Wilson's Phalarope Phalaropus tricolor is a swimming sandpiper species of the New World. It is the largest and most terrestrial of the three phalarope species (Hayman et al. 1986), which are broadly known for their reversed sex-role mating system (Colwell & Jehl 2020). Wilson's Phalarope distribution range is entirely continental. It typically breeds in open habitats adjacent to inland wetlands on prairies and agricultural lands in western parts of the United States and southwestern and central Canada (Hayman et al. 1986, Colwell & Jehl 2020). On migration, this species occurs on a wide variety of freshwater lakes, ponds and small pools showing a preference for alkaline waters. Wilson's Phalarope winters in the October–April period across altiplano from Bolivia to Argentina and returns to the breeding grounds in late April and early May (Hayman et al. 1986, Colwell & Jehl 2020). The species is a rare, but regular vagrant in Western Palearctic with most observations reported from British Isles (Alström & Colston 1991). Here, we report on the first observation of Wilson's Phalarope in the territory of Serbia. In the early morning of 22 September 2019, whilst birdwatching on the northern shore of alkaline lake Rusanda close to the village of Melenci (Banat District, Northern Serbia), the first author spotted one individual of Wilson's Phalarope approximately 20 m from the lakeshore (coordinates 45.525952 N, 20.302900 E), foraging together with 12 Dunlins Calidris alpina and three Little Ringed Plovers Charadrius dubius. At first glance, the observer had an impression that it was Marsh Sandpiper Tringa stagnatilis – a regular, but scarce autumn migrant through northern Serbia. Yet, the general structure of the observed bird was pretty different. The observed specimen was notably smaller, short-legged with a thinner and finer bill than Marsh Sandpiper. Besides, the feeding habit significantly differed from that of Marsh Sandpiper. During a short period of observation, the bird was actively feeding in shallow water (1–3 cm deep), making jerky, vigorous darting left-right movements with its head and bill. After five minutes of observation, all the birds flew together to the opposite side of the lake. Before flying off, the observed bird was photographed (Figure 1). Later in the same day, photographs of an unusual bird were displayed by few Internet birding groups, where numerous birdwatchers identified it as Wilson’s Phalarope. Indeed, the additional analysis of photographs by both authors reaffirmed the identification. The observed and photographed specimen was distinguished from similar Grey Phalarope Phalaropus fulicarius and Red-necked Phalarope Phalaropus lobatus by its greyer (paler) plumage, distinctly longer bill, lack of bold black eye-patch and bright yellow colour of legs. Other somewhat similar wader species like Lesser Yellowlegs Tringa flavipes are characterized by their significantly different proportions, behaviour and not so pure whitis
三色矶鹬是一种生活在新大陆的游泳矶鹬。它是三种phalarp物种中最大和最陆生的物种(Hayman et al. 1986),以其异性角色交配系统而闻名(Colwell & Jehl 2020)。威尔逊的Phalarope分布范围完全是大陆。它通常在美国西部和加拿大西南部和中部草原和农业用地的内陆湿地附近的开放栖息地繁殖(Hayman et al. 1986, Colwell & Jehl 2020)。在迁徙时,本物种出现在各种淡水湖,池塘和小池塘中,显示出对碱性水的偏好。威尔逊Phalarope在10月至4月期间从玻利维亚到阿根廷穿越高原过冬,并在4月底和5月初返回繁殖地(Hayman et al. 1986, Colwell & Jehl 2020)。该物种是一种罕见的,但经常在西古北地区流浪,大多数观察报告来自不列颠群岛(Alström & Colston 1991)。在这里,我们报告威尔逊的法拉洛在塞尔维亚境内的第一次观察。2019年9月22日清晨,在靠近Melenci村(塞尔维亚北部巴纳特区)的Rusanda碱性湖北岸观鸟时,第一作者在距离湖岸约20米的地方(坐标45.525952 N, 20.302900 E)发现了一只威尔逊Phalarope个体,与12只Dunlins Calidris alpina和3只Little ring Plovers Charadrius dubius一起觅食。乍一看,观察者有一个印象,那是沼泽矶鹬,一种经常经过塞尔维亚北部,但秋季稀少的候鸟。然而,观察到的鸟的总体结构却大不相同。观察到的标本明显比沼泽矶鹬更小,腿短,喙更细。此外,其摄食习性与沼泽矶鹬有显著差异。在短时间的观察中,这只鸟在浅水(1-3厘米深)积极进食,头部和喙部做出剧烈的左右运动。经过五分钟的观察,所有的鸟一起飞到湖的另一边。在飞走之前,观察到的鸟被拍照(图1)。同一天晚些时候,一些网上观鸟团体展示了一只不寻常鸟的照片,许多观鸟者认为它是威尔逊Phalarope。的确,两位作者对照片的进一步分析证实了这一身份。观察和拍摄的标本与类似的灰色Phalaropus fulicarius和红颈Phalaropus lobatus的区别在于其更灰色(苍白)的羽毛,明显更长的喙,缺乏大胆的黑色眼罩和明亮的黄色腿。其他一些类似的涉水物种,如小黄腿,其特点是它们的比例、行为和下面的白色不那么纯。第二天,武卡斯vuukas vu科维奇重新找到了这只鸟,并在飞行中拍了几张照片。尾羽白色斑块,羽翼素色深灰色,无头突41 (184/185):31 - 32,2020 10.2478/ acroo -2020-0003
