Following IUCN guidelines wild populations of the Western Honey Bee are here defined as self-sustaining groups of free-living colonies.
The attribute “self-sustaining” is applied in relation to a ten-year period and refers to the capacity of the free-living cohort (i.e., group of colonies) to persist for at least that duration by maintaining itself through the reproduction of its member colonies, without relying on the immigration of swarms from managed ones (as there is no genetic division among free-living and managed cohorts). The period of ten years is used, as it corresponds to length of three generations (following IUCN guidelines, the average generation length of a Honey Bee colony was calculated as 3.3 years, see Habitats and Ecology section).
Last assessed: 17 July 2025
Scope of assessment: Europe
IUCN Red List Assessment: Data Deficient
European Union Assessment: Endangered
Generation Length: 3.3 Years
Habitat Type: Forest, Shrubland, Grassland, Wetlands, Supratidal, Terrestrial, Other
Research Classification Scheme: Research needed
Taxonomy
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Hympenoptera
Family: Apidae
Genus: Apis
Abstract
Western Honey Bee (wild population) Apis mellifera has most recently been assessed for The IUCN Red List of Threatened Species in 2025.
Justification
European regional assessment: Data Deficient (DD)
EU 27 regional assessment: Endangered (EN)
Colonies of the Western Honey Bee (Apis mellifera) can be managed or free-living (or wild-living). The latter are colonies that nest in cavities they choose themselves and are unmanaged by humans. Following IUCN guidelines for the assessment of species composed of both managed and wild subpopulations, wild populations of the Western Honey Bee are here defined as self-sustaining groups of free-living colonies. The attribute “self-sustaining” is applied in relation to a ten-year period and refers to the capacity of the free-living cohort (i.e., group of colonies) to persist for at least that duration by maintaining itself through the reproduction of its member colonies, without relying on the immigration of swarms from managed ones (as there is no genetic division among free-living and managed cohorts).
Recent density estimation indicates that, in Europe, managed colonies outnumber free-living ones, making this the region with the lowest density of free-living Western Honey Bee colonies worldwide (see Geographic Range section).
Evidence derived from the study of both managed and free-living Western Honey Bee colonies strongly suggests that, if left unaided, Honey Bees face numerous threats that significantly limit their capacity to establish and maintain wild self-sustaining populations (see Threats section). This is supported by a recent analysis based on survival data from free-living Honey Bee populations from seven countries in Europe, estimating a current median population decline of 56% (measured in number of colonies) per decade (see Population section). The period of ten years is used, as it corresponds to length of three generations (following IUCN guidelines, the average generation length of a Honey Bee colony was calculated as 3.3 years, see Habitats and Ecology section).
Given the current evidence on the threats affecting colony survival and the estimated population decline, wild Western Honey Bee populations in the European Union are therefore assessed as Endangered (A2abe). Notably, population decline data also indicated a similar level of threat for the non-EU countries of Switzerland and England. At the wider Pan European level, the species is retained as Data Deficient at present, given the paucity of data on the distribution, survival rates, and population trends of free-living colonies in this larger region.
EU 27 regional assessment: Endangered (EN)
Colonies of the Western Honey Bee (Apis mellifera) can be managed or free-living (or wild-living). The latter are colonies that nest in cavities they choose themselves and are unmanaged by humans. Following IUCN guidelines for the assessment of species composed of both managed and wild subpopulations, wild populations of the Western Honey Bee are here defined as self-sustaining groups of free-living colonies. The attribute “self-sustaining” is applied in relation to a ten-year period and refers to the capacity of the free-living cohort (i.e., group of colonies) to persist for at least that duration by maintaining itself through the reproduction of its member colonies, without relying on the immigration of swarms from managed ones (as there is no genetic division among free-living and managed cohorts).
Recent density estimation indicates that, in Europe, managed colonies outnumber free-living ones, making this the region with the lowest density of free-living Western Honey Bee colonies worldwide (see Geographic Range section).
