There are two crested larks, confusingly similar in appearance, resident in Portugal and both are common in their preferred habitats. In the Algarve the Crested Lark Galerida cristata is a bit of a ‘beach bum’, occupying weedy areas and dunes at the back of the sands. The Thekla Lark, on the other hand prefers more hilly, broken ground. To add to the confusion, in the extreme south-west of the Algarve Theklas dominate right down to the coast, as at Boca do Rio. In the undulating plains of the northern provinces, both species occur, with Theklas inhabiting ridges, rocky outcrops, the sides of river valleys and open woodland. In agricultural areas, Crested Larks are more likely to be found, although both species will take advantage of winter stubble.
Even experienced birdwatchers sometimes have problems separating the two. Crested Larks in this part of their range are a warmer brown; Theklas usually colder grey/brown. But in summer juvenile Theklas are as brown as Crested! I have found the most reliable features to be the stronger facial pattern of Thekla and its shorter, broader based bill. Plumage apart, the calls are subtly different to the trained ear (Thekla’s is slightly ‘flutier’), but a very good rule of thumb is the almost unrivalled tameness of Thekla. Any dog walker on a rural track will have encountered Thekla Larks, which can be approached to within a few metres. Crested Larks are noticeably shyer here, although this does not seem to apply in some other parts of its range.
Whilst the Crested Lark has a wide distribution in Continental Europe, western Asia and Africa, the Thekla Lark is ‘our’ bird, confined to Iberia and North Africa. It is highly sedentary and thought to be monogamous. Males perform song flights throughout the breeding season, and sometimes in winter. They circle slowly with fluttering beats of their rounded wings, sometimes hovering in one spot for a while, and then plunge vertically to the ground or a low perch. The song content combines fluty notes with whistles and varied phrases incorporating excellent mimicry of other species found in the area.
Unlike some other members of the family, like the Skylark, Theklas do not form flocks outside the breeding season, remaining in pairs or small family groups throughout the year.