Behavior

The Ruddy Shelduck is a highly aggressive species, especially during the breeding season. Physical interactions include chases and pecking attacks against predators, conspecifics, and other species. Daily time budgets can vary throughout the year, with feeding activity decreasing in April, and an increase in flight, courtship, and agonistic behavior during the breeding period. It is generally monogamous, and pair bonds may last several years. Courtship displays can be initiated by the male or the female.

Walking, Running, Hopping, Climbing, etc.

On land it moves comfortably, as seen in the movement of adults with newly hatched ducklings from nest sites to the nearest wetlands; birds often traverse several kilometers on foot during these movements (see Nest Site). The running speed on the ground has not been studied. However, Schäffer (128 Schäfer, E. (1938). Ornithologische Ergebnisse zweier Forschungsreisen nach Tibet. Journal für Ornithologie 86 (Supplement):1–349. Close ) noted in Tibet that ducklings and their parents ran very fast on the ground when he tried to capture them.

Flight

Excellent flier, as demonstrated by its migration across thousands of kilometers from Central Asia to wintering sites in southern Asia and southeastern Europe. See Movements and Migrations.

Swimming

Birds swim in water when foraging, but there is no specific information or studies on swimming in Ruddy Shelduck.

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

No information.

Sleeping, Roosting

No information.

Daily Time Budget

In the Oum El Bouaghi wetlands (Hauts Plateaux, Algeria), the mean percent of daylight hours spent on activities throughout the year were as follows: feeding (50.6% ± 1.8 SE of time), loafing (21.8% ± 1.0 SE), sleeping (11.6% ± 1.0 SE), swimming (7.4% ± 0.7 SE), preening (6.7% ± 0.8 SE), flying (1.0 % ± 0.2 SE), courtship (0.9% ± 0.2 SE), and agonistic behavior (0.3% ± 0.1 SE) (n = 328 h). The maximum time devoted to feeding peaked during winter and decreased from April onwards, when there was an increase of flight, courtship, and agonistic behavior (63 Boulkhssaïm, M., A. Ouldjaoui, A. H. Alfarhan, and B. Samraoui, B. (2013). Distribution, breeding phenology and time budget of Ruddy Shelduck Tadorna ferruginea during the annual cycle in the Hauts Plateaux, north-east Algeria. Ostrich 84(2):129-136. Close ).

In another study carried out at Oglat Eddaira Lake (northeastern Hauts Plateaux, Algeria), most of the diurnal time budget across the year was devoted to feeding (68%), followed by preening (16.77%), swimming (9.85%), sleeping (4.67%) and flying (1.22%) (171 Benaradj, A., N. Charchar, H. Boucherit, M. L. Ouakid, and M. Houhamdi (2022). Phenology and diurnal behaviour of Ruddy Shelduck Tadorna ferruginea at Oglat Eddaira (Ain Ben Khlil) wetland, Southwest of Algeria. Ekológia (Bratislava) 41(1):70–77. Close ). In wetlands of the Oued Righ valley (Algerian Sahara), diurnal time budget in winter was mainly devoted to feeding (51.2%), followed by sleeping (18.8%), swimming (9.3%), preening (6.3%), agonistic behavior (4.38%), courtship (3.5%), resting (3.0%), flying (2.33%), and walking (0.6%) (172 Nouidjem, Y., A. Zoubiri, S. Merouani, and F. Mimeche (2021). Ecology and behavioral response of Ruddy Shelduck (Tadorna ferruginea) in the wetland complex of Oued Righ valley (Algerian Sahara). Algerian Journal of Biosciences 02(01):1–5. Close ).

Similarly, the predominant diurnal activity at Chott el Hodna (central Hauts Plateaux, Algeria) throughout the year was feeding (50.5%), followed by sleeping (20.5%), swimming (8%), preening (7%), courtship (4.1%), resting (4%), agonistic behavior (3%), flying (1.5%), and walking (1%) (173 Bounab, C., Y. Nouidjem, E. Bensaci, E. Y. Guergueb, A. Chagra, M. Bara, A. Bouzegag, M. Benyahia, and M. Houhamdi (2017). Study of the Ruddy Shelduck (Tadorna ferruginea) diurnal behavior in Chott El-Hodna (Central Haut Plateaux of Algeria). Journal of Entomology and Zoology Studies 5(2):1034–1037. Close ).

