Roosting tree selection of Cinereous Vulture in breeding season in Turkey– E. Yamac Roosting Tree Selection of Cinereous Vulture Aegypius monachus in Breeding Season in Turkey ELIF YAMAC Biology Department, Science Faculty, Anadolu University, Eskisehir, Turkey Email: [email protected] Received 7 August 2006: accepted 27 November 2006 Abstract: In this study, the characteristics of roost trees selected by Cinereous Vulture Aegypius monachus were compared with those of the same number of paired, randomly selected trees on Turkmenbaba Mountain, north-western Turkey during September to October of 2003–2005 after the fledging period. All roost trees selected were Black Pine Pinus nigra . These trees were either dominant (65%) or intermediate (35%) in the canopy. Most roost trees were mature in terms of diameter at breast height (39.47 cm) and had flat canopies. The mean distances from the roost tree to the nearest occupied nest and unoccupied nest were 189±138.9 m and 83±74.4 m respectively. It was found that Cinereous Vultures selected roost trees that provided the best views to detect aerial predators at a distance and territorial intruders. Keywords: Roosting, Tree Selection, Cinereous Vulture, Aegypius monachus , Breeding Season, Turkey ﺍﻧﺘﺨﺎﺏ ﺩﺭﺧﺘﺎﻥ ﺩﺭ ﻓﺼﻞ ﺟﻮﺟﻪ ﺁﻭﺭﻱ ﻛﺮﻛﺲ ﺳﻴﺎﻩ ( Aegypius monachus) ﺩﺭ ﺗﺮﻛﻴﻪ ﭼﻜﻴﺪﻩ : ﺩﺭ ﺍﻳﻦ ﭘﮋﻭﻫﺶ، ﻭﻳﮋﮔﻲ ﻫﺎﻱ ﺩﺭﺧﺘﺎﻥ ﮐﺎﺝ ﺳﻴﺎﻩ ﺍﻧﺘﺨﺎﺏ ﺷﺪﻩ ﺗﻮﺳﻂ ﻛﺮﻛﺲ ﺳﻴﺎﻩ ( Aegypius monachus) ﺑﺎ ﻣﻴﺎﻧﮕﻴﻦ ﺟﺎﻣﻌﻪ ﺗﺼﺎﺩﻓﯽ ﺁﻣﺎﺭﯼ ﺍﻳﻦ ﺩﺭﺧﺘﺎﻥ ﺩﺭ ﻛﻮ ﻩ ﻫﺎﻱ ﺗﺮﻛﻤﻦ ﺑﺎﺑﺎ، ﺷﻤﺎﻝ ﻏﺮﺏ ﺗﺮﻛﻴﻪ ﻃﻲ ﺳـﭙﺘﺎﻣﺒﺮ ﺗـﺎ ﺍﻛﺘﺒـﺮ ﺳـﺎ ﻝﻫـﺎ ﻱ ۶- ۲۰۰۳ ﺑﻌﺪ ﺍﺯ ﺷﺮﻭﻉ ﭘﺮﻭﺍﺯ ﺟﻮﺟﻪ ﻫﺎﻱ ﺁﺷﻴﺎﻧﻪ ﺍﻱ ﻣﻘﺎﻳﺴﻪ ﮔﺮﺩﻳﺪ . ﻫﻤﻪ ﺩﺭﺧﺘﺎﻥ ﺍﻧﺘﺨﺎﺏ ﺷﺪﻩ ﻛـﺎﺝ ﺳـﻴﺎ ﻩ ( Pinus nigra ) ﺑﻮﺩﻧﺪ ﻛﻪ ﺩﺭ ﺗﺎﺝ ﭘﻮﺷﺶ ﭼﻴﺮﻩ ( ۶۵ %) ﻳﺎ ﺯﻳﺮﭼﻴﺮﻩ ( ۳۵ %) ﺩﺍﺷﺘﻨﺪ. ﺑﻴﺸﺘﺮ ﺩﺭﺧﺘﺎﻥ ﺍﺯ ﻧﻈﺮ ﻗﻄﺮ ﺑﺮﺍﺑﺮ ﺳـﻴﻨﻪ ﺑـﺎﻟﻎ ﺑﻮﺩﻧـﺪ ( ۳۹,۴۷ ﺳﺎﻧﺘﻲ ﻣﺘﺮ )ﻭ ﺗﺎﺝ ﭘﻮﺷﺶ ﺗﺨﺖ ﺩﺍﺷﺘﻨ ﺪ . ﻓﺎﺻﻠﻪ ﻣﻴﺎﻧﮕﻴﻦ ﺩﺭﺧﺖ ﺗﺎ ﻧﺰﺩﻳﻜﺘﺮﻳﻦ ﺁﺷﻴﺎﻧﻪ ﻓﻌﺎﻝ ﻭ ﻏﻴﺮﻓﻌﺎﻝ ﺑﻪ ﺗﺮﺗﻴﺐ ±۱۳۸,۹ ۱۸۹ ﻭ ۷۴,۴± ۸۳ﻣﺘﺮ ﺑﻮ ﺩ . ﻧﺘﺎﻳﺞ ﺑﻴﺎﻧﮕﺮ ﺍﻳﻦ ﺑﻮﺩ ﻛﻪ ﻛﺮﻛﺲ ﺳﻴﺎﻩ ﺩﺭﺧﺘﺎﻧﻲ ﺭﺍ ﺍﻧﺘﺨﺎﺏ ﻛﺮﺩ ﻛـﻪ ﺩﺍﺭﺍﻱ ﺩﻳـﺪ ﻣﻨﺎﺳـﺐ ﺑـﺮﺍﻱ ﻛﻨﺘـﺮﻝ ﺷﻜﺎﺭﮔﺮﺍﻥ ﺍﺯ ﻫﻮﺍ ﺩﺭ ﻳﻚ ﻣﺴﺎﻓﺖ ﻣﺸﺨﺺ ﻭ ﻫﻤﭽ ﻨﻴﻦ ﻣﺰﺍﺣﻤﺎﻥ ﺍﺯ ﺳﻄﺢ ﺯﻣﻴﻦ ﺑﺎﺷﻨﺪ . INTRODUCTION birds especially, immature and adult individuals concentrate in communal roosts (Donazar et al. Raptor conservation studies are mostly centred 1994), an example being the highly gregarious on the nest site selection to determine habitat vulture species. These birds roost together, soar requirements of the species. But no studies have together, and if the carcass is large enough, feed attempted to describe roost tree characteristics together. Even during the breeding season, that could provide valuable information for birds will often nest in close proximity to a conservation management. Roosting is a winter roost and will occasionally return to the characteristic behaviour observed throughout roost for the night (Sibley et al. 1989). the gamut of bird species ( e.g. Cramp & One vulture that roosts near the nest tree to Simmons 1980, Ceballos & Donazar 1990, guard the young is the Cinereous Vulture Whitaker & Stauffer 2003). Amongst social Aegypius monachus (Cramp & Simmons 1980). 