The Sociable Lapwing in Europe Eduardo De Juana
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The Sociable Lapwing in Europe Eduardo de Juana Abstract Records of the Sociable Lapwing Vanellus gregarius in western and central Europe were analysed. Sightings in these areas reached 20–21 per year in 2003–05, the most recent years for which complete data were available, with records from France, Spain and Portugal amounting to one-third of the European total during the decade 1996–2005. While most occurred in spring or autumn, records in the Iberian Peninsula were concentrated in the winter months. Spring movements appeared to be, on average, faster and to follow a more southerly route than those in autumn. Numbers reported were only slightly lower in spring than in autumn, suggesting that winter mortality rates may be low. In autumn, about 60% of birds that were aged were in juvenile/first-year plumage. The observed patterns, taking into account the numbers and distribution of observers and the species’ habitat preferences, support the hypothesis that small numbers of Sociable Lapwings may winter regularly in Iberia. he formerly abundant Sociable presents the results of an analysis of records Lapwing Vanellus gregarius is now a in western and central Europe. TCritically Endangered wader, its world population estimated to be around 5,600 Trends across Europe breeding pairs. It breeds in Kazakhstan and Records of Sociable Lapwings were sought adjacent parts of south-central Russia, and from as many countries as possible in winters primarily in Israel, Eritrea, Sudan western and central Europe. Most data were and northwest India (Tomkovich & Lebedeva extracted from the annual reports of national 2004; www.birdlife.org). In western and rarities committees, although for Italy a central Europe, records are erratic and its variety of other sources were used (e.g. status is that of a presumed vagrant, with Moltoni 1968, 1978, Brichetti & Fracasso most records being of single birds in spring 2004, Rivista Italiana di Ornitologia, Rivista or autumn (Glutz von Blotzheim et al. 1975; Italiana di Birdwatching). The number of Snow & Perrins 1998). There is, however, an dated records available for analysis was 466, emerging pattern of occurrence in the much higher than in previous compilations; Iberian Peninsula in winter, suggesting the for example, 2.6 times the figure quoted by possibility that these birds may be part of a Mitchell & Young (1997), and 7.4 times that regular (though very small) wintering popu- by van den Berg (1984). The annual total for lation, rather than vagrants (de Juana 1991, western and central Europe reached 21 in 2006). A similar theory has been suggested 2003, 20 in 2004 and 21 in 2005 (information with regard to records in France (Dubois et for subsequent years was not available for all al. 2008). Given the global status of the countries in the region). species and the threats it faces, which include The recent increase in sightings across large-scale changes to its breeding habitat in western and central Europe as a whole has the steppes of central Asia, together with been rather uneven, however; numbers in hunting pressure on migration (notably in some countries have increased, while those in Syria and Iraq), it seems important to others have changed little or declined (fig. 1). examine these ideas further. This paper For example, comparing the period 84 © British Birds 104 • February 2011 • 84–90 The Sociable Lapwing in Europe 1976–1985 with 1996–2005, it is clear that while records from Germany, France and the 70 Iberian Peninsula have increased by roughly an order of magnitude, those in the Nether- 60 Britain & Ireland lands have remained fairly constant while Netherlands those in Britain declined by c. 50%. Germany The occurrence patterns of vagrants in a 50 France Iberia given area may be strongly biased by the presence and distribution of potential 40 observers (Alerstam 1990; Fraser 1997). To what extent does this affect the apparently 30 changing patterns of Sociable Lapwing occurrence in Europe? Records from the 20 Iberian Peninsula, which have shown a par- ticularly marked increase, may be linked to the increasing number of observers, at least 10 in part. Taking membership of the Spanish Ornithological Society (SEO/BirdLife, 0 www.seo.org) as an index of the numbers of 56–65 66–75 76–85 86–95 96–05 active birdwatchers in that country, and grouping the data in ten-year periods, a sig- Fig. 1. Sociable Lapwing Vanellus gregarius records in key parts of western and central nificant correlation (P < 0.05) is apparent Europe between 1956 and 2005 (graph shows between the mean number of members the ten-year total for each country/area). The (which have increased from 31 in 1956–65 to differences are highly significant (χ2 = 63, P < 0.001). 