Herring schooling manoeuvres in response to killer whale attacks

Nøttestad, Leif; Axelsen, Bjørn Erik

doi:10.1139/z99-124

Cited by 101 publications

(73 citation statements)

References 26 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Most of the research on collective escape induced by the predator has been conducted in fish (e.g. Nøttestad and Axelsen 1999; Gerlotto et al 2006). One such a study concerned the relation between intensity of threat by a predator pike ( Esox lucius ) and patterns of collective escape of schools of minnows ( Phoxinus phoxinus , Magurran and Pitcher 1987; Magurran 1990).…”

Section: Introductionmentioning

confidence: 99%

Complex patterns of collective escape in starling flocks under predation

Storms

Carere

Zoratto

et al. 2019

Behav Ecol Sociobiol

View full text Add to dashboard Cite

Collective behaviour of animals has been a main focus of recent research, yet few empirical studies deal with this issue in the context of predation, a major driver of social complexity in many animal species. When starling ( Sturnus vulgaris ) flocks are under attack by a raptor, such as a peregrine falcon ( Falco peregrinus ), they show a great diversity of patterns of collective escape. The corresponding structural complexity concerns rapid variation in density and shape of the flock over time. Here, we present a first step towards unravelling this complexity. We apply a time series analysis to video footage of 182 sequences of hunting by falcons on flocks of thousands of starlings close to two urban roosts during winter. We distinguish several types of collective escape by determining the position and movement of individuals relative to each other (which determines darkness and shape of the flock over time) as well as relative to the predator, namely ‘flash expansion’, ‘blackening’, ‘wave event’, ‘vacuole’, ‘cordon’ and ‘split’. We show that the specific type of collective escape depends on the collective pattern that precedes it and on the level of threat posed by the raptor. A wave event was most likely to occur when the predator attacked at medium speed. Flash expansion occurred more frequently when the predator approached the flock at faster rather than slower speed and attacked from above rather than from the side or below. Flash expansion was often followed by split, but in many cases, the flock showed resilience by remaining intact. During a hunting sequence, the frequencies of different patterns of collective escape increased when the frequency of attack by the raptor was higher. Despite their complexity, we show that patterns of collective escape depend on the predatory threat, which resembles findings in fish. Significance statement Patterns of collective escape in flocks of starlings have always intrigued laymen and scientists. A detailed analysis of their complex dynamics has been lacking so far, and is the focus of our present study: we analysed video footage of hunting by falcons on flocks of thousands of starlings and show how patterns of collective escape (namely flash expansion, blackening, wave event, vacuole, cordon and split) depend on the preceding pattern and on details of attack. A higher frequency of attack during a hunting sequence resulted in a higher frequency of collective escape events. Flash expansion happened most often when the predator attacks at greater speed. A wave event was most likely when the raptor attacks at medium (rather than high or low) speed. These results provide a first quantitative approach to social complexity in collective avoidance of a predator. Electronic supplementary material The online version of this article (10.1007/s00265-018-2609-0) contains supplementary material, which is available to authorized users.

show abstract

Section: Introductionmentioning

confidence: 99%

Complex patterns of collective escape in starling flocks under predation

Storms

Carere

Zoratto

et al. 2019

Behav Ecol Sociobiol

View full text Add to dashboard Cite

show abstract

“…1) and schools of newly metamorphosed herring (Fig. 2), using a high-resolution multibeam sonar system (Ridoux et al 1997;Nøttestad and Axelsen 1999). To the best of our knowledge this is the first time that such an approach has been applied to study interactions between fish and seabirds.…”

Section: Introductionmentioning

confidence: 99%

Pretty patterns but a simple strategy: predator-prey interactions between juvenile herring and Atlantic puffins observed with multibeam sonar

Axelsen¹,

Anker‐Nilssen²,

Fossum³

et al. 2001

Can. J. Zool.

