Nature (Season 35) – Super Hummingbirds

Biographies of 3 scientists featured in film

Air date: 10/12/2016
  1. Alejandro Rico-Guevara, PhD.

Post Doctoral Research Scientists, University of California Berkeley

Alejandro is a functional morphologist using nectar-feeding birds as a study model to bridge the gap between our knowledge of ecological and co-evolutionary patterns and their underlying mechanisms.

In our show Alejandro describes his research into the hummingbird tongue. Hummingbird tongues pick up a liquid, calorie-dense food that cannot be grasped; a physical challenge that has long inspired the study of nectar-transport mechanics. Existing biophysical models predict optimal hummingbird foraging on the basis of equations that assume that fluid rises through the tongue in the same way as through capillary tubes.

Alejandro’s work demonstrates that the hummingbird tongue does not function like a pair of tiny, static tubes passively drawing up floral nectar via capillarity. Instead he shows the tongue tip as a dynamic liquid-trapping device that changes configuration and shape dramatically as it moves in and out of fluids.

  1. Christopher Witt, PhD.

Assistant Professor and Curator of Birds, Department of Biology and Museum of Southwestern Biology, University of New Mexico

Chris is an evolutionary biologist and ornithologist. In our show he demonstrates the reason why hummingbirds can live at high altitudes. How do hummingbirds survive at high altitudes, where oxygen is so limited?

Chris’ research has shown that hummingbird species living at high altitudes have evolved hemoglobin with enhanced oxygen-binding properties so they can thrive in oxygen-poor environments. This enhanced oxygen-binding property is derived from the same mutations that arose independently in these birds’ hemoglobin genes.

He reveals how a (seemingly) tiny genetic substitution changes the structure of the blood protein, hemoglobin, thereby enhancing its oxygen-binding properties. In turn, these genetic substitutions (or “mutations,” if you prefer) have opened up new possibilities for hummingbirds by allowing some species to colonize high elevation home ranges in South America’s Andes Mountains.

  1. Marcelo Araya Salas, PhD.

Post Doctoral Researcher, Cornell University

Marcelo’s research focuses on using Neotropical study systems and novel analytical methods to evaluate ideas in behavioral and evolutionary biology. In our show, we follow Marcelo’s research on the Long-billed hermits, in Costa Rica. In this species the male hermits spend 9 months of the year singing on a lek. The females visit the leks to find their potential mates. Marcelo has over 2,000 hours of research footage of the Long-billed hermits at their leks.