River-Lab 5 Guide Manual
EASTERN BELTED KINGFISHER (Megaceryle alcyon)
Kingfishers contribute to the health
and productivity of a basin system in several
important ways.
These include the
kingfisher’s positive effect on the
populations of fish in their territoryboth
through territorial protection and by
predation. They also help control some
problem species and enrich the system as
kingfisher eggs or young become food for
other animals.
All the benefits of toning fish populations are made possible through kingfisher
predation. The kingfisher’s diet is primarily small to medium-size fish. Kingfishers keep
the numbers of these fish from becoming too large for the amount of food that their
habitat can produce for them. Thus, kingfisher predation protects the fish in their
territory from weakness due to limited food and resulting disease and possible loss of the
species from that area. Only the most alert and swift fish escape the kingfisher’s keen
eyes and well-aimed dives. Eliminating the less fit not only strengthens the more fit with
more available food; it increases the chances for the more fit to reproduce successfully
and pass on their traits.
Kingfishers also prevent a body of water from being overfished by diving birds.
This fiercely territorial bird drives others of its own species and even larger diving birds
away from its chosen area. Its vigilance prevents overfishing on small to medium-size
fish.
Kingfishers also eat mice, frogs, crabs, crayfish, salamanders, and insects. They
will even eat fruit in times of necessity (as when the water is too rough for fishing).
Their consumption of mice and plant-eating land insects is especially beneficial to the
basin system. Such animals reproduce so quickly that their unchecked population growth
would create an unhealthy imbalance of life in a basin system. Although kingfishers
sometimes eat small young trout, they also benefit trout by consuming organisms such as
water beetles and minnows that prey on trout spawn and young fry.
The kingfisher (10–13 inches long) is a large-headed, grayish-blue diving bird
with a double-pointed crest, a dark, spear-like bill (about 3 inches long), a short tail, and
small feet. Its plumage is waterproof. Its white collar and chest are separated by a band
of blue-gray feathers. The female has an additional band of cinnamon feathers on her
belly and sides. A kingfisher’s loud, harsh, rattling call is often heard before the bird is
seen. In flight, its wings move in an irregular pattern of long and briefer strokes,
suggesting a readiness for quick maneuvers.
5GM – 33
© 1999 Mill River Wetland Committee, Inc.
River-Lab 5 Guide Manual
EASTERN BELTED KINGFISHER, cont’d
Kingfishers can be found wherever the fishing is goodalong streams and near
ponds, lakes, and estuaries. This solitary “king” of the fishing birds is a master diver.
From a high perch it plunges into the water headfirst, and with deadly accurate aim,
scoops up a small fish in its bill. It can dive into shallow water, pulling out of the dive as
it grabs the fish. The kingfisher usually takes its catch to a nearby rock, where it beats
the fish to death and then flips it into its bill headfirst, swallowing it in a single gulp.
Once mature, kingfishers pair for life. The male must first impress a female with
his fishing ability and stamina. He may have to present her with fish after fish over the
course of more than a day before she accepts him by picking up his offering. His skills
and persistence demonstrate his ability to help feed their young and defend their territory
and nest, so that kingfishers will continue to make their invaluable contributions to their
basin systems.
The male and female will use their feet and beaks to dig a nesting tunnel into the
side of a river bank. The average tunnel is three to seven feet deep, but may be as long as
fifteen feet. In the nesting area at the tunnel’s end the female lays five to eight glossy
white eggs (rarely 10 to 14), which will hatch in sixteen to twenty-one days. The chances
of all the offspring surviving are low. Even the daring efforts of the kingfisher parents
cannot always succeed in luring away predators such as raccoons, rats, and snakes.
These animals can dig down into or enter the nest tunnel to prey on the eggs or young.
The young that survive will leave the nest four weeks after hatching. After a season of
schooling by their parents they will be chased from the parents’ territory. They will
move on to find territories of their own, where they can carry on the benefits of
kingfisher contributions to their basin system.
© 1999 Mill River Wetland Committee, Inc.
5GM - 34