Charles E. Taylor

Charles E. Taylor
University of California, Los Angeles | UCLA · Department of Ecology and Evolutionary Biology

Ph.D.

About

199
Publications
15,041
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5,629
Citations

Publications

Publications (199)
Article
Full-text available
The long-held view that birdsong is exclusively a male trait has been challenged recently by a number of studies and reviews highlighting the prevalence of female song. Despite that, there remains a lack of knowledge on the function of female song, with most evidence thus far focusing on females performing duets with males in courtship displays, ty...
Preprint
Full-text available
The long-held view that bird song is exclusively a male trait has been challenged recently by a number of studies and reviews highlighting the prevalence of female song. In spite of that, there remains a lack of knowledge on the function of female song, with most evidence thus far focusing on females performing duets with males in courtship display...
Article
Full-text available
The Bird Song Diamond (BSD) project is a series of multifaceted and multidisciplinary installations with the aim of bringing contemporary research on bird communication to a large public audience. Using art and technology to create immersive experiences, BSD allows large audiences to embody bird communication rather than passively observe. In parti...
Article
We explored how Yellow Warblers (Dendroica petechia) alter their songs when encountering noise in Grand Teton National Park. Different strategies for avoiding signal masking are used by other species of birds, yet there is a lack of information of birds’ responses to higher noise levels -- above 65 dB; such levels are often found in National Parks...
Article
We explored how Yellow Warblers (Dendroica petechia) alter their songs when encountering noise in Grand Teton National Park. Different strategies for avoiding signal masking are used by other species of birds, yet there is a lack of information of birds’ responses to higher noise levels–above 65 dB; such levels are often found in National Parks tha...
Article
Hidden MarkovModels (HMMs) have been studied and used extensively in speech and birdsong recognition but they are not robust to limited training data and noise. This work present a novel method to training GMM-HMMs with extremely limited data—and possibly noisy—by sharing HMM components and generating more training samples that cover the variation...
Article
[abstFig src='/00290001/22.jpg' width='300' text='Spatial-cue-based probabilistic model' ] This paper addresses bird song scene analysis based on semi-automatic annotation. Research in animal behavior, especially in birds, would be aided by automated or semi-automated systems that can localize sounds, measure their timing, and identify their source...
Article
Many birds have songs with variable structure and sequences. In earlier studies, we characterized some features from the song structures of California Thrashers (Toxostoma redivivum). In the Thrashers, there were a large number of phrase types, dozens to hundreds and the songs that were sequences of these many phrases were not random, but show some...
Article
Automatic phrase detection systems of bird sounds are useful in several applications as they reduce the need for manual annotations. However, birdphrase detection is challenging due to limited training data and background noise. Limited data occur because of limited recordings or the existence of rare phrases. Background noise interference occurs b...
Article
We use the phase difference among sensors, by solving the phase wrapping problem based on the cross-spectrum between sensors, to obtain the DOA without exhaustive search in the 2D angle space. The proposed approach does not need the typical sensor separation or inter-frequency separation requirements. Simulation results with narrowband, wideband si...
Article
Birds are frequently vocal. Monitoring their songs and calls has provided much useful information about their ecology and behavior. Recording bird songs and locations can be resource intensive, frequently requiring two or more observers, causing considerable disturbance and possible only for short times. Passive arrays of acoustic sensors offer the...
Poster
Full-text available
Animal language may be regarded as a complex adaptive system. Although there is software for identifying linguis- tic units or “phrases” in animal vocalisations, packages for analysing the grammatical properties of phrases sequences are scarce. PajaroLoco is an open-source Mathematica package for the study of these features. This paper is a demonst...
Conference Paper
Birdsong may be regarded as a complex adaptive system. In this paper we study the relationship between complexity and consistency of an evolving model of Cassins Vireo syntax, using a genetic algorithm to approximate a Minimal Consistent Deterministic Finite-state Automata (MCDFA) capable of accepting vocal sequences produced by birds of the study...
Article
Bird songs make an attractive model for studying complex systems. They may range from simple repeated sequences, to complex sequences of different phrase types, much like human language. There is probably no single way to best characterize their complexity. We should avoid saying that that “bird songs are in complexity class X”. The diversity of ex...