Evidence derived from the study of both managed and free-living Western Honey Bee colonies strongly suggests that, if left unaided, Honey Bees face numerous threats that significantly limit their capacity to establish and maintain wild self-sustaining populations (see Threats section). This is supported by a recent analysis based on survival data from free-living Honey Bee populations from seven countries in Europe, estimating a current median population decline of 56% (measured in number of colonies) per decade (see Population section). The period of ten years is used, as it corresponds to length of three generations (following IUCN guidelines, the average generation length of a Honey Bee colony was calculated as 3.3 years, see Habitats and Ecology section).
Given the current evidence on the threats affecting colony survival and the estimated population decline, wild Western Honey Bee populations in the European Union are therefore assessed as Endangered (A2abe). Notably, population decline data also indicated a similar level of threat for the non-EU countries of Switzerland and England. At the wider Pan European level, the species is retained as Data Deficient at present, given the paucity of data on the distribution, survival rates, and population trends of free-living colonies in this larger region.
Range Description
The Western Honey Bee is native to the whole of Europe (Ruttner 1988), with the exception of Iceland, the Faroe Islands, the Azores (Weissmann et al. 2017), and northern parts of Scandinavia. However, managed colonies have been introduced in these non-native areas and are now widespread across Europe due to management by beekeepers. Recent density estimation indicates that managed colonies vastly outnumber free-living ones, making Europe the region with the lowest density of free-living Honey Bee colonies (Visick and Ratnieks 2023).
A collaborative effort between Honey Bee Watch (HBW) and its research partners (see Conservation section) has facilitated the collection of the locations of 1,684 free-living colonies’ nests across 15 European countries for this present assessment. These data have been used to construct a map of confirmed sightings of free-living colonies in Europe that could be used for planning future investigations on potential self-sustaining populations, from which reliable estimates of the extent of occurrence (EOO) and area of occupancy (AOO) could be derived.
Beyond the European region, the Western Honey Bee is native to Africa, the Middle East, and Central and West Asia.
A collaborative effort between Honey Bee Watch (HBW) and its research partners (see Conservation section) has facilitated the collection of the locations of 1,684 free-living colonies’ nests across 15 European countries for this present assessment. These data have been used to construct a map of confirmed sightings of free-living colonies in Europe that could be used for planning future investigations on potential self-sustaining populations, from which reliable estimates of the extent of occurrence (EOO) and area of occupancy (AOO) could be derived.
Beyond the European region, the Western Honey Bee is native to Africa, the Middle East, and Central and West Asia.
Description
A recent study (Kohl and Rutschmann, submitted) synthesised the survival rates of free-living colonies monitored at 698 nest sites in seven European countries (France, Germany, Luxembourg, Poland, Spain, Switzerland, United Kingdom) between 2013–2025, estimating an overall median population decline of 56% over a projected ten-year period. Although additional colonies are being monitored in other countries, such as Ireland (Browne et al. 2020), Serbia (Bila Dubaić et al. 2021), and Italy (Fontana et al. 2023), this survival-rates analysis represents the only synthesis available to date that estimates population decline based on observed survival data. Given the extensive geographical scope of this analysis, covering different types of landscapes and habitats (e.g., forest, semi-natural, agricultural, urban, etc.), this estimate can be considered an indicator of the suspected decline of wild Western Honey Bee populations within countries of the EU27 range, plus Switzerland and southeast England.
At the broader Pan European scale, the estimated decline might be less pronounced as, for instance, understudied regions (e.g., eastern and far eastern European areas) could contain higher quality habitats that better support wild populations (e.g., see Requier et al. 2020). However, we suggest that a decline should be precautionarily considered even at this level, as free-living colonies in these areas are exposed to the same threats as those in the studied regions. Nevertheless, given the lack of survival data on free-living colonies from such regions, for the present assessment, it is not possible to assess a precise conservation status for wild Western Honey Bee populations at that scale.
