{"id":7788,"date":"2026-10-09T04:36:51","date_gmt":"2026-10-09T04:36:51","guid":{"rendered":"https:\/\/wordpress.viu.ca\/biol325\/?p=7788"},"modified":"2026-10-09T05:15:21","modified_gmt":"2026-10-09T05:15:21","slug":"its-a-bird-its-a-boat-no-its-a-pied-billed-grebe","status":"publish","type":"post","link":"https:\/\/wordpress.viu.ca\/biol325\/2026\/10\/09\/its-a-bird-its-a-boat-no-its-a-pied-billed-grebe\/","title":{"rendered":"It’s a bird, it’s a boat– no, it’s a Pied-billed Grebe!"},"content":{"rendered":"\n

Meet The Pied-billed Grebe<\/h2>\n\n\n\n
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Order: Podicipediformes<\/a><\/div>\n\n\n\n
Family: Podicipedidae<\/em><\/a><\/div>\n\n\n\n
Scientific Name: Podilymbus podiceps<\/em><\/a><\/div>\n<\/div>\n\n\n\n

Pied-billed grebes (Podilymbus podiceps<\/em>) are fun-sized waterbirds; their chunky bodies are smaller than a crow (Corvus brachyrhynchos<\/em>) but larger than a robin (Turdus migratorius<\/em>) (Cornell University, 2026)<\/a>. At first glance, they can appear to lack a tail because it is so small, and they get their name from the dark, vertical stripe on their bill during breeding plumage (Cornell University, 2026). In winter plumage, they are mainly brownish, with a thick bill and short neck (Cornell, 2026). It could be speculated that they \u201clack a tail\u201d because the pied-billed grebe is not a bird at all, but a submarine. When they want to go below the water\u2019s surface, they squeeze air out of their feathers and internal air sacs to hunt more easily underwater (Sundstrom, 2018)<\/a>. Essentially, they fold like a lawn chair and drop like an anchor.<\/p>\n\n\n

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Pied-billed grebe sinking, by McGowan, 2020<\/a><\/figcaption><\/figure>\n<\/div>\n\n\n

These submarine birds are also highly adaptable. One example of this is where they can be found: in water. They really are not picky, living in any slow body of water ranging from fresh to brackish, as long as adequate vegetation and prey are available (Cornell University, 2026). This can be ponds, lakes, estuaries, and everything in between. <\/p>\n\n\n\n

This easy-to-please outlook also translates to their diet of anything that happens to be in their vicinity. As opportunistic predators, they will eat a variety of things from crustaceans to fish and frogs (Cornell University, 2026). Further, in 2016, Scholz witnessed a pied-billed grebe (PBG) swallowing a live common yellowthroat (Geothlypis trichas<\/em>) like a pill that was fighting for its life (Scholz & Hayes, 2017)<\/a>.<\/p>\n\n\n\n

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Check out this PBG initiating sink mode: SUBMARINE<\/mark><\/strong><\/a><\/div>\n<\/div>\n\n\n
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Pied-billed grebe carrying young, by Muller, 2020<\/a><\/figcaption><\/figure>\n<\/div>\n\n\n

PBGs aren’t just foodies; they are wonderful parents. They build nests on floating vegetation for their broods of two to 10 eggs, with both parents expressing parental care (Cornell University, 2026). When their chicks hatch, all bright-eyed and downy-feathered, they climb onto their parent\u2019s back for their first week of life (Cornell University, 2026). When the parents need to dive with their fluffy children, they throw them under their wing like a textbook when your bag and hands are full. Occasionally, chicks will pop out from under a clamped wing, but no parent is perfect.
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Pied-billed grebe distribution, by NatureServe, 2026<\/a><\/figcaption><\/figure>\n<\/div>\n\n\n

These birds can be found from Northern Canada to southern South America, claiming the title of grebe with the widest distribution (Muller & Storer, 2020)<\/a>. Their annual range goes as far north as Central America, with their breeding range extending further. This wide distribution, variety of habitats, as well as their generalist diet, are all contributing factors to why PBGs are listed as low concern for their conservation status on the IUCN list (Cornell University, 2026). A low status on the IUCN means that the species are at a low risk of extinction, but there could still be local declines in certain areas. PBGs are actually considered special concern\/threated\/endangered in New York, Connecticut, Massachusetts, New Jersey, and Vermont, USA as of 2024 (Hayden<\/a>). This is mainly attributed to habitat degradation and loss (Hayden, 2024). <\/p>\n\n\n

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Figure by NatureServe, 2024<\/figcaption><\/figure>\n<\/div>\n\n\n