Article
Full-text available
We describe songs of the California Thrasher (Toxostoma redivivum), a territorial, monogamous species whose complex songs are composed of extended sequences of phonetically diverse phrases. We take a network approach, so that network nodes represent specific phrases, and links or transitions between nodes describe a subgroup structure that reveals...
Article
Annotation of phrases in birdsongs can be helpful to behavioral and population studies. To reduce the need for manual annotation, an automated birdsong phrase classification algorithm for limited data is developed. Limited data occur because of limited recordings or the existence of rare phrases. In this paper, classification of up to 81 phrase cla...
Article
Full-text available
Projects on the acoustic monitoring of animals in natural habitats generally face the problem of managing extensive amounts of data, both needed for- and produced by- observation or experimentation. While there are many publicly accessible databases for recordings themselves, we are aware of none for annotated song sequences. In this paper, we desc...
Conference Paper
Full-text available
Bird songs may serve as models of complex adaptive systems, similar to human language. Recent interest in analyzing acoustic sequences of animal communication has led to development of several software tools for identifying the elements of such sequences, but few for actually analyzing them. Previous work in our laboratories showed that graphs repr...
Article
Full-text available
Animal acoustic communication often takes the form of complex sequences, made up of multiple distinct acoustic units. Apart from the well-known example of birdsong, other animals such as insects, amphibians, and mammals (including bats, rodents, primates, and cetaceans) also generate complex acoustic sequences. Occasionally, such as with birdsong,...
Article
In this paper, we present simulations and experimentally collected bird song data collected using a modified Voxnet acoustic array node (with four microphones) to perform 3D direction-of-arrival (DOA) estimation of various bird sources. We used the Approximate Maximum-Likelihood (AML) algorithm to construct the steering matrix in the beamforming pr...
Conference Paper
In this paper, we present a comparative study on the application of pattern recognition algorithms to the identification of bird individuals from their song. A collection of experiments on the supervised classification of Cassin’s Vireo individuals were conducted to identify the algorithm that produced the highest classification accuracy. Prelimina...
Article
In this paper, we present simulations and experimentally-collected bird song data collected using a modified Voxnet acoustic array node (with four microphones) to perform 3D directionof-arrival (DOA) estimation of various bird sources. We used the Approximate Maximum-Likelihood (AML) algorithm to construct the steering matrix in the beamforming pro...
Conference Paper
The performance of a sparse representation-based (SR) classifier for in-set bird phrase verification and classification is studied. The database contains phrases segmented from songs of the Cassin's Vireo (Vireo cassinii). Each test phrase belongs to one of 33 phrase classes - 32 in-set categories, and 1 collective out-of-set category. Only in-set...
Conference Paper
In this paper, we present a novel approach to birdsong phase classification using template-based techniques suitable even for limited training data and noisy environments. The algorithm utilizes dynamic time-warping and prominent (high-energy) time-frequency regions of training spectrograms to derive templates. The algorithm is evaluated on 32 clas...
Conference Paper
A bird phrase segmentation method using entropy-based change point detection is proposed. Spectrograms of bird calls are usually sparse while the background noise is relatively white. Therefore, considering the entropy of a sliding time-frequency block on the spectrogram, the entropy dips when detecting a signal and rises when the signal ends. Rath...
Conference Paper
In this paper, we present simulation and experimental studies of localization and source separation for a bio-complexity bird study based on a new wireless acoustic array node named Voxnet. The Approximate Maximum Likelihood (AML) method is used to estimate blindly the direction-of-arrivals (DOAs) of sources which can be used to both locate the sou...
Conference Paper
Acoustic sensor arrays are recognized as an important development for field studies of animal behavior and ecology. While birds live in a 3D world and all dimensions seem important for most birds, use of these arrays has been limited almost entirely to 2D. A notable exception was the development by S. Asgari of Approximate Maximum Likelihood method...
Conference Paper
A bird phrase segmentation method using entropy-based change point detection is proposed. Spectrograms of bird calls are usually sparse while the background noise is relatively white. Therefore, considering the entropy of a sliding time-frequency block on the spectrogram, the entropy dips when detecting a signal and rises when the signal ends. Rath...
