The black-legged kittiwake (Rissa tridactyla) is a seabird species in the gull family Laridae.

This species was first described by Carl Linnaeus in his landmark 1758 10th edition of Systema Naturae as Larus tridactylus.

The black-legged kittiwake was formally described in 1758 by the Swedish naturalist Carl Linnaeus in the tenth edition of his Systema Naturae.

Occasional individuals have pinky-grey to reddish legs, inviting confusion with red-legged kittiwake.

The inside of their mouth is also a characteristic feature of the species due to its rich red colour.

A second-year juvenile resembles a hatch-year regarding the plumage, though the bill is no longer solid black but instead has a greenish colour.

[15] A third-year bird will also exhibit a small zone of bright yellow/orange at the base of its mostly greenish bill.

It is only at four years old that the bill will reach an overall colour of bright yellow and complete its mature plumage.

Before and during copulation, the female will often call by making a series of short high pitched "squeak".

Unlike larger gulls, their flight is light with the wings beating in fast strokes.

Kittiwakes are colonial nesters that form monogamous pairs and exhibit biparental care, meaning that both take part in nest building, incubation and chick rearing.

Kittiwake pairs both participate in building the nest in which the female will lay their eggs.

[25]Building the nest in order to welcome their fragile eggs is a tedious task and requires time and energy.

The parents begin with a layer of mud and grass in order to form a platform that will cushion and help to isolate the eggs from the cold ground.

[25] The egg colour is variable, ranging from white, brownish to turquoise with dark brown speckles.

[18] Once the eggs are laid, the parents will take turns and incubate their clutch for an average period of 27 days.

The downy young of kittiwakes are white, since they have no need of camouflage from predators, and do not wander from the nest like Larus gulls for obvious safety reasons.

[9] Instances of kittiwakes following whales are also common since they benefit from the fish fragments expelled by these huge marine mammals.

[9] Fishers and commercial fishing boats are also the frequent witnesses of big groups of kittiwakes, often mixed with other gull species and terns, hovering around their ship in order to benefit from the scraps rejected in their sewage water or thrown overboard.

[8] Due to the pelagic lifestyle of kittiwakes, they rarely interact with humans on the land, other than occasional sight near the ocean's coast.

[citation needed] The increasing nesting population has created challenges, as the gulls produce ammonia-smelling faeces, discolouring buildings and streets, as well as the noise pollution generated by their constant 'kittiwake' calling.

One such initiative involves the establishment of "Kittiwake hotels", artificial bird cliff structures built to encourage nesting away from urban facades.

[24] The hotels have, along with mitigation measures preventing nesting on the city's structures, had success in attracting kittiwakes without having a negative impact on breeding.

[1] The last IUCN Red List report in 2017, the species was moved from "least concern" to a "vulnerable" status on a global scale.

Their tendency to hang around them in hope of a good meal can lead to entanglements in fishing gear, often resulting in death by drowning.

[37] Studies show that sandeels and many copepods populations are being negatively impacted due to increasing sea surface temperature.

[36] Such effect on marine species can have tremendous impact on breeding kittiwakes which rely almost exclusively on pelagic fishes, making food more scarce in a time of high energetic needs.

[37] There are still no global conservation plans for the black-legged kittiwake though the species is closely monitored for population trends shifts.

However, the black-legged kittiwake is protected under the Migratory Bird Treaty Act of 1918 that has been ratified by the US, Canada, Mexico, Russia and Japan.