My First Encounter<\/h1>\n\n\n\n

I first saw a PBG and knew I was witnessing one, about five years ago. I was walking alongside a pond on Prince Edward Island (PEI) in May when I heard a cacophony of monkeys howling from the water. You can imagine my surprise when I looked over and saw a PBG instead. It was alone, hooting and making a series of \u201ckuk-kuk-kuk\u201d noises. When I approached to confirm it was indeed a PBG, and not PEI\u2019s first monkey, it sank below the water and stared at me with nothing but its eyes above the surface. <\/p>\n\n\n\n

Pied-billed grebe song, by Elliot et al., 2026<\/a><\/figcaption><\/figure>\n\n\n
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Pied-billed grebe in non-breeding plumage, by Hausler, 2020<\/a><\/figcaption><\/figure>\n<\/div>\n\n\n

You can often hear PBGs when they are courting or when they are defending their territory. The S.S. PBG is an attack vessel, preferring a solitary lifestyle, which explains why I only saw one. They will chase and attack any bird invading their territory, including other PBGs, especially during breeding season, which ranges from early spring to mid-autumn (Muller & Storer, 2020). As most other submarines, they will often attack from below, causing many birds to flee when a PBG dives towards them (Muller & Storer, 2020).
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Check out this submarine strike: PBG vs Ruddy duck (Oxyura jamaicensis)<\/em><\/mark><\/strong><\/a><\/div>\n<\/div>\n\n\n\n

Pied-billed Grebe Interactions and Effects<\/h1>\n\n\n\n

Why Are Alligators So Cranky?<\/h2>\n\n\n\n
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“My Mama says that alligators are ornery because they got all them teeth and no toothbrush.”<\/strong> \u2014 Bobby Boucher, The Waterboy (1998)<\/em><\/p>\n<\/blockquote>\n<\/blockquote>\n<\/blockquote>\n<\/blockquote>\n<\/blockquote>\n\n\n

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Figure of Romer et al.’s observations, by O’Carroll, 2025<\/a><\/figcaption><\/figure>\n<\/div>\n\n\n

Bobby and I will have to disagree. I think it is possible that the American alligator (Alligator mississippiensis<\/em>) is ornery because it’s being followed around by PBGs. Romer et al. conducted a study on the \u2018Coordinated movement of multiple pied-billed grebes in association with an American alligator<\/a>\u2019. One day in January, they set off to survey Palm Beach, Florida. During their study, they observed two PBGs following an alligator at a very close distance for around 10 minutes. Maintaining the same distance from the alligator throughout the observation, the birds would dive repeatedly behind the large predator. The dives were very consistent with PBG foraging dives, but the researchers did not confirm any prey capture. <\/p>\n\n\n\n

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Check out their video: NUCLEAR SUBMARINES<\/mark><\/a><\/div>\n<\/div>\n\n\n\n

The authors suggest that this study may document a previously unrecognized nuclear follower foraging association between the two species. In this association, the nuclear species (in this case, the alligator) flushes prey while the follower eats what has been disturbed (Somaweera & Somaweera, 2021)<\/a>. This interaction can be seen in many other animals, like when crows follow wolves, anticipating scavenging the leftovers of a hunt. The interesting part of this dynamic, to me, is that alligators are known predators of PBGs. At one point in this survey, one bird even fled from the alligator, highlighting their predator-prey dynamic. If I were the alligator, I would not be impressed to have my lunch following me around. 
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Build It, and They Will Come<\/h2>\n\n\n\n

Everything in nature is connected, so it is not a surprise that when grebes (Podicipedidae<\/em>), like PBGs, build floating nests, it ripples through the community. From 2010 to 2017, Hayes et al. studied vertebrates other than grebes using the nests of western grebes (Aechmophorus occidentalis<\/em>) in California.<\/a> They noted that 47 vertebrate species utilized these nests, from fish to mammals. Western grebe nests can be two to three feet in diameter, whereas PBGs are only 38 cm in diameter (Cornell University, 2026<\/a>; Hammerson, 1995<\/a>). This small size could potentially limit the types of species that can utilize PBG nests, but there has still been evidence of use.<\/p>\n\n\n

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Pied-billed grebe adult and juvenile on floating nest, by Cronin, 2017<\/a><\/figcaption><\/figure>\n<\/div>\n\n\n

In fact, Hayes et al. note that marsh wrens (Cistothorus palustris<\/em>) have been known to use PBG nests. They would search the nests for insects within the vegetation (Chamberlin, 1977)<\/a>. When they weren\u2019t getting their fill, they were also seen using these nests for their mating displays (Deusing, 1939)<\/a>. The males would use the nest as their stage and put on a show by flapping and fluttering their wings. <\/p>\n\n\n\n

