Species: Cerorhinca monocerata

Rhinoceros Auklet
Species

    A large, chunky, seabird with a large head and bill and a short thick neck; upperparts are blackish brown, with paler sides, neck, and throat; belly white, grading into dark breast; adults in breeding plumage (acquired in winter) have two prominent white plume streaks on each side of the head (indistinct in basic plumage) and a yellow, upward-directed horn at the base of the orange or yellowish bill (horn is absent in nonbreeding plumage); immatures lack the horn and the white head plumes, and the bill is dusky and the eyes are darker; average length 38 cm (NGS 1983).

    Science Review:

    Articles:

    A tale of two islands

    Were the islands half full of auklets or were they half empty? One scientist offers an insider's view of a newly published study of two Pacific seabird colonies. He says having good data for the paper was key, but finding the right title didn't hurt.

    Adult breeding rhinoceros auklet (Cerorhinca monocerata). Photo: Frostnip (CC BY-NC 2.0)
    Whir! Chunk! Capture! The art of tagging rhinoceros auklets on Protection Island

    Where do Protection Island's rhinoceros auklets go to find their food? Scientists hope GPS tags will offer new insight into the bird's still mysterious foraging behavior. Biologist and science writer Eric Wagner reports from the field. 

    A single sea bird floating on the water with several thin silvery fish in its beak.
    A health check for seabirds

    Scientists are still trying to understand what caused the deaths of thousands of rhinoceros auklets in the Salish Sea in 2016. Some studies point to disease as a central factor in that incident and potentially other large seabird die-offs along the coast. That is prompting a deeper look at what makes these birds sick, and how local populations are faring. We followed a group of researchers as they gave a health checkup to a breeding colony of rhinoceros auklets on Protection Island.

    Rhinoceros auklets near Protection Island. Photo: Peter Hodum
    Nights in the lives of the rhinoceros auklets of Protection Island

    More than 70 percent of the seabird population of Puget Sound nests on a single island in the Strait of Juan de Fuca. That includes a massive colony of rhinoceros auklets that has drawn the interest of scientists and birders alike. Our writer Eric Wagner visited the island this summer and reports on a long-term study of the auklets that is revealing new information about the health of seabirds in the Salish Sea. 

    Breeding adult Rhinoceros Auklet flying low above the water. San Juan Islands, WA - July, 2016. Photo: Mick Thompson (CC BY-NC 2.0) https://www.flickr.com/photos/mickthompson/28777858956
    Citizens now the leading cause of toxics in Puget Sound

    New research presented at the 2014 Salish Sea Ecosystem Conference shows that some of the greatest dangers to Puget Sound marine life come from our common, everyday activities. These pervasive sources of pollution are so woven into our lives that they are almost invisible to us, but it’s becoming impossible to ignore their effects.

    Stormwater flowing into catch basin carries contaminants to our waterways. Photo: Ben McLeod (CC BY-NC-SA 2.0) https://www.flickr.com/photos/benmcleod/420158390
    2013 Puget Sound Marine Waters Overview

    A report from the Puget Sound Ecosystem Monitoring Program provides an overview of 2013 marine water quality and conditions in Puget Sound from comprehensive monitoring and observing programs.

    2013 Puget Sound Marine Waters Overview
    Marine and terrestrial bird indicators for Puget Sound

    A December 2013 report identifies marine and terrestrial bird species for use as indicators within the Puget Sound Partnership's "Vital Signs" for ecosystem health. 

    Black Scoter (Melanitta nigra). Photo by Dave Menke, U.S. Fish and Wildlife Service.
    2012 Puget Sound Marine Waters Overview

    The Puget Sound Marine Waters 2012 Overview from the Puget Sound Ecosystem Monitoring Program synthesizes conditions measured in 2012 and has been expanded to include observations on seabirds that rely on marine waters. Read an excerpt below, or download the full report.

    Paper: A model approach for estimating colony size, trends and habitat associations of burrow-nesting seabirds

    A paper in the May 2013 issue of The Condor [115(2):356–365, 2013] describes a repeatable and statistically robust approach to monitoring burrow nesting seabirds in the Salish Sea and the California Current that can be applied at single- or multi-island scales. The approach can be applied to both relatively common and important members of the seabird community like the Rhinoceros Auklet and to species of conservation concern like the Tufted Puffin.

