Stories

Guardianes de los Ostreros | Guardians of the Oystercatchers

María de los Angeles Loredo
ANG, Asociación Naturista Geselina

Historia proporcionada por María de los Angeles Loredo
ANG, Asociación Naturalista Geseliana

En el marco de los Pequeños Fondos Manomet para la Conservación de las Aves Playeras del Neotrópico, comenzamos a llevar adelante en agosto de 2025, un proyecto destinado a generar información de base sobre la reproducción del Ostrero pardo y fortalecer herramientas de conservación en Villa Gesell, una localidad costera argentina sometida a una fuerte presión por la actividad turística durante el verano austral.

Woman looking through a spotting scope to view American Oystercatchers.

Guardianes de los ostreros americanos monitoreando aves. Foto de María de los Angeles Loredo

El proyecto tuvo como objetivos determinar la cantidad de parejas reproductivas, localizar y monitorear nidos, y evaluar medidas de mitigación para la especie en dos áreas de trabajo: la Reserva Natural Faro Querandí, un área de dunas de 6000 hectáreas y 20 km de frente costero, y la franja de dunas del norte de la ciudad, zona con un alto nivel de disturbio antrópico. Con la idea de vincular a la comunidad con la conservación de la especie, conformamos el cuerpo de Guardianes de los Ostreros, un grupo de vecinos que participaran en el trabajo de campo y otras actividades destinadas a difundir el ciclo de vida del ostrero y las problemáticas que enfrenta. Al presentar el proyecto hicimos la convocatoria, explicamos sus alcances y cuáles eran las tareas a realizar en campo.

Desde fines de agosto hasta diciembre relevamos sistemáticamente una vez por semana ambos sectores. El primer recuento de parejas lo hicimos las personas a cargo del proyecto, recorriendo ambas zonas en vehículo doble tracción y geoposicionando la ubicación de cada pareja. Una vez que detectábamos nidos, los marcamos con un caño plástico asignándole un número para la pareja y una letra para la puesta. Luego subíamos su ubicación e indicaciones específicas al grupo de whatsapp, medio de comunicación de Guardianes, para que pudieran localizarlos.

Large paper mache American Oystercatcher used in public outreach efforts.

El “Ostrero Viajero” se utiliza en talleres para crear conciencia sobre la especie, sus amenazas y cómo las personas pueden ayudar a reducir las perturbaciones durante los períodos críticos de reproducción. Foto de María de los Angeles Loredo

Los Guardianes completaban las planillas con las observaciones: zona, fecha, hora, número de pareja y letra del nido, ubicación, referencia, intervención, cantidad de huevos, pichones, distancia de huellas al nido, y cualquier otra observación que consideraran pertinente. Tomaban fotos y subían la información al grupo de whatsapp. A su vez, informaban a los curiosos o advertían de la presencia de nidos a quienes estuvieran realizando alguna actividad en playa.

También trabajaron en la colocación de cartelería informativa e indicativa y en la colocación de cubiertas en los nidos protegidos. Con el fin de que estuvieran identificados, hicimos remeras con el logo de Guardianes. Nos asociamos con la Fundación Ecológica Pinamar, ONG de la localidad vecina que aportó un grupo de guardianes muy activo, que trabajó en los monitoreos y contribuyó significativamente en tareas de sensibilización y educación ambiental, con la publicación en redes, difusión de información a vecinos, turistas y en medios de comunicación locales, y la colocación de carteles en comercios. También nos asociamos con un taller de arte local que realizó el “Ostrero viajero” y está trabajando con los niños que acuden al taller. Las guardaparques locales también colaboraron en los monitoreos y brindan charlas en las escuelas haciendo foco en nuestro ambiente nativo, la reserva y el ciclo de vida del ostrero.

Aunque el proyecto como parte de los pequeños fondos es limitado, esto fue solo el principio. Tenemos mucho trabajo por delante y pretendemos consolidar el programa Guardianes de los Ostreros como una experiencia de conservación participativa con continuidad a largo plazo y hacerla extensiva a otras localidades costeras. El proyecto permitió generar información inédita para la localidad y al mismo tiempo, construir una red comunitaria comprometida con la protección del Ostrero Pardo y de los ambientes costeros que la especie utiliza para reproducirse.

María de los Angeles Loredo
ANG, Asociación Naturista Geselina

ENGLISH TRANSLATION

Story provided by María de los Angeles Loredo
ANG, Geselian Naturalist Association

As part of the Manomet Small Grants Program for the Conservation of Neotropical Shorebirds, we began implementing a project in August 2025 aimed at generating baseline data on the breeding of the American Oystercatcher and strengthening conservation tools in Villa Gesell, an Argentine coastal town under heavy pressure from tourism during the southern hemisphere summer.

Guardians of the American Oystercatchers monitoring birds. Photo by María de los Angeles Loredo

The project’s objectives were to determine the number of breeding pairs, locate and monitor nests, and evaluate mitigation measures for the species in two study areas: the Faro Querandí Nature Reserve—a 6,000-hectare dune system with a 20-km coastline—and the dune strip north of the city, an area with a high level of human disturbance. With the aim of engaging the community in the conservation of the species, we formed the “Guardians of the Oystercatchers,” a group of local residents who would participate in fieldwork and other activities designed to raise awareness about the oystercatcher’s life cycle and the challenges it faces. When we presented the project, we issued a call for participants, explained its scope, and outlined the tasks to be carried out in the field.

