On August 1st, a group of orcas was observed in Punta Loma, near Puerto Madryn, Chubut, practicing intentional beaching in a colony of South American sea lions. Later, they moved towards Playa Paraná and, in the afternoon, attacked a southern right whale calf just 700 meters from Las Canteras beach, in the El Doradillo Natural Protected Area. This area hosts the highest concentration of southern right whale mothers and calves in the region.
Some orcas approached the coast so closely that they offered a unique spectacle to visitors. The audiovisual record of the event confirmed the attack and showed that the group continued moving north, interacting with other whales along the way. On the same day, 155 whales were counted in the area, a noteworthy figure within the “Measuring Whales” project.
While this type of event is rare, these observations provide key information to understand the interactions between predators and prey in the sea. Long-term studies indicate that the presence of orcas influences the behavior and distribution of southern right whales in Península Valdés.
Predation exerts an evolutionary pressure that shapes the defensive behavior and habitat choice of whales. Since the 1980s and 1990s, many females with calves have moved from the outer coast—with more orcas—towards Nuevo and San José Gulfs, where the risk of attacks decreases.
**[View Image here](https://storage.googleapis.com/media-cloud-na/2025/08/ballenas-y-orcas-en-el-doradillo-ICB-2-300×169.jpg.webp)**
## A Natural Balance Under Pressure
Research between 1972 and 2000 recorded 117 encounters between orcas and southern right whales, with attacks in only 10% of the cases, but with a high risk for the calves. In response, whales developed defensive strategies such as the “rosette formation,” where adults surround the calves with their tails outwards to protect them.
The movement towards safer areas seems to have reduced encounters and attacks, although they still occur. Valdés offers natural advantages: shallow waters, lower orca density, and abundance of other prey for predators.
The interaction between orcas and whales is part of the natural balance, but constant observation allows for detecting changes and threats. Preserving these spaces is crucial to ensure that both species continue to fulfill their role in the marine trophic chain.
**[View Image here](https://storage.googleapis.com/media-cloud-na/2024/11/unnamed-4-300×169.jpg)**
## Reproduction and Survival of the Southern Right Whale
The reproduction of the southern right whale is a slow and strategic process. Females give birth every three to five years, and gestation lasts approximately 12 months. This low reproductive rate means that the loss of a single calf has a significant impact on population recovery.
In breeding areas like Península Valdés, mothers seek shallow and calm waters that hinder the approach of predators. Here, calves stay with their mothers during the first months, a critical period for their development and learning.
The survival of each calf is crucial not only to maintain a stable population but also to conserve the ecological role of the species. As large filter-feeding cetaceans, southern right whales help recycle nutrients in the ocean and maintain the health of marine ecosystems.
Source: Instituto de Conservación de Ballenas.