    Rhinoceros Auklet carrying sand lance. Photo by Peter Hodum.
    Marine birds

    More than 70 bird species regularly utilize Puget Sound during some or all stages of their life histories, but only a portion of these are actively being investigated.

    Brandt's cormorant (Phalacrocorax penicillatus). Photo by Finley and Bohlman, courtesy U.S. Fish and Wildlife Service
    Protection Island

    Protection Island, a National Wildlife Refuge in the Strait of Juan de Fuca, provides important habitat for seabirds and marine mammals.

    Protection Island. Image courtesy of NOAA.
    Sounds of rhinoceros auklets and chick

    Audio recordings of rhinoceros auklets on Protection Island.

    Rhinoceros Auklet carrying sandlances. Photo by Peter Hodum.
    Kingdom
    Animalia
    Phylum
    Craniata
    Class

    Aves

    Order

    Charadriiformes

    Family

    Alcidae

    Genus

    Cerorhinca

    Classification
    Other Global Common Names
    Alca Rinoceronte - Macareux rhinocéros
    Informal Taxonomy
    Animals, Vertebrates - Birds - Other Birds
    Formal Taxonomy
    Animalia - Craniata - Aves - Charadriiformes - Alcidae - Cerorhinca

    A large, chunky, seabird with a large head and bill and a short thick neck; upperparts are blackish brown, with paler sides, neck, and throat; belly white, grading into dark breast; adults in breeding plumage (acquired in winter) have two prominent white plume streaks on each side of the head (indistinct in basic plumage) and a yellow, upward-directed horn at the base of the orange or yellowish bill (horn is absent in nonbreeding plumage); immatures lack the horn and the white head plumes, and the bill is dusky and the eyes are darker; average length 38 cm (NGS 1983).

    Short General Description
    A small seabird (auklet).
    Migration
    false - true - true - Auklets from British Columbia probably winter off the coasts of California and Oregon.
    Non-migrant
    false
    Locally Migrant
    true
    Food Comments
    Eats small fishes, crustaceans, squid. Dives under water after prey. Chick diet varies among years and localities; predominant species may include Pacific sandlance, Pacific herring, night smelt, Pacific saury, rockfish, anchovy, juvenile salmon, etc. Off British Columbia, epipelagic schooling fishes were the prey most often delivered to chicks; most foraging occurred in the upper 10 m, though most birds sometimes dove to 20-60 m; usually foraged in water considerably deeper than 15 m (Burger et al. 1993).
    Reproduction Comments
    Egg are laid May-June in Alaska and British Columbia, late April-June in Washington. Clutch size is 1. Incubation lasts 39-52 days (average 46), by both sexes. Nestling period lasts 40-70 days (reported means: 52-55 days) (Harfenist 1995, Auk 112:60-66). One or both parents may feed the chick each night. Young independent while they complete development at sea after fledging. Appears to retain same mate in subsequent years. Breeding success of about 50-60% may be typical (Johnsgard 1987). Nesting density sometimes >1 nest burrow per sq m.
    Ecology Comments
    Usually seen alone or in small groups on the ocean. <br><br>Introduced arctic fox (predator) may explain absence throughout almost all of Aleutian chain. Commonly preyed on by great horned owl on Protection Island, Washington (Hayward et al., 1993, Auk 110:133-135).
    Length
    38
    Weight
    520
    NatureServe Global Status Rank
    G5
    Global Status Last Reviewed
    1996-11-27
    Global Status Last Changed
    1996-11-27
    Other Status

    LC - Least concern

    Conservation Status Map
    <img src="http://www.natureserve.org/explorer/servlet/GetMapGif?CA.BC=S4&US.AK=S4&US.CA=S3&US.OR=S2&US.WA=S4" alt="Conservation Status Map" style="width: 475px; height: auto;" />
    Global Range
    H - >2,500,000 square km (greater than 1,000,000 square miles) - H - BREEDING: islands along Pacific coast of North America, south-coastal and southeastern Alaska south to central California; eastern Asia from southern Sakhalin and southern Kurile islands south to Korea, Japan. NON-BREEDING: off Pacific coast from southern British Columbia south to Baja California; also in Asia (AOU 1983).
    Global Range Code
    H
    Global Range Description
    >2,500,000 square km (greater than 1,000,000 square miles)
    ELEMENT_GLOBAL.2.106458