Breeding Success and Sex Predict Return Rates in the Common Kingfisher Alcedo atthis

The Common Kingfisher Alcedo atthis and the Greater Pied Kingfisher Ceryle lugubris breed sympatrically along the Chikuma River in central Japan. These kingfisher species differ in body size, with the latter being much larger than the former. To understand the potential mechanisms that might play a role in food-niche differentiation between these two species, we studied their foraging ecology in the breeding seasons of 2005 and 2006. Specifically, we compared the foraging habitat, foraging behavior, and food delivered to nestlings between the two kingfishers. We video-recorded the food delivered to nestlings during the day, and our results indicated that these species differed in their foraging ecology in several respects: (1) Common Kingfishers caught prey at sites where the water flow was calm, while Greater Pied Kingfishers hunted at sites where the water flowed rapidly; (2) Greater Pied Kingfishers dove from a higher position and caught fish in deeper water than Common Kingfishers; and (3) Co...

Capsule The winter diet of Common Kingfishers Alcedo atthis using two rivers in central Spain was 94.9% fish, all of which were non-native species. Aims To determine the composition Common Kingfisher diet in an area recently colonized by non-native fish species, and to compare estimated prey size during the winter to that of fish fed to nestlings during the breeding season. Methods The diet was studied by analysis of pellets collected from the River Duero (lentic, still water) and River Pisuerga (lotic, riverine) in central Spain. Fish size (total length and biomass) calculated from paired remains contained in each pellet. Results Prey items were almost exclusively fish (94.9% of all prey), with a small proportion of non-native Red Swamp Crayfish Procambarus clarkii (4.9%) and aquatic insects (0.2%). The diet consisted of only five species of fish, all of which were non-native. The Common Bleak Alburnus alburnus and Eastern Mosquitofish Gambusia holbrooki were the prey captured most often in the River Pisuerga and River Duero, respectively. Estimated length of fish prey ranged from 1.5 to 10.5 cm, but 53.6% of individuals were between 3 and 5 cm. Mean biomass of the fish consumed was also small (1.08 g per fish). Mean values of both fish total length and biomass were lower than the measurements reported elsewhere in Europe during the breeding season. Conclusion Native fish species have disappeared from the diet of Common Kingfishers in our study area, probably because the non-native species are more common.

Generalist predators are able to exploit diverse prey depending on its spatial and temporal availability. Here, we examined how the diet of a generalist fish-eating predator, the Common Kingfisher Alcedo atthis, varied at the small spatial scale and throughout the breeding season. Analysis of debris collected from six nests showed that the diet composition of five breeding pairs significantly differed, although they bred in close proximity. Prey choice also differed between birds that reared their young at the beginning and at the end of the breeding season. Overall, kingfishers consumed seven fish species, with Roach Rutilus rutilus as the most frequent prey taken both at the beginning and at the end of the breeding season.

Capsule Non-fish prey constitutes an important component of the diet of many fish-eating birds.Aims In the present study, the role of non-fish prey in the diet of the Common Kingfisher Alcedo atthis was evaluated.Methods The species and size spectrum of prey in the diet was studied at 15 nest sites on 6 trout streams, 1 river and 1 reservoir in the Czech Republic, using the analysis of the nest sediment.Results 16 933 individual prey items were identified (99.93% fish and 0.07% non-fish prey). European Perch Perca fluviatilis, Roach Rutilus rutilus and Bleak Alburnus alburnus dominated the diets on the reservoir; Gudgeon Gobio gobio, European Chub Squalius cephalus and Roach those on the river; and Gudgeon, European Chub, Bullhead Cottus gobio, Roach, Bleak and Brown Trout Salmo trutta m. fario those in the trout streams. The sizes of their fish prey ranged from 16 to 134 mm in total length (LT) with an average size of 66 mm. The remains of non-fish prey were detected in only 5 of 30 nest sediments. The non-fish prey were mostly composed of large aquatic insect larvae: dragonflies Anax sp. and Aeshna sp., Common Club-tail Gomphus vulgatissimus and Great Diving Beetle Dytiscus marginalis. Kingfishers also took Spiny-cheek Crayfish Orconectes limosus, Newt Triturus sp. and a Lizard Lacerta sp. The estimated sizes of the non-fish prey ranged from 30 to 90 mm.Conclusion The catch of non-fish prey appears to be accidental, and is more likely a result of target misinterpretation (fish-like body and fish-like movement) than a Kingfisher regularly switching to prey other than fish. The unique finding of a Lizard is the first record of an amniotic vertebrate in the diet of Common Kingfisher.

