The Portugal National Forestry Institute and international research partners have concluded that what was long believed to be a single rabbit species is actually two distinct evolutionary lineages that separated 2 million years ago—and one of them, found primarily in Portugal, is quietly vanishing.
Why This Matters
• Portugal's native rabbit (now proposed as Oryctolagus algirus) faces potential extinction while being masked by healthier eastern populations.
• Conservation strategies for the past century have been based on flawed taxonomy, hiding a 70% population collapse in the western lineage.
• Predators like the Iberian lynx depend almost exclusively on this rabbit, making its decline a threat to the entire Mediterranean food web.
• Urgent reclassification is needed to trigger species-specific protection measures before the Iberian rabbit disappears.
Hidden in Plain Sight for a Century
A multinational team led by researchers from Spain's Consejo Superior de Investigaciones Científicas (CSIC), working alongside scientists from Portuguese and British universities, has published findings in July 2026 in the journal Biological Conservation that upend more than 100 years of accepted zoology. The European rabbit, a keystone species across Mediterranean ecosystems and the ancestor of all domestic rabbits worldwide, is not one species but two: the Iberian rabbit (Oryctolagus algirus) and the European rabbit (Oryctolagus cuniculus sensu stricto).
The split is far from trivial. Genetic, morphological, reproductive, behavioral, and ecological evidence demonstrates that these two lineages diverged roughly 2 million years ago during glacial periods, when isolated populations evolved independently in separate refuges—one in the valley of the Ebro River, the other near the Gulf of Cádiz. Despite living in proximity for millennia, they have remained reproductively isolated, a hallmark of true speciation.
The discovery is particularly consequential for Portugal, where the Iberian rabbit represents the native form. Every rabbit hopping through cork oak groves, Mediterranean scrubland, or agricultural margins in Portugal belongs to the declining western lineage—not the stable eastern one that colonized much of the world.
More Than Genetics: A Suite of Differences
The distinctions between the two species extend well beyond DNA sequences. The Iberian rabbit is generally smaller, darker, and lighter in body mass. It reaches sexual maturity earlier but produces fewer offspring per litter, a reproductive strategy adapted to different ecological pressures. Studies have identified divergence in growth rates, gut microbiome composition, parasite communities, and even the nutritional properties of the meat.
Behaviorally, the Iberian rabbit is considered less social than its eastern counterpart. These differences reflect deep evolutionary trajectories shaped by distinct climates, predator guilds, and vegetation communities over the span of 2 million years—a period longer than the existence of modern humans.
The western lineage occupies all of Portugal, the western half of Spain, and some Atlantic islands and North African sites where humans introduced it. The eastern lineage dominates the rest of Spain and gave rise to the invasive populations now thriving across Europe, Australia, New Zealand, Argentina, Chile, and numerous islands—where it often wreaks ecological havoc.
What This Means for Residents
For anyone living in Portugal, this is not an abstract taxonomic debate. The rabbit is a keystone species in Mediterranean ecosystems, sustaining roughly 40 predator species, including two of the peninsula's most iconic and endangered animals: the Iberian lynx (Lynx pardinus) and the Spanish imperial eagle (Aquila adalberti). Both are specialist predators that rely overwhelmingly on rabbits for survival. A collapse in rabbit numbers directly jeopardizes the fragile recoveries these species have achieved through decades of conservation investment.
The Portugal-based Iberian rabbit has suffered a 70% population decline since 2008, driven primarily by viral diseases—myxomatosis since the 1950s and a newer hemorrhagic disease variant (RHDV2) since the early 2010s. Habitat loss from agricultural intensification, overgrazing, afforestation with production forests, and roadkill have compounded the problem. Yet because conservationists treated the rabbit as a single species, the severity of the western decline was statistically diluted by healthier eastern populations.
The Iberian rabbit is already classified as "Endangered" on the IUCN Red List as of 2018. The Portugal Red Book of Vertebrates lists it as "Vulnerable," but that classification predates the taxonomic split and may understate the urgency.
Conservation Overhaul Underway
Recognition of two species demands an immediate revision of management protocols. The transnational LIFE Iberconejo project, co-funded by the European Union and launched in 2021, is coordinating efforts across Portugal and Spain. It brings together government agencies, scientists, conservation groups, farmers, and hunters to monitor populations, standardize data collection, and implement habitat recovery measures.
Key actions include the first-ever Iberian census of the rabbit using automated data systems, development of common monitoring protocols, and deployment of 28 conservation measures tailored to local conditions. The Portugal Institute for Nature Conservation and Forests (ICNF) oversees seasonal census efforts, counting individuals and latrines to track population health in critical lynx reintroduction zones.
Habitat management focuses on revegetation, protection of hedgerows and shrubs, thinning of forests, and densification of cork oak woodlands. In areas where populations have nearly vanished, conservationists are installing artificial shelters, planting food crops, and—where justified—conducting repopulation campaigns using rabbits certified for health and genetic purity as Oryctolagus cuniculus algirus.
Crucially, the research team urges an urgent ban on translocations of the eastern lineage into western territories. Introducing eastern rabbits into Portugal risks competition, hybridization, and the effective replacement of the native form—a scenario conservationists call "extinction by substitution."
The Risk of Cryptic Diversity
The rabbit case highlights a broader challenge in conservation biology: cryptic diversity. Species that look identical to the naked eye but harbor profound genetic and evolutionary differences are easily overlooked until it's too late. The Portugal rabbit population represents 2 million years of independent evolution—a heritage that cannot be replaced by introducing genetically distinct animals from across the border.
The Iberian Rabbit Coordination Committee (ERICC), a collaborative body involving stakeholders from both countries, is pushing international conservation authorities to formally recognize the split. Without updated taxonomy, funding, legal protections, and recovery plans remain misaligned with biological reality.
What Residents Can Do
While conservation efforts rest primarily with government agencies and organizations, residents of Portugal can contribute meaningfully. If you encounter rabbits in rural areas, report sightings and population observations to local wildlife authorities or ICNF—baseline data from residents helps track recovery. Support habitat conservation by respecting protected areas, avoiding disturbance to rabbit warrens, and advocating for local land-use policies that prioritize Mediterranean vegetation. For hunters and landowners, coordinate with the LIFE Iberconejo project regarding sustainable management practices that prioritize the survival of the western lineage. Even small actions—protecting shrubland, maintaining hedgerows on private land, and spreading awareness—contribute to a landscape where the Iberian rabbit can recover.
A Test for Mediterranean Ecosystems
The fate of the Iberian rabbit will reverberate through the entire Mediterranean ecosystem. Its decline has already contributed to setbacks in lynx and eagle recovery programs. If the western lineage continues to fade, the cascading effects could destabilize predator-prey dynamics, vegetation structure, and nutrient cycling across Portugal's cork oak savannas, scrublands, and agricultural mosaics.
For residents, the implications extend to agriculture and rural livelihoods. Rabbits can cause crop damage, but they also sustain hunting traditions and tourism linked to wildlife observation. Balancing these interests requires nuanced, species-specific management—not a one-size-fits-all approach based on outdated science.
The research published in July 2026 in Biological Conservation represents a turning point. It transforms the Portugal rabbit from a regional variant of a common species into a distinct evolutionary lineage fighting for survival. Whether that recognition comes in time to prevent its extinction will depend on how quickly conservation policy adapts to the new reality.
