Lesser Whitethroat 40. Sylvia

In his correspondence with H. Freiherr Geyr von Schweppenburg (1930), Baron Snouckaert van Schauburg stated his belief that Lesser Whitethroats in The Netherlands were not common breeding : “Ïn 1887-1896 I lived on an estate between Haarlem and Leiden, the same where the old Temminck had lived. As a young man I industriously collected birds there, and I made quite a nice collection of local birds. I saw curruca for the fi rst time in 1895, i.e. after a stay of eight years. That’s when I found a dead female on the ground on 18 May, and I shot the matching male on 23 May. That is all!” His only observation on an estate near Doorn in 1903 to 1912, where the nowadays is a widespread breeding , was of two birds on 3 August 1905: “and, apparently on migration, which I both shot.” By that time, it was already common knowledge that European Lesser Whitethroats wintered in eastern , where, for example, Robert Hartmann (1863) encountered many in “impenetrable Nile acacias” just north of Dongola on 25 March 1860. Later studies showed the species to be particularly abundant in Acacia-dominated semi-open wood- and scrubland across Sudan and Ethiopia; in fact, the only autecological study on the species in its wintering habitat, by Sven Mathiasson (1971) in January-February 1961 and 1964, comes from this vegetation zone. The past decades, however, have brought tremendous changes in the main wintering range of Lesser Whitethroats, particularly in Dar- fur in western Sudan. Although Schlesinger & Gramenopoulos (1996) found no evidence for climatic-induced change in the woody vegetation in Sudan in 1943-1994, the persistent drought in the 1980s did bring desertifi cation and

4450 Livvinng onn thee edge ecological problems. These were the triggers for conflict, which eventually led to war in Darfur in 2003 (turning into genocide and depopulation), disruption of traditional land use patterns and huge loss of livestock. The latter resulted in a rebounding vegetation in Darfur (most evident in 2007), but the adverse effects of the displacement of people on vegetation are now clearly visible in eastern Chad (Schimmer 2008). Today’s Darfur is very different from the Darfur visited by Gerhard Nikolaus (1987, observations in 1976-84), R. Trevor Wilson (1982, observations in the 1970s), P. Hogg et al. (1984, mostly observing birds between 1930 and 1954), and Admiral Lynes (1924-1925, fieldwork in 1920). Suffi- ciently different to affect Lesser Whitethroats? We do not yet know.

Breeding range a concentration of recoveries has indeed occurred (Wernham et al. 2002). Another similar leg on their journey would carry the birds to The vast and continuous distributions of the Lesser Whitethroat Greece, from where the species crosses the eastern Mediterranean which winter in sub-Saharan Africa extend irregularly on a relatively broad front, given the many recoveries in coastal Lib- southwards down to 37°-43°N and eastwards into Russia and be- ya, the Egyptian delta and Cyprus (Fig. 254, Fransson et al. 2005). yond. Further east still, other subspecies occur. Highest breeding Obviously, many birds use this region for refuelling, as all recap- densities prevail in western, central and eastern , as far north tured birds caught in northwestern Jordan in autumn showed an as southern Finland. The European population is estimated at 1.8- increase in body mass, at an average of 4.45% per day (Khoury 2004). 4.4 million pairs (BirdLife International 2004a). Ringing activity from 8 September-13 October 1965 near Bahig, 32 km southwest of Alexandria, Egypt, and 8 km from the Mediterra- nean coast, did not reveal obvious weaklings, despite a large indi- Migration

The entire European population migrates south or southeast to converge in the Middle East and continues towards the wintering grounds in central West Africa and in East Africa (Wernham et al. 2002, Fransson et al. 2005; Fig. 254). Some birds straggle as far west as Senegal, where Rodwell et al. (1996) mention 30 records between 30 October and 22 March 1984-1994 for the Djoudj. A remarkable recovery of a Danish bird (ringed 24 April 1994) came from Guinea, where it was recaptured on 16 October 1994 (euring; Fig. 254). The scarcity of Lesser Whitethroats in West Africa is corroborated by the few observations in Morocco, where only 4 autumn and 30 spring observations have been reliably recorded (Thévenot et al. 2003), and two birds in Mauritania in 2003 (16 April and 14 October; Salewski et al. 2005). Post-juvenile dispersal of British birds normally starts when birds are 30-38 days old, and still in active moult of wing coverts (Norman 1992). Fat loads prior to departure from the breeding grounds are usually less than 10% of total body mass, as reported for southern Gotland, (Ellegren & Fransson 1992), enabling a non-stop flight of slightly more than 300 km. Adults had significantly higher fat loads than juveniles. Furthermore, fat loads showed a positive correlation with the progress of autumn. The fattest birds, presum- ably those which are about to depart, are capable of flying through two successive nights, representing a nonstop flight of some 770 km, although a maximum of 1270 km is just possible (Ellegren & Fig. 254 European origins of 306 Lesser Whitethroats recovered be- Fransson 1992). If British-ringed birds follow a similar strategy on tween 4° and 37°N. From: euring, Mullié et al. (1989) and Meininger et autumn migration, they should reach northern Italy, which is where al. (1994).

Leesseerr Whhiitethhrroat SSylviaa curruca 451