Behavior

Walking, Running, Hopping, Climbing, etc.

The European Bee-eater runs on the ground with fast steps and can move backwards as fast as forwards; on branches, it can also move sideways (528 Koenig, L. (1951). Beiträge zu einem Aktionssystem des Bienenfressers (Merops apiaster). Zeitschrift für Tierpsychologie 8:169-210. Close ). Older nestlings can move backwards with similarly fast short steps to move from the entrance of the burrow back into the nest chamber (Bastian and Bastian, unpublished data).

Flight

The flight of the European Bee-eater varies between soaring-gliding, steady flapping, and fast powered phases. Additionally, there are flights with alternating sequences of short flapping and gliding phases. In one study, individually radar tracked migrating birds had a mean flight speed of 12.2 ± 2.6 m/s (range 7–19 m/s; 566 Bruderer, B. and A. Boldt. (2001). Flight characteristics of birds: I. radar measurements of speeds. Ibis 143 (2):178-204. Close ). Birds in Sicily migrated in the autumn with a very similar mean flight speed of 12.3 ± 0.6 m/s (467 Cicero, G., A. Pastorino, and M. Panuccio (2017). Radar tracking of Bee-eaters on migration. Conference: Radar Aeroecology - Applications and Perspectives, Rome, Italy. Close ). Birds tracked using radio telemetry had a flight speed over ground of 10.1 ± 6.5 m/s in flapping flight and 10.3 ± 1.5 m/s in soaring-gliding flight in Israel (606 Sapir, N., M. Wikelski, M. D. McCue, B. Pinshow, and R. Nathan (2010). Flight modes in migrating European Bee-Eaters: heart rate may indicate low metabolic rate during soaring and gliding. PlosOne 5:e13956. Close ).

European Bee-eater flight appears swallow-like with its regular alternation between rapid wingbeats and gliding flight; however, the wings are stiffly and horizontally stretched, and the tail is spread. When hunting or when approaching the nest, gliding flight is used more often. The wingbeats consist of a moderately strong upstroke of approximately 45° and a very strong downstroke in which the wing tips almost touch each other under the body, especially when accelerating after takeoff from a perch or after leaving the nest (8 Glutz von Blotzheim, U. N., and K. M. Bauer (1980). Handbuch der Vögel Mitteleuropas. Band 9 Columbiformes-Piciformes. Akademische Verlagsgesellschaft, Wiesbaden, Germany. Close ). When disturbed at the nest or in aerial fights with conspecifics, it is able to hover (373 Larsen, A. A. (1949). Yuglende Biaeder i Danmark. Dansk Ornitologisk Forenings Tidsskrift 43: 129–149. Close , 528 Koenig, L. (1951). Beiträge zu einem Aktionssystem des Bienenfressers (Merops apiaster). Zeitschrift für Tierpsychologie 8:169-210. Close ) or even to fly short distances backwards (618 Mountfort, G. (1957). Nest-hole excavation by the Bee-eater. British Birds 50:263-267. Close ).

Soaring-gliding flight consists of a soaring and a gliding phase. During soaring flight, the bird uses thermal updrafts, circling over the rising air. During gliding, the bird sinks again and moves horizontally; during the glide, the bird will find a new thermal to rise up before gliding again. Soaring-gliding flight sequences can be used continuously for a long time without the need to flap; over long-distance flights, a bird can use soaring-gliding flights for 2–43 min (mean of 9.5 ± 14.2 min) before it needs to flap its wings again (606 Sapir, N., M. Wikelski, M. D. McCue, B. Pinshow, and R. Nathan (2010). Flight modes in migrating European Bee-Eaters: heart rate may indicate low metabolic rate during soaring and gliding. PlosOne 5:e13956. Close ). Flapping flight is characterized by two alternating phases, a series of wing beats lasting an average of 1.39 ± 1.84 s, followed by a pause of similar duration (606 Sapir, N., M. Wikelski, M. D. McCue, B. Pinshow, and R. Nathan (2010). Flight modes in migrating European Bee-Eaters: heart rate may indicate low metabolic rate during soaring and gliding. PlosOne 5:e13956. Close ). In one study at a staging site in Israel using radio telemetry, weather conditions like temperature and changes in barometric pressure influenced flight mode when birds departed; no effect of tailwind assistance was found. In addition to influencing when birds departed, conditions also dictated the flight style they used: birds departed using soaring-gliding at much higher temperatures than those that departed by flapping (510 Sapir, N., M. Wikelski, R. Avissar, and R. Nathan (2011). Timing and flight mode of departure in migrating European bee-eaters in relation to multi-scale meteorological processes. Behavioural Ecology and Sociobiology 65:1353-1365. Close ). Regardless of flight mode, birds were able to compensate for lateral drift during migration (518 Sapir, N., N. Horvitz, M. Wikelski, R. Avissar, and R. Nathan (2014). Compensation for lateral drift due to crosswind in migrating European Bee-eaters. Journal of Ornithology 155:745-753. Close ).

During foraging at a stopover site, birds used flapping and soaring flight, circling and ascending above the stopover sites without moving horizontally in gliding flight (606 Sapir, N., M. Wikelski, M. D. McCue, B. Pinshow, and R. Nathan (2010). Flight modes in migrating European Bee-Eaters: heart rate may indicate low metabolic rate during soaring and gliding. PlosOne 5:e13956. Close ).

Preening, Head-Scratching, Stretching, Sunbathing, Bathing, Anting

Preening consists of jerky movements, while every 1–2 s the bill snaps and grasps a feather that is then pulled through the top of the bill (8 Glutz von Blotzheim, U. N., and K. M. Bauer (1980). Handbuch der Vögel Mitteleuropas. Band 9 Columbiformes-Piciformes. Akademische Verlagsgesellschaft, Wiesbaden, Germany. Close ). While perched, the bird cleans its bill by strongly rubbing it against a branch. Sunbathing can also occur while a bird is perched on a branch; birds will sit with their backs to the sun with mantle feathers fanned. Birds may also show a “broken-neck” posture with sunbathing, but this is less common (62 Fry, C. H. (1984). The Bee-eaters. T. & A. D. Poyser, London, UK. Close ). In addition, birds may lie flat on the ground, with wings and tail spread, and the back-plumage fanned to sunbathe. Birds raise their wings and stretch when they wake up; when stretching, both feet remain on the perch, and one wing is stretched and spread backward while simultaneously half the tail is spread.

Flight bathing occurs mainly in extremely hot temperatures; it is frequently observed in Hungary (297 Fintha, I. (1968). Beobachtungen über den Bienenfresser (Merops apiaster), seine Brutverhältnisse, seine Nahrung an der Szamos. Aquila 75: 93–109. Close ). When bathing in flight, a bird approaches the water surface at an angle and touches the water; this is usually repeated several times, with the depth a bird reaches into the water increasing with each progressive dive, until it finally submerges completely. When birds dive into the water, predatory fish such as pike (Esox lucius; 297 Fintha, I. (1968). Beobachtungen über den Bienenfresser (Merops apiaster), seine Brutverhältnisse, seine Nahrung an der Szamos. Aquila 75: 93–109. Close ) or sharks (607 Yosef, R., D. Zakai, M. Rydberg-Hedaen, and R. Nikolajsen (2002). An unusual record of a European Bee-eater Merops apiaster from Eilat – inside a tiger shark Galeocerdo cuvier. Sandgrouse 24:140–142. Close ) will occasionally try to grab them. After diving, a bird will shake water from its plumage while in flight and fly to a perch afterwards to preen (273 Krimmer, M., R. Piechocki, and K. Uhlenhaut (1974). Über die Ausbreitung des Bienenfressers und die ersten Brutnachweise 1973 in der DDR. Falke 21: 42–51, 95–101. Close , 4 Walter, B., K. Nottmeyer-Linden, and U. Romer (1992). Observations of a brood of Bee-eaters (Merops apiaster) at Bad Laer in lower Saxony. Charadrius 28(1): 33–43. [In German]. Close , 404 Peters, T., and H. Trapp (2006). Bruten des Bienenfressers (Merops apiaster) bei Meißen 2004–2006. Actitis 41: 3–20. Close ). Rain-bathing also occurs regularly, such as during a thundershower (273 Krimmer, M., R. Piechocki, and K. Uhlenhaut (1974). Über die Ausbreitung des Bienenfressers und die ersten Brutnachweise 1973 in der DDR. Falke 21: 42–51, 95–101. Close ).

