About This Project

Flying at incredible speeds, often upside down and backwards, hummingbirds truly have superpowers! These aerial acrobatics help them defend flowers and avoid attacks! We want to uncover the dark side of the tiniest birds by examining their adaptations for fighting. In many hummingbird species, males have teeth-like spines and daggers on their bill tips and can inflict serious damage! However, based on our studies, these weapons should make it harder for males to drink nectar. How do they do it?

Ask the Scientists

What is the context of this research?

If you have spent any time watching hummingbirds at a feeder, it quickly becomes obvious that they are not delicate little fairies, but intense cut-throat fighters! They are literally less like Tinkerbell, and more like Zorro!

All hummingbirds are aggressive, but we have found that in some species, the males have modified their bill tips to become impressive weapons. We want to understand why these weapons occur only in males, and only in some species.

In our previous work on how hummingbirds drink nectar, we have examined the morphology of tongues and beaks, and found that the close interaction between the bill tips and tongue allows hummingbirds to extract nectar at impressive speeds. Therefore we expect these weapons to make feeding on nectar more challenging and less efficient in males.

What is the significance of this project?

The elegant fit between a hummingbird's bill and the flowers they pollinate has long been an example of co-evolution. When males and females have distinct bill shapes, these differences have traditionally been ascribed to differences in floral foraging between the sexes (termed ‘ecological causation’).

But in contrast, we have shown that when males have different bills than females, it is the result of the struggle for territorial dominance through male-male combat, rather than the result of feeding on different flowers.

Bill modifications should lower feeding efficiency, and seem to contradict the selective pressures towards feeding on nectar. By examining the nectar extraction efficiency of males with weapons, we can tease apart the roles of natural and sexual selection in hummingbirds.

What are the goals of the project?

We aim to examine the costs and benefits of bill weapons in male hummingbirds. We have developed customized ‘high-speed camera traps’ that allow us to efficiently collect data of birds drinking nectar in the wild. We have trained wild hummingbirds to feed on modified feeders in front of high-speed cameras, allowing us to quantify the exact amount of nectar extracted per lick.

By studying habituated populations of Sparkling Violetear Hummingbirds (Colibri coruscans) in Colombia, we can track individuals in different territories and film these same individuals as they feed on nectar in our modified feeders. This will allow us to compare the feeding efficiency of territorial males, juvenile males and females, and statistically relate these differences to the bill shape details of each group.