White-winged Black Tern (Chlidonias leucopterus) overwintering in Spain [Fumarel alibanco en invierno en España]

Although scarce, albeit regular in both migration periods, there are very few records of White-winged Black Tern (Chlidonias leucopterus) in Spain during the winter months (December to February). The aim of this post is to collect them.

The species, almost restricted to the Mediterranean seaboard (e.g. only 21 known records in Galicia, the latest for the autumn period on 31.10.1989, see Aves Raras en Galicia blog) is a typical migrant. In the NE, it appears the last days of April and has a peak in the first ten days of May and it can be present until early June in scarcer numbers. Post-breeding migration begins during the summer, in late July and into August with further juveniles seen during September and sometimes October being the last records of the 2nd tenth of the month (Gutiérrez et al 1995 Els Ocells del Delta del Llobregat, Lynx Editions). Migration dates can be a bit modified depending on latitude in the country.

However, there are a number of records in Spain in winter that have never been considered as a whole. Perhaps there are even more still hidden in some notebooks (they are welcome for this review and can be included as as comment in this post). Indeed, the species does not appear in the recent Atlas dels ocells de Catalunya a l'hivern 2006-2009 (Catalan winter bird atlas) and other authors either mention it as a migrant or refer to the single overwintering records as accidental.

Once some recent records and older citations have been reviewed, there appear to be at least a few records for the different E Spain communities (North to South):

Catalunya (n=2)

• Barcelona. One bird seen off La Ricarda lagoon, Llobregat delta, Barcelona, on January 1997 during the January Winter Bird Count (Reserves Naturals Delta del Llobregat/ Generalitat de Catalunya)
• Tarragona. A first winter individual was seen at ricefields between l'Encanyissada and la Nòria, Ebre Delta, Tarragona on 4.12.2000 in company of +20 Chlydonias hybridus (D.Bigas, R.Gutiérrez, X.Larruy, F.López, J.Castelló), news featured in Rarebirdspain website and the Anuari d'Ornitologia de Catalunya. See a photo below.

L'Embut, Delta de l'Ebre, 4.12.2000 © Ricard Gutiérrez

  
Comunitat Valenciana (n=1)

• València. A bird rested in l'Albufera de València from 27.11.1994 until 20 March 1995 (J.I.Dies, Bosco Dies, Ardeola 42(2): 225, Aves de la Comunitat Valenciana 1999.

Castilla - La Mancha (n=1)

• Ciudad Real. One 1w was present at Laguna de la Veguilla, Alcázar de San Juan at least from 8.1.2012 (Ángel González Mendoza) to 14.1.2012 (Eduardo Martín Ferrero) and 28.1.2012 (Juan Carlos Marín). See a photo below from 8.1.2012 and another from 14.1.2012 here.

Laguna de la Veguilla, Alcázar de San Juan, Ciudad Real, 8.1.2012 © Ángel González

Andalucía (n=4+)

• Huelva. Paterson (1997) Seabirds of Spain and Portugal, Lynx Editions, comments that there are at least 8 records for the period 1986-1989 at Odiel marshes, all in autumn-winter.  
• Cádiz. One individual in winter plumage was seen at Lagunas del Puerto de Santa Maria, Cádiz, on 6.12.1998 (P. Almaráz) Ardeola 46(1):159 
• Almería. A 1st winter was at Cañada de las Norias, El Ejido, Almería on 12.12.2000 (Carlos Gutiérrez Expósito). Ardeola 49(1) 2002 :190-191
• Granada  On 16.1.2011 a bird was seen at Charca de Suárez, Motril, Granada (J.Caro, Jesús DC.), see an entry and photos in Jesús DC blog here. 
• Almería. A bird was at Cañada de las Norias, El Ejido, Almería on 31.1.2012 and it has been present at least some weeks that January, perhaps a bird seen also the year before (Raimundo Martín via Avesforum).

For the rest of the Iberian Spanish shore, the species is very rare even in migration in Murcia region (see Anuario Ornitológico de la Región de Murcia). It is probable that there will appear more observations from Andalusia, given the references above and that the area holds large wetlands suitable for marsh terns.

Besides the fact that for example in 2012 some other Eastern species have been mentioned overwintering in Spain (e.g. Pallid Harrier Circus macrourus or Red-footed Falcon Falco vespertinus), del Hoyo et al 1996 HBW vol 3 mentions the species overwintering S of Sahara up to Senegal coasts, where it might be abundant at times, albeit most of the migration movement is referred to E Europe route rather than the Western one through Spain. As in cases outlined above, a combination of irregular mostly first winter birds not wanting to travel further South or perhaps the initial stages of the establishment of a small new overwintering area in Mediterranean Spanish seaboard could explain the very scarce, although no longer accidental, given time and range span of existing records, presence of this species during the winter in Spain.

World distribution map (Source: www.avibirds.com)

Resumen. Fumarel alibanco en invierno en España. Se recogen un mínimo de 8 citas de fumarel aliblanco invernando en España (meses de Diciembre a Febrero): Catalunya 2, Comunidad Valenciana 1, Castilla-La Mancha 1 y Andalucía 4+ (hay una referencia sin cuantificar). Se agradecerian más observaciones para completar el panorama esbozado. Siendo una especie migratoria escasa en Iberia, que inverna al sur del Sáhara, la presencia de algún ave invernal en la Península, particularmente en la vertiente mediterránea bien puede ser debida a primeros años que no viajen hasta sus cuarteles de invernada o al inicio de un proceso de cambios de áreas de invernada como ha sucedido algún año con el aguilucho papialbo (Circus macrourus), notablemente en 2011-2012 o recientemente con el cernícalo patirrojo (Falco vespertinus). En cualquier caso, aunque muy raro y escaso, el fenómeno no parece merecer el carácter de accidental dada su presencia dilatada en tiempo y espacio.