In Lake Poyang (Jiangxi Province, China), most of the diurnal time budget during the winter season was devoted to foraging (51.63 %), followed by resting (25.76 %), preening (9.05 %), locomotion (5.89 %), vigilance (5.34 %), flying (1.19 %), and agonistic behavior (1.14 %) (164 Shao, M., J. Zeng, W. He, Y. Zhi, H. Gong, F. Yang, and N. Dai (2022). Wintering behavior and foraging strategies of six wild duck species in Poyang Lake. Chinese Journal of Ecology 41(2):294–299. Close ). Wintering pairs of Ruddy Shelduck at Lashihai Lake (China) significantly increased feeding time from January (52.4% in males, 62.6% in females) to March (72.4% in males, 76.7% in females) (174 Quan, R. C., and L. W. Cui (2013). Winter pairs of ruddy shelducks at Lashahai Lake, southwest China. Integrative Zoology 8(s1):46-49. Close ).

For Ruddy Shelduck wintering at Lake Kuyucuk (Türkiye), most flights between roosting sites and surrounding farmland for foraging were concentrated during the early morning and late afternoon (175 Meissner, W., and M. Remisiewicz (2008). Daily arrival and departure patterns of Ruddy Shelduck Tadorna ferruginea, Northern Pintail Anas acuta and Mallard Anas platyrhynchos during early autumn at Kuyucuk Lake, northeastern Turkey. Podoces 3(1–2):39–44. Close ).

Vigilant behavior has been little studied. Wintering pairs spent much time lifting their heads periodically and scanning for 1–3 s when foraging on grassland. Males did not significantly vary their scanning rates between January and March, but the scanning rate of female significantly differed depending on distance from the male, being lower when closer to its mate (176 Quan, R. C., L. W. Cui, and X. J. Wen (2003). Sexual Differences in Vigilance of Paired Ruddy Shelduck in Winter. Waterbirds 26(3):335–337. Close ).

Ruddy Shelduck is a highly aggressive species, especially during breeding season (177 Johnsgard, P. A. (1965). Handbook of Waterfowl Behavior. Cornell University Press, Ithaca, New York, USA. Close , 3 Cramp, S., and K. E. L. Simmons, Editors (1977). The Birds of the Western Palearctic. Volume 1. Ostrich to Ducks. Oxford University Press, Oxford, UK. Close , 33 Hughes, B., and A. J. Green (2005). Ruddy Shelduck Tadorna ferruginea. In Ducks, geese and swans. Volume 1: General chapters, and Species accounts (Anhima to Salvadorina) (J. Kear, Editor). Oxford University Press, Oxford. pp. 426–429. Close ). However, when in flocks during molting and wintering, there are few aggressions, and individual birds maintain distance from each other (3 Cramp, S., and K. E. L. Simmons, Editors (1977). The Birds of the Western Palearctic. Volume 1. Ostrich to Ducks. Oxford University Press, Oxford, UK. Close ).

Physical Interactions

Physical interactions include chasing and pecking attacks on predators, conspecifics, and other species. It usually strikes with wings in addition to pecking (177 Johnsgard, P. A. (1965). Handbook of Waterfowl Behavior. Cornell University Press, Ithaca, New York, USA. Close , 3 Cramp, S., and K. E. L. Simmons, Editors (1977). The Birds of the Western Palearctic. Volume 1. Ostrich to Ducks. Oxford University Press, Oxford, UK. Close ).

Intraspecific Interactions

During the threat display, it spreads its wings somewhat, fans the tail, and lifts the head and bill while uttering threat calls ( 3 Cramp, S., and K. E. L. Simmons, Editors (1977). The Birds of the Western Palearctic. Volume 1. Ostrich to Ducks. Oxford University Press, Oxford, UK. Close ). These displays can also lead to chasing and pecking (128 Schäfer, E. (1938). Ornithologische Ergebnisse zweier Forschungsreisen nach Tibet. Journal für Ornithologie 86 (Supplement):1–349. Close ).

Interspecific Interactions

In Western Sahara (Morocco), the territory was defended against predators, including Black Kite (Milvus migrans), Osprey (Pandion haliaetus), Booted Eagle (Hieraaetus pennatus), and Brown-necked Raven (Corvus ruficollis) (60 Valverde, J. A. (1957). Aves del Sáhara Español. Estudio Ecológico del Desierto. Instituto de Estudios Africanos, Consejo Superior de Investigaciones Científicas, Madrid. Close ). See Response to Predators.

For other interspecific interactions, see Nonpredatory Interspecific Interactions.

