Abstract
This study provides information on the discovery and preliminary ecological assessment of a new nest colony of the Great cormorant Phalacrocorax carbo (Linnaeus, 1758) in the Uzbek part of the Fergana Valley. Field studies conducted during the 2024 breeding season revealed the presence of nest colonies on two islands along the Syr Darya River. However, due to the existence of a border regime, the main work was carried out on the same island. In the study area, nests were found on 54 trees. Nests are mainly located in the poplar tree (Populus pruinosa Schrenk). Conducting monitoring using direct observations and camera traps, we recorded the nest occupancy, morphometric indicators of eggs, and the growth dynamics of chicks. The results show that the morphometric characteristics of great cormorant eggs can vary significantly depending on regional and ecological conditions. The chicks’ weight increased rapidly from the moment they hatched until they flew away, although some deaths were also observed. Spatial analysis showed the expansion of colonies and the accumulation of nests, which indicates the successful settlement of the species in the region. These results provide important initial data on the ecology of the reproduction of the Great cormorant in Central Asia, emphasize the species' adaptability to local habitats, and indicate the need for continuous observations to develop conservation measures.
References
Abdusalyamov IA (1971) Fauna of Tajikistan. Volume 1. Birds. Dushanbe, 402 pp. [In Russian]
An ES, Botman KS, Goncharov VE, Dudura IM, Kulbashnaya LYa (1980) Protected Territories of Uzbekistan. Tashkent, 70 pp. [In Russian]
Baratov PB (1996) Natural Geography of Uzbekistan. Tashkent, 264 pp. [In Uzbek]
Baratov PB, Mamatkulov M, Rafikov A (2002) Natural Geography of Central Asia. Tashkent, 440 pp. [In Uzbek]
Bogdanov MN (1882) Essays on the Nature of the Khiva Oasis and the Kyzyl-Kum Desert. Tashkent, 155 pp. [In Russian]
Dementiev GP, Gladkov NA (1951) Birds of the Soviet Union. Volume 1. Soviet Science Publishing House, 642 pp. [In Russian]
Elizabeth CC, Susan BE, James AD, and Matthew IP (2012) Impacts of Double-Crested Cormorants (Phalacrocorax auritus) and Other Colonial Waterbirds on Plant and Arthropod Communities on Islands in an Urban Estuary. Waterbirds 35(sp1): 4–12. https://doi.org/10.1675/063.035.sp102
Fedchenko AP (1875) Journey to Turkestan. Volume 1. Moscow, 177 pp. [In Russian]
Gladkov NA (1935) New data on the distribution of birds in the Amu Darya delta. Bulletin of Samarkand State University 21: 83–91. [In Russian]
Gladkov NA (1949) Observations on the birds of Komsomolsky Island (Aral Sea). Nature Conservation 8: 29–43. [In Russian]
Hasanov IA, Gulomov PN, Qayumov AA (2010) Physical Geography of Uzbekistan (Part 2). Tashkent, 161 pp. [In Uzbek]
Hebert CE, Pasher J, Weseloh DVC, Dobbie T, Dobbyn S, Moore D, Minelga V, Duffe J (2014) Nesting cormorants and temporal changes in Island habitat. The Journal of Wildlife Management: 78: 307–313. https://doi.org/10.1002/jwmg.659
Hoyt DF (1979) Practical methods of estimating volume and fresh weight of bird eggs. The Auk 96(1): 73–77.
Kashkarov DN (1927) Results of the expedition of the Main Central Asian Museum to the area of Lake Sary-Chilek. Tashkent, 112 pp. [In Russian]
Kenzhegulov KK (1965) On the number and economic importance of Pelecaniformes birds in the lower reaches of the Amu Darya delta. Bulletin of the Karakalpak Branch of the Academy of Sciences of the Uzbek SSR 3(21): 49–51. [In Russian]
Kenzhegulov KK (1964) Ecology of the Great Cormorant in the Amu Darya Delta and the Aral Sea. Bulletin of the Karakalpak Branch of the Academy of Sciences of the Uzbek SSR 4(18): 55–60. [In Russian]
Kostin VP (1956) Notes on the avifauna of the left bank of the lower reaches of the Amu Darya and Ustyurt. Proceedings of the Institute of the Zoology and Parasitology Academy of Sciences of the Uzbek SSR 8: 81–127. [In Russian]
Kovshar AF (2019) Birds of the Tien Shan (Middle Asian part of the mountain system in the limits of Kazakhstan, Kyrgyzstan, Uzbekistan, Tajikistan). Volume 1. Non-passerines. Almaty, 560 pp. [In Russian]
Kovshar AF, Berzovikov NN, Gistov AP, Yerokhov SN, Zhatkanbayev Azh, Kovshar VA (2012) Gaviiformes-Anseriformes. Fauna of Kazakhstan in 30 volumes. Vol. 2. Birds. Part 1. Almaty, 293 pp. In Russian]
Lakin GF (1973) Biometry. Higher School, Moscow, 343 pp. [In Russian]
Lebyazhina IP (1991) Structure and dynamics of the summer population of birds of the Sary-Chelek State Biosphere Reserve. Fauna and ecology of terrestrial vertebrates of Kyrgyzstan. Bishkek, 48–51. [In Russian]
Maslov NM (1947) Birds of the Bukhara region. Collection of scientific works of the Bukhara State Pedagogical Institute. Natural Science. Bukhara, 45–70. [In Russian]
Matulevičiūtė D, Motiejūnaitė J, Uogintas D, Taraškevičius R, Dagys M, Rašomavičius V (2018) Decline of a protected coastal pine forest under the impact of a colony of great cormorants and the rate of vegetation change under ornithogenic influence. Silva Fennica 52(2): 131–146. https://doi.org/10.14214/sf.7699
