This beautiful, medium sized NON-PIGEON may be a familiar sight if you hang around the ocean here in the Pacific Northwest. With its striking jet-black plumage, bright-white upperwing patches, and scarlet-red feet, the Pigeon Guillemot is hard to overlook. This species of Alcid (web-footed marine diving bird) spends its time diving along rocky nearshore areas in search of food, where they use their powerful wings to essentially fly underwater for nearly two and a half minutes at a time!

Get to Know the PIGU

Appearance

This bird species is seasonally dimorphic, meaning the Pigeon Guillemot has two morphs, or “plumages,” depending on the time of year; however, males and females are indistinguishable from each other!

Pigeon Guillemot’s display their iconic “breeding plumage” during the summer months (March-September), when they appear black to dark-brown overall and display a prominent white patch on their wing that has a single small black line running through it.

The “nonbreeding plumage” of the Pigeon Guillemot is seen throughout the winter months (October-March), when they replace their dark feathers with a more blended black and white counter-shaded appearance.

Regardless of plumage state, the little red feet are always a great way to dissolve any uncertainty when attempting to identify this bird.

Juvenile Pigeon Guillemot’s are born between May and July and are covered in thick brown-black down feathers. These warm down feathers are soon lost as a juvenile undergoes a pre-juvenile moult and enters its “juvenile plumage.” The juvenile plumage often overlaps heavily with an adult’s non-breeding plumage and normally can’t be differentiated in the field with 100% confidence. A juvenile Pigeon Guillemot will moult its juvenile plumage the following year, between March and April. At this point, it will adopt the signature breeding adult plumage!

Distribution

Diet and Foraging

Pigeon Guillemot’s are on a strictly seafood diet!
All their meals consist of invertebrates and marine fishes, such as Sculpins, Gunnels, Pricklebacks, Sand lances, Herring, Crabs, Shrimps (with the occasional polychaetes, gastropods, or bivalves).

A large proportion of a Pigeon Guillemot’s diet consists of fish compared to invertebrates, likely a result of larger lipid deposits in the vertebrates, which provide more energy compared to most invertebrates. A 1972 study (Koelink) suggests breeding Pigeon Guillemot’s need roughly 90 grams of fish daily to maintain their weight; that’s 20% of their body weight a day! (Adult PIGU= ~485 grams)

Pigeon Guillemot’s are incredibly capable swimmers and divers. They keep their wings partially open and flap to propel themselves. Most species of alcids use their feet only as rudders in the water, but Pigeon Guillemot’s use their feet for both steering and propulsion!

Although there are no accessible videos of Pigeon Guillemot’s swimming viewed from blow, most members of the Alcidae family swimming in a similar manner. The videos below provide a closer look at the underwater swimming style of alcids!

Pigeon Guillemot’s typically dive directly to the seabed, where they search through vegetation or rocky nooks in search of prey. They probe around with their bill in a zig-zag manner while kicking their webbed feet to fight their buoyancy, which is constantly forces them upwards.

If the prey is snack-sized, it’s likely consumed while underwater and foraging continues; however, if the prey is a larger fish or crab, it’ll be brought back to the surface and manipulated in the bill. When manipulating food at the surface, it’s common for gulls to attempt piracy and get an easy meal!

Breeding and Nesting

Pigeon Guillemot’s are monogamous, meaning they only have one mate at any given time, and they are monogamous for life!
Breeding season begins between April to June (varies geographically), when older males arrive at breeding sites weeks to months before breeding females or inexperienced males. Older, more experienced males arrive early to secure the most optimal nest site for themselves and their mate. Colonies typically disperse by August to September.

This species of alcid is quite adaptive in its nest site use. Typically, quality nest sites are rocky cliffs with crevices and cavities that provide shelter. However, Pigeon Guillemots will also nest in old burrows, tree cavities, driftwood piles, and abandoned structures and wooden nest boxes.

Research Spotlight

Impacts of Non-Native Predators

Many species of seabirds, including the Pigeon Guillemot, have large breeding colonies adapted to nest and raise nestlings on isolated islands, where terrestrial predators are limited or absent. Unfortunately, introduced species such as raccoons, mink, rats and cats pose a significant threat to a seabird breeding colonies that have evolved to breed in relative isolation of terrestrials predators. Their presence increases the predation pressure on eggs, nestlings, and even adult birds. Additionally, persistent predators may discourage future breeding pairs from returning to a specific site (Towns et al., 2011). However, the removal of these introduced predators may play an important role in rebuilding colony success by decreasing predation pressure. This is very important for supporting ecologically significant species such as Pigeon Guillemot’s.