At the broader Pan European scale, the estimated decline might be less pronounced as, for instance, understudied regions (e.g., eastern and far eastern European areas) could contain higher quality habitats that better support wild populations (e.g., see Requier et al. 2020). However, we suggest that a decline should be precautionarily considered even at this level, as free-living colonies in these areas are exposed to the same threats as those in the studied regions. Nevertheless, given the lack of survival data on free-living colonies from such regions, for the present assessment, it is not possible to assess a precise conservation status for wild Western Honey Bee populations at that scale.
Habitat and Ecology
Generally, the species is found nesting in temperate forests, shrublands, grasslands, and even in artificial terrestrial habitats, where it can forage for pollen, nectar, propolis, honeydew, and water. Free-living colonies are critically dependent on the availability of suitable nesting sites, such as tree cavities (e.g., cavities resulting from wood decay or excavated by the Black Woodpecker (Dryocopus martius); Oleksa et al. 2013, Kohl and Rutschmann 2018, Requier et al. 2020, Visick and Ratnieks 2023b). However, the species also nests in anthropogenic structures such as cavities in walls, in the roofs of buildings (Browne et al. 2020, Bila Dubaić et al. 2021), and hollow electric power poles (Rutschmann et al. 2022). High densities of colonies have been observed in cities, as shown by Dubaić et al. (2021) in Belgrade, Serbia, and Rutschmann et al. (2025) in Munich, Germany, suggesting that urban environments can also be highly favourable for Honey Bees, as they may provide long-lasting and diverse floral resources and reduced exposure to pesticides in comparison to prevailing agricultural systems. Although these conclusions are locally or regionally context-specific, they could be applicable to other cities in Europe (Rutschmann et al. 2025). While forests have historically served as a primary nesting habitat for Western Honey Bee, recent research suggests that Honey Bees find a richer foraging environment in open habitats as opposed to managed forests, which suffer from a lack of pollen resources in late summer (Requier et al. 2015, Rutschmann et al. 2023).
The Western Honey Bee is a haplodiploid eusocial insect resembling a superorganism with sophisticated communication among nestmates. It has a particular reproductive system, termed polyandry, whereby one queen mates with between 1 to 49 males/drones (Neumann et al. 1999, Palmer and Oldroyd 2000, Hernández-García et al. 2009). Queens can travel considerable distances to locate a suitable drone congregation area (DCA), where they can mate with drones from various surrounding colonies. Colonies reproduce by fission when swarms leave with the mated old queen (prime swarm) and with the first virgin daughter queens (afterswarms or casts). From the study of Honey Bee colonies in Germany, the average number of offspring produced was estimated to be around two swarms per colony per year (Rutschmann et al. 2025). Mating takes place in the air during a nuptial flight of the virgin queen in the spring and summer months (from as early as March in southern European countries), preferably on sunny days with little wind.
According to IUCN guidelines about generation length, the Western Honey Bees’ generation length should be calculated as the average age of established colonies, with “established colonies” defined as those that have survived at least one year. By analysing the survival rates of two self-sustaining wild Honey Bee populations living outside of Europe, their generation length has been calculated as 3.3 years (Kohl and Rutschmann submitted), and therefore, has been used in this assessment.
The Western Honey Bee is a haplodiploid eusocial insect resembling a superorganism with sophisticated communication among nestmates. It has a particular reproductive system, termed polyandry, whereby one queen mates with between 1 to 49 males/drones (Neumann et al. 1999, Palmer and Oldroyd 2000, Hernández-García et al. 2009). Queens can travel considerable distances to locate a suitable drone congregation area (DCA), where they can mate with drones from various surrounding colonies. Colonies reproduce by fission when swarms leave with the mated old queen (prime swarm) and with the first virgin daughter queens (afterswarms or casts). From the study of Honey Bee colonies in Germany, the average number of offspring produced was estimated to be around two swarms per colony per year (Rutschmann et al. 2025). Mating takes place in the air during a nuptial flight of the virgin queen in the spring and summer months (from as early as March in southern European countries), preferably on sunny days with little wind.
