Distress Calls of Birds in a Neotropical Cloud Forest¹

Abstract

Distress calls are loud, harsh calls given by some species of birds when they are captured by a predator or handled by humans. We recorded the frequency of distress calls and struggling behavior in 40 species of birds captured in mist nets during the dry season in a Costa Rica cloud forest. We tested the following hypotheses proposed to explain the function of distress calls: (1) calling for help from kin or reciprocal altruists; (2) warning kin; (3) eliciting mobbing behavior; (4) startling the predator; and (5) distracting the predator through attraction of additional predators. Our results did not support the calling‐for‐help, warning kin, or mobbing hypotheses. Indeed, genera that regularly occurred with kin or in flocks were not more likely to call than non‐flocking genera. There was no relationship between calling frequency and struggling behavior as predicted by the predator startle hypothesis. Genera of larger birds tended to call more than smaller birds, providing some support for both the predator distraction hypothesis and predator startle hypotheses. Calls of higher amplitude may be more effective in startling the predator. Distress calls of larger birds may also travel greater distances than those of smaller birds, supporting the predator manipulation hypothesis, but this requires further testing.

Habitats matter: the incidence of and response to fear screams in a habitat generalist, the vinous-throated parrotbill Paradoxornis webbianus

“…We found that about 21 % of parrotbills gave screaming calls while being handled. It is interesting to note that this proportion of callers is similar to previous results that showed a positive relationship between body mass and scream tendency in birds (Neudorf and Sealy 2002). Overall, individual morphology and flock size were not associated with screaming behavior, but females tended to scream more than males in this species.…”

“…He argued that this is adaptive because captured prey scream to attract other individuals that are able to disturb the original predators (e.g., conspecifics, secondary predator), and in closed habitats where visual cues of predation are relatively limited, acoustic cues will be used by captured prey to announce their desperate situation. However, such habitat differences in the tendency to scream could be confounded by other biological factors; for example, the tendency to scream tended to differ markedly between species with different body sizes that live in a similar habitat (Neudorf and Sealy 2002). Nevertheless, this study proved that such effects of habitat type on screaming propensity are valid even in a species inhabiting diverse habitats; parrotbill populations occupying closed habitats screamed significantly more than populations living in open areas, strengthening the view that fear screams may have survival value that differs between habitats.…”

“…Within a species, various factors such as age, sex, and season may be related to the propensity to scream (Haftorn 1999;Laiolo et al 2009;Freeberg and Branch 2013). Despite such efforts, however, the reason for this variability remains unclear (Rohwer et al 1976;Högstedt 1983;Koenig et al 1991;Neudorf and Sealy 2002). Furthermore, few studies have addressed how the propensity for fear screams varies among populations in a species, and why this variability exists.…”

“…However, not all individuals in a species produce screams; instead, there is a remarkable intra-and interspecies variation in the propensity to scream (Norris and Stamm 1965;Perrone 1980;Inglis et al 1982;Högstedt 1983;Jurisevic and Sanderson 1998;Neudorf and Sealy 2002;Møller and Nielsenc 2010;Lingle et al 2012). For example, Neudorf and Sealy (2002) showed that the propensity for fear screams varied from 0 to 100 % between tropical bird species.…”

“…For example, Neudorf and Sealy (2002) showed that the propensity for fear screams varied from 0 to 100 % between tropical bird species. Similarly, Hödl and Gollmann (1986) found that the proportion of individuals emitting distress calls differed between ten species of neotropical frogs, and Russ et al (2004) reported interspecific differences in the propensity to scream in pipistrelle bats.…”