{"title":"Wilson’s Phalarope Phalaropus tricolor – a new species for avifauna of Serbia","authors":"M. Mareš, Draženko Z. Rajković","doi":"10.2478/acro-2020-0003","DOIUrl":"https://doi.org/10.2478/acro-2020-0003","url":null,"abstract":"Wilson's Phalarope Phalaropus tricolor is a swimming sandpiper species of the New World. It is the largest and most terrestrial of the three phalarope species (Hayman et al. 1986), which are broadly known for their reversed sex-role mating system (Colwell & Jehl 2020). Wilson's Phalarope distribution range is entirely continental. It typically breeds in open habitats adjacent to inland wetlands on prairies and agricultural lands in western parts of the United States and southwestern and central Canada (Hayman et al. 1986, Colwell & Jehl 2020). On migration, this species occurs on a wide variety of freshwater lakes, ponds and small pools showing a preference for alkaline waters. Wilson's Phalarope winters in the October–April period across altiplano from Bolivia to Argentina and returns to the breeding grounds in late April and early May (Hayman et al. 1986, Colwell & Jehl 2020). The species is a rare, but regular vagrant in Western Palearctic with most observations reported from British Isles (Alström & Colston 1991). Here, we report on the first observation of Wilson's Phalarope in the territory of Serbia. In the early morning of 22 September 2019, whilst birdwatching on the northern shore of alkaline lake Rusanda close to the village of Melenci (Banat District, Northern Serbia), the first author spotted one individual of Wilson's Phalarope approximately 20 m from the lakeshore (coordinates 45.525952 N, 20.302900 E), foraging together with 12 Dunlins Calidris alpina and three Little Ringed Plovers Charadrius dubius. At first glance, the observer had an impression that it was Marsh Sandpiper Tringa stagnatilis – a regular, but scarce autumn migrant through northern Serbia. Yet, the general structure of the observed bird was pretty different. The observed specimen was notably smaller, short-legged with a thinner and finer bill than Marsh Sandpiper. Besides, the feeding habit significantly differed from that of Marsh Sandpiper. During a short period of observation, the bird was actively feeding in shallow water (1–3 cm deep), making jerky, vigorous darting left-right movements with its head and bill. After five minutes of observation, all the birds flew together to the opposite side of the lake. Before flying off, the observed bird was photographed (Figure 1). Later in the same day, photographs of an unusual bird were displayed by few Internet birding groups, where numerous birdwatchers identified it as Wilson’s Phalarope. Indeed, the additional analysis of photographs by both authors reaffirmed the identification. The observed and photographed specimen was distinguished from similar Grey Phalarope Phalaropus fulicarius and Red-necked Phalarope Phalaropus lobatus by its greyer (paler) plumage, distinctly longer bill, lack of bold black eye-patch and bright yellow colour of legs. Other somewhat similar wader species like Lesser Yellowlegs Tringa flavipes are characterized by their significantly different proportions, behaviour and not so pure whitis","PeriodicalId":53560,"journal":{"name":"Acrocephalus","volume":"41 1","pages":"31 - 32"},"PeriodicalIF":0.0,"publicationDate":"2020-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45907008","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract Grassland birds were surveyed in two mountain pastures (Zaprikraj and Zapleč) in the southern part of the Julian Alps, Slovenia. The survey was carried out during the mornings between 26 and 30 June 2005. Due to the incomplete survey (only one visit, no nocturnal or targeted surveys and late season survey), the surveyed birds’ breeding density is only a rough estimate. 167 pairs belonging to 12 species were counted, with Tree (average density of 1.64 p/10 ha) and Water Pipit (average density of 1.60 p / 10 ha) being the most abundant. Both were observed in all altitudinal belts. The highest density in individual altitudinal belt was calculated for Red-backed Shrike Lanius collurio (3.78 p/10 ha) and Water Pipit (3.61 p/10 ha). In well preserved grasslands in the study area, most species reached high breeding densities compared to other parts of Slovenia and all were recorded higher than during the 1992 survey, although still mostly within limits of the elevations elsewhere in Slovenia. Breeding density of Skylark Alauda arvensis decreased with the elevation. Whinchat Saxicola rubetra, Skylark and Red-backed Shrike used significantly gentler slopes, while Pipits showed no preference for particular slopes.
