Common Grashopper Warbler

Locustella naevia

Order: Passeriformes
Family: Locustellidae
Presence in the Strait: Migrant
Abundance: scarce
Protection in Spain: Special protection (List)
In Spanish: Buscarla pintoja

Photograph: Stefan Hage, Birds.se, CC BY-SA 3.0, vía Wikimedia Commons

Length: 13 cm
Weight: 15 g

Presence in the Strait

Scarce migrant. Difficult to see due to its shy habits, so may be commoner.

Identification

Dull brownish bird that creeps in grass like a mouse, fanning tail nervously. Olive-brown upperparts with dark streaks and spotting, buff underparts with streaked flanks and rounded tail with long, dark-centred undertail coverts.

Movements

Prenuptial migration with peaks in 1st hf. May; postnuptial in 2nd hf. September and 1st hf. October.

Ring recoveries

Germany (1).

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

32 %

Peak in September. 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: 4 August 1995
Latest record: 14 November 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: DD · Data deficient · 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.

Where they come from

1 birds ringed in other countries and recovered in the area.

Germany1

See the journey on the map

Same genus in the Strait

Savi´s Warbler14–14 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: Locustellidae
GBIF taxon key: 2493548

Sources

Distribution and calendar: Bioestrecho's own database, ingested from GBIF and OBIS
Photograph: Stefan Hage, Birds.se, CC BY-SA 3.0, vía Wikimedia Commons
Taxonomy: GBIF backbone, pending WoRMS for marine taxa
Editorial text: written by Bioestrecho
Last revised: 8 September 2026

Common Grashopper Warbler

Presence in the Strait

Identification

Movements

Ring recoveries

Gallery