Millicent S. Ficken

VOCAL REPERTOIRE OF THE BLACK-CAPPED CHICKADEE

Describes the physical characteristics, usages, and probable functions of 11 vocali- zations of adult Black-capped Chickadees and 2 of the young. Some modifications of the vocal repertoire as compared with other passefines are associated with sociality and hole-nesting. The Fee-bee, usually considered the song of this chickadee, is less complex than some call notes and also has some differences in function compared to the songs of other passefines. The two most complex calls (Chick-a-dee and Gargle) are associated with social activities. Vocal signals tend toward sexual segregation, which may be important in a monomorphic species. The vocalizations of this species are compared with those of other parids, and selection pressures acting on the structure of vocalizations are discussed. The more complex vocalizations of this species are being

Temporal Pattern Shifts to Avoid Acoustic Interference in Singing Birds

Two species of forest birds, the least flycatcher and the red-eyed vireo, when breeding in the same season in the same habitat, adjust their temporal pattern of singing to avoid the overlapping of songs. The avoidance of acoustic interference is more marked in the flycatcher, which has a briefer song than the vireo.

Regulation of vocal amplitude by the blue-throated hummingbird, Lampornis clemenciae

Animals that rely on vocal communication must broadcast sound so that a perceptible signal is transmitted over an appropriate distance. We found that male blue-throated hummingbirds modified the amplitude of their vocalizations in response to both naturally occurring and experimenter-controlled changes in ambient noise levels. This phenomenon is known as the Lombard effect and may increase the efficiency of acoustic signalling. This study demonstrates the effect under natural field conditions and documents the first hummingbird species (Apodiformes: Trochilidae) to show this behaviour. We measured sound pressure levels (SPLs) of Serial Chip territorial advertisement calls across a natural range of ambient noise, primarily due to creeks within male territories. We found a significant correlation between the amplitude of Serial Chips and the amplitude of background noise. To test this relationship, we broadcast recordings of creek noise at high and low amplitudes while target individuals were producing Serial Chip vocalizations. We measured vocal SPLs before and during the playback. Individuals responded to changes in playback creek noise by changing the amplitude of Serial Chip production. We also measured transmission properties of Serial Chip calls through natural habitat to calculate the approximate amplitude of vocalizations at the position of the calling bird. We suggest that amplitude regulation of vocalizations contibutes to signal transmission distance along with the established relationships between singing behaviour, acoustic structure and habitat. Copyright 2003 Published by Elsevier Ltd on behalf of The Association for the Study of Animal Behaviour.

Associations among members of a black-capped chickadee flock

SummaryOne color-banded black-capped chickadee flock was studied intensively at a winter feeder in Wisconsin. Flock structure was examined by measuring association among flock members in three ways: spatial proximity, temporal association, and association of individuals during flock movements. Additional information was obtained on aggressive interactions at and near the feeder. By midwinter, the strongest attachments were between males and females who subsequently mated; pair attachments strengthened as the breeding season approached. Lower ranked individuals in the dominance hierarchy showed weaker associations with other flock members in early spring than did more dominant individuals. The strong attachment to the mate may have implications for altruistic behavior within the winter flock.

Responses of Four Warbler Species to Playback of Their Two Song Types

RECENTLY renewed attention has been focused on the communicatory function of avian vocalizations (e.g. Marler, 1967; Smith, 1966). One problem in avian communication studies is determining what the message of a vocalization is for the recipient. The purpose of this study was to use song playback experiments to determine if intraspecific song variants have different messages. Few studies of the role of song have been made in species where each individual has more than one song type, although Hinde (1958) studied vocal responses of Chaffinches (Fringilla coelebs) to their two song types in captivity. Many species of warblers have two song types that apparently differ in motivation and function (Ficken and Ficken, 1962, 1965; Morse, 1966, 1967). The American Redstart (Setophaga ruticilla), Chestnutsided Warbler (Dendroica pensylvanica), and Yellow Warbler (D. petechia) possess an accented ending song (AE) and an unaccented ending song (UE). The Yellow Warbler also sings intermediate songs (IE) (Morse, 1966). In all three species song type AE is given more commonly by undisturbed, unmated males, while type UE songs are more common after pairing and during territorial encounters (Ficken and Ficken, 1965). The Black-throated Green Warbler (D. virens) has two song types, referred to as A and B by Morse (1967).

A COMPARATIVE ANALYSIS OF PASSERINE MOBBING CALLS

We examined the acoustic structure of mobbing calls of 52 species of passerines representing an array of taxa. Marler suggested that calls given during mobbing have char- acteristics enhancing locatability that include abrupt onsets and a wide frequency range. Only about one-half of the species we studied produced calls during mobbing that had these characteristics. However, clicks (probably produced by bill snapping) sometimes were given during dives at predators. Vocalizations given during mobbing were quite diverse in acoustic structure. Two trends were noted: phylogenetic patterns; and possible convergence in certain species engaged in interspecific flocking. Received 4 May 1995, accepted 7 September 1995.