Territorial Behavior

In Western Sahara, territory defense took place on land and in water, and birds showed continuous aggression. Adults attacked opposing pairs with a lowered neck and flattened back, and chased each other in flight (60 Valverde, J. A. (1957). Aves del Sáhara Español. Estudio Ecológico del Desierto. Instituto de Estudios Africanos, Consejo Superior de Investigaciones Científicas, Madrid. Close ).

Mating System

The Ruddy Shelduck is primarily monogamous, and seems to form pairs during the winter season, since most birds arrive at the breeding grounds already paired. A male and a female captured and fitted with satellite transmitters at a stopover site in Qinghai (China) continued their southward migration using separate routes until they reached the same wintering area in Myanmar. Subsequently, they were recorded together throughout the winter, and followed a shared route northward during spring migration towards their breeding grounds in Mongolia (133 Prosser, D. J., J. Y. Takekawa, S. H. Newman, B. Yan, D. C. Douglas, Y. Hou, D. Xing, D. Zhang, T. Li, Y. Li, D. Zhao, W. M. Perry, and E. C. Palm (2009). Satellite-marked waterfowl reveal migratory connection between H5N1 outbreak areas in China and Mongolia. Ibis 151(3):568-576. Close ). From 24 March to 13 May 2000, eight paired birds, two flocks of three bird each, and two single birds arrived in the Ulaganskaya steppe (Altai, Russia). In Stavropol Krai (Russia), it migrates to breeding grounds in pairs or in small groups of 4–10 birds in late February–early March (108 Malovichko, L. V., I. A. Zhigarev, G. I. Blokhin, M. K. Chugreev, and V. A. Ostapenko (2018). Sovremennoye sostoyaniye i osobennosti rasprostraneniya Ogarya (Tadorna ferruginea Pallas, 1764) na territorii Stavropilskogo kraia. Vestnik Tverskogo Gosudarstvennogo Universiteta. Seriya: Biologiya i Ekologiya 4:69–80. Close ).

Nonbreeders were also observed in Altai during the nesting period (137 Kuchin, A. P., N. A. Kuchina, and A. N. Konunova (2000). The current state of Ruddy Shelduck in Altai and adjoining steppe plains. Casarca 6:209–220 Close ). Some single males may harass paired males in attempts to mate with the female, as observed in Tibet (128 Schäfer, E. (1938). Ornithologische Ergebnisse zweier Forschungsreisen nach Tibet. Journal für Ornithologie 86 (Supplement):1–349. Close ).

In Askania-Nova (Ukraine), monogamy was the dominant mating system; however, in years of high density, there were also mating groups consisting of one male and 2–4 females (178 Zubko, V. N., A. S. Mezinov, and A. B. Popovkina (2003). Osobennosti gnezdovaniya ogarya Zapovednike ‘Askaniya-Nova’. Casarca 9:183–213. Close ).

Operational Sex Ratio

Average group size of wintering Ruddy Shelduck at Lashihai Lake (China) was 8.6 birds (n = 30 groups), and the overall sex ratio was 1.44:1.00 (M:F), being significantly biased toward males (1.93:1.00) in groups larger than 10 birds (174 Quan, R. C., and L. W. Cui (2013). Winter pairs of ruddy shelducks at Lashahai Lake, southwest China. Integrative Zoology 8(s1):46-49. Close ).

Courtship

In Tibet, males courted females with hanging wings that were strongly stretched forward, and walking around the female with a stretched out and strongly flared neck while making magpie-like creaking sounds (128 Schäfer, E. (1938). Ornithologische Ergebnisse zweier Forschungsreisen nach Tibet. Journal für Ornithologie 86 (Supplement):1–349. Close ).

Females in captivity may incite males with a repeated gaaa call, sticking their neck flat out and performing lateral beak movements directed towards a male, which responds first with a threatening chorr call and later with a friendlier two-syllable cho-ho. The female often continues this until a male threatens the indicated opponent male. The male that reacts more strongly to the female is chosen as the mating partner (169 Heinroth, O. (1911). Beiträge zur Biologie, namentlich Ethologie und Psychologie der Anatiden. Proceedings V of the International Ornithological Congress, Berlin, 1910, 598-702. Close , 177 Johnsgard, P. A. (1965). Handbook of Waterfowl Behavior. Cornell University Press, Ithaca, New York, USA. Close , 8 Bauer, K., and U. Glutz von Blotzheim (1969). Handbuch der Vogel Mitteleuropas. Band 3. Frankfurt am Main, Germany. Close ). Heinroth (169 Heinroth, O. (1911). Beiträge zur Biologie, namentlich Ethologie und Psychologie der Anatiden. Proceedings V of the International Ornithological Congress, Berlin, 1910, 598-702. Close ) observed a correlation between the amount of white plumage on a female's head and the strength of her inciting behavior (177 Johnsgard, P. A. (1965). Handbook of Waterfowl Behavior. Cornell University Press, Ithaca, New York, USA. Close ). From his description, it may be inferred that he suggested that females with more white on head incited more, though this is not explicitly stated.

