a lead goose known as Piu-Piu, have been observed responding when called by officers. Photo Credit: Karel Pesorna/Shutterstock
At the São Pedro de Alcântara prison in the southern Brazilian state of Santa Catarina, officials have adopted an unconventional approach to perimeter security by using geese to help guard the facility and aid surveillance. The flock of geese has replaced guard dogs and now patrols part of the prison grounds, complementing electronic systems and human oversight.
Prison director Marcos Roberto de Souza said the animals have become a valuable part of the institution’s layered security strategy. The geese are kept in the green space between the inner fence and the main outer wall, where their loud honking helps draw attention to any unusual activity around the perimeter.
The birds, which include a lead goose known as Piu-Piu, have been observed responding when called by officers, emitting distinctive honks that staff interpret as alerts to their attention. De Souza explained that their natural vigilance and tendency to vocalise at unfamiliar sounds make them effective in this role.
Cost and practicality cited by officials
Geese seen as affordable and effective guards
De Souza said that maintaining the geese is significantly more affordable than keeping guard dogs, which require training, healthcare and ongoing care. By contrast, the geese are relatively low-maintenance and are naturally wary of strangers, making them well suited to the quiet, rural location of the prison.
“We have electronic surveillance, in-person surveillance and finally the surveillance of the geese, which replaced the dogs,” the director said, highlighting that the birds are one of several layers of security.
The use of geese for patrol does not mean the prison has abandoned other security methods. Cameras, regular guard rotations and physical barriers remain in place, with the flock of birds acting as an additional alert system rather than a sole defence measure.
How the geese operate
Natural instincts supplement technology
The geese spend much of their time wandering the strip of grass between the two fences but have been documented returning to an on-site pond and interacting with staff. When officers call out to them, Piu-Piu and the other geese respond with characteristic honks, a behaviour that officials say helps them assess the birds’ readiness and alertness.
De Souza noted that the quiet of the environment enhances the effectiveness of the geese, as their calls can be heard clearly across parts of the compound. He said the birds’ presence adds a natural alarm that supplements both human and electronic systems without incurring the costs typically associated with guard dogs.
While this approach to security is unusual, geese have historically been known for their ability to raise alarms. Their alerting behaviour has been documented in other settings where their loud honking serves as a deterrent or early warning system.
Operational context and limitations
Part of a broader security framework
Despite the novel appearance of geese on patrol, officials emphasise the birds are not relied upon alone and that the prison continues to invest in standard security infrastructure and training for personnel. The geese are one component of a multi-layered framework designed to prevent escapes and maintain order.
There is no indication from officials that the geese have been involved in any actual escape prevention or direct interventions, but de Souza and his team maintain they are a valuable early warning system that complements cameras, guards and other technology.
Key points
- A penitentiary in São Pedro de Alcântara, Santa Catarina, Brazil, has replaced guard dogs with geese for perimeter surveillance.
- The geese patrol the area between fences, honking to alert staff to unusual activity.
- Officials say tending the geese is cheaper and simpler than maintaining guard dogs.
- The flock is part of a layered security system that still includes human guards and CCTV.
- Geese are not the sole security measure but act as a supplementary early warning system.
Innovation in correctional security
The use of geese in a modern prison setting highlights a creative adaptation of natural animal behaviour in service of security needs. While not widespread, the practice reflects efforts to blend cost-effective measures with traditional infrastructure in corrections. The case in Santa Catarina has drawn international interest as a novel example of how institutions can combine low-tech solutions with existing technology to enhance vigilance.
Experts in animal behaviour note that geese are highly vocal and territorial, making them well suited as alarm systems in quiet environments. Their inclusion in a prison’s security framework underscores how unconventional methods can find a role alongside more standard approaches to maintaining safety and preventing escapes.