Sleeping, Roosting

The European Bee-eater sleeps with its neck retracted and the bill directed forward and up; in cold weather, it will gather closely with other individuals all oriented in the same way and facing the same direction, resting in the crown of a clump of trees or in riparian shrubs (619 Finch, R. S. (1971). The European Bee-eater. Honeyguide 65:19-20. Close ). During the pre-breeding, incubation, and nestling periods, both the adult male and female can spend the night in the burrow until nestlings are about 14 d old (528 Koenig, L. (1951). Beiträge zu einem Aktionssystem des Bienenfressers (Merops apiaster). Zeitschrift für Tierpsychologie 8:169-210. Close , 538 Conrads, K., and M. Quelle (1981). Erster Brutnachweis des Bienenfressers (Merops apiaster) 1978 in Westfalen. Berichte des Naturwissenschaftlichen Vereins Bielefeld 25:53-80. In German Close , 62 Fry, C. H. (1984). The Bee-eaters. T. & A. D. Poyser, London, UK. Close ); studies have also shown that only the female sleeps in the breeding burrow during the incubation period, with the male sleeping outside (553 Schumann, G. (1971). Brut des Bienenfressers Merops apiaster 1971 in Nordhessen. Luscinia 41: 153-159. Close , 431 Bastian, H.-V., A. Bastian, S. Essel, and D. T. Tietze (2019). Space use and daily movement patterns of the European Bee-eater Merops apiaster during breeding and post-breeding. Ardea 107: 321–327. Close ). After the breeding period, adults rarely sleep in burrows, but instead gather at communal roosts in trees that can be up to 3 km away from the colony. In some colonies, even during the breeding period, adults may all roost away from the colony such that no adults are present at the colony at night (330 Lomont, H. (1946). L’extension du Merops apiaster L. en Camargue. Bulletin du Muséum d'Histoire Naturelle Marseille 6: 81–88. Close , 523 Biber, O. (1971). Contribution à la biologie de reproduction et à l’alimentation du Guêpier d’Europe Merops apiaster en Camargue. [Contribution to the biology of reproduction and diet of the European Bee-eater Merops apiaster in the Camargue region (France)]. Alauda 39(3):209-212. Close , 553 Schumann, G. (1971). Brut des Bienenfressers Merops apiaster 1971 in Nordhessen. Luscinia 41: 153-159. Close , 381 König, C., and U. von Wicht (1973). Eine erfolgreiche Brut des Bienenfressers (Merops apiaster) in Hegau. [Successful breeding of the Bee-eater (Merops apiaster) in Hegau]. Anzeiger der Ornithologischen Gesellschaft in Bayern 12(1): 52–56. Close , 273 Krimmer, M., R. Piechocki, and K. Uhlenhaut (1974). Über die Ausbreitung des Bienenfressers und die ersten Brutnachweise 1973 in der DDR. Falke 21: 42–51, 95–101. Close , 414 Pittocopitis, R. (2007). Dreijährige Studien an einer in Rheinland-Pfalz 2004 neu entstandenen Brutpopulation von Merops apiaster. Ornithologische Mitteilungen 59: 260–276. Close , 431 Bastian, H.-V., A. Bastian, S. Essel, and D. T. Tietze (2019). Space use and daily movement patterns of the European Bee-eater Merops apiaster during breeding and post-breeding. Ardea 107: 321–327. Close ). Birds begin moving to roosts about 1–2 h before dusk (409 Walter, E.-C. (1996). Erstmaliger Brutnachweis für den Bienenfresser (Merops apiaster) im Regierungsbezirk Trier. Dendrocopus 23: 25–28. Close , 404 Peters, T., and H. Trapp (2006). Bruten des Bienenfressers (Merops apiaster) bei Meißen 2004–2006. Actitis 41: 3–20. Close , 197 Gerber, A., W. Leuthold, and M. Kéry (2011). Der Bienenfresser Merops apiaster in der Schweiz: Durchzug und Bruten. Der Ornithologische Beobachter 108: 101–116. Close ). Roost trees tend to be tall with a sparse crown located in an open landscape or along the edge of hedgerows, including in open fields, floodplains, or on forest edges; if preferred roosts are not available, wires (620 Hall, D. G. (1983). Birds of Mataffin, Eastern Transvaal. Southern Birds 10:1–55. Close ) and reed thickets can also be used (621 Banik, M. V., and O. O. Brezgunova (2020). Behaviour of European Bee-eaters Merops apiaster at communal roosts. Troglodytes 9-10:77-82. In Ukranian Close ).

Physical and Communicative Interactions

A threatened bird will stretch its body horizontally while giving hoarse, elongated Daaaa calls; it will also strongly fluff its neck and back plumage, fluff its throat to a smaller degree, and push its head forward with its bill open while giving bill-snaps. An attacked bird will sit stiffly upright with tight flattened plumage, its head back, and its bill open (528 Koenig, L. (1951). Beiträge zu einem Aktionssystem des Bienenfressers (Merops apiaster). Zeitschrift für Tierpsychologie 8:169-210. Close ).

If the level of aggression is similar in two interacting individuals, the interactions will escalate first to harmless confrontations with bill-twists and bill shaking, followed by more aggressive fights with bill snapping, spread head-plumage, hitting the opponent hard with its spread wing (622 Goodwin, D. (1952). Dominant and submissive behaviour of Bee-eaters. British Birds 45:32-33. Close ), and flittering (8 Glutz von Blotzheim, U. N., and K. M. Bauer (1980). Handbuch der Vögel Mitteleuropas. Band 9 Columbiformes-Piciformes. Akademische Verlagsgesellschaft, Wiesbaden, Germany. Close ), whereby both opponents can fall from their perch in the eagerness of the fight (Bastian and Bastian, unpublished data). After the end of the fight, both birds often sit relaxed, side by side, for a while (622 Goodwin, D. (1952). Dominant and submissive behaviour of Bee-eaters. British Birds 45:32-33. Close ).

Territorial Behavior

Territorial behavior starts when a pair begins to dig the breeding burrow, with the intensity increasing during the digging process, and reaching its peak when the burrow is complete. In one study, each pair defended its breeding burrow, as well as several perches close to the burrow, which typically consists of branches or clumps of earth (623 Hahn, V. (1981). Zur sozialen Organisation des Bienenfressers Merops apiaster. [On the social organization of the European Bee-eater (Merops apiaster)]. Journal of Ornithology 122(4):429-434. [In German with English summary]. Close ). Early arriving pairs established large territories, with later arriving birds subsequently establishing territories in between these larger ones. Over the course of a season, the initially large territory of early arriving pairs usually shrinks as more territories are established. In one study, newly arriving pairs were attacked by established territory holders more often, but these disputes typically lasted only 4–5 d (623 Hahn, V. (1981). Zur sozialen Organisation des Bienenfressers Merops apiaster. [On the social organization of the European Bee-eater (Merops apiaster)]. Journal of Ornithology 122(4):429-434. [In German with English summary]. Close ). Most newly arriving pairs were able to establish a territory, despite the aggression of already established birds, but some could not maintain a territory (623 Hahn, V. (1981). Zur sozialen Organisation des Bienenfressers Merops apiaster. [On the social organization of the European Bee-eater (Merops apiaster)]. Journal of Ornithology 122(4):429-434. [In German with English summary]. Close ). Later territorial conflicts rarely occur either at breeding burrows or at the preferred roosting places (533 Handl, B. (2009). Vergleichende Studie an frei lebenden und im Zoo gehaltenen Bienenfresser (Merops apiaster). Diploma Thesis, Universität Wien, Austria. Close ).

