Although I agree that looking to the breeding bird development is probably the best way to monitor this population we include this species also in our East Atlantic Flyway assessment reports based on non-breeding January IWC counts. The couns confirm the small population size and tendency to decline.
Fully endorse this suggested status change, for all the reasons laid out above. The previous listing was clearly erroneous, and the sooner it is corrected, the sooner a more realistic threat assessment can be invoked to influence directly relevant conservation and development decisions.
Comments on RED LIST STATUS: DAMARA TERN (Sternula Balaenarum)
By Jean-Paul ROUX
I fully support the reassessment of this species and the proposed change from Vulnerable (or Least Concern which in my view was a mistake in 2020) to Endangered under the criteria C1+2a(ii) as detailed in this document.
My additional preliminary comments are:
A) Under the heading Specific Questions: Do you have any 2026 colony counts or estimates of the 2026 population size?
The Elizabeth Bay colony in southern Namibia (approximately 26.917 S, 15.247 E and adjacent to an extensive coastal diamond mine), which had been surveyed in previous years including in Braby 2011 and in Simmons Braby and Braby 2015*) and noted as declining, was thoroughly re-surveyed on 24 January 2026, and no breeding activity and no bird presence was detected. This leads to the conclusion that this colony is now probably extinct (Dr J Kemper and Dr M Lemerle pers com). This new information confirms the previously assumed declining trend of the population.
It should be noted that due to the difficulty of accessing remote locations in the coastal Namib desert, as well as due to access restrictions due to the Diamond Act regulations for the last century, some potential suitable breeding habitats for Damara terns have been poorly surveyed to date. A few additional breeding localities of this species are suspected to occur within the Tsau//Khaeb National Park in previously unsurveyed areas (so they are not suspected to be recently established, but rather undiscovered to date). Such potential additional breeding localities are unlikely to support large numbers of breeding pairs and are therefore not expected to have consequences for the present assessment, and in particular for the overall declining population trend. However, if new localities are confirmed and assessed by further monitoring efforts, they should be included in future conservation priorities and in threat assessments related to proposed large-scale industrial developments in the region.
*This important reference which gives detailed account and size and trend estimates of all known Damara tern colonies in Namibia at the time has been omitted from the document: Simmons RE, Braby RJ, Braby SJ. 2015. Damara Tern Sternula balaenarum (Sterna balaenarum). Pp 91-95 in: Simmons RE, Brown CJ and Kemper J (Eds). Birds to watch in Namibia: Red, rare and Endemic species. Ministry of Environment and Tourism and Namibia Nature Foundation. Windhoek, Namibia.
B) In Annex 1, under the heading Subpopulation structure: The justification: “This species is migratory and change breeding colony between years, and therefore likely occurs as a single subpopulation” Should be considerably watered down for several reasons:
a. While there are a few examples of marked birds changing breeding colony between years, this was attributed to excessive disturbance on the original colony (RJ Braby pers. com.) and the change of colony was extremely local (95% of the species) could reasonably be estimated at about 15 000 Km2 which is only about 1.6% of the present estimate. Again, it should be noted that this criterion, as presently calculated, is giving an extremely misleading and unrealistic result when applied to the Damara Tern.
b. The recent results from Allport et al 2022 show that the rather outlying south-eastern population (in the Eastern Cape Province) migrates along the East coast of southern Africa (instead of tropical western Africa)… As this breeding population is distant (by more than 500 km) from the West coast birds and migrates through a different pathway to a different wintering destination it is probable that it might constitute a distinct subpopulation from the rest of the species. This considerably weakens the assumption that the species likely occurs as a single subpopulation as stated.
c. Similarly, the small Western Cape Province population being distant by more than 700 km from the rest of the west coast colonies is also likely to be an isolated subpopulation.
d. Further recent evidence from studies being currently conducted in Namibia suggests that the species might actually be fragmented at an even finer scale (including between breeding sites, migrants vs non migrant subpopulations, timing of breeding (including winter breeding) etc…) e.g. Roux et al. 2025.**
** Roux JP, Boorman M, Braby J, Braby RJ. Fijn RC. 2025, A new longevity record for the Damara tern Sternula balaenarum. Namibian Journal of Environment 10, B-12
C) Still in Annex 1, the Extent of Occurrence (EOO) is given as 945 000 Km2. As this criterion is calculated using the minimum convex polygon method and seems to include all subpopulations (including that of the Eastern Cape province) it should be noted that this huge area encompasses a large portion of southern Africa including places up to about 500 km inland and the western edge of the Kalahari Desert. This is therefore very unrealistic for a strictly coastal bird. As this criterion was used in the previous assessment to justify a Least Concern status, this caveat should be noted and emphasized in the text.
Further, the EOO of the Northern Cape Province, Namibian and Angolan part of the population (which constitutes >95% of the species) could reasonably be estimated at about 15 000 Km2 which is only about 1.6% of the present estimate. Again, it should be noted that this criterion, as presently calculated, is giving an extremely misleading and unrealistic result when applied to the Damara Tern.