While wintering from January to March at Lashihai Lake (China), when a single unpaired male approached paired birds within 10 m, the female uttered threat calls, lowered their head, and stretched out their neck. The paired male then uttered threat calls, and displayed by lifting its head and bill, with its tail fanned and wings spread, followed by a rush to the unpaired male that then flew away (n = 3) (174 Quan, R. C., and L. W. Cui (2013). Winter pairs of ruddy shelducks at Lashahai Lake, southwest China. Integrative Zoology 8(s1):46-49. Close ).

Sometimes aerial displays occur in which the male rises high and dives down with wings folded, descending near its mate (7 Isakov, Y. A. (1952). Podsemeystvo utki Anatinae. In Ptitsy Sovetskogo Soyuza. 4. (J. P. Dementiev and N. A. Gladkov, Editors), Gosudartvennoe Izdatel’stvo Sovetskaya Nauka, Moscow, Russia. pp. 344–635. Close ).

Courtship activities were observed at the end of April in Tibet (128 Schäfer, E. (1938). Ornithologische Ergebnisse zweier Forschungsreisen nach Tibet. Journal für Ornithologie 86 (Supplement):1–349. Close ); at Chott el Hodna (Hauts Plateaux, Algeria), courtship activities were observed mainly from January onwards (173 Bounab, C., Y. Nouidjem, E. Bensaci, E. Y. Guergueb, A. Chagra, M. Bara, A. Bouzegag, M. Benyahia, and M. Houhamdi (2017). Study of the Ruddy Shelduck (Tadorna ferruginea) diurnal behavior in Chott El-Hodna (Central Haut Plateaux of Algeria). Journal of Entomology and Zoology Studies 5(2):1034–1037. Close ). The length of the courtship season in Algeria is unknown, but the laying of the eggs takes place between January and April (179 Isenmann, P., and A. Moali (2010). Oiseaux d’Algerie [Birds of Algeria]. Societé d’Études Ornithologiques de France, Muséum National d’Histoire Naturelle, Paris, France. Close ).

Copulation

Copulation occurs in water and on land, preceded by mutual head-dipping movements while the male utters his two-syllable call. After copulation, first the female, then the male, begin to call. The male remains for a few seconds, holding on to the female's neck plumage, then standing on the female's back, and then slowly sliding sideways into the water and slightly lifting the wing turned away from the female (177 Johnsgard, P. A. (1965). Handbook of Waterfowl Behavior. Cornell University Press, Ithaca, New York, USA. Close , 8 Bauer, K., and U. Glutz von Blotzheim (1969). Handbuch der Vogel Mitteleuropas. Band 3. Frankfurt am Main, Germany. Close ).

Pair Bond

It has been suggested that Ruddy Shelduck pairs for life (170 Delacour, J. ed. (1954-1964). The Waterfowl of the World. 4 Vols. Country Life, London. Close ), but information of banded birds was lacking, and Johnsgard (177 Johnsgard, P. A. (1965). Handbook of Waterfowl Behavior. Cornell University Press, Ithaca, New York, USA. Close ) expressed doubts on a life duration of pair bonds. Pair bonds of banded birds in Askania-Nova (Ukraine) lasted 3–12 years (178 Zubko, V. N., A. S. Mezinov, and A. B. Popovkina (2003). Osobennosti gnezdovaniya ogarya Zapovednike ‘Askaniya-Nova’. Casarca 9:183–213. Close ).

Extra-Pair Mating Behavior/Paternity

No information.

Brood Parasitism of Conspecifics

In Askania-Nova (Ukraine), 61% of clutches contained eggs from more than one female. Several females were observed visiting the same nest during the egg-laying period, and despite many nest boxes that were empty and available, numerous females laid eggs in other females' nest (178 Zubko, V. N., A. S. Mezinov, and A. B. Popovkina (2003). Osobennosti gnezdovaniya ogarya Zapovednike ‘Askaniya-Nova’. Casarca 9:183–213. Close ). See Breeding.