Mikheev AV (1975) Guide to Bird Nests. Moscow, 171 pp. [In Russian]
Minayev N (1983) Nesting of the Great Cormorant on Lake Tuzkan. Ecology of Plants and Animals in Uzbekistan’s Nature Reserves. Tashkent, 61–65. [In Russian]
Mukhina EA (1983) Nesting near-water and waterfowl birds of the Arnasay Reserve. Ecology of plants and animals in Uzbekistan’s Nature Reserves. Tashkent, 66–82. [In Russian]
Myand R (1988) Intrapopulation variability of avian eggs. Valgus, Tallin, 195 pp. National Encyclopedia of Uzbekistan (2013) Tashkent, 856 pp.[In Uzbek]
Romanoff AL, Romanoff AJ (1949) The Avian Egg. Moscow, 550 pp. [In Russian]
Sagitov AK (1987) Birds of Uzbekistan. Volume I. Pelecaniformes. Tashkent, 291 pp. [In Russian]
Salikhbaev KhS (1956) Vertebrates of protective forest plantations of Uzbekistan. Proceedings of the Institute of Zoology and Parasitology Academy of Sciences of the Uzbek SSR 8: 129–193. [In Russian]
Santoul F, Segura G, Mastrorillo S (2004) Environmental determinants of Great Cormorant (Phalacrocorax carbo) distribution in small man-made waterbodies – a case study of gravel pits in southwest France. Hydrobiologia 528: 179–186. https://doi.org/10.1007/s10750-004-2341-9
Severtzow N (1880) Etudes sur le passage des oiseaux dans l’Asie centrale. Bulletin de la Société impériale des naturalistes de Moscou 55(2), 234 pp. [In Russian]
Sharipov M (1974) Ecology and importance of birds in the cities of the Fergana Valley. PhD Thesis, Institute of Zoology, Academy of Sciences of the Uzbek SSR, Tashkent. [In Russian]
Shernazarov ESh (2007) Order Pelicaniformes. Great Cormorant. The birds of middle Asia. Volume 1. Almaty, 574 pp. [In Russian]
Shernazarov ESh, Ostapenko MM, Lanovenko EN, Paramonov SE (1985) The number and some biological features of the Great Cormorant in the south-eastern Kyzylkum. Uzbek Biological Journal 1: 41–43. [In Russian]
Shwiff SA, Kirkpatrick KN, DeVault TL, Shwiff SS (2015) Modeling the economic impacts of double-crested cormorant damage to a recreational fishery. Human-Wildlife Interactions 9(1): 36–47.
Sidorenko AI, Siokhin VD (2016) Nesting of Great Cormorants (Phalacrocorax carbo) on man-made structures in Ukraine. Biosystems Diversity 24(2): 308–316. https://doi. org/10.15421/011640 [In Russian]
Simon JE, Pacheco S (2005) On the standardization of nest descriptions of Neotropical birds. Revista Brasileira de Ornitologia 13(2): 143–154.
Steffens W (2010) Great cormorant–substantial danger to fish populations and fisheries in Europe. Bulgarian Journal of Agricultural Science 16(3): 322–331.
Stolzmann J (1897) Oiseaux de la Ferghana. Bulletin de la Société impériale des naturalistes de Moscou 1: 54–81. [In Russian]
Sydorenko A (2023) Biocenotic influence of the great cormorant (Phalacrocorax carbo L.) in the Azov-Black Sea region of Ukraine. In IOP Conference Series: Earth and Environmental Science 1254(1): 012013. https://doi.org/10.1088/1755-1315/1254/1/012013
Szinai P (2014) Status of the breeding population of Great cormorants in Hungary in 2013. In: Bregnballe T, Lynch J, Parz-Gollner R, Marion L, Volponi S, Paquet JY, Carss DN, van Eerden MR (Eds) Breeding numbers of Great cormorants Phalacrocorax carbo in the Western Palearctic, 2012–2013. IUCN-Wetlands International Cormorant Research Group Report. Scientific report from DCE – Danish Centre for Environment and Energy, Aarhus University (99): 121–125. http://dce2.au.dk/pub/SR99.pdf
Tertitski G, Cherenkov A, Semashko V (2014) Status of the breeding population of Great cormorants in the Onega Bay of the White Sea (Russia) in 2013. In: Bregnballe T, Lynch J, Parz-Gollner R, Marion L, Volponi S, Paquet JY, Carss DN, van Eerden MR (Eds) Breeding numbers of Great cormorants Phalacrocorax carbo in the Western Palearctic, 2012–2013. IUCN-Wetlands International Cormorant Research Group Report. Scientific report from DCE – Danish Centre for Environment and Energy, Aarhus University (99): 187–189. http://dce2.au.dk/pub/SR99.pdf
Tobirov O (2022) Methodology for Assessing the Tourist Potential of the Nature of the Fergana Valley using GIS Technologies and Experimental Methods. Preprint. https://doi.org/10.20944/preprints202209.0181.v1
Vizi A (2014) Status of the breeding population of Great cormorants in Montenegro in 2012. In: Bregnballe T, Lynch J, Parz-Gollner R, Marion L, Volponi S, Paquet JY, Carss DN, van Eerden MR (Eds) Breeding numbers of Great cormorants Phalacrocorax carbo in the Western Palearctic, 2012–2013. IUCN-Wetlands International Cormorant Research Group Report. Scientific report from DCE – Danish Centre for Environment and Energy, Aarhus University (99): 143–145. http://dce2.au.dk/pub/SR99.pdf
Zarudny NA (1916) Birds of the Aral Sea. Proceedings of the Turkestan Department of Russian Geographical Society 12(1), 229 pp. [In Russian]

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