The world of kingfishers
Geetha Iyer
“Talk less, Fisher Blue! Keep your kindly wishes
Fly off and preen yourself with the bones of fishes!”
– Tom Bombadil (Adventures of Tom Bombadil by J R R Tolkein)
We take certain creatures around us for granted and hardly pay any attention to them. Like the kingfisher, for example. You might ask what is there to know about them. Do you know that there are 90 different types of kingfishers found worldwide? Or that there are 12 different kinds to be found in India? A pair of pied kingfishers have been around my house for the past two months and their chatter has been quite interesting. Their presence made me look at the world of kingfishers more closely and I came to know so much that I have now started looking out for them and the time spent has been nothing but pure pleasure. I am sharing some of these learnings with you in this piece. It’s not possible to describe all the 12 species found in India in this limited space and so I have chosen to dwell upon the more commonly seen ones.
Kingfisher facts
Ask anyone and they are bound to tell you that kingfishers only eat fish and do so by diving into the water. But not so. Kingfishers are generalized feeders who will eat anything from insects such as grasshoppers, beetles, termites, and even snakes, lizards or other small vertebrates. Basically they will eat any creature they can catch and kill. Surprising, isn’t it? Names – common or scientific – can be quite misleading. There are three families of kingfishers. The small kingfishers belong to Family Alcedinidae. The pied kingfishers to Family Cerylidae. The species belonging to these two families are experts at diving and feeding on fishes. The third family Halcyonidae comprise the large tree kingfishers which occupy a wide range of habitats – from rain forests to woodlands to scrublands and some even our backyards – and feed on a wide variety of prey. The Australian kookaburra is a tree kingfisher.
The blue colour of the bird’s feathers are not due to the presence of special pigments in them but is the result of the layers in feathers reflecting only the blue wavelengths of light. Compare the image of the collared kingfisher given here with one on page 51. Observe the next time you see the bird and you will find that the degree of blue that you will see in the kingfisher changes depending on the position you are observing it from and the extent of illumination falling on the bird. Thus as the bird flies the colours will appear indigo, or royal blue, or other shades of blue to sometimes even shades of green.
The kingfishers generally make cavities to nest. Most dig holes on the earthen banks of rivers or streams or man-made ditches. Some may use tree holes and a few forest species even use arboreal nests of termites. But their nests are dirty and smelly with the bony remains of fish or prey scattered around.
Alcedo atthis or common kingfisher
This bird with its iridescent plumage is not easily spotted due to its shy nature. It is 17 cm long and weighs around 35-40 gms. The males have an orangish body, whereas the females are more brownish. The food is mostly fish or aquatic invertebrates. It waits on a perch near the water and dives when a fish is spotted. Kingfishers have a very sharp eyesight. They use both monocular (while on land or airborne) and binocular vision (in water). They are also thought to have excellent colour vision. They are skilled divers who can compensate for refraction and reflection when hunting for prey underwater and can also judge the depth at which the prey is under water. Observe the bird and you will see it bob its head several times before plunging to grab its prey. Does this action somehow help it to judge the distance or the dive it must take?
This kingfisher can dive into the water at a maximum speed of close to 90 km/h and has the ability to grab its prey from up to a depth of 60 cm. Having taken the fish, it is then able to instantly turn and using its wings like oars surface out of the water beak first. It has been calculated that if the kingfisher is not to lose its prey, then this entire operation has to take place within three seconds. So the kingfisher’s diving is quite precisely timed.
The eyes remain open underwater as they are protected by a transparent nictitating membrane. Once out of the water it flies back to its perch, adjusts the fish to hold it near the tail and begins to beat it on the perch several times, till the fish dies! Then the fish is swallowed head first. Pellets consisting of fish bones and other undigested parts are regurgitated occasionally every day.
Ceryle rudis or pied kingfisher
This bird is one of the most advanced and specialized divers amongst kingfishers. Its preying technique is specially adapted to feeding fish but it is also known to take frogs, molluscs, or insects when fish are scarce. A black and white kingfisher, it is 25 cm long and weighs anywhere between 68-100 gms. Its hunting strategy is unique and not noticeable in other kingfisher species. It will select a perch that is above or near the banks of a water body for surveying its prey. Once it spots a fish it will hover above the water at a fairly good height, remaining stationery and then when it is sure of its prey, dives vertically down, bill first to get the fish. It has a bony plate which is joined to the prefrontal bone of the skull that acts like a sliding screen for the eye when the bird plunges into the water. The hovering action is something to be seen to be believed. The last time I saw it hover I timed it – it was up there with its body vertical, bill pointing downwards and hovering away for a good 15 seconds. Unfortunately for the bird, at the end of the 15 seconds it had to fly back to its perch, the electric wire that went directly over the waterbody. The temple tank in front of my house is loaded with fish, the pied kingfishers therefore are not always disappointed. They are capable of catching two fish in one dive and swallow fish that are less than 2 cm long while still in air. I read an account of their behaviour where it appears that having managed to catch a tilapia – a kind of fish – 9 cms long, one kingfisher took it to the perch and walloped it nearly 100 times before consuming it.
This kingfisher species fishes not only over fresh water but dives for fish in estuaries and oceans. Its breeding habits are interesting too. Cooperative breeding is noticed where the breeding pair is helped by other birds that may be unrelated to them or even their own offspring whose breeding attempts may have failed. At night they roost in groups, sometimes hundreds of them perched close to each other on branches of trees.