Degree of Sociality

Ruddy Shelduck is a gregarious species that assembles in large flocks during molting and wintering seasons (3 Cramp, S., and K. E. L. Simmons, Editors (1977). The Birds of the Western Palearctic. Volume 1. Ostrich to Ducks. Oxford University Press, Oxford, UK. Close , 33 Hughes, B., and A. J. Green (2005). Ruddy Shelduck Tadorna ferruginea. In Ducks, geese and swans. Volume 1: General chapters, and Species accounts (Anhima to Salvadorina) (J. Kear, Editor). Oxford University Press, Oxford. pp. 426–429. Close ). In Stavropol Krai (Russia), Ruddy Shelduck wintering flocks of 198.8 ± 194.9 SD individuals, range 5–600 (n = 14), were observed in agricultural areas, where they feed, and moved to salt lakes to overnight, where they congregated in large aggregations of over 500 birds (108 Malovichko, L. V., I. A. Zhigarev, G. I. Blokhin, M. K. Chugreev, and V. A. Ostapenko (2018). Sovremennoye sostoyaniye i osobennosti rasprostraneniya Ogarya (Tadorna ferruginea Pallas, 1764) na territorii Stavropilskogo kraia. Vestnik Tverskogo Gosudarstvennogo Universiteta. Seriya: Biologiya i Ekologiya 4:69–80. Close ).

However, during the breeding season there is an increase of agonistic interactions among males, which show territorial behavior (8 Bauer, K., and U. Glutz von Blotzheim (1969). Handbuch der Vogel Mitteleuropas. Band 3. Frankfurt am Main, Germany. Close ).

Play

No information.

Nonpredatory Interspecific Interactions

Interactions between Ruddy Shelduck and other bird species were observed in Constance Lake (Germany) during the spring and summer of 2007. Aggressive behavior was recorded only during the breeding season. Outside of the breeding season, Ruddy Shelduck was observed in mixed flocks with other waterbirds. A total of 25 attacks by Ruddy Shelduck on other bird species were observed. The attacks lasted 30 s to 4 min, and the birds mostly escaped by fleeing or diving. Mallard (Anas platyrhynchos), Tufted Duck (Aythya fuligula), Gadwall (Mareca strepera), and Common Pochard (Aythya ferina) were involved in these interactions (180 Bauer, H. G., W. Fiedler, G. Heine, and I. Seier (2011). Bestandsdynamik, Verbreitung und Brutbiologie der Rostgans Tadorna ferruginea an Bodensee und Hochrhein - negative Auswirkungen auf einheimische Vogelarten? Ornithologischen Jahreshefte für Baden-Württemberg 27:103-121. Close ). Other species, however, including Eurasian Coot (Fulica atra), Great Crested Grebe (Podiceps cristatus), Great Cormorant (Phalacrocorax carbo), Mute Swan (Cygnus olor), and Gray Heron (Ardea cinerea) were generally tolerated even during the breeding season (180 Bauer, H. G., W. Fiedler, G. Heine, and I. Seier (2011). Bestandsdynamik, Verbreitung und Brutbiologie der Rostgans Tadorna ferruginea an Bodensee und Hochrhein - negative Auswirkungen auf einheimische Vogelarten? Ornithologischen Jahreshefte für Baden-Württemberg 27:103-121. Close ). Ruddy Shelducks were attacked 17 times by native waterfowl during the observation period, most often by Mute Swan. These aggressive encounters with swans had the longest duration (180 Bauer, H. G., W. Fiedler, G. Heine, and I. Seier (2011). Bestandsdynamik, Verbreitung und Brutbiologie der Rostgans Tadorna ferruginea an Bodensee und Hochrhein - negative Auswirkungen auf einheimische Vogelarten? Ornithologischen Jahreshefte für Baden-Württemberg 27:103-121. Close ).

Mobbing and Harassment

No information.

Non-aggressive Interactions

In Mongolia, Ruddy Shelducks were recorded by camera traps sharing the burrow with Mongolian marmot (Marmota sibirica) (181 Suuri, B., O. Baatargal, B. Badamdorj, and R. P. Reading (2021). Assessing wildlife biodiversity using camera trap data on the Mongolian marmot (Marmota sibirica) colonies. Journal of Arid Environments 188:104409. Close ).