Mating System and Operational Sex Ratio

The European Bee-eater is usually monogamous; bigamy is known, but rare (624 Avery, M. I., J. R. Krebs, and R. E. Hegner (1984). A case of bigamy in the European Bee-eater (Merops apiaster). Auk 101(3):609-610. Close ). In a sample of 100 nests, a female was found alone only twice; however, even in these rare cases, it was unclear whether the female was mated to a male that also had another mate or if her breeding partner had gone missing (624 Avery, M. I., J. R. Krebs, and R. E. Hegner (1984). A case of bigamy in the European Bee-eater (Merops apiaster). Auk 101(3):609-610. Close ). At solitary nests, the sex ratio, including possible breeding helpers, is close to 1:1, but in breeding colonies, the ratio is shifted to 1.5–2:1 in favor of males (596 Fry, C. H. (1972). The social organisation of bee-eaters and co-operative breeding in hot-climate birds. Ibis 114:1-14. Close ).

Courtship, Copulation, and Pair Bond

Behavioral displays in the context of sexual attraction include courtship greeting, courtship feeding, and copulation. During mating, males and females stay within sight of each other when weather conditions are favorable. The birds almost always rest at the same time and hunt together, often calling to each other (603 Konstantinov, V. M., and L. V. Malovichko (1998). Behavioral strategies of breeding partners and their importance for breeding success in the Golden Bee-eater Merops apiaster. Russkiy ornitologicheskiy zhurnal 54:10-15. In Russian Close ). Mate choice and mating usually start with the end of the molt period, either on the non-breeding grounds or during spring migration. Birds usually arrive at their breeding grounds already paired (528 Koenig, L. (1951). Beiträge zu einem Aktionssystem des Bienenfressers (Merops apiaster). Zeitschrift für Tierpsychologie 8:169-210. Close , 596 Fry, C. H. (1972). The social organisation of bee-eaters and co-operative breeding in hot-climate birds. Ibis 114:1-14. Close ).

Courtship Greeting

If mate choice occurs at the breeding colony and not before birds arrive, it starts immediately after arrival (8 Glutz von Blotzheim, U. N., and K. M. Bauer (1980). Handbuch der Vögel Mitteleuropas. Band 9 Columbiformes-Piciformes. Akademische Verlagsgesellschaft, Wiesbaden, Germany. Close ). In these cases, courtship greeting occurs, with one bird taking a rather upright position, vibrating its fanned tail, slightly raising its crown feathers, opening its wings halfway if the partner sits beside it (625 Hahn, V. (1982). Beobachtungen zum Sozialverhalten des Bienenfressers. [Observations on the social behavior of Bee-eaters]. Gefiederte Welt 106(10):327-329. Close ), or spreading both wings if facing its partner, presenting the reddish underwing coverts (528 Koenig, L. (1951). Beiträge zu einem Aktionssystem des Bienenfressers (Merops apiaster). Zeitschrift für Tierpsychologie 8:169-210. Close , 62 Fry, C. H. (1984). The Bee-eaters. T. & A. D. Poyser, London, UK. Close ). With a similar wing spread behavior, an individual may also sit facing the colony wall on small perches and repeatedly fly and return to the same perch, spreading its wings each time it lands. It has been suggested that this specific behavior relates to choosing a location for the burrow and is not explicitly part of courtship (216 Klaus, S., A. Christner, and G. Dechant (2013). Bruten des Bienenfressers Merops apiaster im Thüringer Saale-Holzland-Kreis 2007-2012. Anzeiger des Vereins Thüringer Ornithologen 7: 333–340. Close ).

The courtship greeting may be followed by another ritualized behavior in which a bird adopts a stiff, erect posture with most feathers flat against the body and slightly spread wrists which keep the wingtips crossed over the downward pointing tail. Simultaneously, the crown plumage is flattened and the nape plumage is bristled. In this posture, the whole body will give short, upward jerking movements every few seconds, and the bird will continue to flatten its crown feathers and puff out its yellow throat feathers, which emphasizes the black ring bordering the throat; birds will give rolling didirüp calls during this display (8 Glutz von Blotzheim, U. N., and K. M. Bauer (1980). Handbuch der Vögel Mitteleuropas. Band 9 Columbiformes-Piciformes. Akademische Verlagsgesellschaft, Wiesbaden, Germany. Close , 626 Álvarez, F., and F. Hiraldo (1974). Estructura de las galerías de nidificación del Abejaruco (Merops apiaster) en Doñana. [The structure of nesting tunnels of Bee-eaters, Merops apiaster in Doñana]. Doñana: Acta Vertebrata 1(1):61-67. [In Spanish with English summary]. Close ). Finally, the courtship greeting will often conclude with a bird slowly and ritually banging its bill against the perch at the feet of its mate, as if hitting an insect against the branch (62 Fry, C. H. (1984). The Bee-eaters. T. & A. D. Poyser, London, UK. Close , 627 Gohlke, R. (2015). Untersuchung von Agrarumweltmaßnahmen zum Schutz der Vogelarten Bienenfresser und Wachtel in Rheinland-Pfalz. Thesis, Hochschule Geisenheim University, Geisenheim, Germany. Close ).

Courtship Feeding

A more frequently seen, and an overall more conspicuous aspect of courtship behavior in the European Bee-eater, is courtship feeding. In the entire behavioral repertoire of the species, courtship feeding seems to be the only behavior that only males perform (528 Koenig, L. (1951). Beiträge zu einem Aktionssystem des Bienenfressers (Merops apiaster). Zeitschrift für Tierpsychologie 8:169-210. Close , 377 Baum, L., and E. Jahn (1965). Brut des Bienenfressers, Merops apiaster, 1964 in Schleswig-Holstein. Corax 1(17): 73–82. Close ). After the male has caught an insect for courtship feeding, he sits near the female, moves towards her, calls out, and presents the food to her. If the male eats the caught insect himself, he sits silently at some distance from the female and eats the prey (603 Konstantinov, V. M., and L. V. Malovichko (1998). Behavioral strategies of breeding partners and their importance for breeding success in the Golden Bee-eater Merops apiaster. Russkiy ornitologicheskiy zhurnal 54:10-15. In Russian Close ). In Africa, courtship feeding has been observed on the breeding grounds in southern South Africa (628 Winterbottom, J. M. (1959). Courtship feeding in European Bee-eater. Ostrich 30:44. Close ) but not on the non-breeding grounds. In Europe, it has been observed upon arrival on the breeding grounds (62 Fry, C. H. (1984). The Bee-eaters. T. & A. D. Poyser, London, UK. Close ). During courtship feeding, the male sits beside the female on a branch, stone, or earth clump, scans for prey, captures an insect, and returns to the perch while the female watches and perches parallel to him (602 Avery, M. I., J. R. Krebs, and A. I. Houston (1988). Economics of courtship-feeding in the European Bee-eater (Merops apiaster). Behavioral Ecology and Sociobiology 23(2):61-67. Close , 623 Hahn, V. (1981). Zur sozialen Organisation des Bienenfressers Merops apiaster. [On the social organization of the European Bee-eater (Merops apiaster)]. Journal of Ornithology 122(4):429-434. [In German with English summary]. Close ). During egg-laying the female is fed in the breeding burrow or at its entrance (623 Hahn, V. (1981). Zur sozialen Organisation des Bienenfressers Merops apiaster. [On the social organization of the European Bee-eater (Merops apiaster)]. Journal of Ornithology 122(4):429-434. [In German with English summary]. Close ). The female almost always accepts the prey and eats it quickly; the female usually appears calm but will excitedly greet the male when he arrives. The female may solicit a copulation from the male after being fed (62 Fry, C. H. (1984). The Bee-eaters. T. & A. D. Poyser, London, UK. Close ). In between feedings, the female sometimes gives quiet calls (623 Hahn, V. (1981). Zur sozialen Organisation des Bienenfressers Merops apiaster. [On the social organization of the European Bee-eater (Merops apiaster)]. Journal of Ornithology 122(4):429-434. [In German with English summary]. Close ). Males provide particularly large prey to females during courtship feeding (585 Matoušek, B. (1951). [Contribution to the biology of the European bee-eater (Merops apiaster) in Slovakia]. Sylvia 13:122-125. In Slovakian with English summary Close , 602 Avery, M. I., J. R. Krebs, and A. I. Houston (1988). Economics of courtship-feeding in the European Bee-eater (Merops apiaster). Behavioral Ecology and Sociobiology 23(2):61-67. Close ; see Nutrition and Energetics).

