it openly before.

Conservation

The catalogues, Andalusian and Spanish, are what binds; the Red Book assesses the Spanish population with IUCN criteria, and the global Red List is the context.

LCNTVUENCR

Andalusian Catalogue: Special protection (List)
Spanish Catalogue: Special protection (List)
Red Book of the Birds of Spain 2021: LC · Least concern · breeding
Global Red List (IUCN): LC · Least concern

Andalusian Catalogue: Junta de Andalucía, list of 24 April 2025. Spanish Catalogue: MITECO, table of 30 June 2025. Red Book: SEO/BirdLife, 2021 (Annex I). IUCN: via GBIF, 6 September 2026. Red Book and IUCN categories are assessments; catalogue categories are legal obligations.

Phenology compared

Monthly distribution in proportion, by decade. It shows whether the passage is getting earlier or later.

1990–1999

2000–2009

2010–2026

Proportions, not totals: observation effort grew faster than any population.

Same genus in the Strait

Common Chiffchaff11–11 cm · Seasonal · overlapping size
Mountain Chiffchaff11–11 cm · Vagrant · overlapping size
Dusky Warbler11–11 cm · Vagrant · overlapping size
Willow Warbler11.5–11.5 cm · Migrant
Wood Warbler12.5–12.5 cm · Migrant

Species of the same genus that also occur here, ordered by how close they are in size. Being relatives does not mean they are confused in the field, but that is where the doubts start: compare size and season.

Classification

Kingdom: Animalia
Phylum: Chordata
Class: Aves
Order: Passeriformes
Family: Phylloscopidae
GBIF taxon key: 2493070

Sources

Distribution and calendar: Bioestrecho's own database, ingested from GBIF and OBIS
Photograph: Codrin Bucur, CC BY, vía iNaturalist
Taxonomy: GBIF backbone, pending WoRMS for marine taxa
Editorial text: written by Bioestrecho
Last revised: 8 September 2026

Western Bonelli´s Warbler

Presence in the Strait

Identification

Movements

Gallery