{"title":"Grassland bird species in mountain pastures Zaprikraj and Zapleč in the southern Julian Alps, Slovenia","authors":"Dejan Bordjan","doi":"10.2478/acro-2020-0004","DOIUrl":"https://doi.org/10.2478/acro-2020-0004","url":null,"abstract":"Abstract Grassland birds were surveyed in two mountain pastures (Zaprikraj and Zapleč) in the southern part of the Julian Alps, Slovenia. The survey was carried out during the mornings between 26 and 30 June 2005. Due to the incomplete survey (only one visit, no nocturnal or targeted surveys and late season survey), the surveyed birds’ breeding density is only a rough estimate. 167 pairs belonging to 12 species were counted, with Tree (average density of 1.64 p/10 ha) and Water Pipit (average density of 1.60 p / 10 ha) being the most abundant. Both were observed in all altitudinal belts. The highest density in individual altitudinal belt was calculated for Red-backed Shrike Lanius collurio (3.78 p/10 ha) and Water Pipit (3.61 p/10 ha). In well preserved grasslands in the study area, most species reached high breeding densities compared to other parts of Slovenia and all were recorded higher than during the 1992 survey, although still mostly within limits of the elevations elsewhere in Slovenia. Breeding density of Skylark Alauda arvensis decreased with the elevation. Whinchat Saxicola rubetra, Skylark and Red-backed Shrike used significantly gentler slopes, while Pipits showed no preference for particular slopes.","PeriodicalId":53560,"journal":{"name":"Acrocephalus","volume":"41 1","pages":"33 - 39"},"PeriodicalIF":0.0,"publicationDate":"2020-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44992098","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
D. Dobrev, B. Borisov, Vladimir Dobrev, V. Arkumarev, I. Angelov, Stoycho Stoychev
Abstract The Goosander Mergus merganser was not recorded breeding in Bulgaria till recently. We present herewith the very first record of the species breeding in the country and estimate the size of its breeding population in Bulgaria. Thus, we propose a change in its status in the country with more effort to be invested in the survey of this small, isolated population.
{"title":"The Goosander Mergus merganser range expansion on the Balkan Peninsula and a new breeding population in Bulgaria","authors":"D. Dobrev, B. Borisov, Vladimir Dobrev, V. Arkumarev, I. Angelov, Stoycho Stoychev","doi":"10.2478/acro-2020-0002","DOIUrl":"https://doi.org/10.2478/acro-2020-0002","url":null,"abstract":"Abstract The Goosander Mergus merganser was not recorded breeding in Bulgaria till recently. We present herewith the very first record of the species breeding in the country and estimate the size of its breeding population in Bulgaria. Thus, we propose a change in its status in the country with more effort to be invested in the survey of this small, isolated population.","PeriodicalId":53560,"journal":{"name":"Acrocephalus","volume":"41 1","pages":"25 - 30"},"PeriodicalIF":0.0,"publicationDate":"2020-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43908308","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Results of the January 2020 waterbird census in Slovenia","authors":"Luka Božič","doi":"10.2478/acro-2020-0005","DOIUrl":"https://doi.org/10.2478/acro-2020-0005","url":null,"abstract":"","PeriodicalId":53560,"journal":{"name":"Acrocephalus","volume":"41 1","pages":"41 - 53"},"PeriodicalIF":0.0,"publicationDate":"2020-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42115941","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract The Northern Lapwing numbers across Europe are declining owing to its insufficient breeding success. To determine the size, dynamics and habitat use of the lapwing population at Dravsko and Ptujsko polje, a survey was carried out between 2016 and 2018. In 2016, 2017 and 2018, we recorded 148, 130, and 117 pairs, respectively. The population declined during the study and the population trend is uncertain. Approximately 12 to 21% of the national lapwing population was recorded at Dravsko and Ptujsko polje, making them one of the most important breeding areas in Slovenia. The majority of lapwings were found in bare tilled fields and fields with young spring crops that enable unbroken all-round views. Crop data analysis showed a significant preference for maize fields which are mostly bare tillage at the start of the incubation period and therefore act as an ecological trap for lapwings due to the time coincidence of the nesting period and farming operations. For the protection of the lapwing in Slovenia, we recommend a time limit of farming operations or avoiding individual nests while working in the field. Both measures are recommended to be implemented in combination with the provision of suitable foraging habitat for chicks. For greater effectiveness, we propose priority implementation of conser vation measures on traditiona l breeding sites.
