There’s a possibility to see 5 Shag species at Travis Wetland with one of those species having two distinct colour morphs and a variety of variable plumage in between.
This guide should allow you to id any of the species seen at Travis and probably any Shag seen in the Canterbury area.
There is much debate about the genetic placement of Shags in NZ.
The names used in this article are in accordance with those used in “Checklist of the birds of New Zealand” 4th edition 2010.
Black Shag (Phalacrocorax carbo novaehollandiae)
Status: Native, Naturally Uncommon
Identification: This is the largest of NZ’s shags. As it’s name suggests it’s a black shag with browner wings and tail.
It has white patches on it’s cheeks and throat and yellow facial skin that turns orange below the eye during breeding season.
Breeding adults also have white patches on their thighs, white filoplumes on the neck and crown and a small crest on the neck.
Immature similar to adults though more mottled brown and have no white face patch.
Bill: Grey, long solid with a hook at the end.
Breeding: April – January
Distribution: Widespread throughout NZ, but adults tend to stay close totheir nesting areas.
Behavior: Generally solitary.
Similar Species: The little black shag is smaller and has a finer bill and no yellow facial skin.
NZ Birds Online url: http://nzbirdsonline.org.nz/species/black-shag
Little Black Shag (Phalacrocorax sulcirostris)
Status: Native, Naturally Uncommon
Identification: A small black shag that in sunlight has a green sheen on their upper wing.
The wing feathers have a scalloped pattern to them.
They have a short tail.
Immatures are similar but brownish.
Bill: Dark grey / black, Long slender.
Breeding: November – April. Have a look round Horseshoe Lake for the only local breeding colony.
Distribution: Common in the North Is but rare in the South Is.
Behavior: A gregarious species, in the North Is can be seen in flocks of a 100 or more. At Travis a group of 20 would be considered large.
Similar Species: Juvenile little shags can be all black, but they have stubby yellow bills and longer tails.
NZ Birds Online url: http://nzbirdsonline.org.nz/species/little-black-shag
Pied Shag (Phalacrocorax varius varius)
Status: Native, Nationally Vulnerable
Identification: A large shag. Glossy black above from the top of it’s head down it’s back and wings and tail. Underparts and face white.
Skin in front of the eye yellow and pink below the bill. Immature
Bill: Grey, Long with a hook.
Eye: Green with a blue / grey eye ring
Breeding: All year. One of the closest colonies to Travis would be the oxidation ponds.
Distribution: Generally a coastal shag occupying coastal waters, harbours and estuaries.
Behavior: Generally a solitary forager but will roost in nesting colonys and favoured places at night.
Similar Species: There’s not really anything that can be confused with the pied shag. The pied morph of the little shag is way smaller.
NZ Birds Online url: http://nzbirdsonline.org.nz/species/pied-shag
Little Shag (Phalacrocorax melanoleucos brevirostris)
Status: Native, Not Threatened
Identification: This is the smallest shag and also the one that can cause the most confusion.
They have a highly variable plumage ranging from all black to pied.
One of the best ways to identify these shags is to look at the bill in adults it is yellow and short and stubby unlike the Little black that is long fine and dark.
They have yellow facial skin.
Their tail is long compared to the Little black.
Bill: Yellow in adults dark in juv., Short stubby
Breeding: August – May
Distribution: Widespread NZ wide in both coastal and freshwater habitats.
Behavior: Generally solitary when feeding.
Similar Species: black, little pied and pied shags all have plumages that are similar to either the pied or black morphs of the little shag.
However little shags are significantly smaller and have a stubby yellow bill.
NZ Birds Online url: http://nzbirdsonline.org.nz/species/little-shag
Spotted Shag (Strictocarbo punctatus punctatus)
Status: Endemic, Not Threatened
Identification: This shag would be the most unlikely one you would find at Travis but they have been seen there.
They are a medium sized grey brown shag with as their name implies small black spots on their brown wings and back.
They have a white stripe up the side of their neck to above their eye.
Breeding birds have a double crest on their head.
Immature is paler and lacks the white stripe and spots.
Bill: Brown, Long slender hooked.
Eye: Dark brown with a blue eye ring
Breeding: All year, locally September – November. Nearest colony to Travis is Godley Heads.
Distribution: They are mainly found around the South Is in coastal waters and estuaries.
Behavior: Gregarious when in colonies.
Similar Species: There isn’t really any similar species to this slender pale shag in mainland NZ.
NZ Birds Online url: http://www.nzbirdsonline.org.nz/species/spotted-shag