Always Looking to the Skies
Posted on in Heroes of Hawk Mountain by Matías A. Juhant, Darío Podestá, and Gustavo S. Cabanne
It is with deep sorrow that we share the passing of our dear friend and colleague, Sergio Hugo Seipke, on July 5th, 2025. Sergio was a dedicated raptor biologist whose passion and life’s work were devoted to observing, understanding, and educating others about birds of prey around the globe. To many, he was a respected colleague and mentor, always generous in sharing his knowledge about raptors. But to those of us who knew him well, he was also a kind and loyal friend—almost a sibling—deeply connected to the natural world. Above all, Sergio was a devoted father to four children—Sean, Dakota, Iván, and Ángel—who were his greatest pride and joy.
Sergio was born on October 19, 1974, and raised in Eldorado, Misiones, Argentina. His father ran a lumbering operation, which gave young Sergio frequent access to remote areas of lush tropical rainforest. It was there, alongside his father—who taught him to hunt, fish, and, above all, to respect and admire nature—that Sergio’s passion and deep connection to the wild first took root.
In 1993, as a young adult inspired by visits from renowned raptor authorities such as Dr. Jean-Marc Thiollay and Dr. Eduardo de Lucca to his home region of Misiones, Sergio began observing and rigorously studying raptors alongside fellow enthusiast Dr. Gustavo S. Cabanne. From that moment on, he never stopped looking skyward, always hoping to catch a glimpse of a soaring raptor. Iconic species from Misiones—such as the Swallow-tailed Kite, Roadside Hawk, and Rufous-thighed Hawk—ignited his lifelong passion for raptors. Remarkably, those early field observations later became part of the first scientific accounts of Misiones’s raptor community.
Driven by his passion for raptors, Sergio traveled extensively—observing, studying, guiding, and photographing them across every continent where birds of prey are found. By September 2024, he had observed an astonishing 225 raptor species across the globe—a testament to his dedication and deep admiration for these magnificent birds.
This global experience further strengthened his expertise, and Sergio became widely recognized as a leader in raptor identification in South America. He had an extraordinary gift as he could identify raptors at a glance and determine their age class by reading the subtle patterns of molt in their flight feathers—primaries, secondaries, and rectrices. He read feathers as if they were words in a language only a few truly understand. His knowledge of Neotropical raptors was vast, but it was his humility and generosity in sharing that knowledge which left a lasting impact on all who knew him.
Throughout his career, Sergio authored and co-authored numerous scientific articles on raptor biology, migration, taxonomy, and the field identification of Neotropical raptors. As part of his work on several raptor research projects, he collaborated with internationally renowned experts such as MSc. Russell Thorstrom, Dr. Jean-Marc Thiollay, and William (Bill) Clark. Among his most distinguished contributions was his work on the White-collared Kite—one of the world’s most endangered raptors—providing critical insights into its identification and conservation.
His dedication to the field extended beyond individual expertise; Sergio also worked tirelessly to build and strengthen the raptor conservation community in Latin America. In October 2004, he led the Primer Simposio Argentino sobre Investigación y Conservación de Rapaces in La Plata, Argentina—an event born from the need to address and update key issues in raptor biology and conservation within the country. Two years later, in June 2006, he also organized and led the Second Neotropical Raptor Conference in Puerto Iguazú, Argentina, aimed at fostering collaboration and advancing raptor research across the Neotropical region.
Sergio’s journey into global raptor study was deeply shaped by his time at Hawk Mountain Sanctuary, where he trained twice—first in the spring of 2004, and again in the autumn of 2005. As he often reflected, those formative experiences helped him truly grasp the potential of hawkwatching as a powerful tool for conservation. His time at Hawk Mountain revealed to him that raptors could serve as a gateway—captivating people, sparking curiosity, and inspiring a deeper appreciation for the natural world.
In 2013, world-renowned raptor expert and wildlife photographer Bill Clark, a long-time friend of Sergio’s, generously entrusted him with his ecotourism company, Raptours, which specializes in hawkwatching expeditions worldwide. Soon after taking the helm, Sergio organized exceptional raptor tours across Asia, Africa, Europe, and the Americas, forging lifelong friendships wherever he traveled. Under his leadership, Raptours partnered with Hawk Mountain Sanctuary to promote ecotourism, connect people with raptors, and support global efforts to protect raptor diversity—applying the lessons he had learned during his training at Hawk Mountain.
Inspired by years of leading raptor tours across South America—and building on insights from his second visit to Hawk Mountain, with the support of Dr. Keith Bildstein—Sergio set out to realize one of his most ambitious dreams: creating the first-ever field guide dedicated to the raptors of South America. As its lead author, he spent several years traveling across the continent, photographing raptors in their natural habitats and collaborating with his artist friend, Fredy Pallinger, to produce stunning illustrations and detailed descriptions of their biology, behavior, and identification. Sadly, the guide remains unfinished at the time of his passing—a poignant reflection of both his visionary dedication and the deep loss felt by the raptor community.
We, the authors, each share a deep and personal connection with Sergio. I, Matías, first met him in 2003 at the age of 16—a young hawkwatcher eager to learn. As a former Hawk Mountain trainee and now a Research Associate at the Acopian Center for Conservation Learning, I can say without hesitation that Sergio was my mentor. He shaped my skills in raptor identification and the assignment of age classes, and helped define the direction of my career. I will remember him vividly every time I see a Neotropical raptor—especially the gray morph Variable Hawk, a species we spent countless nights discussing. His passion, knowledge, and friendship profoundly influenced the biologist—and the person—I am today.
I, Dario, met Sergio in the early 1990s, and throughout the three decades that followed, we built a strong friendship and shared numerous raptor expeditions across several South American countries. Like Matías, I was also deeply shaped by Sergio’s passion and expertise. These experiences shaped my understanding of raptor biology and gave me the opportunity to collaborate with him as a field photographer, helping to create a photographic archive of South American raptors. This archive became the foundation for the illustrations in the field guide he was passionately preparing. Sergio’s knowledge, dedication, and friendship left a lasting impact on my life and work, and his memory will always stay with me.
Similarly, Gustavo knew Sergio from childhood, and their long-time friendship was more like that of brothers. Together, we explored the world of raptors, passerines, and ground-dwelling creatures. Whenever we look back and recall when and where we first identified a particular bird species, Sergio’s presence is impossible to overlook—and impossible to replace. It is impossible to forget moments like our first sighting of a Tiny Hawk or an Ornate Hawk Eagle.
As we reflect on Sergio’s remarkable life and legacy, we extend our deepest condolences to his family and to all those around the world whose lives he profoundly touched. Sergio left this world at the early age of 50, and he will be remembered not only for his extraordinary knowledge and natural leadership, but also for the warmth and generosity he brought to every encounter. His legacy lives on in the raptors he loved, in the people he inspired, and in our continued commitment to understanding and protecting birds of prey. In every soaring silhouette, every molt pattern studied, and every young hawkwatcher guided by his work, Sergio’s spirit endures. Sergio, you now are free to soar by the eagles, and even above them!