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Supplementary information describing composition of actively-migrating wood warbler flocks triangulated with a 3-D microphone array in the Keweenaw Peninsula, MI, USA.

Song is an important communication signal used by birds and plays an essential role in their life history, including territorial defence and breeding activities. To facilitate this communication, it is common for bird song to vary geographically within a given species. Song dialects occur when geographic variation among song types has distinct boundaries. Research on song dialects has traditionally focused on macrogeographic scales. To determine if dialects can exist on a micro-scale in an isolated population, we recorded and measured characteristics, song structure, and the pattern of geographic variation of Savannah Sparrow (Passerculus sandwichensis) songs. Songs were recorded in May and June in 2017, 2018, and 2019 during the breeding season on Kent Island, New Brunswick. Our results suggest that bird populations are organized into regions of similar-sounding individuals. Birds were more likely to sound similar to their closest neighbour than individuals elsewhere on the island. Thus, significant song variation in Savannah Sparrows appears to occur at a population scale across small geographical distances, exhibiting a micro-dialect. This study provides evidence that dialect patterns, similar to those that occur on a large geographical scale, contribute to the expression of a micro-dialect. This research establishes a foundation for future studies on the function of micro-dialects and the maintenance of vocal learning throughout the animal kingdom.

This word document contains three supplementary text sections, a supplementary figure, eleven supplementary tables, and one supplementary figure.

Many birds and primates use loud vocalizations to mediate agonistic interactions with conspecifics, either as solos by males or females, or as coordinated duets. The extensive variation in duet complexity, the contribution of each sex, and the context in which duets are produced suggest that duets may serve several functions, including territory and mate defense. Titi monkeys (Callicebus spp.) are believed to defend their home range via solo loud calls or coordinated duets. Yet there are remarkably few experimental studies assessing the function of these calls. Observations of interactions between wild established groups and solitary individuals are rare and, therefore, controlled experiments are required to simulate such situations and evaluate the mate and joint territorial defense hypotheses. We conducted playback experiments with three free-ranging groups of habituated black-fronted titi monkeys (Callicebus nigrifrons) to test these hypotheses. We found that titi monkeys responded to the three conspecific playback treatments (duets, female solos, and male solos) and did not respond to the heterospecific control treatment. The monkeys did not show sex-specific responses to solos (N=12 trials). Partners started to duet together in 79% of their responses to playback-simulated rivals (N=14 calls in response to playback). Males started to approach the loudspeaker before females regardless of the type of stimulus. The strength of the response of mated pairs to all three conspecific treatments was similar. Overall, our results are consistent with the idea that black-fronted titi monkeys use their loud calls in intergroup communication as a mechanism of joint territorial defense. © 2015 Wiley Periodicals, Inc.

Melozone biarcuata (Prevost's Ground-sparrow) has traditionally been divided into two allopatric groups based on differences in vocalizations and plumage characteristics: M. b. cabanisi in Costa Rica and M. b. biarcuata/M. b. hartwegi in northern Central America. However, the relationship between these subspecies has not been studied using a modern taxonomic approach. In this study, our objective was to provide the first detailed taxonomic comparison between these three subspecies using an integrative multi-trait analysis. We analyzed morphometric features, qualitative plumage patterns, and quantitative plumage measurements using spectral reflectance from all three subspecies, and we analyzed vocalizations for subspecies M. b. biarcuata and M. b. cabanisi . Our results show that M. b. cabanisi can be readily distinguished from the two other subspecies on the basis of morphometrics (M. b. cabanisi are smaller), plumage patterns (M. b. cabanisi have different facial markings and plumage patches), color differences (M. b. cabanisi have plumage patches that differ in color and brightness), and vocalizations ( M. b. cabanisi have songs and calls that are acoustically distinct from those of M. b. biarcuata). By contrast, the two northern subspecies M. b. biarcuata and M. b. hartwegi were very similar for most traits, supporting previous suggestions that the two northern subspecies should be considered a single subspecies. Our data reveal that the differentiation in phenotypic characteristics between M. b. cabanisi versus M. b. biarcuata and M. b. hartwegi is similar to that reported for other complexes of subspecies where species status has been recognized. We argue that M. b. cabanisi should be treated as a species separate from M. biarcuata and propose that it be called Melozone cabanisi, White-faced Ground-sparrow. Our findings will contribute to the conservation efforts of the White-faced Ground-sparrow, which is endemic to Costa Rica's Central Valley and Turrialba Valley, by bringing focus to conservation policies that preserve ground-sparrow habitat (thickets, shade coffee plantations, and young secondary forest). Copyright © 2014 Magnolia Press

