Exploring how protected areas maintain biodiversity in nature's intricate competitive cycles
Imagine a forest where three animal species are locked in a never-ending game of "rock-paper-scissors." Species A dominates Species B, Species B overpowers Species C, and Species C surprisingly defeats Species A.
This fascinating ecological dynamic, known as cyclic competition, occurs in ecosystems worldwide—from coral reef invertebrates to lizards in California's coastal ranges.
For decades, scientists have observed a puzzling pattern in these systems: the weakest competitor often survives while stronger species face extinction. This counterintuitive outcome, dubbed the "law of the weakest," has captivated ecologists seeking to understand what maintains biodiversity in nature 6 .
Recent research has revealed a potential game-changer in these ecological standoffs: wildlife refuges. These protected areas are proving to be more than just sanctuaries—they're sophisticated tools that can tip the balance toward coexistence in surprising ways.
Cyclic competition represents a fundamental departure from the "survival of the fittest" narrative most people know. In these systems, no single species reigns supreme—each has both an advantage and a vulnerability relative to others in the cycle.
This dynamic creates what scientists call a non-hierarchical relationship, similar to the children's game "rock-paper-scissors" where each element can both defeat and be defeated by another.
Visualization of three-species cyclic competition
For years, scientists have recognized that species mobility plays a crucial role in these cyclic systems. Intuitively, one might think that greater mobility would help species survive by allowing them to access more resources. However, research has revealed a more complex reality.
In 2007, groundbreaking studies showed that mobility could both promote and jeopardize biodiversity in rock-paper-scissors systems 7 . At low mobility levels, species tended to form clusters that protected them from competitors. At moderate mobility, these clusters broke down, making the system vulnerable to collapse. This created what scientists called "critical mobility"—a threshold beyond which coexistence becomes impossible.
This paradox presented a significant challenge for conservation biology: how to maintain biodiversity in systems where movement—an essential ecological process—could trigger irreversible decline.
In 2022, researchers tackled this challenge by investigating how designated wildlife refuges might alter the fate of species in cyclic competition. Using Monte Carlo simulations—computational techniques that model complex systems through random sampling—scientists created spatially extended ecosystems with specific zones designated as protected areas 1 .
The experimental setup mimicked real-world ecological conditions:
Conceptual representation of a simulated landscape with refuge area
The findings challenged conventional thinking about conservation tools. Rather than serving as a complete solution, refuges played a more nuanced—yet crucial—role:
"The refuge can play not groundbreaking but an important role in species survival" 1 .
Specifically, the research revealed that wildlife refuges could postpone extinction events and maintain species coexistence at moderate mobility regimes that traditionally led to system collapse. The effectiveness depended more on competition rates than the portion of territory designated as refuge 1 .
| Condition | Without Refuge | With Refuge |
|---|---|---|
| Low Mobility | Stable coexistence | Enhanced stability |
| Moderate Mobility | System collapse | Coexistence maintained |
| High Mobility | System collapse | Delayed collapse |
| Population Patterns | Clustered distributions | More balanced distributions |
Understanding cyclic competition requires sophisticated research methods. Modern ecologists employ an array of technological tools to unravel these complex interactions:
Primary Function: Remote wildlife monitoring
Application: Tracking species movements and interactions without disturbance
Primary Function: Recording animal sounds
Application: Monitoring presence and behavior of vocal species
Primary Function: Aerial surveying
Application: Mapping habitat use and population distributions
Primary Function: DNA analysis from scat, hair, or saliva
Application: Identifying individual animals and tracking gene flow
These innovations are particularly valuable for studying smaller, less charismatic species like shrews and rodents, which have historically been neglected in research despite their ecological importance 2 .
As research progresses, scientists are discovering that cyclic competition extends far beyond simple three-species models.
In 2025, research revealed that four-species cyclic systems behave dramatically differently from their three-species counterparts. When internal competition occurs within one alliance, it creates an embedded rock-paper-scissors community that can become dynamically unstable .
These "fractured alliances" lead to what mathematicians call "attracting heteroclinic cycles"—complex pathways that populations follow as they compete. Even vanishingly small disturbances in these systems can lead to dramatically different outcomes, highlighting the fragility of multi-species ecosystems .
Recent investigations have revealed that competition within species (intraspecific competition) significantly influences coexistence. Strong intraspecific competition actually promotes biodiversity by preventing any single species from dominating the ecosystem 7 .
This finding helps explain why some ecosystems maintain diversity even when theoretical models predict collapse. It also suggests that conservation strategies should consider both between-species and within-species interactions.
| Factor | Effect on Coexistence | Practical Conservation Implication |
|---|---|---|
| Mobility Level | Either promotes or jeopardizes coexistence depending on intensity | Wildlife corridors must be carefully sized |
| Spatial Scale | Larger areas generally support more stable coexistence | Protected areas need minimum size thresholds |
| Intraspecific Competition | Generally enhances coexistence | Maintaining natural population controls is beneficial |
| Competition Asymmetry | Alters stability conditions | Species-specific management may be necessary |
| Habitat Heterogeneity | Provides natural refuges | Diverse habitats support more stable ecosystems |
The study of cyclic competition and wildlife refuges extends far beyond theoretical ecology. As a WWF-led study highlighted in 2025, wildlife provides vital benefits to people's everyday lives that are often overlooked in policy discussions 4 .
Predators help maintain balanced ecosystems by controlling herbivore numbers
Bats, birds, and insects pollinate plants essential for food production
Animals help maintain forest health by spreading seeds
Balanced ecosystems naturally regulate disease vectors
Wildlife holds significant meaning for indigenous communities
The catastrophic decline of North American sea otters in the 19th century illustrates these connections. The fur trade decimated otter populations, causing:
This cascade of effects demonstrates how the loss of a single species can disrupt entire ecosystems 4 .
The research on wildlife refuges in cyclic competition systems points toward more sophisticated conservation approaches.
Position protected areas to maximize ecological benefits
Consider mobility thresholds in corridor design
Protect both charismatic and lesser-known species
Combine traditional ecological knowledge with modern science
Use technology to track ecosystem health
As we face unprecedented biodiversity loss—with monitored vertebrate populations declining by an average of 73% since 1970—these insights offer hope 4 .
By understanding the intricate dances of competition and cooperation in nature, we can develop more effective strategies to safeguard the rich tapestry of life that sustains our planet.
The humble wildlife refuge, once seen as a simple sanctuary, is emerging as a sophisticated tool in this endeavor—helping to maintain nature's delicate balance one protected space at a time.