Competitive interactions

Competition for nesting sites may occur between Ruddy Shelduck and other species. A nest site on the ruins of Niederhaus Castle (Germany) was used by Peregrine Falcon (Falco peregrinus) during the 2006–2009 breeding seasons, by Eurasian Eagle-Owl (Bubo bubo) between 2010–2017, and by Ruddy Shelduck between 2018–2019 (182 Siering, M., and J. Bäurle (2019). Hinweise auf die Verdrängung eines Uhus Bubo bubo durch Rostgänse Tadorna ferruginea in Konkurrenz um Bruthöhle. Ornithologischer Anzeiger 58:178-181. Close ). In Switzerland, Barn Owl (Tyto alba), Tawny Owl (Strix aluco), and Eurasian Kestrel (Falco tinnunculus) have been chased out of their nesting boxes by Ruddy Shelduck (183 Anderegg, R. (2005). Carton rouge pour le tadorne. Environnement Biodiversité 3/05:49–50. Close ).

Kinds of Predators

In Mongolia, remains of three Ruddy Shelduck were identified among 15 prey items found in an aerie of Golden Eagle (Aquila chrysaetos) (184 Ellis, D. H., P. Tsengeg, P. Whitlock, and M. H. Ellis (2000). Predators as prey at a Golden Eagle Aquila chrysaetos eyrie in Mongolia. Ibis 142(1): 141–142. Close ). In Xinjiang (China), Ruddy Shelduck was identified as prey of Booted Eagle (Hieraaetus pennatus) (185 Wu, D., R. MaMing, X. Liu, Y. Wang, L. Du, and K. Jiang (2016). Time Budget and Diet of the Booted Eagles in the Breeding Season in Xinjiang, China. Raptors Conservation 33:46–53. Close ). Of 199 prey items of White-tailed Eagle (Haliaeetus albicilla) in the Lake Baikal area (Russia), three were Ruddy Shelduck (186 Mlíkovsky, J. (2009). The Food of the White-tailed Sea Eagle (Haliaetus albicilla) at Lake Baikal, East Siberia. Slovak Raptor Journal 3:35–39. Close ). In Bashkiria (Russia), remains of two adult birds and one duckling were found in red fox (Vulpes vulpes) dens, four adults and seven ducklings 7–50 days old in an Eurasian Eagle-Owl (Bubo bubo) nest, an adult bird on the perch of a Peregrine Falcon (Falco peregrinus), and a juvenile in an Imperial Eagle (Aquila heliaca) aerie (120 Karyakin, I. V. (2004). Ruddy Shelduck in Bashkiria. Casarca 10:303–312 Close ). A Peregrine Falcon was also observed consuming a Ruddy Shelduck in the Yuzhno-Uralskiy nature reserve (Russia) (187 Alekseev, V. N. (2015). Peregrine Falcon prey remains as a source of data on the species composition of the avifauna of the Yuzhno-Uralskiy Nature Reserve. Fauna Urala i Sibiri 2:8–15. Close ). In Stavropol Krai (Russia), remains of Ruddy Shelduck were found near red fox dens and in Eurasian Eagle-Owl pellets (108 Malovichko, L. V., I. A. Zhigarev, G. I. Blokhin, M. K. Chugreev, and V. A. Ostapenko (2018). Sovremennoye sostoyaniye i osobennosti rasprostraneniya Ogarya (Tadorna ferruginea Pallas, 1764) na territorii Stavropilskogo kraia. Vestnik Tverskogo Gosudarstvennogo Universiteta. Seriya: Biologiya i Ekologiya 4:69–80. Close ). In the Rangkul Lake area (eastern Pamir Mountains, Tajikistan), eight out of 419 prey items of Eurasian Eagle-Owl were Ruddy Shelduck (188 Gromov, J., and O. W. Jegorov (1953). Material po pitaniju chosjaitswennomu snatscheniju filina wostotschowo Pamir i Kopet-Daga. Zoologicheskii Zhurnal 29(5):389–398. Close ). Ruddy Shelduck was also mentioned by Viellard (52 Viellard, J. (1970). La distribution du Casarca roux Tadorna ferruginea (Pallas). Alauda 38(2):87–125. Close ) as prey of Egyptian Vulture (Neophron percnopterus), but it was probably found as carrion.