Many species of sparrows (Emberizidae) in the temperate zone provide model systems for understanding bird song and singing behaviour. In contrast, the vocal repertoire and vocal behaviour for most tropical sparrows is poorly understood, in spite of their impressive biodiversity. We present here the first detailed quantitative description of vocal repertoires and vocal behaviour of the Rusty-crowned Ground-sparrow (Melozone kieneri), an endemic Mexican sparrow. We provide information on the effect of territory spacing on song repertoire-use and details of the diel pattern of variation in vocal output, using focal, autonomous, and opportunistic recordings of birds in El Tuito, Jalisco, Mexico. Our results demonstrate that Rusty-crowned Ground-sparrows produce three distinct categories of vocalizations - calls, solo songs, and duets - as in other Melozone ground-sparrows. We found that solo songs and duets in this species showed an acoustic structure intermediate to other northern and southern Melozone groundsparrows. Patterns of repertoire-use in male solo songs were highly similar between males holding nearby territories, suggesting that song learning may occur after territory establishment. The diel pattern for output of calls and solo songs showed a pronounced peak early in the morning, indicative of dawnchorus singing behaviour. This study provides the first quantitative investigation of Rusty-crowned Ground-sparrow vocalizations, providing important descriptive information on this little-studied Neotropical Melozone species. © 2014 The Neotropical Ornithological Society.

Loud calls can be heard over long distances due to their high amplitude and low frequency. These calls are commonly used for both within- and between-group communication in many bird and primate species. In the Neotropics, mated pairs of socially monogamous titi monkeys (genus Callicebus) emit conspicuous, coordinated loud calls. These vocalizations appear to play a role in territorial defense, a hypothesis derived from studies of only three of the 31 recognized Callicebus species. Here, we describe the acoustic properties and organization of the loud calls of black-fronted titi monkeys (Callicebus nigrifrons). We compare the behavioral and ecological contexts associated with these vocalizations to investigate their role in within- and between-group communication, resource defense, and mate defense. Black-fronted titi monkeys create loud calls by combining a finite number of syllables to form more complex phrases, which are assembled to compose long sequences of loud calls. Bioacoustic features distinguish the loud calls used in different contexts, involving communication within- and between-groups. We found support for the hypothesis that vocalizations used for between-group communication are cooperative displays used by the mated pair and other group members to regulate access to important food resources, such as fruits. On the other hand, we only found weak support for the mate defense hypothesis. Am. J. Primatol. 76:788-800, 2014. © 2014 Wiley Periodicals, Inc.

1. Radiotelemetry provides a tool for monitoring animals that are difficult to observe directly. Recent technical advances have given rise to new systems that present expanded opportunities for field research. We report the results of the first field test of Encounternet, a new digital radiotelemetry system comprising portable receiver stations and digital tags designed for long-term studies of the social behaviour and ecology of free-living animals. 2. We present results from a series of field tests designed to evaluate the utility of Encounternet for monitoring animals in a neotropical forest, with an emphasis on evaluating mate sampling behaviour in female long-tailed manakins. In this tropical species, females visit leks where males perform elaborate dances on horizontal perches. Females are highly cryptic in both plumage and activities, and therefore, Encounternet might provide unique insights into female behaviour and ecology. 3. Our first two tests revealed that pulse strength and probability of detection decrease with the distance between tag and receiver and that tags placed on a fixed perch near a receiver showed different patterns of reception than more distant tags. Our third test revealed that antenna angle had only a small influence on pulse strength. 4. Blind analysis of simulated bird movements confirmed that the Encounternet system provides reliable information on animal activity. Data from multiple receivers permitted accurate reconstruction of simulated bird movements. Tag detections showed low levels of false negatives and false positives. 5. Female manakins responded well to carrying Encounternet tags attached by an elastic leg harness. Birds flew well upon release and were detected for 7.5 ± 0.8 days after release. Recaptures and re-sightings of females were rare in our large study population, yet there were two occasions where we confirmed that the tag fell off within 1 year. 6. We conclude that Encounternet technology provides an effective tool for monitoring animal ecology and behaviour. We show that it is capable of providing accurate measures of distance and that it is a highly versatile system for studying the ecology and behaviour of free-living animals. We discuss the unique opportunities facilitated by this technology for future ecological and behavioural studies. © 2012 The Authors. Methods in Ecology and Evolution, © 2012 British Ecological Society.