Copulation

A few days after courtship feeding begins, or even coincident with the beginning of courtship feeding, copulation starts, usually on a branch or a ground site defended by the pair (623 Hahn, V. (1981). Zur sozialen Organisation des Bienenfressers Merops apiaster. [On the social organization of the European Bee-eater (Merops apiaster)]. Journal of Ornithology 122(4):429-434. [In German with English summary]. Close ). After being fed, the female will solicit a copulation by laying down almost horizontally against the branch and uttering the gobbling grrüüüüp copulation call. The copulation, which lasts up to 10 s (282 Reid, J. C. (1974). Bienenfresser-Beobachtungen im östlichen Österreich. Egretta 1: 15–22. Close ), sometimes happens so quickly that the female has no time to swallow the insect delivered by the male. During copulation, the female lowers her head and the male presses the tip of his bill on her forehead, which is thought to help him maintain balance (62 Fry, C. H. (1984). The Bee-eaters. T. & A. D. Poyser, London, UK. Close ). The frequency of courtship feeding and copulation rises sharply after completion of the burrow, a few days before egg laying starts, and declines when the clutch is completed. Later, courtship feeding and copulation are suspended (623 Hahn, V. (1981). Zur sozialen Organisation des Bienenfressers Merops apiaster. [On the social organization of the European Bee-eater (Merops apiaster)]. Journal of Ornithology 122(4):429-434. [In German with English summary]. Close ), rarely persisting more than 2 d after the last egg is laid (602 Avery, M. I., J. R. Krebs, and A. I. Houston (1988). Economics of courtship-feeding in the European Bee-eater (Merops apiaster). Behavioral Ecology and Sociobiology 23(2):61-67. Close ). However, a strong bond between the pair is maintained at least until the beginning of autumn migration. It is assumed that males copulate with several females. This appears to be advantageous not only for the male, but also for the females, as the females are obviously not passively, but actively involved in copulation with other males, thereby controlling the males and the additional paternity (603 Konstantinov, V. M., and L. V. Malovichko (1998). Behavioral strategies of breeding partners and their importance for breeding success in the Golden Bee-eater Merops apiaster. Russkiy ornitologicheskiy zhurnal 54:10-15. In Russian Close ).

If helpers are involved, they will also feed the female, but the female does not tolerate copulation with helpers (553 Schumann, G. (1971). Brut des Bienenfressers Merops apiaster 1971 in Nordhessen. Luscinia 41: 153-159. Close ). In juveniles, pseudo-copulation occurs almost daily (629 Pittocopitis, R. (2010). Weitere brutbiologische Daten von Merops apiaster für 2008 und 2009, sowie die Beschreibung der Maßnahmen zur Abwehr von Prädatoren und deren Wirksamkeit. Ornithologische Mitteilungen 62:381-387. Close ).

Degree of Sociality

The European Bee-eater lives gregariously year-round. Especially during migration and on the non-breeding grounds, flocks can contain hundreds of birds.

Breeding in Colonies

While colony breeding is generally the rule for the European Bee-eater, pairs can breed alone. In Camargue, France, 8% of the nests involved solitary pairs (331 Swift, J. J. (1959). Le Guêpier d’Europe Merops apiaster L. en Camargue. Alauda 27: 97–143. Close ), while in Germany, 12% of the nests from 1964–2020 consisted of 1–2 pairs (68 Bastian, H.-V., M. Jais, and A. Bastian (2021). Bienenfresserbruten in Mittel-, Nord- und Westeuropa seit 1960 - Eine Übersicht. Vogelwarte 59:179-187. Close ). Colonies can be made up of several hundred pairs; a colony of 300 pairs has been documented in central Hungary (298 Urbán, S., K. Túri, Z. Vas, and T. I. Fuisz (2013). A successful habitat reconstruction effort, the short history of the European Bee-eater (Merops apiaster) colony at Albertirsa (Hungary). Ornis Hungarica 21: 47–51. Close ), and another colony of 400 has been documented in southern Hungary (294 Szijj, J. (1952-1955). [Bee-eater colonies in Hungary in 1949]. Aquila 59–62: 185–190. In Hungarian. Close ). However, it is thought that there has been a change in colony structure over time, as colonies with several hundred pairs are now very rare, while small colonies have become more common (630 Purger, J. J. (2001). Numbers and breeding distribution of the Bee-eater Merops apiaster in province Voivodina (northern Serbia) between 1987 and 1990. Vogelwelt 122:279-282. Close ). In a survey of 387 colonies in southwestern Germany from 1990 to 2020, only 23% of colonies had more than four pairs, and just 18% had more than 30 pairs (202 Bastian, A., and H.-V. Bastian (2021). Bienenfresser (Merops apiaster) in Rheinland-Pfalz und Nordbaden 1990–2020. Vogelwarte 59:267-277. Close ). In Camargue, only a quarter of the colonies had more than six nests (331 Swift, J. J. (1959). Le Guêpier d’Europe Merops apiaster L. en Camargue. Alauda 27: 97–143. Close ). The median colony size was 5.2 breeding pairs in Germany (202 Bastian, A., and H.-V. Bastian (2021). Bienenfresser (Merops apiaster) in Rheinland-Pfalz und Nordbaden 1990–2020. Vogelwarte 59:267-277. Close ) and 8 in Ryazan, Russia (461 Priklonskiy, S. G. (1970). [Peculiarities of relationship of Golden Bee-eaters with their breeding range at its northern border]. Proceedings of the VII Pre-Baltic Ornithology Congress 1: 83–85. In Russian. Close ). In southern and eastern Slovakia, a negative correlation between colony size and chick condition and survival was described (555 Hoi, H., C. Hoi, J. Kristofik, and A. Darolova (2002). Reproductive success decreases with colony size in the European bee-eater. Ethology Ecology and Evolution 14:99-110. Close ). This relationship, although not significant, tended to be linked to a limitation of nesting sites and food; helpers were also rare at large colonies in this study, and it is possible that a lack of helpers contributed to the negative relationship between annual reproductive success and colony size (555 Hoi, H., C. Hoi, J. Kristofik, and A. Darolova (2002). Reproductive success decreases with colony size in the European bee-eater. Ethology Ecology and Evolution 14:99-110. Close ).