30 Podoces, 2007, 2(1): 30–36 Figure 1. Study area in Turkey, © H. Kostekci. The species is classified globally as “near It is known that one member of pair will be threatened” according to criteria in the present at nest from egg-laying until the chick Conservation of Nature Red List (IUCN 2000) is two months old, and that its mate will either and is rare in Europe. It is included in Annex I roost at the nest or in a nearby tree (Bernis of the European Union Bird Directive and in 1966). Information concerning roosting tree Appendix II of the Bern, Bonn and CITES selection is important if forest managers are to Conventions (BirdLife International 2005). be enabled to determine efficient ways of This species may breed in loose colonies or harvesting timber without harming Cinereous solitarily (Cramp & Simmons 1980, Heredia Vulture populations. The aim of this study was 1996, Moràn-López et al. 2006a), building at therefore to describe the characteristics of roost the top of a tree a huge nest where it lays one trees selected by Cinereous Vulture by egg (Heredia 1996). Incubation is by both comparing actual roost trees to randomly- adults and last 50–54 days (Cramp & Simmons selected trees. To the best of our knowledge, 1980, Heredia 1996, Harrison & Castell 2002). this is the first report on the characteristics of The chick usually spends more than 100 days in roost trees selected by Cinereous Vulture in the nest and remains with the adults 2–3 months Turkey. after fledging before moving (Heredia 1996). 31 Roosting tree selection of Cinereous Vulture in breeding season in Turkey– E. Yamac STUDY AREA The study was conducted on Turkmenbaba Mountain, between Eskisehir and Kütahya in northwest Turkey (39 o24'N, 30 o18'E). The survey was carried out in a 9500 ha area which includes Cinereous Vulture nests (Fig. 1), the whole region comprising 175 km 2. The highest point in the study site is 1826 m above mean sea level (asl), the mean monthly temperatures range from 21.6 oC in July to –1.1 oC in December, and the mean annual precipitation is 373.8 mm. Steppe and forest are the two main habitat types of the study area. The lower limit of forest vegetation is at 1000–1100 m asl. The commonest tree species is Black Pine Pinus nigra pallasiana . Turkish Oak Quercus cerris cerris occurs at lower elevations and Scots Pine P. sylvestris and Oriental Beech Fagus orientalis in more humid sites (Ekim 1978). The study area includes a very rich diversity of wildlife, such as Black Stork Ciconia nigra, Lammergeier Gypaetus barbatus , Egyptian Vulture Neophron percnopterus , Short-toed Eagle Circaetus gallicus, Common Buzzard Figure 2. Roost tree on Turkmenbaba Buteo buteo, Long-legged Buzzard B. rufinus, Mountain, © E. Yamac. Booted Eagle Hieraaetus pennatus , Common Kestrel Falco tinnunculus, Cape hare Lepus September to October of 2003–2005, after the capensis, Persian squirrel Sciurus anomalus, fledging period. The following information was wolf Canis lupus, red deer Cervus elaphus , wild recorded to describe each roost tree: tree boar Sus scrofa, common fox Vulpes vulpes species, tree height, diameter at breast height (Yarar & Magnin 1997, Yamac 2004). (dbh), orientation of roost tree, crown class The area’s main economic activity is (dominant, intermediate or suppressed), roost timber extraction. There is also some grazing tree branches and