The Eastern Kingbird is among the easiest of American birds to identify, being gray
to black above with a clear white breast, and a tail with a prominent white band across
its
tip. Kingbirds are well known for their aggressive nature. The Latin word Tyrannus
means "tyrant, despot or king", referring to their aggressive defense of nests
and mates,
and their domination of other birds. During the breeding season they can often be seen
chasing other birds, many of them much larger, like crows and even hawks. One
observer noted one attacking a low flying airplane. It is easy to attribute human
emotions to these birds, but most of their behavior makes good biological sense. They
are simply trying to eliminate potential predators or competitors. Interestingly enough
other birds, such as American Robins, may nest within inches of Eastern Kingbird nests
and, as a result, come under an umbrella of protection.
Eastern Kingbirds are found throughout the state during the breeding season. It is a
neotropical migrant that winters mostly in Amazonia. Neotropical (New World)
migratory birds breed during our summer in temperate North America, migrating north
each spring from wintering areas, then fly back south to spend the bulk of the year in
Mexico, Central or South America, or the Caribbean.
This bird is found during summer in open areas from grasslands to forest edge. Oddly
enough it can also be found in vacant lots of towns and cites. As an edge species, this is
a bird that has enjoyed an expanding range and increasing numbers as the eastern forests
were cleared. Distribution in Eastern North America in precolonial times may have been
limited to swamps, marshes, edges of lakes and rivers, and open, disturbed environments
like forest blowdowns and forest fires.
Breeding Bird Survey (BBS) data suggest that the continental population has not changed
significantly between 1966-1991. However, abundance in the east has declined
significantly from 1982-1991 (-1.5%/yr), while increasing in the central and western
regions. Many states in the Southeast, including North Carolina, show declining
population trends since 1982, but with persistence this bird in our state can still be
seen
in many open fields with scattered woody vegetation for perches.
Males and females are very similar in appearance. No other North American flycatcher
is entirely black above and white below. There is a noticeable white tip to its black
tail.
The red to orange, small crown patch can be hard to see. The sexes can often be
distinguished by their characteristic postures and the shape of the head. Males tend to
perch rather upright in posture and often maintain a slight "crest" by raising
contour
feathers of the crown. Females normally perch in a more horizontal plane and have a
head more roundish in appearance. Their bill is wide at the base and slightly hooked at
the tip.
During migration, Eastern Kingbirds can be seen alone or in small groups in just
about any habitat. They migrate by day, often stopping during midday hours to feed and
at dark to rest. Breeding pairs are usually monogamous and actively defend the nesting
area. If both survive to the following breeding season, they usually re-mate and reuse
former territories. Eastern Kingbirds are opportunists willing to claim any open site the
promises good hunting and safety for their nest, eggs and young.
Nests are compact, well-constructed cups of grasses, weed stems and oddities like bits
of paper or cloth usually less than 20 feet from the ground. Where available, Spanish
moss is often favored in nest construction. Nests are built by females and they do all the
incubation chores. Both adults feed the young while they are in the nest, and often
continue to do so for up to four weeks after young leave the nest. Eastern Kingbirds
usually eject Brown-headed Cowbird eggs.
The poorly developed voice box places Eastern Kingbirds among the suboscines, or
primitive songbirds. Song-learning has not been demonstrated in suboscines so it is
doubtful that kingbirds learn vocalizations. Numerous calls exist and none would be
described as musical. The calls are high-pitched and tend to be short and explosive,
sounding a bit like the bird is sputtering. A good bit of the calling by males during the
breeding season takes place from prominent perches, such as trees, snags, fence posts or
utility wires.
Interestingly enough, few of the more than 100 flying insects that have been
documented as prey are "flies". About 32% percent of the diet is usually
composed of
bees, wasps, flying ants and their relatives, with up to 25% made up of beetles.
Kingbirds will also take such odd prey as lizards, frogs, snails and even fish.
Fruits make up a significant portion of the diet during the nonbreeding season. Another
common name of this bird is "bee martin", a name associated with its habit of
occasionally focusing on bees from commercial hives as an easy food source. A century
ago, young boys earned "bounty" money by killing kingbirds around beeyards. This
food choice by kingbirds is a rather rare recent option, since honeybees are Old World
imports that accompanied early colonists.
Eastern Kingbirds breed throughout the eastern United States and are also abundant west
of the Mississippi River. They range well into parts of Canada, actually having the most
extensive breeding range of all North American flycatchers. Kingbirds winter entirely in
South America, mainly in Columbia and Ecuador, but other areas as well. They spend
much of their time during winter in flocks along forest edges and other open areas.
Life span not particularly long, but some documented living at least seven years.
Since these birds frequent wood edges, river groves, farms, shelter belts, orchards and
roadsides, they often come into contact with people. Although they are sometimes
claimed to be a serious predator on honeybees, there is little evidence for this. There
habit of eating lots of fruits while in migration and during winter make it a valuable
plant
disperser. Possible conflicts occur relating to pesticides, especially in orchards. An
important cause of mortality in North America may be collisions with automobiles, since
kingbirds often nest and/or forage near roads. Declines in the number of small farms
over the last three decades has probably affected kingbirds negatively due to loss of open
space.
The Birds of North America, No. 253, Eastern Kingbird by M. Murphy, 1996
Neotropical Migratory Birds by DeGraaf and Rappole, 1995, Cornell Press