Dragonflies in North Africa have attracted the interest of naturalists since the mid-nineteen century, which has made them the best known insect group in the region. Such available records spanning over a century and a half have been used to map the spatial distribution of North Africa Odonata. A total of 83 species have been recorded, with one classified as Not Applicable as only a migrant. The greatest concentration of these species has been found in the Maghreb: Tunisia, Algeria and Morocco. Among these species, seven are endemic.
North Africa Freshwater Dragonflies
Freshwater habitats and biodiversity are recognized to be under serious threat at global level. Monitoring freshwater basins is therefore important to prevent the loss of these ecosystems and freshwater dragonflies species have been identified as one of the priority taxa indicators for the overall conservation status of wetland ecosystems.
Within the 82 dragonfly species assessed, almost a quarter (24.4%) is threatened with extinction: 7.3% are Critically Endangered, 8.5% Endangered and 8.5% Vulnerable. Within the not threatened categories, 43 species (52.4%) are classified as Least Concern, 8 taxa (9.8%) as Near Threatened, and 5 species (6.1%) as Data Deficient. A total of 6 species (7.3%) have been assessed as Regionally Extinct.
In the Maghreb, the high mountain range of Morocco is unique in housing a set of Holartic and Eurosiberian species, many of these being endemic and confined to high latitude sites. In contrast with the Maghreb, Odonata in Egypt are dominated by Afrotropical species owing to the key role of the Nile River facilitating the crossing of the Sahara Desert.
The highest number of threatened species is in the north of the Maghreb and the Nile Valley. Two of the Critically Endangered species are already deemed extinct in Algeria and another species (Urothemis edwardsii), found in a single locality in north-east Algeria, is teetering on the verge of extinction.
Out of the seven African endemic species, two have been assessed as Threatened, one as Near Threatened, one is Data Deficient and three are listed as Least Concern. As for the total species richness, the northern Maghreb is the area showing the highest level of endemism. The percentage of North Africa endemic Odonata is higher among damselflies (14.3%) when compared to dragonflies (4.2%), reflecting a higher dispersal power of the latter.
Studies following the assessment recommend that only four of the six species assessed as Regionally Extinct should be maintained in this category. Among these, two (Cordulia aenea and Rhyothemis semihyalina) are clearly extinct in north-eastern Algeria where they were present as Eurosiberian and Afrotropical relicts. The other two (Ceriagrion glabrum and Phyllomacromia picta) were only recorded in the Nile Valley in the past, though new investigations are urgently needed to confirm their extinction.
Data Deficient species
Five species were assessed as Data Deficient, their distribution, population size or regional trend being poorly documented.
Odonata have complex life cycles which need aquatic as well as terrestrial habitats. Major threats to North Africa species include habitat degradation, water pollution, water extraction, dam construction, exotic fish introduction, and drought. Coastal sand dune systems are especially rich in Odonata species but they are exposed to a high level of degradation. Anthropogenic pressures, mainly translated into water extraction and intensive urbanization for tourism, are destroying these habitats in the region. In Algeria, dunary slacks and alder carrs are being quickly degraded and in Morocco intensive coast urbanization for tourism is destroying coastal marshes. Similar situations can be found in Egypt and Tunisia. Moreover, present climate change and related rainfall deficits are leading to increased irrigation and river damming, which results in desiccation of streams.
Conclusions and conservation recommendations
- The conservation status of Odonata is known to be a useful indicator for assessing the ecological status of North Africa ecosystems, and it could be an important tool in setting priorities for species action plans.
- Overgrazing, water over-consumption, chemical pollution, eutrophication, and gravel pitting in main water beds have greatly increased during the last decades. Raising awareness and education should be promoted at a large scale to stop the degradation of ecosystems and species in North Africa.
- While the geographical distribution and conservation status of dragonflies are well known in both Morocco and Tunisia, most countries remain poorly investigated, in particular Egypt and Libyan Arab Jamahiriya, partly due to insecurity and difficulty to go freely anywhere. Gathering actual data and determining trends is therefore an urgent need to preserve biodiversity in these countries.
- In the Northern African region there is a need to increase the local capacity for biodiversity monitoring through links with specialists from other countries.
- A freshwater action plan for the Maghreb, as well as a species action plan for the most endangered species (CR and EN), are highly desirable.