The Northern Bald Ibis population in Morocco had yet another good breeding season in 2018 despite the adverse weather conditions during the chick rearing period.
The breeding population in the two colonies of Souss-Massa National Park and Tamri has reached a record number of 147 breeding pairs (122 pairs in 2017, see graph below). The total population at the end of the season has also increased to 708 birds (590 birds in 2017).
The 147 pairs that laid eggs have produced 335 chicks. However, only 170 chicks have survived to fledging (51% of the total). This gave an overall reproductive success of slightly more than one chick per breeding pair.
It’s essentially these good breeding results in Morocco year after year that prompted the revision of the IUCN conservation status of the species. This revision, published in late 2018, resulted is the down-listing of the species’ status from ‘Critically Endangered’ to ‘Endangered’ (Read: Northern Bald Ibis’ IUCN Red List status updated).
Souss-Massa National Park colonies
At the colonies located inside the national park, a total number of 81 breeding pairs have produced 134 chicks. Of these, 110 chicks have fledged (77% of the total). Six pairs didn’t breed.
Tamri cliff colony
At Tamri, 66 breeding pairs have produced 192 chicks. However, the fledging rate is markedly lower at Tamri as only 60 chicks have fledged (30% of the total). Three pairs didn’t breed.
The trophic factor strongly influences the survival rate of chicks at the Tamri colony. The authors of the report noted that despite the large number of chicks produced at this colony, a large proportion die in the nest, because of the adults’ failure to feed all the chicks. “Indeed, observations have shown that parents can only feed the first chick and the rest of the brood is left to starve. This is also the case for a large number of species” the authors added.
Read more:
Reference:
Oubrou, W. & El Bekkay, M. 2018. Rapport sur la reproduction de l’Ibis Chauve Geronticus eremita dans la région de Souss-Massa, saison 2018. Parc National de Souss-Massa, HCEFLCD. 14 pp
Thank you for all of these informative articles. Do we have a current inventory count for the IBS? I am a docent at the milwaukee county zoo in Wisconsin, USA and I use this information in my conservation message to our guests.