ECR Spotlight – Facundo Fernandez-Duque

Facundo Fernandez-Duque

How did you become interested in biology?

Growing up in northern Argentina, I was surrounded by striking wildlife: from red-bellied piranhas darting through the rivers to plush-crested jays with their piercing yellow eyes. I often found myself asking why these creatures looked and behaved so differently. Why did young tapirs sport coats that bore little resemblance to the adults? Why should piranhas have vivid red bellies at all? As I looked more closely into these questions, each answer sparked new curiosities and fueled my fascination with the natural world's endless intricacies. This early fascination led me to study biology so that I could learn how animals vary not only within their own species but also across different species. Today, I focus on uncovering the mechanisms behind intraspecific and interspecific differences in animal behavior – an endeavor that still feels as thrilling to me as those first nature explorations back home.

Describe your scientific journey and your current research focus

Looking back, I realize that many of my earliest research endeavors centered on a single overarching question: why do we see such variation in animal behavior? My very first project examined the ecology, behavior and demography of the bare-faced curassow (Crax fasciolata), a rare bird in Argentina. I was captivated by why these elusive birds appeared where I grew up but were absent from other seemingly suitable sites. Once I entered college, that same curiosity guided each of my subsequent projects. I explored behavioral differences across phenotypes in red-backed fairywrens, investigated how malarial infections correlate with behavior in black-throated blue warblers, and tackled several other questions that helped shape my broader interests.

Today, my research focuses on the environmental, endocrine and neural mechanisms that drive variation in parental care among species with facultative biparental care. I'm especially fascinated by how different internal and external factors interact to influence not just whether parents care for their offspring but also how and when they do so. By uncovering these mechanisms, I hope to shed light on the remarkable diversity of parenting strategies we see across the animal kingdom.

How would you explain the main findings of your paper to a member of the public?

Birds that raise their young in nests face a unique challenge: sometimes, other bird species sneak their eggs into their nests, tricking them into raising unrelated chicks. To deal with this, some birds have evolved the ability to recognize and reject eggs that don't look like their own. Our study explored how the shape and color of eggs influence this ability in three bird species.

We found that birds pay attention to egg shape, but their sensitivity to these shapes varies depending on their nesting habits. For example, birds that often clean debris out of their nests, like red-winged blackbirds, are more likely to reject eggs that don't look ‘egg shaped’. On the other hand, species like Eastern bluebirds, which nest in enclosed spaces and rarely encounter debris, rely more on egg color to decide whether to keep or reject an egg.

Our work helps us understand how birds use different clues to protect their nests and highlights the complex strategies animals use to adapt to their environments. By studying these behaviors, we can learn more about the fascinating ways nature balances survival and reproduction.

What is the most important lesson that you have learned from your career so far?

I've learned many valuable lessons throughout my career, but one of the most important is the ability to recognize and accept that everything takes more time than anticipated. Early on, I'd get excited about new projects and want to dive in immediately, only to realize there were hurdles like waiting for equipment to arrive, securing permits, or timing fieldwork to align with the breeding season. Even with a detailed and well-thought out timeline, things rarely go exactly as planned. Embracing this reality has not only reduced my stress but also allowed me to approach challenges with greater flexibility and patience. It's a lesson that extends beyond research and has shaped how I navigate other areas of life as well.

What do you like to do in your free time?

In my free time, I enjoy reading, cooking, watching soccer, spending time with loved ones and caring for my pets and plants. Reading has always been a significant part of my life – it's my favorite way to disconnect and recharge. Growing up, we moved frequently, and books became a constant companion. While I love biology-related reads, I'm also drawn to magical realism; favorites include One Hundred Years of Solitude, The Alchemist and The Night Circus. Cooking is another way I unwind – it's hard to focus on your stresses when your favorite music is playing, and you're creating something delicious. Watching soccer, on the other hand, isn't always relaxing…but it's a wonderful way to connect with my family and embrace a big part of Argentine culture. Lastly, I love spending time with my pets and plants – they bring so much joy, and it's a lot of fun caring for them.

What is one thing about you that others might find surprising?

One surprising thing about me is that, as a kid, I used to be a street-performing clown! It all started as a fun activity, performing tricks and routines with a group of friends at plazas, parks and other public spaces. It wasn't about making money; it was about having fun and bringing joy to people passing by. From time to time, we would perform at schools, community events and even hospitals, which made the experience even more meaningful. Although I've traded my clown shoes for a lab coat, I think that experience instilled in me a lifelong appreciation for creativity, spontaneity and connecting with others. It also explains why I'm still pretty silly at times! Most people are shocked to learn about this part of my life, but I love sharing it as it's a fun reminder of how much joy and laughter can bring people together.