Roosting Behavior

Before arriving to the evening roost, birds gather about 90 min before in areas not far away (62 Fry, C. H. (1984). The Bee-eaters. T. & A. D. Poyser, London, UK. Close ). In southwestern Germany, birds foraged in the vicinity of the roost trees for a while before they quickly flew into the trees for the night (Bastian and Bastian, unpublished data). Birds sleep in groups of 4–6 on the downwind side of trees near the treetops (455 Pelchen, H. (1978). European Bee-eaters wintering in Nairobi. Bulletin of the East Africa Natural History Society 1978: 58–59. Close , 493 Every, B. (1982). Observations on the European Bee-eater, summer 1981/2. Bee-eater 33: 25–29. Close ). Overnight, birds maintained a distance of 5–15 cm from one another (8 Glutz von Blotzheim, U. N., and K. M. Bauer (1980). Handbuch der Vögel Mitteleuropas. Band 9 Columbiformes-Piciformes. Akademische Verlagsgesellschaft, Wiesbaden, Germany. Close ); in cold weather, however, birds crowded together shoulder to shoulder and slept in tightly packed rows (62 Fry, C. H. (1984). The Bee-eaters. T. & A. D. Poyser, London, UK. Close , 414 Pittocopitis, R. (2007). Dreijährige Studien an einer in Rheinland-Pfalz 2004 neu entstandenen Brutpopulation von Merops apiaster. Ornithologische Mitteilungen 59: 260–276. Close ). In Nairobi, up to 100 individuals gathered at the roost at sunset (455 Pelchen, H. (1978). European Bee-eaters wintering in Nairobi. Bulletin of the East Africa Natural History Society 1978: 58–59. Close ), and up to 200 individuals roosted at one site in Addo, South Africa (493 Every, B. (1982). Observations on the European Bee-eater, summer 1981/2. Bee-eater 33: 25–29. Close ). At breeding areas in Germany, post-breeding flocks of 100–150 birds were frequently seen (418 Bastian, H.-V., and A. Bastian (2016). Bienenfresser Merops apiaster LINNAEUS, 1758. In Die Vogelwelt von Rheinland-Pfalz. Bd. 3 Greifvögel bis Spechtvögel (Accipitriformes – Piciformes) (C. Dietzen, T. Dolich, T. Grunwald, P. Keller, A. Kunz, M. Niehuis, M. Schäf, M. Schmolz and M. Wagner, Editors). Fauna und Flora in Rheinland-Pfalz, Beih. 48, Landau, Germany. pp. 752–768. Close , 631 Hoffmann, D., and U. Hoffmann (2020). Beobachtungen an einem Rastplatz des Bienenfressers (Merops apiaster) bei Harthausen (Rhein-Pfalz-Kreis, Rheinland-Pfalz). Fauna und Flora in Rheinland-Pfalz 14:725-734. Close ), with a maximum of 300 birds at one site (270 Rupp, J., F. Saumer, and W. Finkbeiner (2011). Brutverbreitung und Bestandsentwicklung des Bienenfressers (Merops apiaster) am südlichen Oberrhein im Zeitraum 1990 bis 2009. Naturschutz am südlichen Oberrhein 6: 31–42. Close ). On Susak Islands, Croatia, <10 to 80 birds roosted together; this variation was explained by weather conditions, but also by the fact that during the breeding season, pairs often spent the night together in their burrows and not at the communal roost roosting (632 Pârâu, L. G., S. A. Kingma, S. E. Weigl, H. L. Dugdale, C. M. Lessells, and J. Schroeder (2017). Dynamics in numbers of group-roosting individuals in relation to pair-sleeping occurance and onset of egg-laying in European Bee-eaters Merops apiaster. Journal of Ornithology 158:1119-1122. Close ).

Social Behavior on Migration and Non-breeding Grounds

During the breeding season, groups of nonbreeders moving around are rarely described (633 Korelov, M. N. (1948). [Information on the ecology and economy significance of Golden Bee-eaters]. Izvestiya Akademii Nauk Gruzii, Seriya Biologischeskaia 51(7):107-123. In Russian. Close ). During the post-breeding period, however, over a period of several weeks, pre-migratory flocks are formed (431 Bastian, H.-V., A. Bastian, S. Essel, and D. T. Tietze (2019). Space use and daily movement patterns of the European Bee-eater Merops apiaster during breeding and post-breeding. Ardea 107: 321–327. Close ), with birds coming together from adjacent colonies (44 Dhanjal-Adams, K. L., S. Bauer, T. Emmenegger, S. Hahn, S. Lisovski, and F. Liechti (2018). Spatiotemporal group dynamics in a long-distance migratory bird. Current Biology 28: 2824–2830.e3 Close ); birds from the same colony do not necessarily follow the same routes. These migratory groups, which are probably formed from multiple family groups (431 Bastian, H.-V., A. Bastian, S. Essel, and D. T. Tietze (2019). Space use and daily movement patterns of the European Bee-eater Merops apiaster during breeding and post-breeding. Ardea 107: 321–327. Close ), are generally stable during migration, do not show a pronounced age or sex structure, and include a large number of unrelated birds (44 Dhanjal-Adams, K. L., S. Bauer, T. Emmenegger, S. Hahn, S. Lisovski, and F. Liechti (2018). Spatiotemporal group dynamics in a long-distance migratory bird. Current Biology 28: 2824–2830.e3 Close ). During migration, if members of a group are separated, they usually come back together on the nonbreeding grounds, despite a journey of up to 14,000 km (44 Dhanjal-Adams, K. L., S. Bauer, T. Emmenegger, S. Hahn, S. Lisovski, and F. Liechti (2018). Spatiotemporal group dynamics in a long-distance migratory bird. Current Biology 28: 2824–2830.e3 Close ; see Migratory Behavior). On the nonbreeding grounds, dynamic groups with coordinated foraging behaviors are formed (44 Dhanjal-Adams, K. L., S. Bauer, T. Emmenegger, S. Hahn, S. Lisovski, and F. Liechti (2018). Spatiotemporal group dynamics in a long-distance migratory bird. Current Biology 28: 2824–2830.e3 Close ).

Migratory groups may be formed on the breeding grounds (431 Bastian, H.-V., A. Bastian, S. Essel, and D. T. Tietze (2019). Space use and daily movement patterns of the European Bee-eater Merops apiaster during breeding and post-breeding. Ardea 107: 321–327. Close ) or just before and during migration, which indicate a wide range of social behaviors in the European Bee-eater (46 Hahn, S., and M. Schulze (2021). Zugwege und Zugstrategien Europäischer Bienenfresser (Merops apiaster) der Westpaläarktis. Vogelwarte 59:215-222. Close ). The overlap of nonbreeding area, migration route, and breeding area of birds migrating in groups indicates high migratory connectivity (44 Dhanjal-Adams, K. L., S. Bauer, T. Emmenegger, S. Hahn, S. Lisovski, and F. Liechti (2018). Spatiotemporal group dynamics in a long-distance migratory bird. Current Biology 28: 2824–2830.e3 Close , 46 Hahn, S., and M. Schulze (2021). Zugwege und Zugstrategien Europäischer Bienenfresser (Merops apiaster) der Westpaläarktis. Vogelwarte 59:215-222. Close ). The close social bonds between bee-eaters could help to explain the often nearly synchronous return to breeding colonies in spring (46 Hahn, S., and M. Schulze (2021). Zugwege und Zugstrategien Europäischer Bienenfresser (Merops apiaster) der Westpaläarktis. Vogelwarte 59:215-222. Close ).

Nonpredatory Interspecific Interactions

Association with Other Bee-eater Species

At Selous Game Reserve in Tanzania, the European Bee-eater was numerous in January together with the Little Bee-eater (Merops pusillus) in savannah habitats, whereas in the open dry forest areas which were close to shallow water bodies, it was less common than the Northern Carmine Bee-eater (Merops nubicus), Böhm's Bee-eater (Merops boehmi), White-fronted Bee-eater (Merops bullockoides),White-throated Bee-eater (Merops albicollis), and Blue-cheeked Bee-eater (Merops persicus) (Bastian and Bastian, unpublished data).

In Oman, the European Bee-eater and the Blue-cheeked Bee-eater breed largely sympatrically and in mixed groups (634 Fry, C. H., J. Eriksen, and B. Al-Arimy (1994). Competitive overlap of co-breeding bee-eaters Merops apiaster and M. persicus. Journal of Ornithology 135:133. Close , 524 Kossenko, S. M., and C. H. Fry (1998). Competition and coexistence of the European Bee-eater Merops apiaster and the Blue-cheeked Bee-eater Merops persicus in Asia. Ibis 140(1):2-13. Close ). While the two differ very little morphologically and ecologically, the European Bee-eater is heavier, has a larger wing-load, a shorter bill, generally takes smaller insects, and uses somewhat different foraging and breeding habitats (634 Fry, C. H., J. Eriksen, and B. Al-Arimy (1994). Competitive overlap of co-breeding bee-eaters Merops apiaster and M. persicus. Journal of Ornithology 135:133. Close ). In the Tashkent region, Uzbekistan, theEuropean Bee-eater usually prefers mountainous and foothill territories, whereas theBlue-cheeked Bee-eater prefers the flat zone of the country (90 Shodieva, F. O., and F. R. Kholboev (2021): Distribution, ecology and significance of the genus bee-eater (Merops) in Uzbekistan. International Journal of Research Publications 84:209-214. Close ).