According to IUCN guidelines about generation length, the Western Honey Bees’ generation length should be calculated as the average age of established colonies, with “established colonies” defined as those that have survived at least one year. By analysing the survival rates of two self-sustaining wild Honey Bee populations living outside of Europe, their generation length has been calculated as 3.3 years (Kohl and Rutschmann submitted), and therefore, has been used in this assessment.
Use and Trade
The Western Honey Bee is considered to be one of the most important pollinators of crops and other plant species (Garibaldi et al. 2013, Hung et al. 2018). However, the scale of pollination services provided by free-living colonies is unclear because of the lack of data on the size and distribution of said populations in Europe.
Honey is not known to be harvested from free-living colonies in Europe, although it is a common activity in some parts of Africa.
Honey is not known to be harvested from free-living colonies in Europe, although it is a common activity in some parts of Africa.
Conservation Actions
Further research on free-living colonies is urgently needed in order to identify self-sustaining populations and to understand the status of populations across the whole Pan European level, focusing on data-poor parts, such as the far Eastern regions. This could be achieved through population ecology studies based on repeated genotyping of colonies and long-term monitoring of their nests to infer demographic parameters at the population level (e.g., Kohl et al. 2022, Moro et al. 2024). Furthermore, research should also focus on gaining a more profound comprehension of the threats impacting such populations. Given the present research gap, acquiring such data is essential and will play a pivotal role in facilitating conservation efforts, potentially driving reforms in both national and international policies (Panziera et al. 2022).
Notably, this research could begin (or continue) by monitoring, sampling, and testing the nest locations gathered for this present assessment (see map produced within this report). Additionally, researchers and citizen scientists can contribute data to Honey Bee Watch and/or to the various initiatives that collected these data points (see below).
In response to the urgent need for data on free-living colonies, an international coalition of researchers and stakeholders focused on free-living Honey Bees was established in 2019 to locate, monitor, study, and protect wild A. mellifera populations. Honey Bee Watch‘s mission is to create an extensive repository of data, protocols, and resources pertaining to free-living colonies, which will be used to empower further research and enable conservation endeavours.
For this reassessment, HBW acknowledges the contributions of numerous partners involved in the study of free-living Honey Bee colonies in Europe, who, along with other initiatives, shared data for building a map of confirmed sightings of free-living colonies in Europe (see Geographic Range section):
Immediate measures considered beneficial for the preservation of wild A. mellifera populations include (i) ensuring the conservation of natural habitats rich in suitable nesting cavities (Oleksa et al. 2013, Kohl and Rutschmann 2018, Requier et al. 2020, Rutschmann et al. 2022), (ii) controlling the spread of invasive Honey Bee predators and parasites, and (iii) promoting the use of native and regional subspecies for beekeeping to avoid non-native genotypes introgression in local wild subpopulations. The latter recommendation is particularly promoted by the International Association for the Protection of the European Dark Bee (SICAMM), the Native Irish Honey Bee Society (NIHBS), and have been endorsed in Italy through the San Michele All’Adige and the Pantelleria declarations (Fontana et al. 2018, 2022), as well as by the Berlin Declaration on Wild Western Honey Bee Conservation in Europe. National-level strategies in line with these objectives also include the legal restriction on the importation of queens of non-native subspecies, which are already active in Serbia, Slovenia, and the Canary Islands, and under consideration in Ireland.
Notably, this research could begin (or continue) by monitoring, sampling, and testing the nest locations gathered for this present assessment (see map produced within this report). Additionally, researchers and citizen scientists can contribute data to Honey Bee Watch and/or to the various initiatives that collected these data points (see below).
In response to the urgent need for data on free-living colonies, an international coalition of researchers and stakeholders focused on free-living Honey Bees was established in 2019 to locate, monitor, study, and protect wild A. mellifera populations. Honey Bee Watch‘s mission is to create an extensive repository of data, protocols, and resources pertaining to free-living colonies, which will be used to empower further research and enable conservation endeavours.
For this reassessment, HBW acknowledges the contributions of numerous partners involved in the study of free-living Honey Bee colonies in Europe, who, along with other initiatives, shared data for building a map of confirmed sightings of free-living colonies in Europe (see Geographic Range section):
- BEEtree-Monitor, Germany
- Blenheim Palace and Estate, United Kingdom
- Boomtreebees, Ireland
- Boughton Estate Honeybee Conservation Project, United Kingdom
- Edmund Mach Foundation, Italy
- Galway Honey Bee Research Centre, University of Galway, Ireland
- Honey Bee Wild, Luxembourg
- Honungsbiföreningen, Sweden
- Instituto Politécnico de Bragança, Portugal
- Kazimierz Wielki University, Poland
- Nature Research Centre, Lithuania
- Office pour les insectes et leur environnement (OPIE), France
- Resilient Bee Project, Italy
- Slovak University of Agriculture in Nitra, Slovakia
- UMR CNRS-IRD-Université Paris-Saclay, France
- University of Belgrade, Serbia
- University of Sussex, United Kingdom
- University of Würzburg, Germany
- Wild Bees Project, France
Immediate measures considered beneficial for the preservation of wild A. mellifera populations include (i) ensuring the conservation of natural habitats rich in suitable nesting cavities (Oleksa et al. 2013, Kohl and Rutschmann 2018, Requier et al. 2020, Rutschmann et al. 2022), (ii) controlling the spread of invasive Honey Bee predators and parasites, and (iii) promoting the use of native and regional subspecies for beekeeping to avoid non-native genotypes introgression in local wild subpopulations. The latter recommendation is particularly promoted by the International Association for the Protection of the European Dark Bee (SICAMM), the Native Irish Honey Bee Society (NIHBS), and have been endorsed in Italy through the San Michele All’Adige and the Pantelleria declarations (Fontana et al. 2018, 2022), as well as by the Berlin Declaration on Wild Western Honey Bee Conservation in Europe. National-level strategies in line with these objectives also include the legal restriction on the importation of queens of non-native subspecies, which are already active in Serbia, Slovenia, and the Canary Islands, and under consideration in Ireland.
References:
Bila Dubaić, J., Simonović, S., Plećaš, M., Stanisavljević, L., Davidović, S., Tanasković, M. and Ćetković, A. 2021. Unprecedented Density and Persistence of Feral Honey Bees in Urban Environments of a Large SE-European City (Belgrade, Serbia). Insects 12(12): 1127. https://doi.org/10.3390/insects12121127
Browne, K.A., Hassett, J., Geary, M., Moore, E., Henriques, D., Soland-Reckeweg, G., Ferrari, R., Mac Loughlin, E., O’Brien, E., O’Driscoll, S., Young, P., Pinto, M.A. and McCormack, G.P. 2020. Investigation of free-living honey bee colonies in Ireland. Journal of Apicultural Research 60(2): 1-12. https://doi.org/10.1080/00218839.2020.1837530
Chen, C., Liu, Z., Pan, Q., Chen, X., Wang, H., Guo, H., Liu, S., Lu, H., Tian, S., Li, R. and Shi, W. 2016. Genomic Analyses Reveal Demographic History and Temperate Adaptation of the Newly Discovered Honey Bee Subspecies Apis mellifera sinisxinyuan n. ssp. Molecular Biology and Evolution 33(5): 1337-1348.
https://conbio.onlinelibrary.wiley.com/doi/10.1111/conl.12693
More information:
https://www.iucnredlist.org/species/42463639/277757621#population