Advances in biotelemetry
A major hurdle in the study of free-living organisms has always been the difficulty of locating, and then maintaining contact with, those organisms while neither disturbing nor loosing track of them. The invention of animal-borne radio telemetry devices helped to revolutionize these efforts, and ushered in a new era in wildlife biology and conservation. For decades, however, the technology remained largely unchanged, and until very recently only relatively large mammals and birds could be monitored in this way.
In the last decade another revolution has occurred, the telecommunications revolution; and radio electronics has undergone an exciting transformation. The extremely small, powerful, efficient, and cheap electronics commonly used in smartphones and Internet Of Things (IOT) devices has made it possible to track the smallest vertebrates. Even more excitingly, the integration of tiny sensors, some no larger than a grain of sand, have made it possible not only to track animals in the wild, but also to extract detailed information about their behavior and physiology, and their environments.
I have sought to leverage this transformative technology in my own work by developing cutting-edge sensor-enabled transmitters (my solar-powered microphone transmitter is pictured at left) to investigate previously intractable questions about sexual selection and cultural evolution.
Sound analysis techniques
The study of animal sound has long been a major challenge for behavioral biologists. Few methods exist that are simultaneously precise, unbiased, accurate, and rapid. More problematic, however, is the use of the "black box" method in the analysis of animal vocal signals: ensuring that variation is parsed in a way that matches animal perceptual abilities is rarely a consideration. This is a particularly odd situation given that in the study of visual variation (for instance the match between cuckoo and host eggshell patterns), consideration of vertebrate visual perceptual abilities has long been a part of analytical methodology. The lag of sound analysis techniques behind analytical methods of other signalling modalities is not due to a lack of understanding of animal acoustic perception, however; a great wealth of information about animal acoustic perception is available to inform the analysis of animal sound.
In my work on the evolution of vocal signals (for instance dialects in Trinidadian hermit hummingbirds), I have sought to address these analytical problems by developing sound analysis tools that are robust and automated, but - more importantly - that utilize current knowledge about animal acoustic perception to shine a light into that "black box."
The tree at left is an example of the results of such an automated dialect analysis. The traces to the right of the tree are pitch traces of vocalizing male little hermits on a single lek on my field site in Trinidad.
BIOTELEMETRY: Tiny birds call for tiny transmitters
Solar-powered microphone radio transmitter
