Alcidae Auks, Murres, and Puffins
Version: 1.0 — Published March 4, 2020
Introduction
These exclusively marine, wing-propelled divers are as agile at sea as they are clumsy on land, and they are fast, direct fliers once they become airborne. The young of different species leave the nest at very different ages depending on the relative safety and food supply near the nest, and those that leave the nest at a young age can undergo the majority of their development at sea, far from land, under the watchful care of a lone parent. Alcids have an enchanting diversity of courtship signals, with facial plumes, large and brightly colored bills, and even olfactory cues, yet in none of the species are males and females differentially adorned.
Habitat
Alcids nest on rocky Arctic and north temperate shorelines. All of them are totally marine in the non-breeding season.
Diet and Foraging
Alcids feed on marine animals, from zooplankton to squid and small fish, seized in the bill during underwater dives.
Breeding
Alcids are monogamous with biparental care. Most species nest colonially, although some, like the Brachyramphus murrelets, are solitary nesters. Most alcids nest on the ground, often in a cavity or rock crevice. Some species, including puffins and some murrelets and auklets, dig their own nest burrows. Others, like the murres, nest on steep cliffs with narrow ledges, where the near-conical shape of their eggs appears to protect them from rolling off. The nest itself is usually minimal or nonexistent. Marbled Murrelets Brachyramphus marmoratus and the closely related Long-billed Murrelet B. perdix often nest on wide horizontal boughs high in old-growth conifers. There they build an atypically substantial nest of sticks and moss. Alcids lay only 1 or 2 eggs. Both male and female are active in nest construction, and both sexes incubate and care for the young. The chicks hatch after an incubation period that varies among species from 27 to 46 days. Though the chicks are precocial, those of some species leave the nest very early and others remain in the nest until they fledge. The timing of nest-leaving appears to have much to do with the distribution of available food. Chicks that stay in the nest until fledging are fed from food sources relatively near the nest; in species that leave the nest early they are essentially escorted to the food supply by a parent and fed there, on rich local food, until they become independent. Thus, within a day or two of hatching, Kittlitz’s Murrelets Brachyramphus brevirostris can trek several kilometers down through talus slopes to enter the water with a parent and swim far offshore to be fed and attended. Similarly, three-week-old murre chicks flutter on half-grown wings down from their cliff nests, crashing on the rocky shore and bouncing and crawling into the water, to make a similar trip up to 50 km offshore to finish development attended by a parent.
Conservation Status
Many alcid species are declining because of habitat destruction, introduction of mammalian predators to breeding islands, and diminished food resources resulting from overfishing and climate change. Seven species (29%) are currently at risk (2 NT, 3 VU, 2 EN). Within the last 200 years the Great Auk Pinguinus impennis, a large, flightless alcid of the North Atlantic, was hunted to extinction for its meat, feathers, fat, and oil.
Systematics History
Alcidae is part of the suborder Lari of the order Charadriiformes. A recent phylogeny based on morphological characters found Alcidae to be sister to a group that contains skuas and terns (Livezey & Zusi 2007), and another refined that hypothesis further to suggest a possible sister relationship with Stercorariidae (Mayr 2011). Many studies based on DNA sequence data consistently place the alcids sister only to Stercorariidae, forming a group that is in turn sister to Laridae (Ericson et al. 2003a, Paton & Baker 2006, Baker et al. 2007a, Fain & Houde 2007, Pereira & Baker 2010). Within Alcidae, there appear to be two clades, recognized here as subfamilies Aethiinae and Alcinae (Friesen et al. 1996, Pereira & Baker 2008).
Conservation Status
Least Concern |
60%
|
---|---|
Near Threatened |
12%
|
Vulnerable |
16%
|
Endangered |
8%
|
Critically Endangered |
0%
|
Extinct in the Wild |
0%
|
Extinct |
4%
|
Not Evaluated |
0%
|
Data Deficient |
0%
|
Unknown |
0%
|
Data provided by IUCN (2023) Red List. More information