A 2026 paper by Stark et al., Seabird population responses after the removal of an introduced predator, studied the impacts of removing a non-native predator, the American mink (Neogale vison), from the Naked Island Archipelago in Prince William Sound in Alaska.

The study observed a breeding colony of Pigeon Guillemot’s that had experienced a 95% decline in local population between 1979 and 2008, attributed to the introduced mink population. Following a mink-removal program in 2014, nestling survival increased from an average of 51% (1989-2008), all the way to 88% in 2017! This large increase in nestling survival in just three years demonstrates the significant impact predation pressure can have on seabird colonies.

The removal of mink also impacted the nesting site selection of the Pigeon Guillemot’s. While the predators were present, the PIGU’s increased their reliance on more predator-proof site locations such as cliff faces. Following the removal of the predators, the seabirds began colonizing previously avoided nesting locations. The occupied nesting locations increased from 20% in 2008 to 48% in 2018! The expansion to previously uninhabited nest sites underlines how non-native predators impact site selection on seabirds and how their removal can allow for a greater capacity and larger overall success of a colony.

The researchers had determined that reproductive success was attributed to an increase abundance of Pigeon Guillemots. The estimated local population abundance increased by ~326% between 2014-2023! The authors suggested that neighboring island colonies immigrated to the Naked Island Archipelago, contributing to a substantial recovery of the islands breeding success in light of decreased predation risk.

Ultimately, the study highlights the importance of managing introduced predators in known seabird conservation areas. By preventing foreign predators from establishing, the colony will face less predation pressure, allowing more juvenile and adult success. Furthermore, removing already-established non-native predators can drastically increase the productivity and size of existing colonies. Although predator prevention and removal can’t solve all problems seabird populations face, it is a large step forward for conservation!

Refrences

IN-TEXT CITATION ON THEIR WAY!!! (sorry lol)

Clowater, J. S., & Burger, A. E. (1994). The diving behaviour of Pigeon Guillemots (Cepphus columba) off southern Vancouver Island. Canadian Journal of Zoology, 72, 863–872. https://doi.org/10.1139/z94-117

Koelink, A. F. (1972). Bioenergetics of growth in the Pigeon Guillemot, Cepphus columba [Master’s thesis, University of British Columbia].

Thoresen, A. C. (1984). Notes on diving times and behavior of Pigeon Guillemots and Marbled Murrelets off Rosario Head, Washington. Western Birds, 15(1), 33–37.

Towns, D. R., Byrd, G. V., Jones, H. P., Rauzon, M. J., Russell, J. C., & Wilcox, C. (2011). Impacts of introduced predators on seabirds. In C. P. H. Mulder, W. B. Anderson, D. R. Towns, & P. J. Bellingham (Eds.), Seabird islands: Ecology, invasion, and restoration (pp. 56–90). Oxford University Press. https://doi.org/10.1093/acprof:osobl/9780199735693.003.0003

Vermeer, K., Morgan, K. H., & Smith, G. E. J. (1993). Colony attendance of Pigeon Guillemots as related to tide height and time of day. Colonial Waterbirds, 16, 1–8.

Ewins, P. J. (2020). Pigeon Guillemot (Cepphus columba), version 1.0. In A. F. Poole & F. B. Gill (Eds.), Birds of the World. Cornell Lab of Ornithology. https://doi.org/10.2173/bow.piggui.01

Pilgrim, N. G., & Gaston, A. J. (2020, October). Analysis of Pigeon Guillemot prey based on photographs from Laskeek Bay, Haida Gwaii. Laskeek Bay Conservation Society. PDF

Stark, S. B., Roby, D. D., Irons, D. B., Kaler, R. S. A., & Osnas, E. E. (2026). Seabird population responses after the removal of an introduced predator. The Journal of Wildlife Management, 90(7), Article e70242. https://doi.org/10.1002/jwmg.70242

Thoresen, A. C. (1989). Diving times and behavior of Pigeon Guillemots and Marbled Murrelets off Rosario Head, Washington. Western Birds, 20, 33–37.