Agonistic Behavior

European Bee-eater breeding burrows are often used by other birds that have similar preferences for breeding habitat and nest site, including the Bank Swallow (Riparia riparia), Common Swift (Apus apus), Eurasian Tree Sparrow (Passer montanus), House Sparrow (Passer domesticus), European Starling (Sturnus vulgaris), Common Myna (Acridotheres tristis), African Pied Starling (Lamprotornis bicolor), Spotted Flycatcher (Muscicapa striata), European Pied Flycatcher (Ficedula hypoleuca), Black Redstart (Phoenicurus ochruros), Northern Wheatear (Oenanthe oenanthe), White Wagtail (Motacilla alba), Common Swift (Apus apus), Eurasian Kestrel (Falco tinnunculus), Little Owl (Athene noctua), Eurasian Wryneck (Jynx torquilla), Eurasian Hoopoe (Upupa epops), and European Roller (Coracias garrulus) (635 Gregori, J. (1990). Bee-eater Merops apiaster in Slovenia. Acrocephalus 43-44:3-10. In Slovene with English summary Close , 316 Viktora, L. (1994). [Some aspects of the nidobiology of European Bee-eater (Merops apiaster) in East-Slovakian lowland.]. Tichodroma 7: 63–66. In Slovakian with English summary Close , 636 Török, I. H. (1999). European Bee-eaters and the occupants of their burrows - friends or enemies? Bird Numbers 8(1):16-17. Close , 637 Petrescu, A., and C. Adam (2001). Interspecific relations in the populations of Merops apiaster L. (Aves: Coraciiformes) of southern Romania. Travaux du Museum National d'Histoire Naturelle "Grigore Antipa" 43:305-322. Close , 630 Purger, J. J. (2001). Numbers and breeding distribution of the Bee-eater Merops apiaster in province Voivodina (northern Serbia) between 1987 and 1990. Vogelwelt 122:279-282. Close , 638 Casas-Crivillé A., and F. Valera (2005). The European bee-eater (Merops apiaster) as an ecosystem engineer in arid environments. Journal of Arid Environments 60:227–238. Close , 533 Handl, B. (2009). Vergleichende Studie an frei lebenden und im Zoo gehaltenen Bienenfresser (Merops apiaster). Diploma Thesis, Universität Wien, Austria. Close , 23 Valera, F. (2009). Abejaruco europeo – Merops apiaster. In Enciclopedia Virtual de los Vertebrados Españoles (A. Salvador and L.M. Bautista, Editors). Museo Nacional de Ciencias Naturales, Madrid, Spain. Close , 639 Vollmar, B. (2013). Brut des Wendehalses (Jynx torquilla) in einer Brutröhre des Bienenfressers (Merops apiaster). Fauna und Flora in Rheinland-Pfalz 12:1151-1152. Close ). Some species that use European Bee-eater nests, however, use old nests left from previous years and widened by erosion or mammal activities. The degree of agonistic behavior towards these potential nest-site competitors is usually weak (533 Handl, B. (2009). Vergleichende Studie an frei lebenden und im Zoo gehaltenen Bienenfresser (Merops apiaster). Diploma Thesis, Universität Wien, Austria. Close ), but sometimes these competitors are attacked and driven away. Some intruding species, including the Rock Sparrow (Petronia petronia) (640 Méric, J.-D. (1973). Moineau soulcie nichant dans un trou de Guêpier. Alauda 41:161-163. Close , 641 Olioso, G. (1974). Moineau soulcie Petronia petronia pris à partie par des Guêpiers d’Europe Merops apiaster. Alauda 42(4): 502. Close , 638 Casas-Crivillé A., and F. Valera (2005). The European bee-eater (Merops apiaster) as an ecosystem engineer in arid environments. Journal of Arid Environments 60:227–238. Close , 23 Valera, F. (2009). Abejaruco europeo – Merops apiaster. In Enciclopedia Virtual de los Vertebrados Españoles (A. Salvador and L.M. Bautista, Editors). Museo Nacional de Ciencias Naturales, Madrid, Spain. Close ), House Sparrow (23 Valera, F. (2009). Abejaruco europeo – Merops apiaster. In Enciclopedia Virtual de los Vertebrados Españoles (A. Salvador and L.M. Bautista, Editors). Museo Nacional de Ciencias Naturales, Madrid, Spain. Close ), and Spanish Sparrow (Passer hispaniolensis) ( 638 Casas-Crivillé A., and F. Valera (2005). The European bee-eater (Merops apiaster) as an ecosystem engineer in arid environments. Journal of Arid Environments 60:227–238. Close ), which often try to usurp European Bee-eater nests, may sometimes be aggressively driven off, but they are also sometimes tolerated and will end up usurping a bee-eater nest. In Luxembourg, a pair of European Bee-eaters, breeding within a colony of Bank Swallows, showed a high degree of aggression towards the swallows, with attacks towards the adults and the killing of at least one young bird (642 Burton, L. (2020). Agressivité inhabituelle d’un couple de Guêpiers d’Europe Merops apiaster sur Hirondelles de rivage Riparia riparia. Regulus Wissenschaftliche Berichte 35:54-59. Close ).

Other non-bird species that use old nests of the European Bee-eater include snakes, such as the Montpellier snake (Malpolon monspessulanus) and the horseshoe whip snake (Hemorrhois hippocrepis), mice, bats, amphibians (including the European green toad [Bufotes viridis]), and invertebrates (638 Casas-Crivillé A., and F. Valera (2005). The European bee-eater (Merops apiaster) as an ecosystem engineer in arid environments. Journal of Arid Environments 60:227–238. Close ).

Response to Mobbing

Small birds usually remain unnoticed (8 Glutz von Blotzheim, U. N., and K. M. Bauer (1980). Handbuch der Vögel Mitteleuropas. Band 9 Columbiformes-Piciformes. Akademische Verlagsgesellschaft, Wiesbaden, Germany. Close ). However, swallows, swifts, sparrows, and wagtails often mob bee-eaters (538 Conrads, K., and M. Quelle (1981). Erster Brutnachweis des Bienenfressers (Merops apiaster) 1978 in Westfalen. Berichte des Naturwissenschaftlichen Vereins Bielefeld 25:53-80. In German Close , 4 Walter, B., K. Nottmeyer-Linden, and U. Romer (1992). Observations of a brood of Bee-eaters (Merops apiaster) at Bad Laer in lower Saxony. Charadrius 28(1): 33–43. [In German]. Close , 273 Krimmer, M., R. Piechocki, and K. Uhlenhaut (1974). Über die Ausbreitung des Bienenfressers und die ersten Brutnachweise 1973 in der DDR. Falke 21: 42–51, 95–101. Close , 404 Peters, T., and H. Trapp (2006). Bruten des Bienenfressers (Merops apiaster) bei Meißen 2004–2006. Actitis 41: 3–20. Close , 416 Ramachers, P. (2010). Erfolgreiche Erstbrut des Bienenfressers (Merops apiaster) im Landkreis Kaiserslautern. Fauna und Flora in Rheinland-Pfalz 11: 1311–1318. Close ; Bastian and Bastian, unpublished data). Mobbing by other birds has been thought to be because these other species want the food items bee-eaters are carrying, and thus they may be kleptoparasitic, or it could be a reaction to the pointed wings of flying birds, such that other species mistake bee-eaters for raptors (538 Conrads, K., and M. Quelle (1981). Erster Brutnachweis des Bienenfressers (Merops apiaster) 1978 in Westfalen. Berichte des Naturwissenschaftlichen Vereins Bielefeld 25:53-80. In German Close , 273 Krimmer, M., R. Piechocki, and K. Uhlenhaut (1974). Über die Ausbreitung des Bienenfressers und die ersten Brutnachweise 1973 in der DDR. Falke 21: 42–51, 95–101. Close ). European Bee-eaters react with beak nudges in the direction of the mobbing birds (273 Krimmer, M., R. Piechocki, and K. Uhlenhaut (1974). Über die Ausbreitung des Bienenfressers und die ersten Brutnachweise 1973 in der DDR. Falke 21: 42–51, 95–101. Close ).