{"title":"Population dynamics and habitat use by Northern Lapwing Vanellus vanellus in agricultural landscape of Dravsko and Ptujsko polje (NE Slovenia)","authors":"Eva Horvat, D. Denac","doi":"10.1515/acro-2019-0009","DOIUrl":"https://doi.org/10.1515/acro-2019-0009","url":null,"abstract":"Abstract The Northern Lapwing numbers across Europe are declining owing to its insufficient breeding success. To determine the size, dynamics and habitat use of the lapwing population at Dravsko and Ptujsko polje, a survey was carried out between 2016 and 2018. In 2016, 2017 and 2018, we recorded 148, 130, and 117 pairs, respectively. The population declined during the study and the population trend is uncertain. Approximately 12 to 21% of the national lapwing population was recorded at Dravsko and Ptujsko polje, making them one of the most important breeding areas in Slovenia. The majority of lapwings were found in bare tilled fields and fields with young spring crops that enable unbroken all-round views. Crop data analysis showed a significant preference for maize fields which are mostly bare tillage at the start of the incubation period and therefore act as an ecological trap for lapwings due to the time coincidence of the nesting period and farming operations. For the protection of the lapwing in Slovenia, we recommend a time limit of farming operations or avoiding individual nests while working in the field. Both measures are recommended to be implemented in combination with the provision of suitable foraging habitat for chicks. For greater effectiveness, we propose priority implementation of conser vation measures on traditiona l breeding sites.","PeriodicalId":53560,"journal":{"name":"Acrocephalus","volume":"40 1","pages":"3 - 22"},"PeriodicalIF":0.0,"publicationDate":"2019-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42905100","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Results of the January 2019 waterbird census in Slovenia","authors":"Luka Božič","doi":"10.1515/acro-2019-0011","DOIUrl":"https://doi.org/10.1515/acro-2019-0011","url":null,"abstract":"","PeriodicalId":53560,"journal":{"name":"Acrocephalus","volume":"40 1","pages":"31 - 43"},"PeriodicalIF":0.0,"publicationDate":"2019-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42483907","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Mitja Denac, J. Hanžel, Dejan Bordjan, Luka Božič, M. Vogrin
{"title":"Rare birds in Slovenia in 2018 – Slovenian Rarities Committee Report","authors":"Mitja Denac, J. Hanžel, Dejan Bordjan, Luka Božič, M. Vogrin","doi":"10.1515/acro-2019-0012","DOIUrl":"https://doi.org/10.1515/acro-2019-0012","url":null,"abstract":"","PeriodicalId":53560,"journal":{"name":"Acrocephalus","volume":"40 1","pages":"45 - 60"},"PeriodicalIF":0.0,"publicationDate":"2019-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44588930","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Massive irruptions of the Siberian Nutcracker subspecies Nucifraga caryocatactes macrorhynchos into Europe and Slovenia to date","authors":"F. Bračko","doi":"10.1515/acro-2019-0010","DOIUrl":"https://doi.org/10.1515/acro-2019-0010","url":null,"abstract":"","PeriodicalId":53560,"journal":{"name":"Acrocephalus","volume":"40 1","pages":"23 - 30"},"PeriodicalIF":0.0,"publicationDate":"2019-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48761799","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract Years ago, the Common Tern Sterna hirundo was known to nest in Slovenia along larger watercourses. Today it only breeds locally in artificially built nesting areas. On the seashore, its nesting was confirmed for the first time in 1983, when 9 pairs bred in the Sečovlje Saltpans. In the same year, we started mapping the breeders in the Sečovlje Saltpans, which has continued till this very day. Since 2010, we have been systematically collecting data on the number of fledged birds. In 1991, the number of breeding pairs increased, which coincides with the increase in other parts of the Mediterranean. Since 1991, the size of the breeding population has been quite stable, ranging from 30 to 70 pairs. The Common Tern’s breeding success in the Sečovlje Saltpans is poor, mainly due to precipitation (40% of all unsuccessful nests) and predation (35%). Long, dry periods without rainfall have a positive effect on the hatching and fledging success. Appropriate water management, artificial islands and access to nesting sites control can prevent the disturbance caused by visitors and, in part, predators such as foxes and martens. At the Sečovlje Saltpans, the Common Tern’s survival depends entirely on the active management. The expected climate change, with increasing sea level rise and consequently more frequent flooding of low-lying areas, further aggravates its existence and survival in the Sečovlje Saltpans.