Positive interactions between birds and mammals are a fascinating aspect of animal behaviour. Feeding associations may consist of local enhancement or facilitation, and in the latter case, of commensalism or mutualism depending on the benefits received by the facilitator. We report here on a previously undescribed feeding association between piscivorous birds and Eurasian otters Lutra lutra. In Spain, common kingfisher Alcedo atthis and grey heron Ardea cinerea were observed closely following foraging otters and benefited from feeding opportunities provided by these. Behavioural observations of otters in central Spain (28.4 hr; 19 days) revealed that an association with kingfishers occurred in 33% of otter foraging events (n = 92). Simultaneous observations in northern Spain (14.2 hr; 16 days) showed an association between otters and kingfishers or grey herons in 41.6% and 11.7% of otter foraging events (n = 77), respectively. The association probability between kingfishers and otters increased significantly when otters foraged closer to the shore and on small fish rather than other prey (crayfish or large fish). Birds fed on prey remain left by the feeding otters, on small fish captured by otters when these were satiated and playing, or on prey displaced by otters. Our observations are consistent with facilitation and commensalism: piscivorous birds gained feeding opportunities provided by the otters, with no apparent costs or benefits to the latter. Similar feeding associations have been described between other species of otters and piscivorous birds (kingfishers, herons, egrets, storks) in Asia, South America and Southern Africa, but had not yet been described in Europe. The occurrence of piscivorous bird–otter associations in different species and regions suggests that this commensalism may be often overlooked but widespread. We have shown that the association can be frequent and is context‐dependent, with benefits for associating birds depending on otters´ behaviour and targeted prey.

Survival is a major life history trait known to be age- and/or sex-specific in many bird species. Regardless of age and sex, the survival of resident birds can be reduced by high mortality during harsh winters. In this study, we used mark-recapture data collected during 2014–2018 to assess return rates and apparent survival in relation to age, sex and winter severity in two Common Kingfisher Alcedo atthis populations from Slovakia and the Czech Republic. During five seasons, we ringed a total of 2261 Kingfishers, 353 adults and 1908 nestlings, which yielded 85 recaptures. In total, we recaptured 13.0% of birds ringed as adults (17.5% males, 8.2% females) and 0.8% of those ringed as nestlings (0.7% males, 0.1% females). Surviving adults returned to the previously used nesting hole in 87.0% of cases. Young birds never returned to the hole where they hatched. Breeding dispersal was significantly shorter than natal dispersal. Returned birds started to breed significantly earlier in the year of their return than in the previous year, but breeding success did not vary between these years. Estimated values of apparent survival were quite low, varied annually, and were negatively affected by winter severity. Males did not differ in apparent survival from females, but adults survived better than juveniles. We discuss the difference in apparent survival between the age categories by varying degrees of site fidelity/philopatry and different mortality rates.