6,464 in 1996–2005) and the number of Sociable Lapwing records in each period with longer traditions of field ornithology, (rising from 0 in 1956–65 to 19 in 1996– such as Britain and Ireland. If that is the case, 2005). Comparable data for other countries then the declining trend shown by the British is lacking, but it seems that the rapid increase and Irish data fits better with the overall in number of birdwatchers in Spain has not decline in the breeding population of the been matched in other European countries Sociable Lapwing (see www.birdlife.org). Juan Sagardía 39. Sociable Lapwing Vanellus gregarius, Boecillo, Valladolid, Spain, April 2010. British Birds 104 • February 2011 • 84–90 85 de Juana Temporal patterns There are European records in every month of the year, although most are in autumn Northeast (mainly September to November with a marked peak in October) and spring, mostly March and April (fig. 3). Records from Sep- tember to November amount to 47.8% of the total in the period prior to 1996 and 39.8% Central of the total during 1996–2005 (differences not significant, χ2 = 3.02, P = 0.06). The decrease in the proportion of autumn records may reflect the influence of the British records, which predominated before 1970 and were mostly in autumn (Vinicombe Southwest & Cottridge 1996). When (all) the records are separated by season, winter (December to Fig. 2. Distribution of records of the February) accounts for 12.1% of the total, Sociable Lapwing Vanellus gregarius included spring (March to May) 32.8%, summer (June in this analysis, by country and region to August) 11.8% and autumn (September to (Northeast, Central and Southwest). November) 43.3%. Geographical patterns When the three regions (as defined above) Fig. 2 shows the distribution of Sociable are considered separately, however, it is clear Lapwing records across western and central that spring and autumn records predominate Europe, and the three geographical regions in the Northeast and Central regions, while adopted in this analysis (Northeast, Central in the Southwest there is a higher percentage and Southwest). In addition, records from of winter records (55.3% of the total, com- the Canary Islands (1), Morocco (1) and pared with 29.8% in autumn, 14.9% in Malta (3), although not shown in fig. 2, were spring and none in summer). In summer, included in the analyses (Giraud-Audine & sightings are almost entirely in the Northeast Pineau 1973; Trujillo 1994; Sultana & Gauci (21.9% of the overall total, with 40.9% in 1982). The majority of records are concen- autumn, 36.3% in spring and 0.9% in trated in middle latitudes (France and winter). These differences in the seasonal dis- Germany together account for c. 40% of the tribution of records among sectors are highly total), while records become rarer in the significant (χ2 = 139; P < 0.001; fig. 4). southwest and, especially, in the north. Predictably, as birds move to and from their breeding grounds in 120 Russia and Kazakhstan, >1996 records from the Northeast 100 <1995 peak earlier in autumn and 80 later in spring than elsewhere. In autumn, the average dis- 60 covery date in the Northeast is 7th October, while in the 40 Central region it is 28th October. In spring, average 20 discovery date is 31st March in the Central region and 13th 0 April in the Northeast. These Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec differences are statistically sig- Fig. 3. Temporal distribution of Sociable Lapwings Vanellus nificant, both in autumn gregarius in western and central Europe (1956–2005) by month; (ANOVA: F = 18.47, P < 0.0001) dated records prior to the end of 1995 are separated from those and in spring (F = 12.45, from 1996 onwards. P < 0.0001). 86 British Birds 104 • February 2011 • 84–90 The Sociable Lapwing in Europe Winter records 60 Southwest Winter records tended to be concentrated in the Southwest 50 Central region, and there appears to be 40 Northeast a clear difference between the 30 proportion of winter records in France (12.4% of the total 20 in winter) and the Iberian 10 Peninsula (53.3%). Fig. 5 0 reveals that, even within the Jul Aug Sep Oct Nov Dec Jan Feb Mar Apr May Jun Iberian Peninsula, winter records tend to be concen- Fig. 4. Monthly distribution of Sociable Lapwing Vanellus trated in the southwest, where gregarius records in the three geographical regions of Europe considered: Southwest, Central and Northeast (see fig. 2). they amount to 72% of the total, compared with 30% in the northeast (χ2 = 6.278, P = 8 0.012). The southwestern part 7 Iberia SW 6 of the Iberian Peninsula Iberia NE 5 (including Extremadura and 4 Andalusia in Spain, and 3 southern Portugal) is also the 2 area where the highest concen- 1 trations of Northern Lapwings 0 Jul Aug Sep Oct Nov Dec Jan Feb Mar Apr May Jun V.