Research projects in the Podos lab are conducted in both field and laboratory settings, mainly (but not exclusively) using songbirds as a model system. Our lab is especially obsessed with bioacoustics -- that is developing methods for analyzing animal sounds and applying them to questions of a biological nature. Questions addressed by lab members have included the following:
How do birds use vocal behavior to mediate social interactions?
How are birds' vocalizations shaped by their morphology and vocal performance capacities?
How do birds recognize and learn species-specific songs?
How is the evolution of vocal signaling influenced by sexual selection?
Species studied by lab members have included sparrows, finches, swallows, chickadees, warblers, grassquits, bellbirds, and long-eared bats. Graduate students in the lab have been affiliated with two graduate programs, Organismal and Evolutionary Biology (OEB) and Neuroscience and Behavior (NSB). Here is an overview of three major research themes in the lab:
BIRD VOCALIZATIONS: PERFORMANCE & FUNCTION
The vocalizations of birds are wonderfully diverse, not only across species but also within species, populations, and individuals. One major focus of our work has been to ask how the structure of songs, as expressed in learning and over evolutionary time, can be shaped by birds' vocal performance capacities -- that is, by how well birds are able to produce different types of vocal patterns. In species of songbirds in New England, we have been characterizing variation in song associated with vocal performance, and conducting tests on the function of these variations, using both song learning and song playback paradigms.
Representative publications:
• Podos, J & Sung, H-C. (2020). Vocal Performance in Songbirds: From mechanisms to evolution. Sakata, J., Woolley, S., and Popp, A. (Eds). The Neuroethology of Birdsong: Springer Handbook of Auditory Research, Volume 63, Springer Press, pp. 245-268.
• Podos, J, Moseley, DL, Goodwin, SE, McClure, J, Taft, BN, Strauss, AVH, Rega-Brodsky, C, & Lahti, DC. (2016). A fine-scale, broadly applicable index of vocal performance: frequency excursion. Animal Behaviour 116:203-212
• Goodwin, SE & Podos, J. (2014). Team of rivals: alliance formation in territorial songbirds is predicted by vocal signal structure. Biology Letters 10:20131083.
• Moseley, D, Lahti, D, & Podos, J. (2013). Responses to song playback vary with vocal performance of both signal senders and receivers. Proceedings of the Royal Society B 280:20131401.
• Lahti, DC, Moseley, DL, & Podos, J. (2011). A tradeoff between accuracy and performance in bird song learning. Ethology 117:802-811
• Podos, J., Lahti, DC, & Moseley, DL. (2009). Vocal performance and sensorimotor learning in songbirds. Advances in the Study of Behavior 40:159-195
EVOLUTION AND VOCAL COMMUNICATION IN DARWIN'S FINCHES
Field research on Darwin's finches of the Galápagos Islands, Ecuador, has aimed to document interconnections between behavior (feeding, singing), morphology (beaks, heads, body size), and evolutionary divergence. Much of our research has focused on relationships between beak diversification, vocal proficieny, and song structure. Our work suggests that birds adapted for greater crushing strength experience greater constraints on vocal proficiency, because of mechanical tradeoffs between force and speed. We have also been evaluating the impacts of beak-related vocal variations on song function, through observational studies of mating patterns and playback studies with territorial males.
Representative publications:
• De León, L., Sharpe, D. M. T., Gotanda, K., Raeymaekers, J. A. M., Chaves, J. A., Hendry, A. P. & Podos, J. (2018). Urbanization erodes niche segregation in Darwin’s finches. Evolutionary Applications 2018:1-15 DOI: 10.1111/eva.12721.
• Podos, J, Dybboe, R, & Jensen, MO (2013). Ecological speciation in Darwin’s finches: parsing the effects of magic traits. Current Zoology 59:8-19. Cover includes photo by JP.
• Podos, J (2010). Acoustic discrimination of sympatric morphs in Darwin’s finches: a behavioral mechanism for assortative mating? Philosophical Transactions of the Royal Society 365: 1031-1039
• Goodale, E. & Podos, J. (2010). Persistence of song types in Darwin’s finches, Geospiza fortis, over four decades. Biology Letters 6:589-592
• Herrel, A, Podos, J, Vanhooydonck, B. & Hendry, AP. (2009). Force-velocity trade-off in Darwin’s finch jaw function: a biomechanical basis for ecological speciation? Functional Ecology 23:119-125
• Huber, SK, de Leon, LF, Hendry, AP, Bermingham, E, & Podos, J. (2007). Reproductive isolation of sympatric morphs in a population of Darwin’s finches. Proceedings of the Royal Society B 274:1709-1714
SEXUAL SELECTION AND COMMUNICATION IN NEOTROPICAL SONGBIRDS
Jeff has had the good fortune to collaborate with researchers in Brazil, with a shared goal of documenting patterns of sexual selection and vocal communication in poorly-studied bird species. A long-term collaborative effort, led by Regina Macedo (University of Brasilia) and Lilian Manica (University of Paraná), examines communication behavior and signal function in blue-black grassquits, at cerrado sites in south-central Brazil. We have asked if and how males vary in their display performance, and if and how these parameters influence mating success. A recently initiated project with Mario Cohn-Haft (National Institute of Amazon Research) focuses on the world's loudest birds, the bellbirds, with an initial interest in documenting how they use their loud songs in courtship.
Representative publications:
• Manica, L, Graves, J, Podos, J, & Macedo, RH (2020). Hidden leks in a migratory songbird: mating advantages for earlier and more attractive males. Behavioral Ecology 31:1180-1191. DOI:10.1093/beheco/araa065.
• Podos, J. & Cohn-Haft, M. (2019). Extremely loud mating signals at close range in white bellbirds. Current Biology 29 R1068-1069
• Macedo, R. H., Podos, J., Graves, J. & Manica, L. (2018). Breeding clusters in birds: ecological selective contexts, mating systems and the role of extra-pair fertilizations. Animal Behaviour 143:145-154.
• Manica, L., Macedo, R. H., Graves, J. & Podos, J (2017). Vigor and skill in the acrobatic mating displays of a Neotropical songbird. Behavioral Ecology 28: 164-173
• Manica, L., Graves, J. & Podos, J. & Macedo, R. H. (2016). Multimodal flight display of a Neotropical songbird predicts social pairing but not extrapair mating success. Behavioral Ecology and Sociobiology doi: 10.1007/s00265-016-2208-x
BONUS
Graduating Podos PhD students are invited (ok, goaded) into participating in a sort of reverse New-Yorker cartoon caption contest. Here's how the contest works: students identify a published quote, preferably from obscure corners of the literature, that resonantes with their PhD project and that holds some sort of personal meaning. Podos then distributes the quote widely by email, along with an invitation to submit cartoons that could accompany the quote. Entries are displayed at the defense party, and a winning entry is selected by the candidate and a panel of "experts". The winning entry and accompanying quote are then published as the frontispiece of the dissertation. Click here to see results to date from Podos lab PhDs:
Amethyst woodstar, Teresopolis, Rio de Janeiro, Brasil: