A bull that is running with the herd is one thing. A bull that is alone on the route is something entirely different. When a bull separates from the manada and stops, it becomes a fundamentally different animal. It is no longer part of a mass moving forward with momentum. It is now defending territory. It is now actively seeking the people around it. This transformation is the moment where the encierro shifts from a race into something more dangerous, more unpredictable, and more demanding of runners who understand what has happened and how to respond.
Why Bulls Stop: Fall or Choice
A bull stops on the encierro route for one of two reasons: it decides to, or it falls.
When a bull falls, the causes are mechanical and environmental. The bulls do not know the route in advance. They run at full speed through a course they are encountering for the first time. They do not see the tight turn ahead of them until they are already in it. They do not anticipate the transition from one surface to another. At this speed, ignorance of terrain is fatal to stability.
Dennis Clancey explains the cascading consequences: “These bulls don’t see the route ahead of time. They’re running incredibly fast. They’re in some ways competing with their brothers to be the fastest or competing for space in the manada.” The bulls are not thinking through a course map. They are reacting in real time, their decision-making limited to micro-second responses to what they sense immediately ahead.
Falls happen most frequently on Estafeta, where the sharp right-angle turn creates centrifugal force. According to sanfermines.net, at the beginning of Estafeta “the centrifugal force causes the bulls to impact against the outer fencing, fall over and become separated from the herd.” A fall at this turn can result in a bull being left behind, alone, as the rest of the manada continues forward.
Falls also happen on wet mornings. The cobblestones lose traction. A bull at speed, pushing with all its weight to maintain momentum through a turn, loses its footing. The physics are unforgiving. The bull goes down. The manada keeps moving.
A bull that chooses to stop is exercising a different decision. Some bulls simply decide that the pace is too fast, the pressure from the crowd is too intense, or the environment is too chaotic. These bulls slow, angle to the side of the route, and stop. They are still dangerous, but they are no longer part of the forward momentum of the run.
A Separated Bull: Behavioral Shift
When a bull separates from the herd, everything changes. The bull’s psychology shifts from following the group to protecting itself and its space.
Dennis articulates this critical distinction: “A bull that is stopped along the run route and is by itself is a fundamentally different animal because it seeks to establish its territory, and it does that by going after the people around it.” A bull in the manada is focused on maintaining position within the group and moving forward. A lone bull is focused on defense and assertion.
The territorial behavior is instinctive. A fighting bull is an animal bred for aggression and dominance. In the manada, that aggression is sublimated into the forward momentum of the group. Alone, with no group structure to contain it, that aggression becomes overt. The bull does not run from people. It runs toward them.
This behavioral inversion is why experienced runners fear a separated bull more than they fear the charging manada. The herd has directional momentum. The herd is moving toward the bullring with singular purpose. A loose bull has no such clarity. It will come at any runner within its perceived territory. It will charge. It will pursue. It will not stop until it has established dominance or the runner has escaped.
The Suelto: A Loose Bull on the Route
The Spanish word for a loose or separated bull is suelto. The term appears frequently in descriptions of encierro encounters, and it carries specific meaning. A suelto is not a bull that has simply slowed down. A suelto is a bull operating independently of the manada, with its own agenda. Okdiario’s encierro coverage has documented numerous instances where a separated bull created extended danger on the route.
On the Jokin Zuasti episode of Ander Etxanobe’s Mozxs Podcast, it was said: “With the herd, you have to keep pace with them coming together. It’s a race. A bull in the herd rarely strays much on Estafeta, on La Curva de Estafeta. So from there, if a loose bull comes through, it’s different attention.” The transition from herding-focused running to suelto-focused survival is immediate and absolute.
Zuasti describes the tactical shift: “A loose bull then, with space—they didn’t eat it like people do today—that’s where you’d give the bull distance, and the bull would come, and you’d feel the bull sometimes coming at you or your companions.” The phrase “give the bull distance” is the opposite of what runners do in the herd. With a suelto, you create space. You do not press close. You create an avenue for the bull to move forward, and you position yourself away from that avenue.
The modern dynamics have intensified this danger. Zuasti notes: “And to maintain that position, you have to be a Juan P and have started with encierros in, say, late ’90s, with certain dynamics, and then with an exceptional mind.” The crowding of contemporary encierros has made suelto scenarios more unpredictable. There is less physical space to move. A separated bull today has fewer options for establishing territory because the street is fuller with runners.
The Role of Pastores: Managing Stopped Bulls
The pastores (herders) are the official handlers of the bulls during the run. There are eight to ten pastores assigned to the encierro, each responsible for a specific section of the route. They are not there to protect runners. They are there to manage the bulls.
According to sanfermines.net, the herder’s job is to “run behind the bulls to ensure that the herd does not break up, to prevent the bulls from running back up the route and to keep runners away from stray bulls.” When a bull stops or separates, the pastores attempt to keep the situation from deteriorating further.
The technical challenge is significant. A pastor cannot herd a stopped bull the way a shepherd herds sheep. A pastor does not have a dog and a staff. He has a stick and an understanding of cattle behavior. The goal is to get the bull’s attention, move it forward again, and reconnect it with the herd or at least get it moving toward the bullring.
The strategy involves positioning, noise, and controlled aggression. The pastor positions himself to funnel the bull forward. He may strike the ground or the walls with his stick to create noise and redirect attention. He may approach from angles that give the bull only one realistic forward direction.
This work is dangerous. A pastor working with a separated, territorial bull is operating in the same space as the animal, with no protection except his knowledge and his stick. Injuries to pastores happen. They are occupational hazards.
Cabestros: The Cleanup Crew
The cabestros are castrated steers, bulls that have been neutered and trained to lead cattle. They appear later in the encierro than the fighting bulls, after most of the manada has already entered the bullring. The cabestros wear bells around their necks, and they serve a critical function: they find any remaining loose or stopped bulls and lead them to safety.
Dennis explains their effectiveness: “Because cabestros have led the bulls from pasture to pasture throughout their life, the bulls will hear them and be led to safety.” The cabestros are not new presences to the bulls. The fighting bulls have known these steers for months, in the corrals and the pastures where the ganaderia (ranch) keeps them. The familiarity creates a bond of herd identity.
When a cabestro enters the route, any remaining loose bulls hear the distinctive bell sounds. Those bells signal the presence of a familiar herd member. The bulls, seeking to rejoin the group, follow the cabestro’s movement toward the bullring. The cabestro becomes a living pathway back to the manada, back to social structure and safety.
This is why cabestros are so effective at managing animals that pastores might struggle to control. The cabestro offers something more powerful than a stick or noise. It offers belonging. Diario AS has reported on how bull stops can double or triple the duration of a single encierro, turning a two-minute run into a prolonged crisis.
What Runners Should Do
When a runner encounters a separated or stopped bull, the tactical response depends on the runner’s experience level and the bull’s behavior.
For inexperienced runners, the answer is simple: move away. Create distance. Get to the side of the street, against a building or fence, and let the bull pass or let the pastores work the situation. The encierro is a test of courage, not suicide. A runner who is not prepared to handle a suelto should not be in its vicinity.
For experienced runners, the options are more complex. The goal is not to escape but to manage the bull’s attention and redirect its movement. On the Jokin Zuasti episode, it was explained: “Then you could do work as three runners in line, calling to the bulls and running in a way where only really the people who were steady got involved—who weren’t going to hesitate and who knew how to hold the bull when it came at you.”
This describes a coordinated approach. Multiple runners, positioned strategically, call to the bull (make noise, establish presence), and create a corridor for the bull to move forward. The runners do not flee. They engage. They hold their position and guide the bull forward through force of coordinated will and body placement.
Zuasti adds: “It’s not the same as the herd race. The herd race is more linear. People sometimes think a bull will never go for you, that it won’t hunt you. But no—it’s getting in the train’s path and holding it. With loose bulls, it was different. It was for bullfighting runners, well said. Much different. And yes, with the loose ones there’s always a lot of danger, lots of danger. The bull, yes, it seeks you. It seeks you.”
A separated bull is actively hunting. It is not indifferent to the runners around it. It is focused on them, actively assessing threat and opportunity. For a runner to hold position with a suelto is to position oneself as part of the bull’s territory, to claim that ground, and to hold it through movement and presence. This is an advanced skill.
Expert Insight: Dennis Clancey on Stopped Bulls
“A bull that is stopped along the run route and is by itself is a fundamentally different animal because it seeks to establish its territory, and it does that by going after the people around it.” “These bulls don’t see the route ahead of time. They’re running incredibly fast. They’re in some ways competing with their brothers to be the fastest or competing for space in the manada.” “It is our luck when they don’t strike out, when they don’t start going after people.” “Because cabestros have led the bulls from pasture to pasture throughout their life, the bulls will hear them and be led to safety.”
— Dennis Clancey, founder of Encierro and member of La Unica Pena
Dennis’s perspective on stopped bulls is not theoretical. He has seen the behavioral shift in real time. He has watched bulls transition from herd animals to territorial predators. The word “luck” in his statement is significant. It acknowledges that the restraint of a separated bull is not guaranteed. It is a matter of chance and circumstance.
Historical Context from the Route
According to sanfermines.net, separated bulls have been part of the encierro for as long as the modern run has existed. The mechanical causes—wet stone, unknown terrain, centrifugal force on turns—are inherent to the route. The Estafeta turn in particular has been a consistent source of falls and separations.
Modern encierros have more separated bulls than the encierros of earlier decades, not because the bulls have changed but because the route is now more crowded. A runner who becomes a stopped bull in a sparse route can establish territory with relative ease. A bull that becomes separated in a crowded modern encierro faces a chaotic environment full of humans, and the result is more unpredictable and more dangerous for everyone involved.
The pastores have adapted over time, developing more refined techniques for redirecting separated animals. But the fundamental situation remains unchanged. A bull that is alone is dangerous. The runner who understands this and positions himself accordingly survives. The runner who does not, who assumes that a separated bull will continue forward without intervention, is gambling.
Spanish Vocabulary
Suelto (SWEL-toh): Loose, or loose bull. A bull that is separated from the herd and operating independently. A suelto is more dangerous than a bull in the manada because it is operating with territorial rather than herd-focused motivation.
Manada (mah-NAH-dah): The herd or group of bulls and steers running together. The herd maintains forward momentum and reduces individual bull aggression.
Pastor (pah-STOR): A herder, one of the eight to ten officials responsible for managing the bulls during the encierro. Pastores work to prevent separations and manage bulls that do become separated.
Cabestro (kah-BES-troh): A castrated steer used to lead cattle. Cabestros wear bells and appear later in the encierro to collect any remaining separated bulls and guide them to the bullring.
Parado (pah-RAH-doh): Stopped or stationary. A parado bull is one that has stopped running.
Frequently Asked Questions
Why do bulls separate from the herd?
Bulls separate either because they fall (due to wet stone, unknown terrain, or turns taken at too-high speeds) or because they choose to stop (due to exhaustion, stress, or disorientation). A bull that falls is suddenly behind the manada. A bull that chooses to stop is stationary.
What happens when a bull becomes separated?
The bull’s behavior changes. Instead of focusing on maintaining position in the herd, it focuses on territorial defense. It becomes actively aggressive toward runners around it.
How do pastores handle a separated bull?
Pastores use sticks, positioning, and noise to direct separated bulls forward. The goal is to get the bull moving toward the bullring again, either to reconnect it with the herd or simply to remove it from the route.
What are cabestros used for?
Cabestros are castrated steers that appear later in the encierro to collect any remaining bulls on the route. The bulls recognize the cabestros from pasture life and follow them toward the bullring.
Is a separated bull more dangerous than a bull in the herd?
Yes. A bull in the herd is focused on maintaining position and forward momentum. A separated bull is territorial and actively aggressive. Runners fear separated bulls more than they fear the charging manada.
What should a runner do if they encounter a separated bull?
Inexperienced runners should move away and create distance. Experienced runners may position themselves strategically with other runners to guide the bull forward. The appropriate response depends on the runner’s skill level.
Can a bull be moving at full speed and still be considered separated?
Yes. A bull can be separated from the herd and still be running at high speed. The critical factor is herd status, not speed. A separated bull running at the herd’s pace is still fundamentally different from a bull moving with the herd.
When a bull stops, the encierro becomes a different event. Understanding the behavioral shift from herding to territorial aggression is essential for runners who want to position themselves effectively on the route. For a detailed guide to how the entire route functions, read our overview of the complete encierro route. To explore the section where most separations occur, visit our guide to the Estafeta curve.