Deusing also watched a turtle try to climb onto a PBG nest, possibly intending to use it to soak up the sun, but unfortunately for the turtle, the attack submarine was on the nest and denied its entry with a quick bill strike (1939).<\/p>\n\n\n\n

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Teach a Bird to Fish…<\/h2>\n\n\n\n

Brown looked at floodplains, flooding, and salmon-rearing habitat in British Columbia<\/a>, and found an interesting association with PBGs. When considering juvenile coho salmon (Oncorhynchus kisutch<\/em>), the two most active predators in Washington, USA were belted kingfishers (Megaceryle alcyon<\/em>) and juvenile PBGs (Brown, 2002). Around 93% of the belted kingfisher’s coho prey were at depths of less than 0.6m, where the PBGs caught them from deeper below. <\/p>\n\n\n

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Coho salmon range map, by Pacific Salmon Atlas, 2005<\/a><\/figcaption><\/figure>\n<\/div>\n\n
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Pied-billed grebe range map, by NatureServe, 2026<\/figcaption><\/figure>\n<\/div>\n\n\n

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I would like to note that the coho spawning distribution (green) overlaps very closely with the divide between PBG annual (purple) and breeding (pink) distribution. Coho return to spawn as early as October, and eggs are deposited from November to January (Wild Salmon Center, n.d.<\/a>). Eggs will incubate for 1.5 to four months before emerging, where they will live in freshwater for 12-18 months (Wild Salmon Center, n.d.). During this time, they go from alevins to fry to parr before becoming smolts and heading towards the sea (Wild Salmon Center, n.d.). These small stages need slow-moving streams, which happen to be one of the habitat types utilized by PBGs. <\/p>\n\n\n\n

PBG chicks start to hunt for their own prey around June to July; at this time, any coho spawned in January may be at their fry stage (Hugh, 2016<\/a>). It cannot be said that young PBGs intentionally seek out fry and parr, but it would be a very interesting idea for future research and study to explore this predator-prey relationship in depth. It is also important to note two things: <\/p>\n\n\n\n

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The two map ranges suggest a geographic overlap, but cannot guarantee they are using the same waters<\/a><\/div>\n\n\n\n
All timelines involving coho depend on water temperature and other environmental fluctuations (Wild Salmon Center, n.d.)<\/a><\/div>\n<\/div>\n\n\n\n

A Summary of Your New Friend: The Pied-billed Grebe<\/h1>\n\n\n\n

This relatively solitary grump of a bird can often be found singing in sluggish water full of vegetation, like marshes (Sundstrom, 2018). If a PBG is spooked or disturbed, it will sink low into the water; this allows them to hide from perceived threats, as well as hunt prey and sneak up on unsuspecting individuals. <\/p>\n\n\n\n

PBGs are secretive by nature; they migrate at night, take to the long vegetation during breeding, and even cover up eggs with vegetation when leaving the nest (Sundstrom, 2018). <\/p>\n\n\n\n

As is any vessel of worth, PBGs are highly efficient. They can build nests in one to five days, egg incubation is complete in 23 to 27 days, and once they are hatched, the chicks are precocial and ready to swim and catch a ride on their parent(s) (Sundstrom, 2018). <\/p>\n\n\n\n

Their generalist diet and ability to use a variety of habitats may help PBGs persist across a wide range, but they are still threatened by habitat loss and degradation. If their wetland habitats continue to be damaged or lost, local populations may decline. Theoretically, a PBG could occupy any habitat where water, food, vegetation, and other necessary environmental conditions are available. However, competition, predation, and other ecological factors restrict where it can successfully live and reproduce. This difference between the habitats a species could potentially occupy and those it actually uses is the difference between its theoretical and realized niche. We must protect their realized niche to keep our attack submarines thriving.<\/p>\n\n\n\n

Pied-billed Grebe Fun Facts<\/h1>\n\n\n
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Pied-billed grebe, by Tuscon Wildlife, 2023<\/a><\/figcaption><\/figure>\n<\/div>\n\n\n
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PBGs migrate at night<\/a><\/div>\n\n\n\n
Both parents incubate the eggs<\/a><\/div>\n\n\n\n
PBGs don’t have webbed feet! They have flappy toes<\/a><\/div>\n<\/div>\n\n\n\n
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PBGs eat their own feathers: they form a somewhat sieve-like structure in their stomach! Ideally, this helps prevent possibly harmful food fragments from passing into the intestine; they get coughed out as pellets with the feathers<\/a><\/div>\n<\/div>\n\n\n\n
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