1. Using arrays of microphones, biologists can monitor the position of free-living animals based on the sounds they produce. Microphone array technology exploits differences in sound arrival times at each microphone to calculate an animal's position. This technology provides new opportunities for studying animal ecology and behaviour and has many advantages over tracking technologies that require capturing animals and fitting them with external devices, or technologies that focus on one individual in isolation of the activities of nearby animals. 2. The efficacy of microphone arrays for triangulating the position of wild animals has been established through previous studies. Yet widespread use of microphone array technology has been limited by many factors: arrays are expensive, custom manufactured, and cumbersome. Consequently, microphone arrays are used infrequently, in spite of their transformative potential for studying animal ecology and behaviour. 3. We conducted a field test of a new wireless microphone array system that has multiple advantages over previous systems: it is relatively inexpensive, commercially available, includes an integrated global positioning system (GPS) for time-synchronizing microphones, and it is small enough to fit in a backpack. We set up an array of four stereo recorders (each with a pair of stereo microphones) at 12 sites and tested the system's accuracy for estimating the location of loudspeakers broadcasting 25 types of bird, mammal and frog sounds. 4. We found that this system produced accurate location estimates based on multi-channel recordings of many types of acoustic signals. The average location accuracy was 1.87 ± 0.13 m, on par with cable-based microphone array systems. Location accuracy was significantly higher when the recorders were closer together and when sounds were broadcast inside the area bounded by the microphones. Accuracy tended to be higher in field vs. forest habitats. 5. We discuss how this system may be used to enhance studies of animal ecology and behaviour across a wide range of contexts. As with previous arrays, this system will allow researchers to monitor animals that produce distinctive acoustic signals. In contrast to previous microphone arrays, this system is affordable, portable and commercially available. Consequently, this system stands to dramatically enhance research on wild, free-living animals. © 2012 The Authors. Methods in Ecology and Evolution © 2012 British Ecological Society.

1. Animals produce sounds for diverse biological functions such as defending territories, attracting mates, deterring predators, navigation, finding food and maintaining contact with members of their social group. Biologists can take advantage of these acoustic behaviours to gain valuable insights into the spatial and temporal scales over which individuals and populations interact. Advances in bioacoustic technology, including the development of autonomous cabled and wireless recording arrays, permit data collection at multiple locations over time. These systems are transforming the way we study individuals and populations of animals and are leading to significant advances in our understandings of the complex interactions between animals and their habitats. 2. Here, we review questions that can be addressed using bioacoustic approaches, by providing a primer on technologies and approaches used to study animals at multiple organizational levels by ecologists, behaviourists and conservation biologists. 3. Spatially dispersed groups of microphones (arrays) enable users to study signal directionality on a small scale or to locate animals and track their movements on a larger scale. 4. Advances in algorithm development can allow users to discriminate among species, sexes, age groups and individuals. 5. With such technology, users can remotely and non-invasively survey populations, describe the soundscape, quantify anthropogenic noise, study species interactions, gain new insights into the social dynamics of sound-producing animals and track the effects of factors such as climate change and habitat fragmentation on phenology and biodiversity. 6. There remain many challenges in the use of acoustic monitoring, including the difficulties in performing signal recognition across taxa. The bioacoustics community should focus on developing a common framework for signal recognition that allows for various species' data to be analysed by any recognition system supporting a set of common standards. 7. Synthesis and applications. Microphone arrays are increasingly used to remotely monitor acoustically active animals. We provide examples from a variety of taxa where acoustic arrays have been used for ecological, behavioural and conservation studies. We discuss the technologies used, the methodologies for automating signal recognition and some of the remaining challenges. We also make recommendations for using this technology to aid in wildlife management. © 2011 The Authors. Journal of Applied Ecology © 2011 British Ecological Society.

