In this blog post, author Rafael Dias delves into the world of avian abundance and richness, with a ‘Behind the Paper’ look at his research article “The spatial scaling of multiple dimensions of functional diversity in habitat islands“. Rafael explains why small places can matter in big ways for functional diversity, shares the logistics of organizing cross-country research efforts, and discusses balancing research, teaching and creativity.
About the paper
What makes a habitat valuable: the number of species it holds, or the variety of ways those species live and interact? Ecologists have long known that larger habitats usually host more species, a pattern called the species–area relationship. But that is only a sketch of diversity. We asked whether habitat size also shapes functional diversity – the variety of roles species play in ecosystems.
Functional diversity has three dimensions. Richness is how many roles exist, like the number of colours on a palette. Divergence shows how different those roles are, like the contrast between shades. Regularity reflects how evenly roles are represented, showing whether the composition feels balanced or if some areas remain blank. Together, they add colour, contrast and balance to the sketch, giving a fuller picture of how ecosystems work.
We measured bird traits such as diet, body size and foraging style in three “habitat island” systems of southern Brazil: wet grasslands, bulrush marshes and sandy washouts. Unlike true islands cut off by water, these patches sit in permeable landscapes that some birds can cross, making them more comparable to habitats fragmented by human activity, where much of biodiversity now persists. Our aim was to test whether larger habitats influence not just how many bird species are present, but also the range of roles they bring.
The results were striking. Richness rose quickly with habitat size, as bigger patches held more species and thus more roles. Divergence increased only slightly, showing species overlapped in function. Regularity often declined, with some roles overrepresented while others were absent. While most patterns reflected species numbers, environment or competition sometimes influenced which roles were filled. Unexpectedly, some small and medium patches contained unique combinations of roles missing from the largest ones.
This shows why diversity cannot be reduced to species counts. Larger habitats are valuable, but they do not automatically capture the full range of functions. Smaller patches, often overlooked, can add rare and irreplaceable details to the canvas. In a fragmented world, conserving function is as important as conserving species – and small places can matter in big ways.
About the research
This project began in an unusual way. Tom Matthews had reviewed one of our earlier papers on diversity–area relationships, signed his review, and suggested that functional diversity–area relationships deserved closer attention. The idea stayed with me, and when I finally had time, I began drafting analyses with my former students and close friends, Vinícius and Andros. It soon felt natural to invite Tom – not only because he had planted the seed, but because he is a leading name in the field. I sent an email, hoping he would remember our earlier exchange and, fingers crossed, agree. He bravely did. From then on, the four of us worked entirely online, spread across Brazil, Portugal, and England, relying on email and WhatsApp. Despite the distance and never meeting in person, the collaboration was smooth, productive, and often hilarious.
The data came from earlier surveys: a funded grassland study, and self-financed beach and wetland projects with Andros and Vinícius during their undergraduate years. Each recorded the full avifauna of habitat patches, which meant long hours walking their perimeters with handheld GPS to measure area. Only the bulrush study had species–area relationships in mind. Adventures were plentiful: we nearly got stranded on the beach as the tide rose, slogged knee-deep through marsh mud while feeding leeches and dodging giant water bugs, and got jabbed by spiny plants in bogs. Later came the trait work, when I single-handedly measured hundreds of museum specimens. It was oddly relaxing, though hard on the eyesight, and gave me the chance to handle historic specimens collected by naturalists I admire and to spend time with museum friends.
Although results were largely as expected, we were still surprised by some patterns. Adding abundances to functional richness made little difference, divergence mirrored richness a lot, and despite being rare, patterns of trait similarity and trait spread had no relationship with area and varied depending on whether richness, divergence, or regularity was assessed.
Next steps could include testing these patterns on true islands and other types of habitat islands and using simulations to help us understand whether trait similarity and trait spread arise from competition, habitat filtering or something else. Our dataset is fully available, and we hope young ecologists will take it further and surprise us.
About the author
My fascination with nature began at five, when my parents gave me a book set called Os Bichos. Inspired by my father and uncles, I decided then I wanted to be a scientist, even without knowing what that meant. That same year, when my family moved to the US, I discovered field guides, and museums, sparking a lifelong passion for birds. Back in Brazil, I tried different courses before completing a degree in biology, a master’s in zoology, and, much later, a PhD in ecology. Today I am an Associate Professor at the Universidade Federal de Pelotas, a free public institution, where I also coordinate the graduate programme in Animal Biodiversity.
I have taught for more than 20 years, seeing students become researchers, colleagues, and friends. Teaching has been as much about learning from them as guiding them. I’m curiosity-driven, and after each project I often shift to new things. I also remain open and ready to change when shown a better path. My focus today is mentoring with honesty and purpose, while juggling teaching, researching, and the bureaucracy of academia. Living with neurodivergence makes me both creative and restless: it sharpens my critical thinking but also leaves me anxious and frustrated, especially when facing red tape.
Outside work, I painted birds, played drums and sang – both poorly – in chaotic rock bands. I enjoy birding, sleeping, IPAs, ice cream, suffering with G. E Brasil de Pelotas, and celebrating small victories. Weekend churrascos with my father, brothers, sister and friends is something I wish I did more often, while sharing life with my wife and our twin boys remains my daily treasure. Looking back, I know luck and privilege opened doors, but passion, persistence, and listening to others kept me moving forward.
My advice to young scientists: First, be sure this is truly the path you want. If it is, stay curious and questioning. Value people above work and remember that less is more. Make science meaningful. Don’t become clones of your supervisors, even if they expect it – ask your mentors to teach you their failures as well as their successes. Learn when to be serious and when not. Balance comes from knowing your priorities, and a loving family gives purpose to everything.
