Common Grasshopper Warbler
Locustella naevia
The adult is about 12.5 cm (5 in) long, and weighs 11.5–16 grams (0.41–0.56 oz). It is a secretive bird and can be hard to see, but its presence is easily detected because of its characteristic song. The upper-parts are pale olive-brown, each feather having a central darker brown streak. The cheeks are greyish, the irises are brown and there is a faint eye streak behind the eye. The upper mandible of the beak is dark brown and the lower mandible yellowish-brown. The underparts are cream-coloured or yellowish-buff with a few dark brown spots and streaks on the breast and flanks.
ID text from Wikipedia, CC BY-SA 4.0
Savi's Warbler
Locustella luscinioides
The upper-parts of Savi's warbler are a uniform dark reddish-brown, sometimes with a slight greenish tinge. It has indistinct buff eye-stripes, dark lores and pale brown ear-coverts. The brown beak is slender and the irises are also brown. The chin, throat and belly are whitish-buff and the rest of the underparts sandy brown. In the breeding season, both upper-parts and underparts are slightly paler. The legs are brown. The bird is around 14 cm (5.5 in) long. The song is a trill very similar to that of the grasshopper warbler but slightly lower pitched and less prolonged.
ID text from Wikipedia, CC BY-SA 4.0
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