Page 564 - Atlas Sea Birds Ver1

not approach the threshold for VU under the range size 2011). Factors influencing this parameter included coastal
criterion, a population size which (although small) did not development that caused a colony extinction (Braby 2011),
approach the threshold for VU under the population size off-road driving at, and coastal mining or prospecting
criterion (< 10,000 mature individuals with a continuing near breeding colonies (Braby et al. 2001, Simmons et al.
decline estimated to be > 10% in ten years or three 2015), tidal flooding of low-lying colonies and attraction
generations, or with a specified population structure) and of predators to colonies (Kolberg 2022), e.g. through
a population trend that did not approach the threshold for discarding fish offal nearby (Braby 2011, Simmons et al.
VU under the population trend criterion (> 30% decline over 2015). In the Skeleton Coast National Park, most nesting
ten years or three generations, BirdLife International 2021). failures were attributable to predation of eggs by mammals
Information updated since that finding suggests that in (Simmons and Braine 1994). In order to mitigate these
2024 the correct classification of Damara Terns in Namibia pressures spatial planning should target protection of and
and Angola would be EN. effective management at breeding localities, with priority
being given to larger colonies, such as Caution Reef.
Important Bird and Biodiversity Areas Damara Terns have low dispersal probabilities so that
protection of existing breeding sites is important for this
Important Bird and Biodiversity Areas (IBAs) are identified species (Braby et al. 2012). Safeguarding Damara Terns
through the use of specific criteria. Criterion A1 is that from recreational distur bance has been shown to increase
‘the site is known or thought regularly to hold significant breeding density and chick production (Braby et al. 2009).
numbers of a Globally Threatened species’ (BirdLife We conclude that despite Damara Tern breeding
International 2020). Guidelines for the application of IBA populations spanning a wide expanse of desert coastline
criteria recommend that to meet A1 “a site must support: at in Namibia and Angola, two comparisons of numbers at
least 15 individuals (the equivalent of 5 Pairs/Reproductive known colonies indicate declines of 52% over 30 years and
Units) of a CR or EN species with a global population of 23% in 11 years. These equate to 64% and 77% declines
>1,500 individuals …” (BirdLife International 2020). In view over three generations, respectively, meeting a major IUCN
of this, and given that the species’ population is > 1,500 criterion for the Damara Tern to be re-classified as globally
individuals, should the Damara Tern be reclassified as EN, Endangered (from Least Concern). This would bring it
all sites holding ≥ five pairs would be considered IBAs. more in line with its Critically Endangered status in South
There are 31 such sites in Namibia and one in Angola Africa. We urge the IUCN red list authorities to reconsider
(Table 2). For a VU species having a population > 1,500 their present classification based on these new data and
individuals, sites holding ≥ 10 pairs would be considered analyses. We also call for conservation actions to limit
IBAs (BirdLife International 2020). negative anthropogenic influences on this diminutive tern,
To estimate the proportions of the global population of including addressing off-road driving and poorly planned
Damara Terns counted at breeding localities in Namibia coastal development, which displace this sensitive species
and Angola the most recent minimum estimate for these from preferred breeding localities.
countries (721 pairs) was combined with that for South
Africa (52 pairs, Martin et al. 2024) to obtain a minimum References
overall population for the species of 773 pairs. Twenty-two
localities in Namibia and none in Angola held ≥ 1% of the BirdLife International. 2000. Threatened birds of the world. Lynx
overall population (Table 2). The most important breeding Edicions, Barcelona, Spain.
locality for Damara Terns was at Caution Reef, between BirdLife International. 2020. Guidelines for the application of the
Swakopmund and Walvis Bay, which hosted c.19% of IBA criteria. Final version, July 2020. 18 pp. Downloaded
the species’ population, followed by Durissa Bay Pans from http://datazone.birdlife.org/ on 20 May 2022.
(c. 6%, Table 2). The minimum estimate of 120 solitary pairs BirdLife International. 2021. Sternula balaenarum. The IUCN Red
List of Threatened Species 2021: e.T22694699A179473845.
(Braby 2011) accounted for 15% of the overall population. https://dx.doi.org/10.2305/IUCN.UK.2021-3.RLTS.
T22694699A179473845.en. Accessed on 13 May 2022.
Conservation Braby J. 2010. New migration records for Damara Tern Sternula
balaenarum. Ornithological Observations 1: 38–41.
Species such as Damara Terns that have a deferred age Braby J. 2011. The biology and conservation of the Damara Tern in
at breeding and high adult survival may be particularly Namibia. PhD thesis. University of Cape Town, South Africa:
sensitive to increases in adult mortality. Seabirds were 233 pp.
trapped and killed in Angola, including in Iona National Braby J, Braby RJ, Braby N, Simmons RE. 2009. Protecting
Park, where Angola’s only known Damara Tern colony Damara Terns Sterna balaenarum from recreational
disturbance in the Namib Desert increases breeding density
was found, and in several countries farther north, to which and overall success. Ostrich 80: 71–75.
Damara Terns migrate in their non-breeding season (Braby Braby J, Braby SJ, Braby RJ, Altwegg R 2011. Immature survival
2010). Numbers of Damara Terns harvested were unknown and age at first breeding of Damara terns: conservation from
but should be investigated and legislation to mitigate such a non-breeding perspective. Ardea 99:185–190.
mortality should be implemented (Braby 2011). Beaches Braby J, Braby SJ, Braby RJ, Altwegg R. 2012. Annual survival
used by Damara Terns in Nigeria were often polluted and and breeding dispersal of a seabird adapted to a stable
put the terns at risk of entanglement (see photo on p. 549). environment: implications for conservation. Journal of
Ornithology 153: 809–816.
In Namibia, reproductive success of Damara Terns Braby R, Braby SJ, Simmons RE. 1992. 5000 Damara Terns in the
decreased between 1991 (Braby et al. 1992) and 2010, northern Namib Desert: a reassessment of world population
when it was thought to be limiting the population (Braby numbers. Ostrich 63: 133–135.

558