Tara, Sea swallow, Black-billed tern, Kahawai bird, Southern tern, Swallow tail
The white-fronted tern (Sterna striata ), also known as tara, sea swallow, black-billed tern, kahawai bird, southern tern, or swallow tail, was first described by Johann Friedrich Gmelin in 1789. A medium-sized tern with an all-white body including underwing and forked tail, with grey hues on the over the upper side of the wing. In breeding adults a striking black cap covers the head from forehead to nape, leaving a small white strip above the black bill.
This is the most abundant tern in New Zealand. It can be observed feeding on shoaling fish along the entire coastline and many of the smaller outlying islands. Breeding occurs from October to January on rocky cliffs, offshore islands and along the coast where pairs will nest on shingle, sand, shell or rock. Flocks may contain hundreds of breeding pairs that will nest in close proximity to one another. Large numbers of juveniles and some adults migrate to the south-east coast of Australia and parts of Tasmania in the autumn, with small numbers establishing breeding colonies on Flinders and Cape Barren Islands in the Bass Strait.
Due to mammalian predators introduced to New Zealand, such as ferrets and stoats, the white-fronted tern has recently been given the New Zealand national conservation status of at risk/in decline.
The white-fronted tern is described as an average-sized bird. Its dimensions are 35–43 cm (14–17 in) in length, with a wingspan between 79 and 82 cm (31 and 32 in); the male weighs on average 130 g (4.6 oz). Females are marginally smaller, but this is difficult to determine when observing individuals in the wild.
Breaking down their monochromatic colouring, the white-fronted tern's lightest features are its all-white body, tail and underwing, with the upper side of the wings a light silvery grey hue. Through the breeding season there can be a faint pink coloration on the breast, but this is not always visible. The darkest features are the beak, black cap, eyes, feet and the shadowing on the outermost edge of the wingtips. The long ebony-like bill is slender and comes to a sharp point that dulls in colour at the tip. The crown is jet black, interrupted by a variably narrow white band between forehead and bill. The black cap continues over the crown and finishes at the nape. Inky black round eyes sit within the cap. The legs are stumpy with a deep burgundy black tone. A defining feature of the white-fronted tern is its forked tail, most recognisable when in flight and commonly drawing comparisons with a swallow's tail. In the breeding season, the outermost feathers of the tail lengthen, accentuating the already deep fork.
The black cap of non-breeding adults retreats towards the top of the forehead and above the eyes, while at the same time losing some of its intensity. Immature white-fronted terns are similar but have speckles of white through the cap. Along with a slight coloration on the wings and tail, which appear as a brownish cream.The juvenile plumage is very pronounced with flecks of light to dark grey and warm milky browns on the upper side of the wing, back, and mantle. the cap is incomplete and mottled, having dark black markings in front of and behind the eyes.
White-fronted terns are the most abundant tern in New Zealand and live along the entire coastline. In the North Island, there are significant populations from Auckland to the Bay of Plenty including the Coromandel Peninsula and they are widespread along the coast from Wellington, up towards Manawatu. In the South Island, they are a familiar sight in the Marlborough Sounds and along the east coast into Canterbury, Otago and Southland, where they can be seen year-round. Stewart Island also has flocks and breeding pairs throughout the year. Apart from the main coastline of New Zealand they also populate many of the smaller islands, with large numbers of breeding pairs observed on both the Chatham and the Auckland Islands. They seldom head inland, but there have been recordings of them in the Canterbury area, where they travel up the large braided rivers to feed and nest.
th large numbers of breeding pairs observed on both the Chatham and the Auckland Islands. They seldom head inland, but there have been recordings of them in the Canterbury area, where they travel up the large braided rivers to feed and nest.
White-fronted terns can be found in a variety of coastal habitats. With large flocks preferring coastal waters, harbours, bays and estuaries where they are content to live on either sand, shell or shingle ground. Occasionally living on the stony banks of Canterbury's braided rivers.
Not confined to just main coastal areas, white-fronted terns frequent coastal cliffs, offshore rock-stacks and small islands.White-fronted terns can also be found on human-made structures. as in Tauranga Harbour, where breeding pairs have taken up residence on disused concrete support structures.
White-fronted terns are carnivorous, fishing mainly in coastal waters. However, on the odd occasion they will head inland a few kilometres, following rivers and creeks to find food. Their diet is predominantly smaller fish such as smelt and pilchards while also including larval fish. Their preference when feeding at sea is for shoaling fish, that are being forced to the surface in large groups by kahawai and kingfish. When feeding, they will dive from 3 to 10 m above the surface into the shoal of fish, just entering the water in a very shallow dive. They can feed like this off the coast in huge flocks that are made up of hundreds to thousands of birds. They will feed alongside other birds such as gannets, shearwaters and gulls. When diving for fish, they are highly efficient. Their forked tails and adept flying skills allow for great movement above the water surface.
A recent audit published by the Department of Conservation has given S. striata a New Zealand national conservation status of "At risk, declining". While also gaining the regional conservation status of "Regionally Endangered" for the Wellington region.