The Cracidae rank among the most threatened families of Neotropical birds, and studies of their vocal behavior may help guide conservation and monitoring efforts. We describe the vocal behavior of Great Curassows (Crax rubra), a little-studied Cracid species currently listed as vulnerable. From 2008 to 2010, we recorded curassows in northwest Costa Rica using both handheld and automated digital recorders. Analysis of recordings revealed that Great Curassows had a vocal repertoire of five call types. Yip and bark calls are sex-specific alarm calls of short duration (0.12 and 0.08 s, respectively). The descending whistle is a longer duration alarm call (2.18 s) produced primarily by males. The snarl is a short call (0.67 s) associated with a threat display produced by adults with dependent young. The boom call was the most common Great Curassow vocalization, and was given only by males. Boom calls are long (8.86 s), low-frequency ( < 150 > Hz), multisyllable calls comprised of four stereotyped phrases. Great Curassows often uttered boom calls well before dawn, with a peak in activity at dawn and the hours following. Males produced bouts of repeated boom calls that lasted an average of 35 min, but sometimes continued for more than 5 h. Boom calls were given from February to June, with a peak in late April and early May when breeding begins. Discriminant analysis of boom calls of birds from 10 different locations revealed interindividual variation in call structure that may be useful for bioacoustic monitoring of individuals. Our results suggest that automated recorders might provide a way to monitor the abundance of male curassows because their boom calls are given frequently during the period from February to June and can be detected at distances up to 250 m. © 2011 The Authors. Journal of Field Ornithology © 2011 Association of Field Ornithologists.

The allometric relationship between body size and song frequency has been established in previous studies of temperate and tropical bird communities. However, the relationship between body size and the frequency of distress calls has been examined in only one study of temperate birds. We examined size-frequency relationships in the distress calls and songs of a Neotropical bird community in northwestern Costa Rica. In 2008 and 2009, we recorded distress calls and determined the body mass of 54 mist-netted birds representing 38 species, 35 genera, and 14 families. We obtained songs for these same species from sound libraries and commercially available compact discs. For each vocalization, we measured minimum frequency and frequency of maximum amplitude. Larger birds produced lower-frequency distress calls and songs than smaller birds. Phylogenetically controlled analyses revealed that the frequency of maximum amplitude was negatively correlated with body mass for both distress calls and songs. Minimum frequency was negatively correlated with mass for distress calls, but not songs. Our analyses suggest that the influence of phylogeny on the relationship between frequency characteristics and body size is modest. Pair-wise comparisons across 37 species revealed that distress calls and songs had similar minimum frequencies, but songs had significantly lower frequencies of maximum amplitude than distress calls. This difference may arise from differences in signal function. Lower-frequency sounds should transmit farther through forest habitats and songs must often transmit longer distances to reach their intended audience than distress calls. Our results support the general theory that body size is negatively correlated with the frequency of acoustic signals by demonstrating that this pattern holds true for both distress calls and songs in a Neotropical bird community. © 2011 The Authors. Journal of Field Ornithology © 2011 Association of Field Ornithologists.

Many animals defend territories against conspecific individuals using acoustic signals. In birds, male vocalizations are known to play a critical role in territory defence. Territorial acoustic signals in females have been poorly studied, perhaps because female song is uncommon in north-temperate ecosystems. In this study, we compare male vs. female territorial singing behaviour in Neotropical rufous-and-white wrens Thryothorus rufalbus, a species where both sexes produce solo songs and often coordinate their songs in vocal duets. We recorded free-living birds in Costa Rica using an eight-microphone Acoustic Location System capable of passively triangulating the position of animals based on their vocalizations. We recorded 17 pairs of birds for 2-4 consecutive mornings and calculated the territory of each individual as a 95% fixed kernel estimate around their song posts. We compared territories calculated around male vs. female song posts, including separate analyses of solo vs. duet song posts. These spatial analyses of singing behaviour reveal that males and females use similarly sized territories with more than 60% overlap between breeding partners. Territories calculated based on solo vs. duet song posts were of similar size and similar degrees of overlap. Solos and duets were performed at similar distances from the nest for both sexes. Overall, male and female rufous-and-white wrens exhibit very similar spatial territorial singing behaviour, demonstrating congruent patterns of male and female territoriality. © 2011 Blackwell Verlag GmbH.