Conference Paper
In this paper, we present simulation and experimental studies of multiple bird source separation based on the Voxnet acoustic array node. The Approximate Maximum Likelihood (AML) method is used to estimate blindly the direction-of-arrivals(DOAs) of the sources to generate the steering vectors in order to separate the sources via beamforming. Simula...
Article
Birds do not always vocalize at random, but may rather divide up soundspace in such a manner that they avoid overlap with the songs of other bird species. In effect, a high degree of communication efficiency can be achieved by many simultaneously active vocalists that finely integrate songs with minimal overlap. We describe this phenomenon from sev...
Article
Full-text available
Bird songs are acoustic communication signals primarily used in male-male aggression and in male-female attraction. These are often monotonous patterns composed of a few phrases, yet some birds have extremely complex songs with a large phrase repertoire, organized in non-random fashion with discernible patterns. Since structure is typically associa...
Data
Statistical prosperities of repetitions of same phrase. (EPS)
Data
Comparison of degree distributions of different individuals. (EPS)
Data
Full-text available
Detailed description of California Thrasher song and of a method of phrase classification. (PDF)
Data
Repertoire diversity in the acoustic feature space. (EPS)
Data
Audio file of a California Thrasher song. (WAV)
Article
An automated system capable of reliably segmenting and classifying bird phrases would help analyze field recordings. Here we describe a phrase segmentation method using entropy-based change-point detection. Spectrograms of bird calls are often very sparse while the background noise is relatively white. Therefore, considering the entropy of a slidin...
Article
There is growing interest in how to automate analysis of acoustic monitoring of bird vocalizations -- especially for monitoring bird behavior and biodiversity. I will review some of the main approaches to this problem and describe how this is being approached in our laboratory. We break the problem down to: event recognition; classification; locali...
Article
Bird Songs typically comprise a sequence of smaller units, termed phrases, separated from one another by longer pauses; songs are thought to assist in mate attraction and territory defense. Studies of bird song would often be helped by automated phrase classification. Past classification studies usually employed techniques from speech recognition,...
Article
In this abstract, we present a beamforming method for estimating the directions and locations of multiple sources and separating each source's spectrum from field data collected by a wireless acoustic sensor network. Each acoustic sensor is equipped with four microphones that receive acoustic signals in a time-synchronized manner. The difference in...
Article
This paper evaluates the performance of a sparse representation-based (SR) classifier for a limited data, bird phrase classification task. The evaluation database contains 32 unique phrases segmented from songs of the Cassin's Vireo (Vireo cassinii). Spectrographic features were extracted from each phrase-segmented audio file, followed by dimension...
Conference Paper
Full-text available
Adaptive walk on a fitness soundscape [7] is a new kind of interactive evolutionary computation for musical works. This system provides a virtual two-dimensional grid called a “soundscape” in which each point corresponds to a genotype that generates a sound environment. By using the human abilities of localization and selective listening, the user...
Article
The ability to monitor interactions between individuals over time can provide us with information on life histories, mating systems, behavioural interactions between individuals and ecological interactions with the environment. Tracking individuals over time has traditionally been a time- and often a cost-intensive exercise, and certain types of an...
Article
This article summarizes the work in our laboratories toward developing adaptive sensor arrays for monitoring bird vocalizations. We have focused on four species of antbird in a tropical rainforest in Mexico. Preliminary results of individual identifications using support vector machines are presented. We also describe our initial attempts at higher...
Article
Alarm calling is common in many species. A prevalent assumption is that calling puts the vocalizing individual at increased risk of predation. If calling is indeed costly, we need special explanations for its evolution and maintenance. In some, but not all species, callers vocalize away from safety and thus may be exposed to an increased risk of pr...
Article
Full-text available
Acoustic localization is a promising method to passively observe vocal animal species, but remains difficult and time consuming to employ. To reduce the labor intensity and impact of deployment, an acoustic localization system has been developed consisting of battery powered wireless sensor nodes. The system also has the ability to perform an acous...
Data
Full-text available
Recruitment letters, research information sheets and questionnaires for rural and urban populations, doctors, scientists and traditional healers.
Data
Most trusted organizations for issues related to biotechnology among rural and urban populations, doctors, scientists and traditional healers.
