In this article, we will meet 10 incredible diving birds. We will also discuss their biology, behaviour and dive technique.
Birds that dive for fish
Several bird species feed on fish, however some dive to catch the fish underwater. Some of them are:
– Penguins;
– Pelicans;
– Gannets;
– Murres;
– Ospreys;
– Albatross;
– Cormorants;
– Loons;
– Puffins;
– American Dippers.
Penguins
Penguins are very popular diving bird species. They are carnivorous birds that feed on crustaceans, cephalopods, and mostly on fish. The differences in items of penguins’ diet are defined by their distribution, beak shape and size, hunting performance. Between the fish species that are penguins prey is:
– Anchovies;
– Sardines;
– Cod;
– Opal fish;
– Pilchards;
– Other small fish.
Penguins rely their diet exclusively on the ocean. Thus, they depend on the water quality and health of the marine environment. Penguins also adapt their foraging items according to the local conditions, in a manner to reduce the amount of energy spent to hunt. Thus, they can vary their diet throughout the year, according to the prey seasonality and availability.
These birds have incredible swimming capacities and include astonishing eyesight sense. Some penguins hunt in groups. Some of the penguin species can navigate for more than 800 kilometres from their nests to forage. Penguins swallow the prey whole. They also have a specialized digestive system to store food for the chicks when back to the nesting areas.
Penguins also have their wings modified into flippers. Thus, penguins are not able to fly, although, they are incredibly well-succeeded swimmers. Differently from foot-propelled diving birds, the penguins depend on their swimming abilities on flipper propulsion.
Penguins also use their flipper to communicate with conspecifics. From aggressive to courtship behaviours, the penguins can use the flippers to tap, slap, or wave to other penguins. In addition, the flippers also provide propulsion on land, while tobogganing.
The Emperor Penguin holds the world’s record for the deepest diving bird. They can dive to depths over 530 metres and hold their breath for more than 15 minutes.
Pelicans
Pelicans are also very popular birds, however, in coastal areas. They are famous due to the huge pouches under their beaks. However, only two Pelican species dive to catch food. They are the Brown Pelican and the Peruvian Pelican.
They observe and detect their prey from up to 20 metres above the surface of the water. Then, they plunge hitting the surface with the beak first. Their impact on the water surface normally stuns the prey. Thus, the prey is scooped up into the pouch.
These pelican species have many adaptations to resist the impacts on the water surface. Their behaviours are specialised to perform a posture to not injury their necks. They also have air sacs that function similarly to a cushion when hitting the surface.
The Brown Pelicans are almost exclusively piscivorous. Between their most common prey are:
– Mullets;
– Anchovies;
– Herrings.
The Brown Pelicans are distributed along the North American coast to Peruvian coasts, occupying also the Caribbean coastline. They have migration seasonal patterns.
Gannets
Gannets can dive from a distance of 30 metres above the water surface. Their speed can reach up to 100 kph when hitting the water surface. Similarly to the Pelicans, the Gannets are plunge-diving birds. They can catch prey from 12 to 15 metres deep.
These birds have a worldwide distribution. They can be found from the northern Atlantic to temperate waters around Africa and Australia.
These birds have specific adaptations to their hunting style, they are:
– Absence of external nostrils, which are located inside the mouth;
– Existence of air sacs in the face and on the chest;
– Eye position favourable to binocular vision.
Murres
Murres are birds classified as auks. However, they look very similar to a penguin referring to their colour pattern. They also swim underwater to capture their fish prey. These birds normally feed on cod, herrings, and other similar fish.
Murres are found in the northern oceanic areas. There are only two species of Murres. One of them, the Thick-billed Murre, holds the Guinness record for deepest dive from the flight. This species can reach up to 210 metres deep and dive around 20 consecutive times. Thick-billed Murres can hold their breath for up to 4 minutes.
Ospreys
Ospreys are also known as Sea Hawks, River Hawks, and Fish Hawks. By these popular names, we can identify they are a fish-eating bird species. Their diet is based almost exclusively on fish. Although it is extremely rare, Ospreys can also feed on small reptiles, birds, and rodents.
These birds are classified as cosmopolitan, due to their worldwide distribution. They typically inhabit areas close to bodies of water, where they can get their food from. They can dive through the water surface from up to 30 metres high,
Ospreys also have some adaptations to dive-hunting strategy. They have very long, sharp claws in reversible toes with specialised gripping feet, closable nostrils, and dense and oily plumage.
Albatrosses
Albatrosses are very large sea birds. They can grow up to 3.7 metres in wingspan. Albatross species occupy the northern and the southern oceans. Their diet is very wide, they feed on cephalopods, fish, and crustaceans.
Albatrosses live in huge colonies and have ritualised dances during the breeding season. There are 22 recognised albatross species. The Light-mantled Albatross can dive and reach depths of 12.5 metres. Although, few Albatross species only dive to up to 1 metre deep.
