Predator–induced take–off strategy in great tits (Parus major)

Abstract

When birds are attacked by predators the initial take-o¡ is crucial for survival. The strategy in the initial phase of predator evasion is probably a¡ected by factors such as body mass and presence of cover and conspeci¢cs, but it may also be a response to the character of the predator's attack. In choosing an angle of £ight, birds face a trade-o¡ between climbing from the ground and accelerating across the ground. This is, to our knowledge, the ¢rst study investigating whether the attack trajectory of a raptor a¡ects the take-o¡ strategy of the prey bird. First-year male great tits (Parus major) adjusted take-o¡ angle to a model predator's angle of attack. Birds attacked from a steep angle took o¡ at a lower angle than birds attacked from a low angle. We also compared take-o¡s at dawn and dusk but could not ¢nd any measurable e¡ect of the diurnal body mass gain (on average 7.9%) in the great tits on either £ight velocity or angle of ascent.

The effects of radar on avian behavior: Implications for wildlife management at airports

“…steeper take-off angles) depending on predator attack speed and distance (Howland, 1974;Witter and Cuthill, 1993). This tradeoff between acceleration and take-off angle has been demonstrated by Kullberg et al (1998), and male and female cowbirds may optimize acceleration versus take-off angle differently. Our results seem to indicate that males are optimizing maneuverability in escape flights, and females are optimizing acceleration.…”

“…We measured the vertical take-off angle when the animal passed 50 cm from the start of flight (Figure 3b). A distance of 50 cm was chosen because it was within the range of distances used to measure take-off angle in other studies (Kullberg et al, 1998;Lind et al, 2002). We measured the vertical take-off angle by measuring the angle of the flight compared to a line at the level of the bird's beak at the start of flight, parallel to the ground (Figure 3b).…”

Animal escapology II: escape trajectory case studies

“…take-off angle, which appears to be a fundamental determinant of prey survival in birds (Cresswell, 1993;Kullberg et al, 1998;Kullberg and Lafrenz, 2007). Predator-prey interactions beyond the initial prey startle response have also been examined, taking into account the relative locomotor performance (e.g.…”

“…Take-off angle can be affected by a number of factors. When attacked from a low attack angle, great and blue tits take off more steeply (Fig.11A) than when attacked from a higher angle [great tits Parus major (Kullberg et al, 1998); blue tits Parus caeruleus (Lind et al, 2002)]. Typically, these escaping birds P. Domenici, J. M. Blagburn and J. P. Bacon initially fly away from the predator and then make a half loop, attempting to escape by flying above the predator (Lind et al, 2002) (great tits; Fig.11A).…”

Flights of fear: a mechanical wing whistle sounds the alarm in a flocking bird

“…A problem with their use as alarm signals or cues is that wing flight noises may be produced whenever air is forced over feathers during flapping flight, so it is unclear how they could be modulated to encode alarm. However, alarmed birds fly faster or take off at a steeper angle (Kullberg et al 1998;Veasey et al 1998; Van der Veen & Lindströ m 2000), which affects wingbeat kinematics and therefore acoustic amplitude, sound tempo and potentially acoustic frequency (Tobalske et al 2004;Clark 2008;Clark & Feo 2008). Therefore, wing sounds might provide a reliable cue of alarmed take-off or even be an index signal, in which the signal's meaning is closely related to its production and therefore costly to fake (Maynard Smith & Harper 2003).…”