Chilean Skua vs Brown Skua

In short

Chilean Skua and Brown Skua can be challenging to differentiate, especially when immature. The rusty tinge on the underwing and underparts of the Chilean Skua is a key identifier, whereas the Brown Skua lacks this coloration. Additionally, Chilean Skua often exhibits longer central tail feathers and a dark cap.

Identification tips

1. Look for the rusty underwing and underparts in Chilean Skua. 2. Check for longer central tail feathers and a dark cap in Chilean Skua. 3. Observe behavior: Chilean Skua may be seen nesting in colonies, unlike the more solitary Brown Skua. 4. Consider location and season: Chilean Skua is more likely in Chile and Argentina, while Brown Skua is found in subantarctic regions.

Size

Both species are large, robust skuas with similar sizes.

Plumage

Chilean Skua typically has a strong rusty tinge on the underwing linings and sometimes throughout the underparts, strongest on the throat. Brown Skua lacks this rusty coloration and is generally more uniformly brown.

Behaviour

Chilean Skua is unique among southern skuas for nesting in colonies and catching a significant portion of its food in a non-piratic manner. Brown Skua is more solitary and known for its aggressive, piratic feeding behavior.

Habitat

Chilean Skua nests in southernmost Chile and Argentina and migrates to Brazil and Peru in the non-breeding season. Brown Skua is found in subantarctic regions and is not as migratory.