Observations on breeding Rosy Starlings in Bulgaria Konstantin Nyagolov, Lyubomir Profirov, Tanyo Michev and Milko Dimitrov 178. Rosy Starlings Sturnus roseus, at breeding colony, Karnobat, Burgas region, Bulgaria, 1996. Konstantin Nyagolov ABSTRACT Formerly regarded as an irregular migratory and breeding species in Bulgaria, Rosy Starling Sturnus roseus now occurs almost annually on the coast of the Dobroudzha region of northeast Bulgaria. In recent years, three regular breeding colonies have been located in the Burgas region of eastern Bulgaria.This species can now be considered an annual migrant, summer visitor and breeding species in Bulgaria. he Rosy Starling Sturnus roseus is an breed (Munteanu 1997). These irruptions are erratic, irruptive visitor to central and often attributed to localised abundance of Twestern Europe. Its breeding range insect populations, which are a key element of extends from Central Asia to west and south the Rosy Starling’s diet; for example, Nankinov Russia, and north to an as yet ill-defined limit. et al. (2000) related the huge invasion in 2000 to Occasional, irruptive range extensions of up to population levels of the grasshopper 1,200 km towards southeast and eastern Europe Dociostaurus maroccanus. In Bulgaria, Rosy occur in spring, often in two or more successive Starling has traditionally been classified as an years, with an 8-10 year periodicity, although irregular migrant and breeding species. the majority of these irruptive birds do not 242 © British Birds 96 • May 2003 • 242-246 Observations on breeding Rosy Starlings Historical information on Rosy Starlings Breeding populations in Bulgaria Known breeding localities are as follows (see Migrant populations and distribution fig. 1): The distribution of migrant Rosy Starlings in 1. Sofia (and surrounding districts) Bulgaria has been relatively well documented, Several colonies, numbering ‘scores of thou- and we traced 147 literature records for the sands of birds’, were reported in 1889; and a period between the mid nineteenth century and ‘small’ colony near Pobit Kamuk in 1920. 1992. Almost all of these sightings were made Subsequently, there have been no known during spring migration, which peaks in the breeding records in this area. second half of May, and only five were of 2. Northeast, Black Sea coast (Balchik-Tyulenovo) autumn migrants. In spring, flock size was typi- Prior to 1916, there were several records of cally between 50 and 100, although there was breeding colonies, but the political history of one observation of c. 500 birds. Surprisingly, this region resulted in a lack of information there were no records of migrant Rosy Starlings between 1916 and 1940. After 1940, a on the southern Black Sea coast, south of breeding colony of several hundred birds was Burgas. Based upon observations of spring found south of Balchik in 1951, a colony of migrants during the last 100 years, we conclude 1,000+ individuals was reported at Cape Kali- that the birds enter Bulgaria from Greece via akra in 1972, and four colonies totalling the valleys of the Maritsa, Arda, Tundzha and 1,780 birds were found in the region in 1975. Struma rivers, cross the Sofia plain and so reach the Danube valley. Flying east along this river 3. East, Black Sea coast (Burgas region) valley, they reach south Dobroudzha. Here, the As early as 1890, there were large flocks of populations apparently divide, some continuing Rosy Starlings and reports of breeding in this northeast into Romania while others fly south district (Reiser 1894). The first confirmed along the Black Sea coast and subsequently breeding colony in the region was discovered breed in the Burgas region. There is currently in 1994 by Nyagolov (1996), and recent no knowledge of their return route in autumn. observations lead us to conclude that It is possible that this circular spring migration breeding now occurs annually in this area. route is the result of the species’ historical breeding distribution. Breeding distribution of Rosy Starling in Bulgaria, 1893-2002 Fig. 1. Location of breeding Rosy Starlings Sturnus roseus in Bulgaria during 1893-1920 (blue dots), 1950-75 (green dots) and 1994-2002 (orange dots). Large dots represent confirmed breeding, small dots represent possible breeding records. British Birds 96 • May 2003 • 242-246 243 Rosy Starlings in Bulgaria Konstantin Nyagolov 179. Stone quarry, Karnobat, Burgas region, Bulgaria, 1996: a breeding site of Rosy Starlings Sturnus roseus. Recent data Our observations, particularly at the Breeding populations Karnobat quarry