Northern gannets (Sula bassana) are considered to obtain prey usually by rapid, vertical, shallow plunge dives. In order to test this contention and investigate underwater foraging behaviour, we attached two types of data-logging systems to 11 parental northern gannets at Funk Island in the North-Wiest Atlantic. We documented, for the first time to the authors' knowledge, gannets performing long, flat-bottomed, U-shaped dives that involved underwater wing propulsion as well as rapid, shallow, V-shaped dives. The median and maximum dive depths and durations were 4.6 and 22.0 m and 8 and 38 s, respectively. Short, shallow dives were usually V-shaped and dives deeper than 8 m and longer than 10 s were usually U-shaped, including a period at constant depth (varying between 4 and 28s with median 8s). Diving occurred throughout the daylight period and deepest dives were performed during late morning. On the basis of motion sensors in the loggers and food collections from telemetered birds, we concluded that extended, deep dives were directed at deep schools of capelin, a small pelagic fish, and we hypothesized that V-shaped dives were aimed at larger, pelagic fishes and squids. Furthermore, these V-shaped dives allowed the birds to surprise their pelagic prey and this may be critical because the maximum swimming speeds of the prey species may exceed the maximum dive speeds of the birds.

Automatic bird sound detection in long real-field recordings: Applications and tools

The Common Kingfisher Alcedo atthis is a fish-eating predatory bird that is reported to prey mainly on pelag- ic, benthic, or both types of fish prey. It still remains unclear whether the species has the capacity to prey indistinctly on all types of fish, regardless of their position within the water column. The aim of our study was to test if kingfishers are able to select particular fish prey or if, by contrast, they feed on the most abundant and accessible fish. We identi- fied the fish prey consumed by kingfishers at 14 nests in total, and also sampled, using electrofishing surveys, fish prey availability on the river stretches where the nests were located. We used Savage's index in order to check whether there was prey selection. Overall, kingfishers preyed upon eight fish species: Bermejuela Acondrostoma arcasii, Bleak Alburnus alburnus, Pyrenean Stone Loach Barbatula quignardi, Ebro Barbel Luciobarbus graellsii, Pyrenean Gudgeon Gobio lozanoi, Ebro Nase Parachondrostoma miegii, Pyrenean Minnow Phoxinus bigerri, and Brown Trout Salmo trutta. The most con- sumed prey were pelagic species (Pyrenean Minnow and Brown Trout). These results suggest that the Kingfisher preys on pelagic species because of their accessibility and avoids bottom-dwelling species, which may remain hidden from this predator. kingfishers preyed mostly on fish of 50 to 60 mm in length, but mean size values varied prey-specifically, possibly because of the vertical specific distribution in relation to the fish age and species and, finally, prey availability.

This note documents the first ever recorded observation – with photographs – of a Common Kingfisher Alcedo atthis predating on a lizard. Specifically, the Kingfisher captured a Wall Lizard Podarcis muralis on the banks of the river Fluvià in Olot, Catalonia, Spain, in 2025, a sighting that adds a rare component to the known predominantly piscivorous diet of this species.

La monogamia es considerada el sistema de apareamiento común en las aves. Sin embargo, análisis moleculares han revelado que, en la mayoría de las aves, pueden ocurrir casos de emparejamientos extrapareja, así como de intercambios de parejas durante o entre las temporadas de reproducción. En este estudio nos centramos en una población de martín pescador común localizada en el río Danubio (Eslovaquia) durante tres temporadas consecutivas de reproducción (2016-2018), analizando un total de 648 individuos correspondientes a 71 adultos y 577 polluelos de 92 nidadas. Los análisis mostraron que seis pollos (1,04%) de tres crías diferentes (3,26%) tenían un padre diferente, aunque ninguno de ellos tuvo una madre distinta. Además, detectamos dos machos polígamos simultáneamente (5,13%). Mientras que un macho se apareó con dos hembras, otro tuvo cuatro parejas. En siete casos (9,6%) encontramos evidencias de intercambio de pareja entre distintas crías, de las que en tres ocasiones (4,11%) se intercambiaron hembras y cuatro veces (5,48%) machos. En general, estos resultados indican que el martín pescador común es una especie social, genéticamente monógama, con una rara ocurrencia de pollos procedentes de emparejamientos extrapareja y poligamia, y en ningún caso procedentes de parasitismo de nido intraespecífico. Este sistema de emparejamiento viene en parte apoyado por el hecho de que, en esta especie, el cuidado parental es llevado a cabo tanto por parte de la hembra como del macho durante un período de reproducción generalmente extenso.—Cepková, M., Melišková, M. y Rubáčová, L. (2023). Baja paternidad extrapareja y poligamia en el martín pescador común Alcedo atthis. Ardeola, 70: 41-58.

