In 2017 Project Biodiversity partnered with the University of Barcelona and Birdlife International to complete an island-wide assessment of migratory bird populations on Sal. This assessment, which focused on examining migration trends and potential environmental threats to the Red-billed Tropicbird, led to the launch of a more extensive assessment to learn more about the island's diverse bird populations. Here, field Director Marcos Hernandez shares more about what inspired these efforts and how new discoveries are helping the bird programme take flight.
Hi Marcos! Tell us a little bit about yourself and your role with Project Biodiversity.
I’m one of the founders of Project Biodiversity and the current Director of the project’s bird monitoring programme. Growing up with a love for nature and the natural world, I was always interested in pursuing a career in conservation. Having worked with marine turtles in Costa Rica, I traveled to Cabo Verde to continue building my skills with the species. At the end of 2017, I transitioned away from turtles for a chance to expand the scope of Project Biodiversity’s work into the field of seabird monitoring and conservation. In my current role I’m responsible for strategy design and implementation as well as organising the day-to-day fieldwork. I also serve as the liaison for our partnership with the University of Barcelona Seabird Project.
A lot of people would say that the most interesting wildlife to see on Sal is the turtles. What would you tell them?
I would say - don’t believe everything that you hear! It’s easy to mistake Sal as somewhat of a barren desert, since it is one of the islands with a more arid climate. But the notion that there isn’t any wildlife beyond turtles just isn’t true! Actually, that is one of the reasons we began the bird assessment programme - until last year, no one really knew much about the bird population on Sal, because there wasn’t anyone studying it. Project Biodiversity stepped in to fill that niche.
What we’ve found over the last year has been really eye-opening. We’ve been able to track the breeding and migration of many different species, from Ospreys, to Petrels to Red-billed Tropicbirds. Our team recently discovered a colony of Cape Verde Little Shearwaters, an endemic species of bird that is threatened and is only found on certain islands in the archipelago. Data also revealed that Sal is the most important breeding site for the Red-billed Tropicbird population in West Africa.
In addition to resident bird populations, there are a number of species that nest in Cabo Verde, including Kentish Plovers, among others. So actually, Sal is less a barren desert and more a bird-lover’s paradise!
What make seabirds (and other bird species) so important to the ecosystems of Sal?
Great question! Birds, especially seabirds, have a critical role to play in ecosystems around the world, and the birds of Sal are no exception. The bird populations here play a critical role as “dispersal agents”, carrying seeds and different nutrients across various parts of the island. There are also species that rely on insects as a key element of their diet, so in that way, they also serve as ecosystem controllers. While not the most flattering aspect of birds, the nitrogen from their excrement also plays a key role in supporting the growth of local vegetation.
Seabirds play a particularly critical role as an indicator species, meaning that the health of their population can reflect the health of the ecosystem as a whole, which for a fragile island ecosystem like Sal, is pretty important.
What inspired Project Biodiversity to start the bird monitoring programme?
We knew there was a wide variety of bird species on Sal, but there was very little specific information on which species there were, which ones were residents or migrants, or numbers on pairs or colonies. We began our programme by trying to learn more about the Osprey and Tropicbird populations. The Red-billed Tropicbird is a emblematic species of Cabo Verde, and so we reached out to the University of Barcelona, who had been doing some preliminary work tracking their migratory patterns, to help us design the programme,which started with a census but has since moved on to tracking migratory and feeding patterns of the breeding pairs.
BiosCV, a partner organization of ours on Boa Vista was doing some really interesting work with Osprey species there. We knew there were some pairs here on Sal, so with their guidance and training, our team was able to develop our own monitoring strategy. The rest since then has been our own efforts to continue to grow our understanding of the role these species play in supporting the ecosystems of Sal.
We know that turtles have a pretty specific nesting season here on Sal. Is it the same for the bird populations? Is it different for different species?
The birds do have specific nesting seasons, which varies by species, but generally it is a little more fluid than the turtle nesting season. The Osprey (Guincho) breeds on Sal from around December to April and The Cape Verde Shearwater (Cagarra) breeds largely in the Summer and Autumn months. The Red-billed Tropicbird (Rabo-de-Junco) population here on Sal breeds year round, but the busiest parts of the season are during the winter months. For birds that feed in Sal’s salt marshes and lagoons, the breeding period is also in winter.
What does a day in the field look like?
One of the exciting (and sometimes stressful) things about this kind of work is that no day is the same! I start the day by reviewing what we’re trying to accomplish that day. If it’s a census, it means we’re counting the number of pairs we see to determine the general makeup of the populations. Other days we might be ringing growing chicks or recovering GPS trackers that we deployed a few days before. Since most of these species nest in Sal’s cliffs, we are always prepared to do a lot of rock climbing! There are also days where we head to the islet, a smaller island off the west coast where the only way to get there is by swimming! That takes a little extra preparation including checking the tides and making sure all of our material bags are packed airtight to keep out the water.
The programme has been collecting information for almost two years now. What has the data shown us so far?
We’ve learned so much about the bird populations here on Sal in just the last year alone. Every species has helped us uncover something new. For example, typically Ospreys are a migratory species, but Sal has a resident population that can be found here year round. Thanks to the work that we’re doing with GPS trackers, we’ve been able to learn more about where the population of Tropicbirds fly throughout the breeding season, and that Sal is the most important breeding site for the Tropicbird population in West Africa. Perhaps most significant has been our discovery of a small colony of Cape Verde Shearwater pairs, an endemic species of Cabo Verde thought to only be nesting on a few other islands.
Our data has also recently been published in Marine Policy as a part of a larger study on seabird migratory patterns. The great thing is, this is just the beginning!
Where do you see the bird programme headed in the future?
Right now, we’re focused on continuing to collect as much data as we can to better understand the full scope of the bird species here on Sal. Having this information will help us better understand the threats to their populations and in turn determine the road to protecting them. In the near future we want the data to be able to help inform policy on how to better protect their habitats and share information that can help the government determine and implement broader measures for conserving the island’s unique biodiversity.
How can people interested in the bird programme get involved?
Firstly - don’t hesitate to reach out! We’re still in the early stages of developing a broader volunteer network, but if you’re interested in our work or getting involved - email us at email@example.com or send us a message on Facebook. We always love to collaborate.
And finally, what's your favorite bird?!
A hard question, but I would have to say Tropicbird - I love their colors and the way they fly!