Playback experiments involve the broadcast of natural or synthetic sound stimuli and provide a powerful tool for studying acoustic communication in birds. Playback is a valuable technique for exploring vocal duetting behavior because it allows investigators to test predictions of the various hypotheses for duet function. Here, we adopt a methodological perspective by considering various challenges specific to studying duetting behavior, and highlighting the utility of different playback designs for testing duet function. Single-speaker playback experiments allow investigators to determine how duetting birds react to different stimuli, but do not simulate duets in a spatially realistic manner. Multi-speaker playback experiments are superior to single-speaker designs because duet stimuli are broadcast with spatial realism and unique and additional predictions can be generated for testing duet function. In particular, multi-speaker playback allows investigators to evaluate how birds respond to male versus female duet contributions separately, based on reactions to the different loudspeakers. Interactive playback allows investigators to ask questions about the time- and pattern-specific singing behavior of birds, and to understand how singing strategies correspond to physical behavior during vocal interactions. Although logistically challenging, interactive playback provides a powerful tool for examining specific elements of duets (such as the degree of coordination) and may permit greater insight into their functions from an operational perspective. Interactive playback designs where the investigator simulates half of a duet may be used to describe and investigate the function of pair-specific and population-wide duet codes. Regardless of experimental design, all playback experiments should be based on a sound understanding of the natural duetting behavior of the species of interest, and should aim to produce realistic and carefully controlled duet simulations. Future studies that couple playback techniques with other experimental procedures, such as Acoustic Location System recordings for monitoring the position of birds in dense vegetation or multimodal techniques that combine acoustic with visual stimuli, are expected to provide an even better understanding of these highly complex vocal displays. ©2010 The Author(s). Journal compilation ©2010 Association of Field Ornithologists.

Dominance relationships structure many animal societies, yet the process of rank attainment is poorly understood. We investigated acquisition of social dominance in winter flocks and its fitness consequences in male black-capped chickadees (Poecile atricapillus) over a 10-year period. Age was the best predictor of rank, and paired comparisons showed high-ranked males to be older than their low-ranked flock-mates. When controlling for age, morphological variables did not predict male social rank, but high-ranked males were heavier, had lower fat scores and were in leaner condition than low-ranked males. Males that survived between years tended to increase in rank over time; however, the rate of rank advancement varied individually. Rank reversals between familiar contestants were rare, and changes in male social rank were associated with changes in flock membership. Average lifetime reproductive success (LRS) of males and females was variable and best predicted by lifespan. Male rank history also influenced realized reproductive success. Birds with higher average rank over their lifespan were more likely to reproduce successfully. However, among successful birds, average rank did not significantly predict LRS. Thus, birds that lived longer and attained high social rank earlier had higher fitness, but this effect was not manifested as fine-scale differences among successful individuals. Taken together, these findings demonstrate the importance of social factors influencing individual fitness. (c) 2007 The Linnean Society of London, Biological Journal of the Linnean Society.

Understanding how climate change will shape species distributions in the future requires a functional understanding of the demographic responses of animals to their environment. For birds, most of our knowledge of how climate influences population vital rates stems from research in temperate environments; even though most of the Earth's avian diversity is concentrated in the tropics. We evaluated effects of Southern Oscillation Index (SOI) and local temperature and rainfall at multiple temporal scales on sex-specific survival of a resident tropical bird, the Rufous-and-White Wren Thryophilus rufalbus, studied over 15 years in the dry forests of northwestern Costa Rica. We found that annual apparent survival of males was 8% higher than females, more variable over time, and responded more strongly to environmental variation than female survival, which did not vary strongly with SOI or local weather. For males, mean and maximum local temperatures were better predictors of survival than either rainfall or SOI, with high temperatures during the dry season and early wet season negatively influencing survival. These results suggest that, even for species adapted to hot environments, further temperature increases may threaten the persistence of local populations in the absence of distributional shifts.

Understanding how climate change will shape species distributions in the future requires a functional understanding of the demographic responses of animals to their environment. For birds, most of our knowledge of how climate influences population vital rates stems from research in temperate environments; even though most of the Earth's avian diversity is concentrated in the tropics. We evaluated effects of Southern Oscillation Index (SOI) and local temperature and rainfall at multiple temporal scales on sex-specific survival of a resident tropical bird, the Rufous-and-White Wren Thryophilus rufalbus, studied over 15 years in the dry forests of northwestern Costa Rica. We found that annual apparent survival of males was 8% higher than females, more variable over time, and responded more strongly to environmental variation than female survival, which did not vary strongly with SOI or local weather. For males, mean and maximum local temperatures were better predictors of survival than either rainfall or SOI, with high temperatures during the dry season and early wet season negatively influencing survival. These results suggest that, even for species adapted to hot environments, further temperature increases may threaten the persistence of local populations in the absence of distributional shifts.