Although I agree that looking to the breeding bird development is probably the best way to monitor this population we include this species also in our East Atlantic Flyway assessment reports based on non-breeding January IWC counts. The couns confirm the small population size and tendency to decline.
https://flyway.waddensea-worldheritage.org/news/new-report-shows-current-trends-migratory-waterbird-populations-east-atlantic-flyway.
Fully endorse this suggested status change, for all the reasons laid out above. The previous listing was clearly erroneous, and the sooner it is corrected, the sooner a more realistic threat assessment can be invoked to influence directly relevant conservation and development decisions.
Comments on RED LIST STATUS: DAMARA TERN (Sternula Balaenarum)
By Jean-Paul ROUX
I fully support the reassessment of this species and the proposed change from Vulnerable (or Least Concern which in my view was a mistake in 2020) to Endangered under the criteria C1+2a(ii) as detailed in this document.
My additional preliminary comments are:
A) Under the heading Specific Questions: Do you have any 2026 colony counts or estimates of the 2026 population size?
The Elizabeth Bay colony in southern Namibia (approximately 26.917 S, 15.247 E and adjacent to an extensive coastal diamond mine), which had been surveyed in previous years including in Braby 2011 and in Simmons Braby and Braby 2015*) and noted as declining, was thoroughly re-surveyed on 24 January 2026, and no breeding activity and no bird presence was detected. This leads to the conclusion that this colony is now probably extinct (Dr J Kemper and Dr M Lemerle pers com). This new information confirms the previously assumed declining trend of the population.
It should be noted that due to the difficulty of accessing remote locations in the coastal Namib desert, as well as due to access restrictions due to the Diamond Act regulations for the last century, some potential suitable breeding habitats for Damara terns have been poorly surveyed to date. A few additional breeding localities of this species are suspected to occur within the Tsau//Khaeb National Park in previously unsurveyed areas (so they are not suspected to be recently established, but rather undiscovered to date). Such potential additional breeding localities are unlikely to support large numbers of breeding pairs and are therefore not expected to have consequences for the present assessment, and in particular for the overall declining population trend. However, if new localities are confirmed and assessed by further monitoring efforts, they should be included in future conservation priorities and in threat assessments related to proposed large-scale industrial developments in the region.
*This important reference which gives detailed account and size and trend estimates of all known Damara tern colonies in Namibia at the time has been omitted from the document: Simmons RE, Braby RJ, Braby SJ. 2015. Damara Tern Sternula balaenarum (Sterna balaenarum). Pp 91-95 in: Simmons RE, Brown CJ and Kemper J (Eds). Birds to watch in Namibia: Red, rare and Endemic species. Ministry of Environment and Tourism and Namibia Nature Foundation. Windhoek, Namibia.
B) In Annex 1, under the heading Subpopulation structure: The justification: “This species is migratory and change breeding colony between years, and therefore likely occurs as a single subpopulation” Should be considerably watered down for several reasons:
a. While there are a few examples of marked birds changing breeding colony between years, this was attributed to excessive disturbance on the original colony (RJ Braby pers. com.) and the change of colony was extremely local (95% of the species) could reasonably be estimated at about 15 000 Km2 which is only about 1.6% of the present estimate. Again, it should be noted that this criterion, as presently calculated, is giving an extremely misleading and unrealistic result when applied to the Damara Tern.
b. The recent results from Allport et al 2022 show that the rather outlying south-eastern population (in the Eastern Cape Province) migrates along the East coast of southern Africa (instead of tropical western Africa)… As this breeding population is distant (by more than 500 km) from the West coast birds and migrates through a different pathway to a different wintering destination it is probable that it might constitute a distinct subpopulation from the rest of the species. This considerably weakens the assumption that the species likely occurs as a single subpopulation as stated.
c. Similarly, the small Western Cape Province population being distant by more than 700 km from the rest of the west coast colonies is also likely to be an isolated subpopulation.
d. Further recent evidence from studies being currently conducted in Namibia suggests that the species might actually be fragmented at an even finer scale (including between breeding sites, migrants vs non migrant subpopulations, timing of breeding (including winter breeding) etc…) e.g. Roux et al. 2025.**
** Roux JP, Boorman M, Braby J, Braby RJ. Fijn RC. 2025, A new longevity record for the Damara tern Sternula balaenarum. Namibian Journal of Environment 10, B-12
C) Still in Annex 1, the Extent of Occurrence (EOO) is given as 945 000 Km2. As this criterion is calculated using the minimum convex polygon method and seems to include all subpopulations (including that of the Eastern Cape province) it should be noted that this huge area encompasses a large portion of southern Africa including places up to about 500 km inland and the western edge of the Kalahari Desert. This is therefore very unrealistic for a strictly coastal bird. As this criterion was used in the previous assessment to justify a Least Concern status, this caveat should be noted and emphasized in the text.
Further, the EOO of the Northern Cape Province, Namibian and Angolan part of the population (which constitutes >95% of the species) could reasonably be estimated at about 15 000 Km2 which is only about 1.6% of the present estimate. Again, it should be noted that this criterion, as presently calculated, is giving an extremely misleading and unrealistic result when applied to the Damara Tern.
Dr J-P Roux
jp.roux2023@gmail.com
SEACODE Research Group