An observation of wild Apis species has been made in the rural landscape of Idanha-a-Nova, Portugal. Living amongst a cork oak (Quercus suber) tree which is a keystone species of Mediterranean ecosystems, known for its ecological resilience.
Quercus suber serves as a vital resource for wild honeybee populations by offering structural hollow formation, thermal nesting sites and high-quality resins for propolis production.
Traditional apiculture utilised these trees to create cork cylinders hollowed out and stacked vertically to house bees. Marking the bridge from wild bee hunting to mans creation off bee houses.
Cork beehives, called "cortiços" in Portuguese, date back to early Apiculture periods. Cork’s natural properties — lightweight, insulating, breathable, and resistant to moisture and pests — made it an ideal material for traditional beekeeping.
A traditional cortico found standing amongst ancient rock walls of Idanha a nova, Portugal.
Hollows of Quercus suber as Nesting Sites
Old-growth cork oaks frequently develop trunk and branch hollows due to age-related decay processes and biotic interactions. These cavities provide highly suitable nesting habitats for honeybees due to several factors:
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Thermal Insulation: The thick cork bark maintains stable internal temperatures, buffering colonies against external climatic extremes.
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Physical Protection: Cork oak bark is fire-resistant and offers enhanced protection against predators and environmental disturbances.
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Longevity: Mature hollows persist for decades, allowing for the establishment of long-term or successive colonies.
Resin Production and Propolis Collection
Quercus suber trees produce resinous exudates, especially following mechanical injuries or pathogen attacks. Honeybees harvest these resins and blend them with salivary enzymes and beeswax to produce propolis. The bioactive properties of propolis include:
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Antimicrobial Activity: Effective against a range of bacteria, fungi, and viruses, reducing the pathogen load within the hive.
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Immune Enhancement: Propolis components contribute to enhanced individual and colony-level immunity.
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Structural Reinforcement: Bees use propolis to seal cracks, stabilize comb structures, and entomb invaders (e.g., beetles) that cannot be removed.
In Idanha-a-Nova, traditional rural architecture (stone walls, old trees, abandoned buildings) provides abundant nesting sites, favouring natural colony proliferation.
The diverse Mediterranean flora of the region offers an abundant and seasonally continuous food supply for wild colonies.
Key plant species providing nectar and pollen include:
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Lavandula stoechas (Spanish lavender): An early spring bloomer offering rich nectar resources.
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Cistus ladanifer (Gum rockrose): Dominant in many scrublands, providing both pollen and resin.
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Rosmarinus officinalis (Rosemary): A robust, drought-tolerant shrub that flowers profusely.
- Thymus vulgaris (Common thyme): Vital during summer months when other flowers are scarce.
Wild Apis colonies in southern Europe, including Portugal, show a high swarming frequency, allowing them to:
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Rapidly create new habitat
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Maintain genetic variability and establish new ecotypes.
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Increase resistance by natural selection and hybridisation.