Cormorants
The Cormorants are classified as 40 different species. They are usually coastal birds and are cosmopolitan, as they can be found all around the world.
They are very efficient swimmers and get to very high speeds. Cormorants use their webbed feet as propellers. They dive to feed on fish and water snakes.
The Imperial Cormorant can dive up to 46 metres deep in only 40 seconds. After diving, the individual can chase its prey on the sea bottom. Imperial Cormorants can stay in underwear for more than two and a half minutes.
Loons
Loons are physically similar to a duck, in body plan and size. Loons and ducks are classified under the same taxonomic family. There are only five species of Loons. They are distributed in freshwater environments of North America and North Eurasia. The most peculiar Loon is the Red-throated Loon.
The Red-throated Loons are easily identifiable animals. They have a long greyish-black beak that curves slightly upwards. They have grey plumage with a darker back and head. Their distinctive throat has a very strong red plumage, as suggested by their name.
These Loons are piscivorous. Thus, they rely their diet on fish species. However, they can also feed on other animals, such as molluscs, crustaceans and insects. They can dive more than 70 metres down when chasing their prey and stay underwater for up to 5 minutes.
Puffins
Puffins are also auks. They have unique colourful beaks, which give them the popular name of Sea Clowns or Sea Parrots. There are only three species of Puffins. They inhabit offshore islands and isolated areas of the northern coasts. Puffins usually live in huge breeding colonies.
The Atlantic Puffin has extraordinary diving talents. Atlantic Puffins use their wings to dive, thus, their flying abilities are limited. They can dive up to 60 metres down.
American Dippers
The American Dippers are very unique birds. They are classified as songbirds, however, they can catch food underwater. Although they can eat other animals, they prey on small fish.
The American Dippers have adaptations that favour their dive behaviour. They have a translucid extra eyelid and scales closing their nostrils. In addition, they use the wings as propellers to swim.
Threats to Piscivorous Birds
Once piscivorous fish rely on the water to obtain food, they are extremely vulnerable to pollution and waste discharge. In addition to these issues, there is also the problem with discarded fishing gear, which can become dangerous to these animals if not done properly.
Fishing lines and nets are also threats to Piscivorous fish. As they can become tangled. Another pollution threat is plastic waste. They can be lured by plastic debris (bags, balloons, bottle caps) and ingest these instead of fish.
Overfishing can also become a threat to several Piscivorous bird species, if the fish stock is low, some bird species may starve to death.
Conclusion
In this article, we met 10 incredible diving birds. We also discussed their biology, behaviour, foraging technique, and some adaptations to diving. We also highlighted what are the main threats to this specialised group of birds.
If you have any thoughts or doubts, feel free to drop us in a comment below!
Frequently Asked Questions (FAQs): Birds that dive for fish
What are diving birds called?
Diving birds can also be called “pursuit divers”. They receive this name due to the foraging habit of chasing their prey. Some birds which are classified as pursuit divers are the Gannets and pelicans.
Which bird can swim but not fly?
The penguins belong to a bird group that can only swim. Their wings are modified into flippers, thus they are very successful swimmers and can slide on icy lands. However, they are not able to fly. They can also use their flippers to communicate with conspecifics, by tapping, slapping and waving them around.
Where do Cormorant birds live?
Cormorants are cosmopolitan organisms. This means that they can live almost in any aquatic environment with worldwide distribution. They can inhabit coastal areas, lakes, and riverine regions.
What bird can dive the deepest?
The Emperor Penguin can reach up to 530 metres depth during a dive. They can dive for up to 20 minutes and use this time to seek food.
Can penguins fly?
No, Penguins are not capable of flying. Although they have wing structures, these are modified into flippers. Thus, they are very incredible and efficient swimmers. They are capable o swimming at speeds of up to 40 kilometres per hour.
Why do birds dive into the water?
Birds dive into the water to catch their food. This is classified as foraging behaviour. They can dive from the flight, as the Ospreys, or from floating on the water surface.
References
Mayntz, M. 2020. Types of Seabirds. What Are Pelagic Birds? https://www.thespruce.com/types-of-seabirds-387306
Mayntz, M. 2021. Brown Pelican. Pelecanus occidentalis. https://www.thespruce.com/brown-pelican-5069783
10 Cool Facts about Diving Birds like why Gannets don’t break their necks. https://pqspb.org/bpqpoq/10-cool-facts-about-diving-birds-like-why-gannets-dont-break-their-necks/
Blackman, S. How do diving gannets avoid breaking their necks? https://www.discoverwildlife.com/animal-facts/birds/how-do-diving-gannets-avoid-breaking-their-necks/
Avian Report. 18 Frequently Asked Questions About Ospreys. https://avianreport.com/18-frequently-asked-questions-about-ospreys/