Data
Demographic information of rural and urban populations, doctors, scientists and traditional healers.
Data
Necessary conditions for a release of GM corn cited by rural and urban populations, doctors, scientists and traditional healers.
Article
Full-text available
Genetically-modified (GM) mosquitoes have been proposed as part of an integrated vector control strategy for malaria control. Public acceptance is essential prior to field trials, particularly since mosquitoes are a vector of human disease and genetically modified organisms (GMOs) face strong scepticism in developed and developing nations. Despite...
Article
Genetically modified (GM) mosquitoes have been proposed as part of an integrated strategy for the control of dengue fever, chikungunya and malaria. Public consultation is essential prior to field trials. Despite this, very little data is available on perspectives to GM mosquitoes in disease endemic countries (DECs). We conducted a qualitative surve...
Article
Field biologists use animal sounds to discover the presence of individuals and to study their behavior. Collecting bio-acoustic data has traditionally been a difficult and time-consuming process in which researchers use portable microphones to record sounds while taking notes of their own detailed observations. The recent development of new deploya...
Article
Full-text available
Field biologists use animal sounds to discover the presence of individuals and to study their behavior. Collecting bio- acoustic data has traditionally been a difficult and time- consuming process in which researchers use portable microphones to record sounds while taking notes of their own detailed observations. The recent development of new deplo...
Article
Full-text available
MODIS data were used in conjunction with 600 ground survey points to create a 500 m resolution land cover product of Mali. It improves upon previously published land cover products for this region in resolution and accuracy. Of particular importance is the ability to detect small-scale, but important, wetland features such as rice cultivation areas...
Article
Full-text available
John Marshall and Charles Taylor review recent advances in the development of transgenic mosquitoes for malaria control.
Article
Question: Under what conditions will a group of adaptive, communicating agents converge on a single language, and when will there instead be a multiplicity of languages? This is sometimes termed the 'Tower of Babel problem', and is similar to those addressed in Slobodkin's book on simplicity and complexity. Features of the model: Agents learn to sp...
Article
Terrestrial bioacoustic census is a difficult problem because of propagation characteristics, obstructions, the diversity of bioacoustic sources, and the impact of noise. To address this problem we have developed VoxNet, a complete hardware and software platform for distributed acoustic monitoring applications. Each VoxNet node is a portable, self-...
Article
Full-text available
Behavioral and ecological studies would benefit from the ability to automatically identify species from acoustic recordings. The work presented in this article explores the ability of hidden Markov models to distinguish songs from five species of antbirds that share the same territory in a rainforest environment in Mexico. When only clean recording...
Article
Full-text available
The role of chromosomal inversions in speciation has long been of interest to evolutionists. Recent quantitative modeling has stimulated reconsideration of previous conceptual models for chromosomal speciation. Anopheles gambiae, the most important vector of human malaria, carries abundant chromosomal inversion polymorphism nonrandomly associated w...
Article
IntroductionEvolutionary dynamics of languagesTopologies of language populationsLanguage structureNetworks induced by structural similarityConclusion AcknowledgementsReferences
Conference Paper
In this paper, we propose the application of hierarchical self-organizing maps to the unsupervised acoustic classification of bird species. We describe a series of experiments on the automated categorization of tropical antbirds from their songs. Experimental results showed that accurate classification can be achieved using the proposed model. In a...
Article
The "Office du Niger" in the Niono District of Mali oversees irrigation from a dam on the Niger River -- the largest irrigation project in Mali. The facility was first built in 1932, and now irrigates more than 55,000 hectares for rice. A large reservoir in the center of the area provides water throughout the year through a water-control system. Th...
Conference Paper
Full-text available
What permits some systems to evolve and adapt more effectively than others? Gell-Mann [3] has stressed the importance of “compression” for adaptive complex systems. Information about the environment is not simply recorded as a look-up table, but is rather compressed in a theory or schema. Several conjectures are proposed: (I) compression aids in ge...
Conference Paper
Full-text available
In this paper we propose the integration of Data Mining with Hidden Markov Models when applied to the problem of acoustic bird species recognition. We first show how each of them is applied on an individual manner, contrast their results and devise a model to combine them for targeted classifications. Previous work has shown that large collec- tion...