Self Cite

View full text Add to dashboard Cite

Predator-prey interactions between Atlantic puffins (Fratercula arctica) and newly metamorphosed herring (Clupea harengus) were studied in the Lofoten-Røst area in northern Norway using a high-resolution multibeam sonar system. Attacks from diving puffins and predatory fish induced massive predator-response patterns at the school level, including bend, vacuole, hourglass, pseudopodium, herd, and split. All patterns have previously been observed, using the same sonar, in schools of adult herring attacked by groups of killer whales. Tight ball, the prevailing response pattern in adult fish under predation, was not observed, but a new pattern, intraschool density propagation, was found and interpreted as an analogue to tight-ball formations moving rapidly within the school. The observed patterns persisted much longer than in schools of adult herring attacked by killer whales, reflecting the different hunting strategies. Traditionally, the repertoire of predator responses observed in schooling fish has been interpreted as a range of cooperative tactics to trick predators, but this has recently been challenged by authors who suggested that fish that behave the same way produce different patterns at group level simply by maintaining a minimum approach distance to predators and hiding behind conspecifics (the "selfish herd"), and that the particular combination of group size and number and behaviour of predators, rather than different individual tactics, determines the outcome at group level. Our findings support the latter hypothesis.Résumé : Nous avons étudié les interactions prédateurs-proies entre des Macareux moines (Fratercula arctica) et des Harengs (Clupea harengus) fraîchement métamorphosés dans la région de Lofoten-Røst, dans le nord de la Norvège au moyen d'un sonar de haute résolution à faisceaux multiples. Les attaques des oiseaux en plongée et des poissons prédateurs déclenchent des patterns de réaction massive au sein des bancs de harengs : repliement, vacuole, sablier, pseudopode, troupeau et séparation, types de comportement déjà observés, au moyen du même sonar, dans des bancs de harengs adultes attaqués par des épaulards. La formation d'une boule compacte, la réaction la plus fréquente des poissons adultes face à des prédateurs, n'a pas été observée, mais il s'est produit un nouveau pattern dans les bancs de harengs, la pulsion de densité, interprétée comme analogue à la formation d'une boule compacte, mais se déplaçant rapidement dans le banc. Ces patterns ont duré beaucoup plus longtemps que ceux observés dans les bancs de harengs adultes attaqués par des épaulards, ce qui reflète la diversité des stratégies de chasse. Traditionnellement, le répertoire des réactions aux prédateurs observé au sein des bancs de poissons est considéré comme une série de tactiques de coopération pour tromper les prédateurs, mais cette théorie a été remise en question par les auteurs qui croient que ces poissons qui se comportent de la même façon produisent des patterns différents quand ils sont en groupe en s'approchant...

show abstract

“…1) (Gerlotto et al 1999;Nøttestad and Axelsen 1999) was pole-mounted on the side of a 6.4 m boat with the transducer submerged to a depth of 1 m (Guillard et al 2006a). The 60 beams (beam dimensions 1.5°a thwartships and 17° along ships) allowed for a 90°a thwartship observation plane, oriented perpendicularly to the bottom and parallel to the surface (sonar was orientated at 45° to the vertical perpendicular to the line of travel-see Fig.…”

Section: Materials and Proceduresmentioning

confidence: 99%

Three‐dimensional internal spatial structure of young‐of‐the‐year pelagic freshwater fish provides evidence for the identification of fish school species

Guillard¹,

Fernandes

Laloë

et al. 2011

Limnology & Ocean Methods

View full text Add to dashboard Cite

Active acoustic detection and characterization in three dimensions (3D) with multibeam sonars is a powerful technique for ecological studies of schooling fish. The alpine Lake Annecy provides ideal conditions for sampling fish with active acoustic methods: it has calm water, low species diversity, and the density of pelagic fish schools is high. We carried out investigations on the internal 3D morphological characteristics of young-of-theyear (Y-O-Y) pelagic fish schools, using high resolution multibeam sonar in the vertical plane. The objective was to discriminate between the two fish species that school in the lake: perch (Perca fluviatilis) and roach (Rutilus rutilus). To discriminate between these Y-O-Y fish species, we used only one characteristic of their internal spatial structure: the total number of vacuoles, defined as empty volumes inside the school, relative to the school volume. Two distinct linear relationships between school volume and the total number of vacuoles were determined. These two types were consistent with the proportions of the percentage occurrence of the two different species as obtained from pelagic trawl sampling in 2004. In 2008, perch was dominant (93%) in the lake, and only one relationship was detected: this relationship corresponded closely to the one in 2004 attributed to perch. Thus, we assume that the schooling behavior is a phenotypic expression that could be used for remote fish species identification.*Corresponding author: E-mail: patrice.brehmer@ird.fr AcknowledgmentsThis work was supported by the ANSON project (INRA, IRD, IFRE-MER), and we are grateful to the CRH (IRD, IFREMER, UM II; Sète) who provided facilities. The second survey was financially supported by the INRA EFPA department, under the grant 'Innovative Project.' The software used for sonar data extraction was developed during the EU project AVITIS. Special thanks to Yvon Guennegan (IFREMER; Sète) for his help during the first survey, Michel Colon for his help during the two surveys, and Nicolas Givaudan (INRA; Thonon) for previous data analyses. We also thank Marc Taquet (IFREMER; French Polynesia) who attempted to identify species by scuba diving during the 2008 survey. Finally, we are grateful to Keith Mutch of Marine Scotland for producing the 3D graphic.

show abstract

Herring schooling manoeuvres in response to killer whale attacks

Cited by 101 publications

References 26 publications

Complex patterns of collective escape in starling flocks under predation

Complex patterns of collective escape in starling flocks under predation

Pretty patterns but a simple strategy: predator-prey interactions between juvenile herring and Atlantic puffins observed with multibeam sonar

Three‐dimensional internal spatial structure of young‐of‐the‐year pelagic freshwater fish provides evidence for the identification of fish school species

Contact Info

Product

Resources

About