From late August through December, we systematically surveyed both areas once a week. The initial count of breeding pairs was conducted by the project team, who traveled through both zones in a four-wheel-drive vehicle and geotagged the location of each pair. Once we detected nests, we marked them with a plastic pipe, assigning a number to the pair and a letter to the clutch. We then uploaded their locations and specific instructions to the WhatsApp group—the Guardians’ communication channel—so they could locate them. The Guardians filled out the forms with their observations: area, date, time, pair number and nest letter, location, reference point, intervention, number of eggs and chicks, distance of tracks from the nest, and any other observations they deemed relevant. They took photos and uploaded the information to the WhatsApp group. They also informed curious onlookers or alerted people engaged in beach activities to the presence of nests.

The “Traveling Oystercatcher” is used in workshops to raise awareness of the species, its threats, and how people can help reduce disturbance during critical breeding times. Photo by María de los Angeles Loredo

Additionally, they worked on installing informational and directional signage and placing covers over protected nests. To ensure they were easily identifiable, we made T-shirts featuring the Guardianes logo. We partnered with the Pinamar Ecological Foundation, an NGO from the neighboring town that provided a very active group of guardians. They worked on monitoring efforts and contributed significantly to environmental awareness and education by posting on social media, sharing information with residents, tourists, and local media, and placing signs in local businesses. We also partnered with a local art studio that created the “Traveling Oystercatcher,” and is currently working with the children who attend the workshop. Local park rangers also assisted with monitoring and give talks at schools, focusing on our native environment, the reserve, and the oystercatcher’s life cycle.

Although the project, as part of the small grants program, is limited in scope, this was just the beginning. We have a lot of work ahead of us, and we intend to consolidate the Guardians of the Oystercatcher program as a participatory conservation initiative with long-term sustainability and expand it to other coastal communities. The project generated previously unrecorded data for the community and, at the same time, helped build a community network committed to protecting the American Oystercatcher and the coastal habitats the species uses for reproduction.

Playing Nice on the Beach – Unusual Observations from a Small Island Population of American Oystercatchers

American Oystercatcher clutch. Beth Howard, Mass Audubon

American Oystercatchers are fiercely territorial, and a pair of nesting oystercatchers generally prefers some space between them and their nesting neighbors. However, there is an unusual oystercatcher oasis in Boston Harbor where nine pairs nest within a maximum distance of about 275 meters! This leads to all sorts of fun and unusual behavioral observations regarding these generally-territorial birds.

For example, Mass Audubon monitors have noticed several instances of creche-like behavior, which is when chicks from multiple broods are collectively tended by an adult or adults. This is not at all typical of American Oystercatchers. However, there are two pairs on this island who nest less than 50’ from each other each year, and for several years, they have left both broods with one adult while the other three adults go off to forage. The adult that stays with the chicks switches chick-tending duties with another adult periodically. This collaborative chick-rearing is not what we typically expect from this highly territorial and aggressively defensive species!

On this island oasis, we have also seen collaborative nesting, where a “throuple” (three adults) came together one year to lay eggs and share incubation duties. Additionally, we have seen a case of adoption (by choice, not necessity!). In this situation, one pair of oystercatchers initially had three chicks and another pair had two. The pairs’ nests were within 100’ of each other, and when the chicks hatched, they often hung out together near the territorial boundary. The adults would not allow the other adults into their territories, but the chicks were allowed to freely come and go between territories. At one point, one chick from the pair that had two decided not to return, and instead joined the trio and were fed and defended by the adoptive parents as a fourth member of the brood until they all fledged. The solo chick also fledged, and continued to spend time with the other chicks, but stayed with the original set of parents.

Some Things We Learn from Banding

At the southern end of the Boston Harbor Islands is a small harbor with four small islands. As the established population of American Oystercatchers in Boston Harbor is successful, their chicks and other young oystercatchers often return to the same general area to try to establish a territory of their own. One year, a young banded bird showed up with a mate and established a new nesting territory on one of the islands. Because of the band, we were able to learn that this was a bird who was three years old and had not previously nested elsewhere.

Two American Oystercatchers on a rocky beach.

American Oystercatchers. Beth Howard, Mass Audubon

We were able to see how young birds move in and search for territories by following this bird’s nest attempts over eight years. Year after year, we saw the pair try out different sections of the same island, then different types of substrate, and eventually, three different islands before settling on what appears to be their final choice of nesting location. We can see them learning and refining their process with every attempt. They are choosing areas with more forgiving substrate, and are nesting higher above the wrack line to avoid tidal overwash. Avian predators are hard to avoid, but the pair is learning to choose locations with a good vantage point for spotting predators approaching, while also using natural features to conceal their location as well as they can.

We see a lot of oystercatchers moving through the area, and without a banded bird being part of this pair, we might not have understood that it was the same pair switching up their locations from year to year, and trying new things. Because of the bands, we are able to observe and understand a little bit more about how young birds arrive on scene, establish their own territories, learn from their prior choices, and make new decisions on where to nest each year. We can see their confidence grow as they return, claim territory, make a nest, and lay eggs earlier and earlier each year. This year, they chose a good spot and nested at about the same time as the older, more experienced pairs did. Perhaps this will be the year they fledge chicks from what appears to be their preferred territory!