How to identify the Purple Swamphen

To correctly identify the Purple Swamphen (Porphyrio porphyrio), 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

45-50 cm

Wingspan

90-100 cm

Weight

600-1200 g (males typically larger than females)

Physical features to check

1. 1

   Plumage

   Overall feather coloration and pattern.

   Adults display iridescent deep purple-blue plumage over most of the body, with a darker, almost black back and wings. The undertail coverts are conspicuously white, often flicked during display. Some subspecies may show more greenish or bluish tones.

2. 2

   Beak shape

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

   Large, robust, conical bill, bright red in color. It extends into a prominent, fleshy red frontal shield that covers the forehead.

3. 3

   Eye color

   Iris color and any distinctive eye markings.

   Red to reddish-brown.

4. 4

   Leg color

   Leg and foot color.

   Long, sturdy legs and large feet are bright red to reddish-pink.

5. 5

   Distinguishing features

   Standout features that separate this species.

   The combination of large size, brilliant purple-blue plumage, prominent red bill and frontal shield, and white undertail coverts are diagnostic. Its long, unwebbed red toes are well-adapted for walking on floating vegetation.

6. 6

   Juvenile appearance

   How young birds differ from adults.

   Juveniles are duller overall, with a more brownish-grey plumage and a less vibrant purple wash. The bill and frontal shield are duller, often brownish-red, and the legs are a duller pinkish-brown. The white undertail is present but less prominent.

7. 7

   Seasonal changes

   Plumage variation between breeding and non-breeding seasons.

   No significant seasonal plumage changes. Breeding plumage is essentially the same as non-breeding plumage, though colors may appear more vibrant during the breeding season due to better feather condition.

8. 8

   Sexual dimorphism

   How males and females differ.

   Males are generally slightly larger and heavier than females, with a marginally larger frontal shield, but plumage is identical. Sexes are difficult to distinguish in the field without direct comparison or behavioral cues.

Key field marks

• Size and Shape. Look for a large, robust rail, about the size of a domestic chicken, with a somewhat hunched posture when walking.
• Plumage Color. Observe the striking deep purple-blue body plumage, which can appear almost black in poor light but shines iridescent purple in good light.
• Bill and Frontal Shield. Note the prominent, bright red, conical bill and the large, fleshy red frontal shield extending onto the forehead. This is a key identifier.
• Legs and Feet. Identify the long, sturdy, bright red legs and large, unwebbed red feet, often seen stepping on floating vegetation.
• Undertail Coverts. Look for the conspicuous white undertail coverts, which are often flicked up and down, especially when agitated or displaying.
• Behavior. Watch for its characteristic gait, high-stepping through reeds, or its reluctance to fly, preferring to run or swim into cover.
• Vocalizations. Listen for its loud, harsh, and often explosive 'krr-owk' or 'kek-kek-kek' calls, especially at dawn and dusk.

Explore the Purple Swamphen