where Rosy Starlings have The discovery of a breeding colony in a stone bred in every year since 1994, except 1997-98, pit near the town of Karnobat in 1994 led us to suggest that the species should no longer be conduct a thorough search of suitable breeding considered irruptive in Bulgaria, but is better sites in the region in subsequent years, which classified as an annual breeding visitor. Its led to the discovery of further colonies, at breeding range now extends southeast to the Banevo and Chernivrakh (table 1). These Burgas region on the Black Sea coast, where all colonies seem to be well established, and we breeding colonies are in active or disused believe that the Banevo colony has been occu- stone/rock quarries. Munteanu (1997) put the pied since 1960 (Mountfort & Ferguson-Lees total number of breeding Rosy Starlings in 1961). Europe at between 500 and 2,500 breeding pairs. Our data suggest that this may be a con- siderable underestimate, and that there were Table 1. Numbers of breeding Rosy Starlings approximately 5,160 breeding individuals in the Sturnus roseus at three stone/rock quarries in Burgas region, Bulgaria, 1994-2002. Counts Burgas region of Bulgaria alone in 2000, with are of numbers of individuals, not pairs. 2,900 in 2001 and 4,800 in 2002. Year Karnobat Banevo Chernivrakh Food and feeding The principal diet of Rosy Starlings in Bulgaria 1994 100 ? ? consists of various species of grasshoppers 1995 3,000 ? ? (Orthoptera), as well as considerable vegetable 1996 4,000 ? ? matter, including fruits such as mulberries 1997 0 ? ? Morus, cherries, apricots and plums Prunus, figs 1998 0 ? ? Ficus and pears Prunus. In the summer of 2002, 1999 120 ? ? the two breeding colonies near Karnobat had a 2000 2,000 1,800 1,360 significant adverse effect on the quantity of fruit 2001 500 1,100 1,300 in surrounding orchards. In addition to that 2002 3,200 1,600 0 fruit eaten by adults, nestlings are fed with 244 British Birds 96 • May 2003 • 242-246 Rosy Starlings in Bulgaria Konstantin Nyagolov 180. Adult male Rosy Starling Sturnus roseus, Karnobat, Burgas region, Bulgaria, 1996. stoned fruits. Adults may disgorge up to ten or predators, although the starlings often seem to more fruit stones at a time and these litter the pay no attention to a potential predator in their entire area of the colony, while the rocks sur- midst. All three colonies we studied were in rounding the colony are coloured rosy-white or quarries also occupied by nesting Eagle Owls red from the large quantities of excrement. Bubo bubo, but the starlings would alight on the edge of the eyrie even when occupied by Predators and other species nestlings or sitting adults and no interspecific Such concentrations of highly visible, noisy reaction between the two species was noted. birds inevitably attract the attention of several Peregrine Falcons Falco peregrinus were fre- Konstantin Nyagolov 181. Juvenile Rosy Starling Sturnus roseus, Karnobat, Burgas region, Bulgaria, 1996. British Birds 96 • May 2003 • 242-246 245 Rosy Starlings in Bulgaria Konstantin Nyagolov 182. Rosy Starlings Sturnus roseus, Karnobat, Burgas region, Bulgaria, 1996. quently recorded swooping upon the Karnobat References colony, but only one successful capture was Mountfort, G., & Ferguson-Lees, I. J. 1961. Observations on recorded and falcons alighting on the rock face the birds of Bulgaria. Ibis 103: 443-471. Munteanu, D. 1997. Rose-coloured Starling Sturnus roseus. near the colony were ignored. In: Hagemeijer,W. J. M., & Blair, M. J. (eds.), The EBCC Atlas of European Breeding Birds. Poyser, London. Acknowledgments Nankinov, D., Dalakchieva, S., Popov, S. K., Kirilov, A., Iankov, The Bulgarian-Swiss Biodiversity Conservation P.,Stanchev, R., & Shurulinkov, P.2000. Die Invasion des Programme kindly provided the opportunity to carry out Rosenstares in Bulgarien im Jahre 2000. Orn. Mitt.: 240- the field surveys. Kiril Bedev assisted with fieldwork, 244. Stanislav Abadzhiev provided the UTM grid map,Vladimir Nyagolov, K. 1996. A breeding colony of Rose-coloured Pomakov translated the manuscript into English, and Bob Starlings near Karnobat. Neophron 1: 12. (In Bulgarian) Scott encouraged us and commented extensively upon Reiser, O. 1894. Materialien zu einer Ornis balcanica II, the manuscript. Grateful thanks are expressed to all. Bulgarien.Wien. Konstantin Nyagolov, Lyubomir Profirov, Tanyo Michev, Milko Dimitrov Burgas Wetlands Project, Bulgarian-Swiss Biodiversity Conservation Programme, PO Box 167, Burgas 8000, Bulgaria 246 British Birds 96 • May 2003 • 242-246.