Effect of alarm calling by male Red-winged Blackbirds on nestling begging and female provisioning behavior

Abstract

Nestling begging and parental provisioning can attract nest predators and reduce reproductive success, so parents and their offspring might be expected to respond adaptively by minimizing predator‐attracting cues when predators threaten nests. Male Red‐winged Blackbirds (Agelaius phoeniceus) are well known for their antipredator alarm calls that contain information about the approach of potential nest predators. We examined the begging behavior of nestlings and the provisioning behavior of females in response to antipredator alarm calls of males to test the adaptive response hypothesis. Playback experiments provided no evidence that alarm calls function to switch off vocal begging; nestlings were equally likely to beg vocally during playback and control periods. Video recordings showed that male alarm calling had no significant effect on inappropriate vocal begging (in the absence of an adult), but significantly reduced the incidence of spontaneous calling (in the absence of begging). Adult females responded to male antipredator alarm calls by delaying their provisioning visits. In addition, although having no significant effect on use of nest‐arriving calls by females, male alarm calling significantly reduced their use of nest‐leaving calls. We conclude that nestling and female Red‐winged Blackbirds respond to male alarm calls in ways that might reduce the risk of predation, but nestlings beg vocally when females arrive to feed them, regardless of male alarm calling, perhaps to avoid a competitive disadvantage with broodmates.

Noisy anthropogenic infrastructure interferes with alarm responses in Savannah sparrows ( Passerculus sandwichensis )

“…Because many grassland nest predators, such as rodents and snakes [42], are inconspicuous, parental alarm calls may function as a crucial warning system for mated pairs to signal to each other if a predator has been spotted. A similar response to alarm calls has been documented in female red-winged blackbirds [4,43], which delay feeding visits in response to male alarm calls. However, this is the first study that we are aware of to document this behaviour in Savannah sparrows.…”

“…Many animals rely on alarm calls to deter predators [ 1 ], solicit help from conspecifics [ 2 ], and to warn neighbours [ 3 ], mates [ 4 ] and offspring [ 5 ] about impending dangers. Alarm calls may encode complex information regarding urgency [ 6 ], size [ 2 ], type of predator [ 7 ] or predator behaviour [ 8 ].…”

Maternal buffering of stress response in free‐ranging Pacific harbor seal pups in Alaska

“…In a noncaptive, natural setting and from a behavioral ecology perspective, the fact that pups need to vocalize more may serve to facilitate a rapid reunion with the mother shortly after they have been separated. However, it requires energy expenditure and may also attract predators if sustained over time (Bernathen‐Plaisted and Yasukawa , Schmidt et al . ).…”

“…). The decreases in vocalization rate and activity level associated with the increasing duration of the separation may serve to avoid detection by predators in the wild (Insel and Harbough 1989, Bernathen‐Plaisted and Yasukawa , Kesseler et al . , Cure et al .…”

Three sympatric host nestlings eavesdrop on cuckoo nestling distress calls

“…From May to July 2023, we conducted playback experiments on nestlings of three host species aged 6–7 days (oriental reed warbler: n = 15; vinous‐throated parrotbill: n = 14; reed parrotbill: n = 20). The reason for selecting nestlings of this age was that 6–7‐day‐old nestlings exhibit clear begging behavior, respond to human stimuli by begging, and are not excessively fragile (Bernath‐Plaisted & Yasukawa, 2011 ). To avoid the influence of host parents or other birds, we temporarily placed the 6–7‐day‐old nestlings in collected old nests and brought them to a residence near the research site (less than a 5 min ride by electric bike).…”