Campbell shag

The Campbell shag (Leucocarbo campbelli), also known as the Campbell Island shag, is a species of bird in the family Phalacrocoracidae. It is endemic to Campbell Island. Its natural habitats are open seas and rocky shores. It is a medium-sized bird, around 63 cm in length, with a wingspan of 105 cm, weighing between 1.6 – 2 kg. They only breed on Campbell Island and forage within 10 km of the island. Its unique, looped head and elongated beak allow to easily feed on shellfish and marine invertebrates. This is done through foraging dive cycles of high speed and efficiency.

Some taxonomic authorities, including the International Ornithologists' Union, place this species in the genus Leucocarbo. Others place it in the genus Phalacrocorax.

Since L. campbelli evolved on Campbell Island and can only be found there, it is named for this region, 700 km south of New Zealand. The closest relative of the Campbell Island shag is the Auckland Island shag, which, similarly, is endemic to New Zealand and only lives in the Auckland Islands. They are both part of the Leucocarbo genus, also known as the blue-eyed shags, and are grouped together with four other New Zealand shag species to form the "pink-footed shag" group. The blue-eyed shags are named for their blue eye rings and lids, but five of the Leucocarbo species have eye rings and lids that are not blue. Furthermore, there are shag and cormorant species outside of this genus that have blue eye rings.

Blue eyed shag species dispersed from South America during the Pliocene or Early Pleistocene due to cycles of glaciation. Many made their way to New Zealand and speciation occurred due to the geographic isolation on the various islands in the area.

Biologists have long differed in their phylogenetic organisation of cormorants and shags. The species have been grouped together by bone structure, behaviour, and, more recently, by genetic analysis. A 2000 study on cormorant and shag phylogeny found that foot colour might be an indicator of a close genetic relationship in these birds.

The Campbell Island shag is a marine bird with black and white plumage and pink feet. They have a white chin, underparts and wing patches, with a black neck, throat and head. Their black feathers have a metallic greenish blue sheen. In breeding season, adult birds have a head crest, a yellow line above the bill's gape, and facial skin and throat pouch that can range from purple to orange. Juveniles and non-breeding adults have browner plumage instead of all black, as well as duller skin and throat pouches. Nestlings are born naked with black skin. Campbell Island shags have dark brown irises and purplish eye rings. Their bills are greyish brown, and pinkish orange at the tip with a yellow patch at the base.

The Campbell Island shag can only be found on the Campbell Islands and is the only shag present. They can usually be found in enclosed areas like harbours and rocky beaches, but have been known to rest on coastal landforms after foraging in the sea. They tend to stay within 10 km of the main island and remain in shallower waters. A 1975 census counted 1300 nests on the Island, with an estimated 2000 breeding pairs and 8000 total individuals. Different estimates have considered this an over- or underestimation.

Campbell Island shags only breed on Campbell Island and surrounding coastal landforms. Their breeding season lasts from November to February, in enclosed spaces near the water, like caves, alcoves, covered ledges, and beneath overhanging rocks, where they build flat bowls of twigs as nests. They nest in colonies during their breeding season, with up to 150 pairs and 2 light blue eggs per pair.