How to identify the Square-tailed Drongo-cuckoo

To correctly identify the Square-tailed Drongo-cuckoo (Surniculus lugubris), check each of these features. Birds can be tricky: habit, habitat, and call often confirm a sighting that a single photo cannot.

Size at a glance

Length

23-25 cm

Wingspan

Approximately 35-40 cm

Weight

30-40 g

Physical features to check

1. 1

   Plumage

   Overall feather coloration and pattern.

   Adults are entirely glossy black, often with a bluish or purplish sheen in good light. The tail is square-ended, lacking the deeply forked tail of true drongos. Some individuals may show a small white patch on the nape, though this is often concealed or absent.

2. 2

   Beak shape

   Shape and color of the bill: a key field mark.

   Slender, slightly decurved, and black.

3. 3

   Eye color

   Iris color and any distinctive eye markings.

   Dark brown to reddish-brown, with a black orbital ring.

4. 4

   Leg color

   Leg and foot color.

   Blackish-grey to black.

5. 5

   Distinguishing features

   Standout features that separate this species.

   Its overall glossy black plumage, square-ended tail (not forked like drongos), and distinctive calls are key. The lack of a prominent crest or deeply forked tail distinguishes it from drongos. The small white nape patch, if present, is a good field mark.

6. 6

   Juvenile appearance

   How young birds differ from adults.

   Juveniles are duller black, often with some white barring or spotting on the underparts and wing coverts, and sometimes a more prominent white nape patch. The tail may be slightly less square and more rounded at the tips.

7. 7

   Seasonal changes

   Plumage variation between breeding and non-breeding seasons.

   No significant seasonal plumage changes.

8. 8

   Sexual dimorphism

   How males and females differ.

   Males and females are monomorphic in plumage.

Key field marks

• Plumage. Look for an entirely glossy black bird. The sheen can appear bluish or purplish in sunlight.
• Tail Shape. Crucially, observe the tail. It should be square-ended, not deeply forked like a true drongo. This is the most reliable field mark to distinguish it from drongos.
• Vocalizations. Listen for its distinctive, melancholic 'wi-wi-wi' or 'pee-pee-pee-pee' calls. These are very different from drongo calls.
• Behavior. Observe its foraging style (gleaning insects) and its tendency to associate with mixed-species flocks, particularly drongos.
• Nape Patch. If visible, a small white patch on the nape can be a good indicator, though it's often concealed or absent in adults.

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