As their name suggests, bee-eaters predominantly eat flying insects, especially bees and wasps, which are caught on the wing from an open perch.
They form colonies, nesting in burrows tunnelled into vertical sandy banks, often at the side of a river or in flat ground.
Bee-eaters may be killed by raptors; their nests are raided by rodents, weasels, martens and snakes, and they can carry various parasites.
Some species are adversely affected by human activity or habitat loss, but none meet the International Union for Conservation of Nature's vulnerability criteria, and all are therefore evaluated as "least concern".
[10][11] The number of species in each family is taken from the list maintained by Frank Gill, Pamela C. Rasmussen and David Donsker on behalf of the International Ornithological Committee (IOC).
[5][14] Nyctyornis Merops bullockoides M. bulocki Meropogon forsteni Merops breweri M. gularis M. muelleri M. hirundineus M. oreobates M. pusillus M. variegatus M. boehmi M. albicollis M. nubicus M. malimbicus M. orientalis M. leschenaulti M. viridis M. philippinus M. apiaster M. ornatus M. persicus M. superciliosus The bee-eater family contains the following species.
[16][17][18] A 2007 nuclear and mitochondrial DNA study produced a possible phylogenetic tree, although the position of the purple-bearded bee-eater seems anomalous, in that it appears amongst Merops species.
Shorter, rounder wings are found on species that are sedentary and make typically short foraging flights in denser forests and reed-beds.
The bill can bite strongly, particularly at the tip, and it is used as a pair of forceps with which to snatch insects from the air and crush smaller prey.
[5] The plumage of the family is generally very bright and in most species is mainly or at least partially green, although the two carmine bee-eaters are primarily rose-coloured.
Their requirements are simply an elevated perch from which to watch for prey and a suitable ground substrate in which to dig their breeding burrow.
[21] The most unusual migration is that of the southern carmine bee-eater, which has a three-stage migration; after breeding in a band between Angola and Mozambique it moves south to Botswana, Namibia and South Africa before moving north to its main wintering grounds in northern Angola, Congo and Tanzania.
[22] The bee-eaters are diurnal, although a few species may migrate during the night if the terrain en route is unsuitable for stopping or if they are crossing the sea.
The colony's daily routine is to emerge from the nesting holes or roosting branches soon after dawn, preen and sun themselves for an hour, then disperse to feed.
Insects with poisonous stings are first smacked on the branch, then, with the bird's eyes closed, rubbed to discharge the venom sac and stinger.
At some point bee-eaters have been recorded eating beetles, mayflies, stoneflies, cicadas, termites, crickets and grasshoppers, mantises, true flies and moths.
[25] In Israel, a European bee-eater was documented attempting to eat a small bat that it had caught, which probably could not fit down its throat.
[26] Like kingfishers, bee-eaters regurgitate pellets of undigested material, typically 2 cm (0.8 in) long black oblongs.
However, studies show the bee-eaters do not intentionally fly into the apiary, rather they feed on the insects caught on pastures and meadows within a radius of 12 km (7.5 mi) from the colony, this maximum distance being reached only when there is a shortage of food.
Observations show that the birds actually enter the apiary only in cold and rainy periods, when the bees do not leave the hive and other insect prey are harder for the bee-eaters to detect.
[27] Many bee-keepers believe that the bee-eaters are the main obstacle causing worker bees not to forage, and instead stay inside the hives for much of the day between May and the end of August.
Hives close to or under trees or overhead cables are at increased risk as the birds pounce on flying insects from these perches.
[31] In the case of the bee-eaters the nests are burrows dug into the ground, either into the sides of earth cliffs or directly into level soil.
[32][33] There may be several false starts where nests are dug partway before being abandoned; in solitary species this can give the impression of colonial living even when that is not the case.
The hole-nesting lifestyle of bee-eaters means that they tend to carry a higher burden of external parasites than non-hole-nesting bird species.
[44] Fly larvae of the genus Fannia live in the nests of at least European bee-eaters, and feed on faeces and food remains.
There is some human persecution of bee-eaters, with nest holes being blocked, adults shot or limed, or young taken for food.
[5] A study of the southern carmine bee-eater in Zimbabwe showed that it was affected by deliberate interference and persecution and loss of woodlands, and that nesting sites are lost through poor water management leading to river bank damage, dam construction and panning for gold.
The well-studied European bee-eater is trapped and shot on migration in countries bordering the Mediterranean, an estimated 4,000–6,000 annually being killed in Cyprus alone, but with a global population of between 170,000 and 550,000 pairs even losses on that scale make little overall impact.
[47] In Greek mythology, the Theban Botres was fatally struck by his father when he desecrated a ritual sacrifice of a ram to the god Apollo by tasting the victim's brains.