Birds in an Ecological Web

One great way to learn about nature and biology is to study birds. There are many species of birds, both resident and migratory, and they all have their own habits, colors, songs, and ways of life. The popularity of birdwatching has skyrocketed in the US, especially during the pandemic. This seminar will describe one way to look at birds, and to learn about their ecology, evolution, and diversity. We start by focusing on birds’ feeding habits and food preferences. Many birds have to eat and forage constantly, in order to stay alive and to feed their offspring. From this starting point we can then trace and understand all sorts of additional aspects of birds, including (but not limited to) their beaks, their colors, their songs, and their mating systems. We will talk about bird species both local and from South America, particularly from Brazil and from the Galapagos Islands

LDLC encodes a peripheral golgi protein required for normal Golgi function

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Biology, 1995.Includes bibliographical references (p. 111-122).by Steven D. Podos.Ph.D

Zebra Finch Song Phonology and Syntactical Structure across Populations and Continents-A Computational Comparison

StH was supported by an LIBC grant to Clara C. Levelt and CtC

A fine-scale, broadly applicable index of vocal performance: frequency excursion

Our understanding of the evolution and function of animal displays has been advanced through studies of vocal performance. A widely used metric of vocal performance, vocal deviation, is limited by being applicable only to vocal trills, and also overlooks certain fine-scale aspects of song structure that might reflect vocal performance. In light of these limitations we here introduce a new index of vocal performance, \u27frequency excursion\u27. Frequency excursion calculates, for any given song or song segment, the sum of frequency modulations both within and between notes on a per-time basis. We calculated and compared the two performance metrics in three species: chipping sparrows, Spizella passerina, swamp sparrows, Melospiza georgiana, and song sparrows, Melospiza melodia. The two metrics correlated as expected, yet frequency excursion accounted for subtle variations in performance overlooked by vocal deviation. In swamp sparrows, frequency excursion values varied significantly by song type but not by individual. Moreover, song type performance in swamp sparrows, according to both metrics, varied negatively with the extent to which song types were shared among neighbours. In song sparrows, frequency excursion values of trilled song segments exceeded those of nontrilled song segments, although not to a statistically significant degree. We suggest that application of frequency excursion in birds and other taxa will provide new insights into diverse open questions concerning vocal performance, function and evolution. (c) 2016 The Association for the Study of Animal Behaviour. Published by Elsevier Ltd. All rights reserved

A collection of best practices for the collection and analysis of bioacoustic data

The field of bioacoustics is rapidly developing and characterized by diverse methodologies, approaches and aims. For instance, bioacoustics encompasses studies on the perception of pure tones in meticulously controlled laboratory settings, documentation of species’ presence and activities using recordings from the field, and analyses of circadian calling patterns in animal choruses. Newcomers to the field are confronted with a vast and fragmented literature, and a lack of accessible reference papers or textbooks. In this paper we contribute towards filling this gap. Instead of a classical list of “dos” and “don’ts”, we review some key papers which, we believe, embody best practices in several bioacoustic subfields. In the first three case studies, we discuss how bioacoustics can help identify the ‘who’, ‘where’ and ‘how many’ of animals within a given ecosystem. Specifically, we review cases in which bioacoustic methods have been applied with success to draw inferences regarding species identification, population structure, and biodiversity. In fourth and fifth case studies, we highlight how structural properties in signal evolution can emerge via ecological constraints or cultural transmission. Finally, in a sixth example, we discuss acoustic methods that have been used to infer predator–prey dynamics in cases where direct observation was not feasible. Across all these examples, we emphasize the importance of appropriate recording parameters and experimental design. We conclude by highlighting common best practices across studies as well as caveats about our own overview. We hope our efforts spur a more general effort in standardizing best practices across the subareas we’ve highlighted in order to increase compatibility among bioacoustic studies and inspire cross-pollination across the discipline

Calibration of song learning targets during vocal ontogeny in swamp sparrows,Melospiza georgiana

Song learning in songbirds often includes an extended sensorimotor phase, in which birds gradually refine their vocal output to produce accurate copies of previously memorized song models. Increasing accuracy of song model reproduction during this phase occurs as birds refine the neural substrates that underlie vocal control, and as they develop proficiency with the vocal apparatus. We here test the hypothesis that sensorimotor learning also provides birds with an opportunity to calibrate their vocal learning targets, in the event that a bird's own vocal proficiency differs from that required to successfully reproduce song models to which it is exposed. We tutored hand-reared male swamp sparrows with song models that we manipulated to vary in how challenging they would be to reproduce, and then tracked patterns of song development. The calibration hypothesis was supported by two lines of evidence. First, we found that copies of manipulated models underwent comparatively large-scale modifications in syntax and note composition over development, in directions consistent with expectations about motor proficiency relative to the structure of learned models. Second, we found that birds tended to retain selectively, in their crystallized repertoires, song types that appeared to be comparatively easy to produce. Our results are consistent with an 'active' model of song learning, and also suggest a specific mechanism by which learning can act as a creative or a stabilizing force in song evolution

A collection of best practices for the collection and analysis of bioacoustic data

The field of bioacoustics is rapidly developing and characterized by diverse methodologies, approaches and aims. For instance, bioacoustics encompasses studies on the perception of pure tones in meticulously controlled laboratory settings, documentation of species’ presence and activities using recordings from the field, and analyses of circadian calling patterns in animal choruses. Newcomers to the field are confronted with a vast and fragmented literature, and a lack of accessible reference papers or textbooks. In this paper we contribute towards filling this gap. Instead of a classical list of “dos” and “don’ts”, we review some key papers which, we believe, embody best practices in several bioacoustic subfields. In the first three case studies, we discuss how bioacoustics can help identify the ‘who’, ‘where’ and ‘how many’ of animals within a given ecosystem. Specifically, we review cases in which bioacoustic methods have been applied with success to draw inferences regarding species identification, population structure, and biodiversity. In fourth and fifth case studies, we highlight how structural properties in signal evolution can emerge via ecological constraints or cultural transmission. Finally, in a sixth example, we discuss acoustic methods that have been used to infer predator–prey dynamics in cases where direct observation was not feasible. Across all these examples, we emphasize the importance of appropriate recording parameters and experimental design. We conclude by highlighting common best practices across studies as well as caveats about our own overview. We hope our efforts spur a more general effort in standardizing best practices across the subareas we’ve highlighted in order to increase compatibility among bioacoustic studies and inspire cross-pollination across the discipline.Publisher PDFPeer reviewe

Evolutionary Dead End in the Galápagos: Divergence of Sexual Signals in the Rarest of Darwin's Finches

Understanding the mechanisms underlying speciation remains a challenge in evolutionary biology. The adaptive radiation of Darwin's finches is a prime example of species formation, and their study has revealed many important insights into evolutionary processes. Here, we report striking differences in mating signals (songs), morphology and genetics between the two remnant populations of Darwin's mangrove finch Camarhynchus heliobates, one of the rarest species in the world. We also show that territorial males exhibited strong discrimination of sexual signals by locality: in response to foreign songs, males responded weaker than to songs from their own population. Female responses were infrequent and weak but gave approximately similar results. Our findings not only suggest speciation in the mangrove finch, thereby providing strong support for the central role of sexual signals during speciation, but they have also implications for the conservation of this iconic bird. If speciation is complete, the eastern species will face imminent extinction, because it has a population size of only 5–10 individuals