Kinds of Predators

The European Bee-eater is not preferred prey for other birds or mammals (637 Petrescu, A., and C. Adam (2001). Interspecific relations in the populations of Merops apiaster L. (Aves: Coraciiformes) of southern Romania. Travaux du Museum National d'Histoire Naturelle "Grigore Antipa" 43:305-322. Close ) and is only seldomly predated. While the European Bee-eater is not frequently predated, those species that have been documented as predators include the Eurasian Sparrowhawk (Accipiter nisus)(643 Mañosa, S., and D. Oro (1991). Contribución al conocimiento de la dieta del gavilán Accipiter nisus en la comarca de La Segarra (Cataluña) durante el periodo reproductor. Ardeola 38:289-296. Close , 644 Tervelde, L. (2004). Bijeneter Merops apiaster als prooi voor een Sperwer Accipiter nisus. De Takkeling 12:145-146. In Dutch Close ), Booted Eagle (Hieraaetus pennatus) (645 Nevado, J. C., L. García, and J. A. Oña (1988). Sobre la alimentación del águila calzada (Hieraaetus pennatus) en las sierras del norte de Almería en la época de reprodución. Ardeola 3:147-150. Close ), Black Kite (Milvus migrans) (23 Valera, F. (2009). Abejaruco europeo – Merops apiaster. In Enciclopedia Virtual de los Vertebrados Españoles (A. Salvador and L.M. Bautista, Editors). Museo Nacional de Ciencias Naturales, Madrid, Spain. Close ), Eurasian Hobby (Falco subbuteo) (637 Petrescu, A., and C. Adam (2001). Interspecific relations in the populations of Merops apiaster L. (Aves: Coraciiformes) of southern Romania. Travaux du Museum National d'Histoire Naturelle "Grigore Antipa" 43:305-322. Close , 646 Probst, R. (2013). Der Baumfalke in Kärnten. Eine inneralpine Studie zur Ökologie des Kleinfalken. Naturwissenschaftlicher Verein für Kärnten, 64. Sonderheft, Klagenfurt, Austria. Close ), Peregrine Falcon (Falco peregrinus) (647 Heredia, B., F. Hiraldo, L. M. González, and J. L. González (1988). Status, ecology and conservation of the Peregrine Falcon in Spain. In Peregrine Falcon Populations: Their Management and Recovery (T. J. Cade, J. H. Enderson, C. G. Thelander, and C. M. White, Editors), The Peregrine Fund Inc., Boise, Idaho, United States. pp. 219–226. Close , 648 Shafaeipour, A. (2014). Prey selection of the Barbary Falcon (Falco pelegrinoides) in south-western Iran. Zoology in the Middle East 60:13-19. Close ), and Long-eared Owl (Asio otus) (637 Petrescu, A., and C. Adam (2001). Interspecific relations in the populations of Merops apiaster L. (Aves: Coraciiformes) of southern Romania. Travaux du Museum National d'Histoire Naturelle "Grigore Antipa" 43:305-322. Close ), although it is uncertain whether the captured birds were always adults. European Bee-eaters listed in the prey list of the Egyptian Vulture (Neophron percnopterus)( 649 Donázar-Sancho, J. A., and O. Ceballos-Ruiz (1988). Alimentación y tasas reproductoras del alimoche (Neophron percnopterus) en Navarra. Ardeola 35:3-14. Close ) were most likely found dead. During migration, it is sometimes predated by the Eleonora's Falcon (Falco eleonorae) (650 Walter, H. (1979). Eleonora's Falcon. Adaptation to Prey and Habitat in a Social Raptor. Chicago University Press, Chicago. Close , 651 Martín, A., and J. A. Lorenzo (2001). Aves del Archipiélago Canario. Francisco Lemus, La Laguna, Spain. Close ), Sooty Falcon (Falco concolor) (248 Fry, C. H., S. Keith, and E. K. Urban, Editors (1988). The Birds of Africa. Volume 3. Parrots to Woodpeckers. Academic Press, London, UK. Close ), and Eurasian Goshawk (Accipiter gentilis) (637 Petrescu, A., and C. Adam (2001). Interspecific relations in the populations of Merops apiaster L. (Aves: Coraciiformes) of southern Romania. Travaux du Museum National d'Histoire Naturelle "Grigore Antipa" 43:305-322. Close ). There is one record from Malta of a European Bee-eater that was killed by a Yellow-legged Gull (Larus michahellis) (652 Borg, J., J. Sultana, and R. Cachia-Zammit (1992-94). Predation by the Yellow-legged Gull Larus cachinnans on Storm Petrel Hydrobates pelagicus on Filfla. Il-Merill 28:19-21. Close ). The Eurasian Kestrel (Falco tinnunculus), Eurasian Hobby, Eurasian Sparrowhawk, Eurasian Magpie (Pica pica), and Carrion Crow (Corvus corone) are potential predators of nestlings.

Mammalian predators include the mainland raccoon dog (Nyctereutes procyonoides), least weasel (Mustela nivalis), marten (Martes sp.), European badger (Meles meles), red fox (Vulpes vulpes), and feral dogs. Reptiles, including Montpellier snake (Malpolon monspessulanus), horseshoe whip snake (Hemorrhois hippocrepis), and ocellated lizard (Timon lepidus) have all been documented as nest predators that eat eggs and nestlings (331 Swift, J. J. (1959). Le Guêpier d’Europe Merops apiaster L. en Camargue. Alauda 27: 97–143. Close , 653 Pleguezuelos, J. M., S. Honrubia, and J. A. Mateo (1999). Lacerta lepida (Ocellated Lizard). Necrophagia and oophagia. Herpetological Review 30:42. Close , 23 Valera, F. (2009). Abejaruco europeo – Merops apiaster. In Enciclopedia Virtual de los Vertebrados Españoles (A. Salvador and L.M. Bautista, Editors). Museo Nacional de Ciencias Naturales, Madrid, Spain. Close ). Occasionally, young nestlings are even attacked and killed in the breeding burrow by larger ground beetles (Carabidae; 637 Petrescu, A., and C. Adam (2001). Interspecific relations in the populations of Merops apiaster L. (Aves: Coraciiformes) of southern Romania. Travaux du Museum National d'Histoire Naturelle "Grigore Antipa" 43:305-322. Close ).

Manner of Predation

More birds likely fall victim to avian predators during incubation and the nestling feeding period than any other time of the year. When preying on nestlings, avian predators either patrol in slow flight along the colony wall to catch careless young from the nest entrance, or they hang from the breeding burrow and try to reach the young (228 Berkelder, R., V. van der Spek, D. Laponder, J. Duindam, and T. van Schie (2006). [Breeding Bee-eaters Merops apiaster at Monster, the Netherlands, in 2005]. Limosa 79: 155–162. In Dutch with English summary Close , 421 Zieger, G. (2013). Brut eines Bienenfressers im Landkreis MSP 2013. Jahrbuch der Ornithologischen Arbeitsgemeinschaft in Unterfranken, Region 2 2013: 38–42. Close ). Many mammals will catch either adults or eat nestlings and eggs by excavating nests from the top of a bank, from the bottom of a bank, or by digging directly into a bank with a shallow slope that provides access to the burrows (654 Sieber, O. (1980). Causal and functional aspects of brood distribution in Sand Martins (Riparia riparia L.). Zeitschrift für Tierpsychologie 52:19-56. Close , 637 Petrescu, A., and C. Adam (2001). Interspecific relations in the populations of Merops apiaster L. (Aves: Coraciiformes) of southern Romania. Travaux du Museum National d'Histoire Naturelle "Grigore Antipa" 43:305-322. Close , 23 Valera, F. (2009). Abejaruco europeo – Merops apiaster. In Enciclopedia Virtual de los Vertebrados Españoles (A. Salvador and L.M. Bautista, Editors). Museo Nacional de Ciencias Naturales, Madrid, Spain. Close , 447 Heneberg, P. (2013). Decision making in burrowing birds: Sediment properties in conflict with biological variables. Quaternary International 296: 227–230. Close , 125 Koshelev, V. A., O. Y. Pakhomov, and V. A. Busel (2020). The formation of sclerophilic ornythocomplexes in the quarries in the South of Ukraine and their conservation prospects. Ecology, Environment and Conservation 26: 411–419. Close ; Bastian and Bastian, unpublished data). Often, not all birds of a nest are preyed upon.

