Robert Dudley, Professor

Closed (1) How do hummingbirds breathe, drink, and fly at the same time?

Applications for Spring 2019 are now closed for this project.

Hummingbirds, the most diverse group of nectar-feeding vertebrate animals and the tiniest warm-blooded flyers, have evolved unique flying abilities that allow them to feed efficiently on thousands of flowers daily. To support their extreme lifestyles, hummingbirds rely on fast-paced physiological functions. The highest vertebrate metabolic rates ever measured have been recorded from hovering hummingbirds, using a method known as 'feeder-mask based respirometry', which we will use in this project.

To meet the oxygen demands of hovering, the most costly form of locomotion, hummingbird metabolism is supported by efficient air sacs within the avian respiratory system. A vast body of research has addressed trade-offs between ventilation and locomotion in a variety of animals, ranging from insects to humans, but there are no studies on hummingbirds.

Examples of our intended experiments include: 1) Studying how breathing rates and the resulting metabolic rates differ when birds are simultaneously hovering and feeding, hovering only, and feeding only (i.e. while perching); 2) Testing for significant correlations between ventilation and drinking; and 3) morphological (e.g. 3D scans) and performance modeling (e.g. mechanical power output of flight and metabolic input related to feeding efficiency).

Duties and learning outcomes for the Undergraduate Apprentice will be discussed and tailored to each apprentice, but could include laboratory assistance, operating high-speed video and metabolic assessment systems, fieldwork, digitization (R, Matlab, or ProAnalyst) of video sequences, and computed tomography (CT) scans reconstruction, segmentation, and 3D modeling.

Day-to-day supervisor for this project: Alejandro Rico-Guevara, Post-Doc

Qualifications: Required: Attention to detail, good organization skills, punctuality, enthusiasm, and interest in biomechanics, physiology, and/or comparative morphology. Desired: Completion of introductory biology courses. Applicants are encouraged to submit the application with short statement that includes any background that may be relevant for the position. A current transcript, schedule, and CV may be requested by e-mail.

Weekly Hours: 6-8 hrs
Related website: http://alejorico.com

Closed (2) A Global Estimate for Insect Biomass

Closed. This professor is continuing with Fall 2018 apprentices on this project; no new apprentices needed for Spring 2019.

Insects are the most diverse and abundant form of animal life in the terrestrial biosphere, rivalling humans in their global biomass. However, good quantitative estimates for the world's standing mass of insects are missing. This project will involve analysis of the ecological literature to extract data on insect biomass for each of the world's major biomes, followed by algebraic scaling of geographical surface area to obtain a global estimate. This number, in turn, will be compared with existing data sets for human and plant biomass to assess the overall ecological impact of the insects.

Duties for the Undergraduate Apprentice will include downloading and extracting data from numerous scientific papers, compiling spreadsheets for biomass and geographical data, and conducting comparative analyses of the results. Learning outcomes will include increased familiarity with methods of data analysis, learning to write a scientific paper for publication, and increased conversancy with concepts in biogeography, insect diversity, and terrestrial ecology.

Day-to-day supervisor for this project: Robert Dudley

Qualifications: Required: Completion of introductory biology courses, ability to download and analyze scientific articles using Google Scholar. Desired: Knowledge of entomology and ecology; some GIS skills. Applicants are encouraged to submit their application along with a short statement that includes any background relevant for this position, along with a current transcript and curriculum vitae.

Weekly Hours: 6-8 hrs

Related website: https://berkeleyflightlab.org

Closed (3) How do arboreal lizards glide?

Closed. This professor is continuing with Fall 2018 apprentices on this project; no new apprentices needed for Spring 2019.

Any organism that lives in a tree risks falling to the ground. There are many consequences that an organism might face if this were to happen, such as injury or death upon impact with the ground or dangerous encounters with other organisms. As a result, many arboreal organisms have means to influence their body orientation and trajectory as they fall so as to control their descent and minimize the negative repercussions. This project seeks to understand the biomechanics of controlled aerial descent in arboreal lizards by using high-speed videos to record and track the movements of these lizards while gliding. I simulate gliding in lizards by using a vertically-oriented wind tunnel. Even though these organisms lack dedicated airfoils, they still have substantial control of their fall. Understanding such a system may lead to insights regarding the origin of flight in vertebrates.

Tasks: The apprentice will assist in digitizing the videos of the lizards in order to reconstruct the positions of the lizards and their body parts during the glide.

Learning Outcomes: The apprentice will learn how to create three-dimensional reconstructions of video data as well as basic knowledge of how to operate the computer software that we use to do so. The apprentice will also gain experience in collaborating with biologists as well as knowledge in the subjects of biomechanics and morphology.


Day-to-day supervisor for this project: Erik Sathe, Graduate Student

Qualifications: Required: Attention to detail, patience, and both good organization and time-management skills. Also a genuine interest in the subject matter. Applicants are encouraged to submit the application with short statement that includes any background that may be relevant for the position. A current transcript, schedule, and CV may be requested by e-mail.

Weekly Hours: 6-8 hrs

Related website: https://berkeleyflightlab.org/members/erik-sathe-3/

Closed (4) Hummingbird Flight Performance in the Tropics

Applications for Spring 2019 are now closed for this project.

A basic question in the field of biomechanics is: how does size affect movement? Size variation in living organisms today covers a range of 21 orders of magnitude! Size can dictate how an organism occupies space in its ecology and it can impact pace of life and reproduction. Size particularly impacts mode of flight for volant vertebrates. A California condor weighing 10.5 kilograms is obligated to soar while an Anna’s hummingbird weighing 4.5 grams can hover at 40 cycles per second. An intra-class comparison of condors and hummingbirds offers a coarse-grained look at how size may impact movement. Shifting to a finer-grained scale we have a lot to gain in our understanding of the size effects on flight from quantifying the movement of more closely related animals that vary in body size. Quantifying movement gives us a measure of performance, which can then be compared between members of the same species or amongst different species.

The family of hummingbirds, Trochilidae, is an ideal focal taxon to investigate flight performance. Tropical hummingbirds are rich in diversity with just over 350 species and varying from 2 grams to just over 20 grams in size. Our study site is in the country of Colombia where we have filmed hummingbirds in various experimental treatments to collect data that we can analyze here in Berkeley. Borrowing a few principles of biomechanics we can make predictions about how size affects flight performance. We test these predictions by measuring performance in less than 10 species of hummingbirds found in Colombia.


Students will spend the majority of time with image analysis including digitization (R, MATLAB) of high-speed video (Phantom, Fastec, and Hispec cameras filming at 1,000 fps), morphological analysis of images of hummingbirds (Image J), and qualitative analyses of hummingbird flight behavior. Students will gain experience with image digitization and reconstruction of free-flying wild hummingbirds as well as gain knowledge in the fields of biomechanics and ornithology.

Day-to-day supervisor for this project: Ashley Smiley, Graduate Student

Qualifications: Required: a sincere interest in hummingbirds, a detail-oriented mind, punctuality, and patience. Desired: experience in using MATLAB programming language and completion of an introductory biology course. I may request your curriculum vitae or transcript by email. A short statement about why you are interested in this project is highly encouraged.

Weekly Hours: to be negotiated

Related website: https://berkeleyflightlab.org