The long-staying dark morph Western Reef Heron (Egretta gularis) in Essaouira and the nearby Oued Ksob estuary has probably hybridised with the Little Egret (Egretta garzetta) at Essaouira archipelago (Mogador). This has been published recently in the journal Alauda:
Qninba, A., Benhoussa, A., Ibn Tattou, M., El Idrissi Essougrati, A., Ben Haj, S. & Rguibi Idrissi, H. 2011. Cas probable d’hybridation Aigrette garzette Egretta garzetta x Aigrette des récifs Egretta gularis dans l’archipel d’Essaouira (Maroc). Alauda 79: 241-242.
|Western Reef Heron Egretta gularis at Oued Ksob near Essaouira. (© Franck et Océane Dupraz)|
I should be mentioned that similar cases of hybridization were recorded in Thyna/Sfax, Tunisia (H. Dlensi in Isenmann et al. 2005), in l’Albufera de Valencia, Spain (Dies et al. 2001) and in the Camargue, France (Kayser et al. 2000).
Description of hybrids:Any odd-looking egret or apparent hybrid should be reported to the Moroccan Rare Birds Committee in order to gather more information about this subject. To give the reader an idea about the hybrids, I extracted the following from Dies et al. (2001) about the well-known case of hybridisation in Spain: “Apparent hybrids exhibited odd-coloured plumage, with a pale grey body and with white of variable extent on the head, wings and under-parts, even in adult plumage”.
Moroccan hybrids: below are the first hybrids ever recorded in Morocco (thanks to Javier Elorriaga/Tarifa Birding Tours for the photos):
Hybrid Western Reef Heron x Little Egret (Egretta gularis x E. garzetta), Merja Zerga, February 2013. (© Javier Elorriaga).
|Hybrid Egretta gularis x Egretta garzetta, Lower Loukkos marshes, 18 April 2013. (© Javier Elorriaga).|
Hybrid Western Reef Heron x Little Egret, Valencia, Spain. (© Jules Sykes)
Hybrid Western Reef x Little Egret Egretta gularis x E. garzetta, Tarragona, Spain, June 2011 (© Josep Tantull).
More pictures of presumed hybrids "Western Reef Heron x Little Egret" in the Iberian Peninsula from Valencia (October 2008) and Barcelona (June 2008) in the Rare Birds in Spain website.
Dies, J. I., Prosper, J. & Dies, B. 2001. Occasional breeding by Western Reef Egret [Egretta gularis] in eastern Spain. British Birds 94: 382-386.
Isenmann, P., Gaultier, T., El Hili, A., Azafzaf, H., Dlensi, H. & Smart, M. 2005. Oiseaux de Tunisie. Birds of Tunisia. SEOF, Paris.
Kayser, Y., Dietrich, L., Tatin, L., & Hafner, H. 2000. Nidification mixte de l’Aigrette des récifs Egretta gularis en Camargue en 1996. Ornithos 7: 37-40.