Response to Predators

In colonies with increased risk of predation, the European Bee-eater appears to vary the egg mass within a clutch. Increased variation in egg mass also led to increased variation in nestling mass at nests that were at high predation risk (655 Wagner, G. F., E. Mourocq, and M. Griesser (2019). Elevated nest predation risk promotes offspring size variation in birds with prolonged parental care. EcoEvoRxiv January 29. Close ). However, the mechanisms behind egg mass variation and its relation to predation risk needs further study and clarification.

When a larger raptor appears, birds prefer to hide between tree-branches, which serve as a vantage-point; birds are able to effectively hide in the treetops, as the olive-colored mantle protects them from aerial predators, and their blue body plumage can help to camouflage them from below (637 Petrescu, A., and C. Adam (2001). Interspecific relations in the populations of Merops apiaster L. (Aves: Coraciiformes) of southern Romania. Travaux du Museum National d'Histoire Naturelle "Grigore Antipa" 43:305-322. Close ). They respond to the Eurasian Hobby, Peregrine Falcon, Eurasian Sparrowhawk, and Eurasian Goshawk with warning calls and rapidly ascending to the sky in a tight flock closed swarm (228 Berkelder, R., V. van der Spek, D. Laponder, J. Duindam, and T. van Schie (2006). [Breeding Bee-eaters Merops apiaster at Monster, the Netherlands, in 2005]. Limosa 79: 155–162. In Dutch with English summary Close , 404 Peters, T., and H. Trapp (2006). Bruten des Bienenfressers (Merops apiaster) bei Meißen 2004–2006. Actitis 41: 3–20. Close , 656 Pittocopitis, R. (2008). Ergänzende Beobachtungen zu Merops apiaster unter besonderer Berücksichtigung der Ursachen für einen schlechten Bruterfolg in 2007. Ornithologische Mitteilungen 60:112-119. Close ). They attack and chase the Little Owl (Athene noctua), although it is unclear whether the Little Owl actually predates European Bee-eater; bee-eater feathers or bones have never been found in Little Owl pellets (657 Petrescu, A. (1994). Contributions á la connaissance de la nourriture de la chouette Athene noctua (Aves, Strigiformes). Travaux du Muséum National d'Histoire naturelle "Grigore Antipa" 34:391-400. Close ). The response to the Carrion Crow, Eurasian Magpie, and Eurasian Kestrel is variable; sometimes no reaction occurs (4 Walter, B., K. Nottmeyer-Linden, and U. Romer (1992). Observations of a brood of Bee-eaters (Merops apiaster) at Bad Laer in lower Saxony. Charadrius 28(1): 33–43. [In German]. Close , 228 Berkelder, R., V. van der Spek, D. Laponder, J. Duindam, and T. van Schie (2006). [Breeding Bee-eaters Merops apiaster at Monster, the Netherlands, in 2005]. Limosa 79: 155–162. In Dutch with English summary Close , 404 Peters, T., and H. Trapp (2006). Bruten des Bienenfressers (Merops apiaster) bei Meißen 2004–2006. Actitis 41: 3–20. Close ), sometimes they are attacked even at a great distance (658 Besson, J. (1970). Réactions du Gravelot à collier interrompu et du Guêpier à l'égard du Faucon hobereau. Nos Oiseaux 30:264 Close , 282 Reid, J. C. (1974). Bienenfresser-Beobachtungen im östlichen Österreich. Egretta 1: 15–22. Close , 433 Wiegank, F. (1977). Brut des Bienenfresser, Merops apiaster L., 1976 im Raum Zeitz-Weißenfels. Beiträge zur Vogelkunde 23: 229–232. Close ), and sometimes they are chased way (228 Berkelder, R., V. van der Spek, D. Laponder, J. Duindam, and T. van Schie (2006). [Breeding Bee-eaters Merops apiaster at Monster, the Netherlands, in 2005]. Limosa 79: 155–162. In Dutch with English summary Close , 533 Handl, B. (2009). Vergleichende Studie an frei lebenden und im Zoo gehaltenen Bienenfresser (Merops apiaster). Diploma Thesis, Universität Wien, Austria. Close ). The Black Kite, Eurasian Hobby, Eurasian Kestrel, and Carrion Crow that patrol the colony wall and try to capture larger nestlings sitting at the entrances of burrows are attacked by the whole breeding colony (418 Bastian, H.-V., and A. Bastian (2016). Bienenfresser Merops apiaster LINNAEUS, 1758. In Die Vogelwelt von Rheinland-Pfalz. Bd. 3 Greifvögel bis Spechtvögel (Accipitriformes – Piciformes) (C. Dietzen, T. Dolich, T. Grunwald, P. Keller, A. Kunz, M. Niehuis, M. Schäf, M. Schmolz and M. Wagner, Editors). Fauna und Flora in Rheinland-Pfalz, Beih. 48, Landau, Germany. pp. 752–768. Close ). In general, the Red Kite (Milvus milvus) and Common Buzzard (Buteo buteo) remain unnoticed (8 Glutz von Blotzheim, U. N., and K. M. Bauer (1980). Handbuch der Vögel Mitteleuropas. Band 9 Columbiformes-Piciformes. Akademische Verlagsgesellschaft, Wiesbaden, Germany. Close , 4 Walter, B., K. Nottmeyer-Linden, and U. Romer (1992). Observations of a brood of Bee-eaters (Merops apiaster) at Bad Laer in lower Saxony. Charadrius 28(1): 33–43. [In German]. Close , 228 Berkelder, R., V. van der Spek, D. Laponder, J. Duindam, and T. van Schie (2006). [Breeding Bee-eaters Merops apiaster at Monster, the Netherlands, in 2005]. Limosa 79: 155–162. In Dutch with English summary Close ), or birds will give alarm calls without flying up (377 Baum, L., and E. Jahn (1965). Brut des Bienenfressers, Merops apiaster, 1964 in Schleswig-Holstein. Corax 1(17): 73–82. Close ).

Potential ground predators like the red fox (Vulpes vulpes), marten (Martes sp.), and European ground squirrel (Spermophilus citellus), as well as humans, elicit strong reactions. Adults interrupt feeding at once, circling with food in their bills over the colony (538 Conrads, K., and M. Quelle (1981). Erster Brutnachweis des Bienenfressers (Merops apiaster) 1978 in Westfalen. Berichte des Naturwissenschaftlichen Vereins Bielefeld 25:53-80. In German Close ); if the disturbance persists, they perch in trees or bushes in sight of the colony wall. Feeding can be suspended for up to 2 h (217 Harms, H., and B. Ladendorf (2015). Beobachtungen zum Brutverlauf eines Bienenfresserpaares Merops apiaster im Kieswerk Hohen Wangelin. Ornithologischer Rundbrief für Mecklenburg-Vorpommern 48: 208–210. Close ), or predators can be attacked by the whole colony (659 Ursprung, J. (1984). [On the breeding and nesting of Merops apiaster in eastern Austria]. Egretta 27(2):68-79. [In German]. Close ).

The European Bee-eater appears to be able to estimate a predation risk and relocate when a threat is perceived at a foraging site, with males being more likely to switch locations (660 Yosef, R., P. Fehervari, and N. Yosef-Sukenik (2013). Sex dependent risk management in face of perceived danger of socially foraging Bee-eaters (Merops apiaster) during migration. Behavioural Processes 100:169–173. Close ).