Predation of ducklings by Herring Gull (Larus argentatus) has been recorded in Lake Baikal (Russia) (121 Pyzhjanov, S. V. (2000). Ruddy Shelduck at Lake Baikal and in its vicinities (the Irkutsk area). Casarca 6:187-201. Close ), and Yellow-legged Gull (Larus michahellis) has been observed capturing young ducklings in Fuerteventura Island (Canary Islands) (55 Palacios Palomar, C. J. (2002). Primeros datos sobre la fenología y biología reproductora del tarro canelo (Tadorna ferruginea) en Fuerteventura, islas Canarias (Aves: Anatidae). Vieraea 30:1–7. Close , 57 Garcia-del-Rey, E., and J. A. Rodriguez-Lorenzo (2010). Breeding status of the Ruddy Shelduck Tadorna ferruginea at Fuerteventura, Canary Islands: natural colonisation of two habitat types on an oceanic island. Ostrich 81(2): 93-96. Close ). A duckling was found in a nest of Egyptian Vulture in Fuerteventura Island (Canary Islands, Spain) (55 Palacios Palomar, C. J. (2002). Primeros datos sobre la fenología y biología reproductora del tarro canelo (Tadorna ferruginea) en Fuerteventura, islas Canarias (Aves: Anatidae). Vieraea 30:1–7. Close ). Feral cats and dogs were also thought to be a threat to ducklings in Fuerteventura Island (Canary Islands) (55 Palacios Palomar, C. J. (2002). Primeros datos sobre la fenología y biología reproductora del tarro canelo (Tadorna ferruginea) en Fuerteventura, islas Canarias (Aves: Anatidae). Vieraea 30:1–7. Close , 57 Garcia-del-Rey, E., and J. A. Rodriguez-Lorenzo (2010). Breeding status of the Ruddy Shelduck Tadorna ferruginea at Fuerteventura, Canary Islands: natural colonisation of two habitat types on an oceanic island. Ostrich 81(2): 93-96. Close ). In northwestern Africa, ducklings are depredated mainly by jackals (Canis sp.), wild cats (Felis sp.), Brown-necked Raven (Corvus ruficollis), and Western Marsh Harrier (Circus aeruginosus). Occasional predation by Osprey (Pandion haliaetus) has also been observed (52 Viellard, J. (1970). La distribution du Casarca roux Tadorna ferruginea (Pallas). Alauda 38(2):87–125. Close ). Valverde (60 Valverde, J. A. (1957). Aves del Sáhara Español. Estudio Ecológico del Desierto. Instituto de Estudios Africanos, Consejo Superior de Investigaciones Científicas, Madrid. Close ) observed in Western Sahara that a jackal (Canis sp.) approached a flock of Ruddy Shelduck and, when discovered, the birds escaped in flight.

In Bashkiria (Russia), 18.7% of 32 nests were depredated by red fox (Vulpes vulpes) and steppe polecat (Mustela eversmanni) (120 Karyakin, I. V. (2004). Ruddy Shelduck in Bashkiria. Casarca 10:303–312 Close ).

Manner of Depredation

No information.

Response to Predators

Ruddy Shelduck shows highly aggressive behavior against predators (7 Isakov, Y. A. (1952). Podsemeystvo utki Anatinae. In Ptitsy Sovetskogo Soyuza. 4. (J. P. Dementiev and N. A. Gladkov, Editors), Gosudartvennoe Izdatel’stvo Sovetskaya Nauka, Moscow, Russia. pp. 344–635. Close , 189 Ryabitsev, V. K. (2001). Ptitsi Urala, Priuralya i Zapadnoy Sibiri. [Birds of the Urals, Ural Area and West Siberia]. Ural University Press, Yekaterinburg, Russia. (In Russian.) Close ). Both parents care for ducklings and defend them against predators (7 Isakov, Y. A. (1952). Podsemeystvo utki Anatinae. In Ptitsy Sovetskogo Soyuza. 4. (J. P. Dementiev and N. A. Gladkov, Editors), Gosudartvennoe Izdatel’stvo Sovetskaya Nauka, Moscow, Russia. pp. 344–635. Close , 189 Ryabitsev, V. K. (2001). Ptitsi Urala, Priuralya i Zapadnoy Sibiri. [Birds of the Urals, Ural Area and West Siberia]. Ural University Press, Yekaterinburg, Russia. (In Russian.) Close ). Sometimes both parents attack; other times, only the male attacks while the female stays with the ducklings. When in danger, the ducklings throw themselves into the water and dive (8 Bauer, K., and U. Glutz von Blotzheim (1969). Handbuch der Vogel Mitteleuropas. Band 3. Frankfurt am Main, Germany. Close ). During one observation, the male and female flew screaming when a Black Kite (Milvus migrans) approached a duckling. The male attacked the kite, chasing it for more than 200 m. In another instance, the male drove away a White-tailed Eagle (Haliaeetus albicilla) that had approached a duckling close to the female (190 Sokolov, A. Y., O. G. Kiselev, and N. P. Ashurov (2016). Ob agressivnom povedenii ogarya Tadorna ferruginea po otnosheniyu k pernatym khishchnikam. Russkiy Ornitologicheskiy Zhurnal Ekspress-vypusk 25(1233):30–32. Close ). In Lanzarote Island (Canary Islands), adults tending to broods attacked Peregrine Falcon (Barbary) (Falco peregrinus pelegrinoides) (J. A. Amat, unpublished data). In the Main Botanical Garden of the Russian Academy of Sciences (Moscow), a juvenile Black-headed Gull (Chroicocephalus ridibundus) closely approached a pair of adults with ducklings; immediately, the male attacked the gull, pecking it to death (191 Avdeev, V. P. (2016). Napadeniye ogarya Tadorna ferruginea moloduyu ozornuyu chayku Larus ridibundus. Russkiy Ornitologicheskiy Zhurnal Ekspress-vypusk 25(1239):228–229. Close ). In Western Sahara, Valverde (60 Valverde, J. A. (1957). Aves del Sáhara Español. Estudio Ecológico del Desierto. Instituto de Estudios Africanos, Consejo Superior de Investigaciones Científicas, Madrid. Close ) recorded adults tending chicks attacking Black Kite, Osprey, Booted Eagle, and Brown-necked Raven.