Influence of age and body condition on breeding performance in Common Kingfisher Alcedo atthis

О двукратном заселении нор обыкновенным зимородком Alcedo atthis (Alcedinidae, Aves).-Котюков Ю. В. -В 1976 -2000 гг.проводили учёты нор зимородка во время лодочных маршрутов на реках Пра и Ока в Рязанской области.При каждом посещении норы обследовали её содержимое, чтобы установить дату начала и величину кладки, размеры и форму яиц, число и возраст птенцов, отлавливали взрослых птиц.На контрольном участке р.Пра в границах Окского заповедника найдено1087 жилых нор, из которых 17 было заселено повторно в течение сезона.За пределами контрольного участка на реках Ока и Пра найдено 660 жилых нор, в том числе 11 заселённых повторно.Показано, что повторное заселение нор обусловлено, прежде всего, дефицитом гнездопригодных обрывистых склонов и в меньшей степени -дефицитом времени, необходимого для постройки норы к началу очередной кладки.Случаи повторного заселения нор регистрируются достоверно чаще в те годы, когда увеличивается доля самок, гнездящихся 3 -4 раза в течение сезона.В заселённых повторно норах, без должной интерпретации находок, можно наблюдать увеличенные относительно видовой нормы размеры кладки и продолжительность цикла

Sex allocation theory predicts equal offspring sex ratio when costs/benefits of producing each sex are comparable. However, when costs of rearing or fitness values of sexes vary, skewed offspring sex ratio toward the one sex may be beneficial. In this study we analysed seasonal secondary sex ratio (proportion of males) in broods of the Common Kingfisher Alcedo atthis, the socially monogamous, three- to four-brooded (per season) species with biparental care in which adult females are slightly larger than males. Fieldwork was carried out in the Danube river system from Bratislava to Gabcikovo (SW Slovakia) during 2014–2018. In total, 959 nestlings from 149 broods of 78 breeding pairs were sexed, amongst which 483 were males and 476 were females. We considered the following assumptions: 1) no seasonal shift in sex ratio, as studied population occupies habitats rich in food; 2) female biased broods early in the season, as females' rapid maturation enables them to breed in the season they have been born; 3) male biased broods early in the season as several young males have been documented to be nest helpers. However, only a few such cases were observed, so it should be treated with caution. The sex ratio of individual broods ranged from 0 (all female) to 1 (all male), but the mean nestling sex ratio did not deviate from parity. We found no effect of year, brood size, or laying date. Thus, our results agree with outcomes of other avian studies where balanced seasonal sex ratio has been found.

ABSTRACTCapsule: Common Guillemots Uria aalge show delayed breeding and marked age-related changes in reproductive success consistent with improved performance with experience.Aims: To determine age of first breeding and age-related effects on breeding phenology and success of Common Guillemots.Methods: Resighting data from a long-term colour-ringing study of Common Guillemot chicks were combined with observations of breeding phenology and success to follow the recruitment process, breeding phenology and success of 62 birds at a major North Sea colony over a 30-year period.Results: The median age of first breeding of Common Guillemots was 6.6 years. There were no detectable costs of first breeding on return rates or the likelihood of breeding the next season but first time breeders bred later and less successfully. Age of first breeding and lifetime breeding success both varied among individuals but there was no clear optimal age of first breeding and early first breeding was not associated with higher lifetime breeding success.Conclusions: Common Guillemots in the Isle of May population delayed breeding for 3–4 years beyond physiological maturity. The marked increase in breeding success with age was consistent with improved performance with experience rather than selection for higher quality individuals. Findings from this study will inform population models by providing improved estimates of age of first breeding and age-related changes in reproductive performance.