BLUE-THROATED HUMMINGBIRD SONG: A PINNACLE OF NONOSCINE VOCALIZATIONS

Abstract Little is known about the structure and function of hummingbird vocalizations. We studied the vocalizations of Blue-throated Hummingbirds (Lampornis clemenciae) at two sites in southeastern Arizona. Songs were produced by males and females. Male songs consisted of arrays of notes organized in clusters of “song units.” Within sites, all males shared the same song units. Individual differences occurred in some temporal aspects of song, and slight but consistent differences in note structure occurred between the two sites. The organization of units within songs was marked by rigid syntax, and long songs were produced by agglutination of units. Male songs may function in territorial advertisement and mate attraction. Female songs were very different acoustically from those of males and typically were given when females were within a few centimeters of a male. In these situations, the females song often overlapped temporally with the males song. Of the hummingbird species studied so far, the Blue-throated Hummingbird has the most complex songs and is the only known species with complex female songs. Blue-throated Hummingbirds show convergence with oscines in vocal complexity, song organization, song function, and possible learning of some song elements.

A Complex Vocalization of the Black-Capped Chickadee. II. Repertoires, Dominance and Dialects

The gargle, a complex call of the Black-capped Chickadee (Parus atricapillus), was studied during the flocking period at two feeders in southeastern Wisconsin. Gargles are usually associated with aggression and are given more frequently by males than females, the gargler almost always winning the encounter. Dominant birds give gargles more frequently than subordinates. Particular gargle types (unique syllable combinations) are not addressed to specific individuals. Birds have at least 13 gargle types in their repertoires, some having over 30, although the total repertoire size could not be determined. Dominants did not have larger or more diverse repertoires, nor did they show differences as compared with subordinates in the amount of sharing of gargle types. Most gargle types are shared, but each individual has some very rare ones that may not be shared. The frequency with which particular gargle types are uttered varies from year to year at the same feeder and also in different parts of the winter. The frequency of occurrence of particular gargle types indicates that selection may favor call-sharing. At two feeders, 383 m distant, which we studied for 2 years, no flock specific dialects were detected, but in one of the 2 years birds visiting the same feeder tended to share gargle types more with each other than with those at the other feeder. Birds that had strong proximity associations with each other, however, did not show stronger sharing compared to those that were more weakly associated.

What Is the Song of the Black-Capped Chickadee?

potheses. The group of owls in regions without mammalian predators includes those restricted to smaller and more remote islands, since larger islands and continents have or recently had mammalian predators. Full species on islands include 7 tufted forms and 12 forms with tufts that are inconspicuous or lacking. These data weaken the hypothesis of predator mimicry, which predicts that owls of small and remote islands should lack ear tufts. Of the island species, 7 of 19 (37%) are tufted, while on continents 41 of 113 (36%) species are tufted. Thus, islands.and continents have similar proportions of tufted owl species. These results support the camouflage and species recognition theories but not the predator mimicry hypothesis. The evidence also points to a problem with the species recognition hypothesis, i.e., its assumed mechanism may fail to operate. All species with ear tufts are nocturnal and inhabit forest or brushland. For two such owls to approach each other close enough to see silhouettes, they first must communicate in the dark, usually amidst vegetation. This prerequisite long-distance link surely must occur by voice and not by sight. It seems likely that species identification is established during the vocal encounter. If so, the only proposal concerning the function of ear tufts that finds support from my tests is that of camouflage. However, the camouflage hypothesis does not fully explain the occurrence of tufts either, since more than half of the nocturnal, forest-dwelling owls lack tufts, despite the advantage these structures presumably confer. A firmer conclusion awaits field observations of perching and roosting behavior of owls, including site preferences and postures. Such studies should be carried out in part at the vegetation heights at which owls sit, since it is at these heights that owls are seen by most other animals, including other owls. I thank Gary Fugle and Dennis Paulson for invaluable discussion and enthusiasm. Ross Lein, Carl Marti, Stephen Rothstein and Sievert Rohwer reviewed the manuscript.

Long-term persistence of a culturally transmitted vocalization of the black-capped chickadee

Abstract The gargle vocalization of the black-capped chickadee, Parus atricapillus, was recorded at the same site over a 19-year period. This vocalization consists of an array of different note types that are combined to generate various call types. Each male has a large repertoire used in agonistic encounters, and many variants are shared with other members of the population. The vocalization was analysed at several different levels: note types and various lengths of note-type sequences including the whole call. Remarkable stability was shown for all levels, and the main changes observed were minor ones of relative frequency of occurrence. Reasons for stability may include persistence of note types in linkage groups that could be trasmitted as units (memes) and other rules governing ordering of note types in the call (syntax). Also, natural selection may impose some constraints on the process of cultural transmission. We compare our findings with those of the few available long-term studies of bird song. Chickadee gargles are transmitted very precisely compared to other vocalizations that have been previously studied.