At nesting sites on rocky river slopes in Bashkiria (Russia), aggressive interactions were common between Ruddy Shelduck and Common Raven (Corvus corax) but aggression was not observed toward other species, such as Eurasian Jackdaw (Corvus monedula) and Rock Pigeon (Columba livia) (120 Karyakin, I. V. (2004). Ruddy Shelduck in Bashkiria. Casarca 10:303–312 Close ).

During the breeding season, another antipredator strategy was observed in Tunisia: a male, responding to a nearby human, did not flee, but emitted alarm calls to which the female responded from a distance of 100 m. The chicks headed toward the male, while the female continued to utter alarm calls and move away to attract the potential predator's attention (125 Azafzaf, H., M. Amari, and H. Dlensi (2002). Une nidification du Tadorne casarca Tadorna ferruginea sur un site inhabituel du Sud tunisien. Alauda 70(3):422-424. Close ). Gathering together ducklings from multiple broods into a crèche may be another method of protection against predators. In these instances, the crèche is guarded by only a few adults (52 Viellard, J. (1970). La distribution du Casarca roux Tadorna ferruginea (Pallas). Alauda 38(2):87–125. Close ).

An important antipredator strategy outside of the breeding season is flocking behavior. During autumn and winter, this strategy may allow Ruddy Shelduck to devote more time to feeding rather than remaining alert for threats (63 Boulkhssaïm, M., A. Ouldjaoui, A. H. Alfarhan, and B. Samraoui, B. (2013). Distribution, breeding phenology and time budget of Ruddy Shelduck Tadorna ferruginea during the annual cycle in the Hauts Plateaux, north-east Algeria. Ostrich 84(2):129-136. Close ).

Flight is another response to predators (mammals and birds of prey), observed at Chott el Hodna (Central Hauts Plateaux, Algeria) (173 Bounab, C., Y. Nouidjem, E. Bensaci, E. Y. Guergueb, A. Chagra, M. Bara, A. Bouzegag, M. Benyahia, and M. Houhamdi (2017). Study of the Ruddy Shelduck (Tadorna ferruginea) diurnal behavior in Chott El-Hodna (Central Haut Plateaux of Algeria). Journal of Entomology and Zoology Studies 5(2):1034–1037. Close ). At Sebkhet El-Mahmel (Algeria), mean flight initiation distance in response to an approaching human was 167.0 m ± 4.8 SE (n = 24) (192 Halassi, I., A. Elafri, L. Boutabia, and S. Telailia (2022). Monitoring human disturbance: Factors affecting escape behaviour of waterbirds in North African wetlands. African Journal of Ecology Close ). In Changthang Wildlife Sanctuary (Ladakh, India), mean alert distance and flight initiation distance in response to an approaching human were 208.31 m ± 8.57 SE, and 156 m ± 7.94 SE, respectively (193 Mahar, N., P. Dobriyal, R. Badola, and S. A. Hussain (2024). Tourism on the roof of the world: Socio-ecological impacts of tourism on the Indian Trans-Himalaya. Land Use Policy 138:107031. Close ). Adults that have been shot may dive and stay underwater for up to one minute (128 Schäfer, E. (1938). Ornithologische Ergebnisse zweier Forschungsreisen nach Tibet. Journal für Ornithologie 86 (Supplement):1–349. Close , 162 Bannikov, A. G., and P. P. Tarasov (1957). K Biologij Ogarja (Tadorna ferruginea). Trudy Büro Koltschewanija 9:208–214. Close ).