condition of roost tree. (up to 7000 sheep) and certain restricted parts Besides, elevation of the site (asl), degree of of the mountain are used for summer slope, distances from the roost tree to the recreation. nearest occupied (NON) and unoccupied nests (NUN) were also recorded. The roost tree’s MATERIAL AND METHODS direction to the associated nest was defined as roost tree orientation. The roost tree condition Roost trees were found by methodically was taken as good or bad (evidence of fire or searching the forest on foot in breeding season. epiphytic growth). Roost tree branches were Trees were designated as roost trees if an adult measured and classified according to their roosting Cinereous Vulture could be seen on density (branches per vertical arc) I) <10, II) them or droppings, feathers and pellets of the 10–20 and III) >20 (Bakaloudis et al. 2000). species could be found beneath or very near Mean elevation of the site above sea level and them (Ceballos & Donazar 1990). After degree of slope were estimated by plotting the determining the exact location of roost tree by roost tree on 1:25000 scale topographic maps GPS, all roost sites were plotted on a 1:25000 (Bakaloudis et al. 2001). Distances from the topographic map. roost tree to the nearest occupied and To avoid disturbing the vultures, data on unoccupied nests were measured by GPS. roost tree characteristics were collected during Occupied nests were those with an egg, with 32 Podoces, 2007, 2(1): 30–36 evidence that an egg had been laid ( i.e. RESULTS incubating adult or broken eggshells below nest) or containing a nestling. Unoccupied Seventeen roost trees were recorded in the nests were those without an adult, egg, or 2003–2005 period. All of the roost trees were nestling. associated with the related occupied nest trees. In order to compare roost tree characteristics According to study, all roost trees were Black within the same forest stand, the same number Pine Pinus nigra (Fig. 2). All of the randomly (17) of trees was randomly selected from the selected trees were Black Pine except two area located within a 200 m radius of each roost Quercus oaks. No difference was detected tree, (Bakaloudis et al. 2000) . The area centred between roost trees and randomly selected trees on the roost tree was divided into four in terms of their height (Table 1). Cinereous quadrants (northeast, southeast, southwest and Vulture had a tendency to roost on older trees northwest). One quadrant was randomly (mean dbh=39.47 cm) which were significantly selected. To calculate the distance of the different from randomly selected trees random tree along the north-south and the east- (p<0.001). The mean elevation of roost sites asl west axes from the roost tree, two numbers was 1234.5±78 m. The mean slope gradient of between 0–200 were randomly selected. The roost sites was 27.08±10.11˚. Elevation of the intersection of lines extending from the roost actual roost site asl and of calculated slope were tree defined the centred point. At this centred similar to the randomly-selected site values and point, the nearest tree whose dbh was >10cm, showed no significant differences statistically was identified as the randomly-selected tree.