Halcyon smyrnensis or white throated kingfisher
This is the most commonly spotted kingfisher which is a generalist feeder; in fact feeds more frequently on insects and frogs or lizards than on fish. This bird is mainly found in Asia with a very small population in Europe. This medium sized bird is 28 cm long and has a white throat and breast, dark chocolate brown head and underparts with its wings and tail a lovely turquoise blue. It has a large bill which – if you closely observe – is different from the pied and common fishers and more suited to picking up insects and other creatures. They will feed on any creature they can catch and kill. Centipedes, scorpions, rats, mice, medium-sized snakes and even bird nestlings are hunted and eaten. As a group they may eat a wide range of food, but each bird is known to have its preferences and feed only on certain kinds of creatures.
The kingfishers that I now describe are not that commonly seen and are found in specific habitats.
Halcyon capensis or stork billed Kingfisher As their name suggests a large bill red in colour is a striking part of this solitary kingfisher that is found mostly near water bodies that are at the edge of forests or near the coasts. A kingfisher which is 37 cms long, of which their beak is nearly 18-20 cm long. Highly territorial they are known to chase away even larger birds like storks and eagles from their breeding and feeding areas. They hunt near water bodies where there are suitable perches. They are distributed over Central, East, and South India.
Halcyon pileata or black capped kingfisher
Like the other two species described above, this too is a tree kingfisher and is quite widely distributed in tropical Asia. The wings and the back of the body are blue, almost a shade of purplish blue, while the head and the shoulders are black. White near the throat, the under parts are sometimes rufous (reddish brown) coloured. Like other tree kingfishers this feeds more on insects and occasionally on fish. Usually found near coasts and mangroves it’s a bird that feels disturbed at the slightest presence of humans.
Ceyx erithacus or oriental dwarf kingfisher
Smallest of the kingfishers found in India, this bird is endemic to Southeast Asia. Around 13 cms long, it usually prefers streams inside dense and shaded forests. Certain communities in Borneo consider this bird to be a bad omen and unlucky. Warriors going to the battlefield believe that they may not return alive if they see this bird. A group of birdwatchers and I spent quite some time near a stream inside Thattekad forests hoping to spot this beautiful bird. Their nest is a horizontal tunnel and both the parents help incubate the eggs. Geckos, snails, dragonflies, and crickets are part of the diet of the young chicks.
Todiramphus chloris or the collared kingfisher
This bird gets its common name due to the presence of a white collar around the neck. Its body colour varies from blue to green above and white below. There are minor variations in colour amongst different races. Females are greener than the males. This bird is most common near coasts and mangrove swamps, although it can be spotted in gardens near grasslands, woodlands, or even hills on islands.
Blue eared, brown winged, ruddy winged and crested kingfishers are some of the other less commonly met with kingfisher species from India. Of these, the first two species are classified as “near threatened” by the IUCN (International Union for Conservation of Nature), largely due to habitat destruction. The brown winged kingfisher is the largest one from India.
For the classroom
Activity 1: Feather colour
This will require kingfisher feathers. If you have one or two then try this experiment: Stand with your back to the light and examine the feather in reflected light. Note the colour. Repeat the experiment by changing the position of the feather in your hand and note the colours seen. Repeat the experiment by altering the degree of illumination.
Investigate and find out the effect by changing the angle at which the light strikes the feather.
What are your findings? What parameters are important and what are not responsible for the kingfisher feathers appearing in different shades of blue or sometimes bluish green?
Activity 2: Beaks and type of food
Is there a difference in the structure between the beaks of kingfishers that dive to catch fish and those that hunt for insects, lizards, frogs, or small mammals? Scientist have found that some kingfishers have the bill somewhat flattened dorsoventrally while some have dagger-like bills flattened laterally. Observe to find out the relationship between the beak and the type of kingfisher and its food preferences.
Activity 3a: Fun with physics – revise time – distance – speed
If a kingfisher dives from a height of 7.0 m with an average speed of 4.00 m/s how long does it take for the kingfisher to reach the water?
A kingfisher dives with an average speed of 4.6 m/s for 1.4 s. What was the height of the dive?
Activity 3b: Prediction activity
Read this article carefully and then predict the kind of adaptations to be found in a kingfisher for catching fish. You do not have to restrict yourself to what is here but can use your own ideas and thoughts as to what a bird like the kingfisher needs for survival.
Now check from library resources and find out how many of your predictions were correct. Some references are given in this article.
One hint to start you off:
The fish the kingfisher wants to catch is actually in a different position than it would visually appear from the sky due to the difference of the degrees of reflection of light in water and air. How does it deal with this problem?
Activity 4: English – Story writing – Develop referencing and writing skills
The scientific names for the kingfishers namely Ceyx, Alcedo, Halcyon, and the family names are drawn from Greek mythology. An outline of the story may be given and students asked to write the story in their own words.
Greek mythology – Ceyx – son of the Morning Star and husband of Alcyone – daughter of Aeolus, the guardian of the winds. Happily married – boasted that they were like Zeus and Hera – Angered those Gods – create storm – Ceyx in sea dies – Alcyone drowns herself – Compassionate god revives them as birds said to be kingfishers – Guardian of wind Aeolus – Halcyon days when no storm occurs – allows coastal kingfishers to breed.
References
1. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1772125/– For information related to adaptations for vision. (Read for Physics activity)
2. http://www.arkive.org/collared-kingfi sher/todiramphus-chloris/– Descriptions of different kingfishers are available on this site
3. http://carolinabirds.org/HTML/AS_Corac_Kingfi sher.htm – Images and brief descriptions of kingfishers from Asia
4. http://orientalbirdimages.org/birdimages.php?action=birdgroup&Bird_Group_ID=106 – Images of kingfishers from India
5. https://archive.org/stream/monographofalced00shar#page/n7/mode/2up – Monograph on kingfishers of Family Alcedinidae Kingfishers, Bee-eaters and Rollers By C. Hilary Fry, Kathie Fry – Available online for reading
The author is a consultant for science and environment education. She can be reached at scopsowl@gmail.com.