{"title":"37 years of Common Tern Sterna hirundo breeding at Sečovlje Salina","authors":"Iztok Škornik","doi":"10.1515/acro-2019-0008","DOIUrl":"https://doi.org/10.1515/acro-2019-0008","url":null,"abstract":"Abstract Years ago, the Common Tern Sterna hirundo was known to nest in Slovenia along larger watercourses. Today it only breeds locally in artificially built nesting areas. On the seashore, its nesting was confirmed for the first time in 1983, when 9 pairs bred in the Sečovlje Saltpans. In the same year, we started mapping the breeders in the Sečovlje Saltpans, which has continued till this very day. Since 2010, we have been systematically collecting data on the number of fledged birds. In 1991, the number of breeding pairs increased, which coincides with the increase in other parts of the Mediterranean. Since 1991, the size of the breeding population has been quite stable, ranging from 30 to 70 pairs. The Common Tern’s breeding success in the Sečovlje Saltpans is poor, mainly due to precipitation (40% of all unsuccessful nests) and predation (35%). Long, dry periods without rainfall have a positive effect on the hatching and fledging success. Appropriate water management, artificial islands and access to nesting sites control can prevent the disturbance caused by visitors and, in part, predators such as foxes and martens. At the Sečovlje Saltpans, the Common Tern’s survival depends entirely on the active management. The expected climate change, with increasing sea level rise and consequently more frequent flooding of low-lying areas, further aggravates its existence and survival in the Sečovlje Saltpans.","PeriodicalId":53560,"journal":{"name":"Acrocephalus","volume":"40 1","pages":"105 - 112"},"PeriodicalIF":0.0,"publicationDate":"2019-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44246354","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
J. Kralj, M. Martinović, Tomica Rubinić, Davor Krnjeta, L. Jurinović
Abstract Between 2002 and 2019, monitoring of Common Tern Sterna hirundo and Little Tern Sternula albifrons along the Sava River near Zagreb, Croatia was conducted. Natura 2000 site “Sava kod Hrušćice” was designated to protect colony at river islands, with estimated population sizes of 100–150 pairs of Common and 20 pairs of the Little Tern. Flooding of the colony caused breeding failure in several years. Common Terns moved to breed on islands in gravel pits with a total population around 150 pairs, while Little Tern did not breed after 2010. In the last few years, terns have not bred at Hrušćica and the only colony inside the Natura 2000 site is situated on a breeding platform at Siromaja gravel pit. Channelling of rivers and hydropower plants are the main threats, changing natural dynamics of water level and causing reduction of gravel sediment in rivers.
摘要2002年至2019年间,对克罗地亚萨格勒布附近萨瓦河沿岸的普通Tern Sterna hirundo和小Tern Sternula albifrons进行了监测。Natura 2000遗址“Sava kod Hrušćice”被指定为保护河流岛屿上的殖民地,估计种群规模为100-150对Common和20对Little Tern。殖民地的洪水导致几年内繁殖失败。普通燕鸥迁移到砾石坑中的岛屿上繁殖,总种群约为150对,而小燕鸥在2010年后就没有繁殖了。在过去的几年里,燕鸥没有在Hrušica繁殖,Natura 2000遗址内唯一的群落位于Siromaja砾石坑的繁殖平台上。河流和水电站的河道淤积是主要威胁,改变了水位的自然动态,导致河流中砾石沉积物的减少。
{"title":"Dynamics of Common Sterna hirundo and Little Tern Sternula albifrons populations along the Sava River in North-western Croatia between 2002 and 2019","authors":"J. Kralj, M. Martinović, Tomica Rubinić, Davor Krnjeta, L. Jurinović","doi":"10.1515/acro-2019-0002","DOIUrl":"https://doi.org/10.1515/acro-2019-0002","url":null,"abstract":"Abstract Between 2002 and 2019, monitoring of Common Tern Sterna hirundo and Little Tern Sternula albifrons along the Sava River near Zagreb, Croatia was conducted. Natura 2000 site “Sava kod Hrušćice” was designated to protect colony at river islands, with estimated population sizes of 100–150 pairs of Common and 20 pairs of the Little Tern. Flooding of the colony caused breeding failure in several years. Common Terns moved to breed on islands in gravel pits with a total population around 150 pairs, while Little Tern did not breed after 2010. In the last few years, terns have not bred at Hrušćica and the only colony inside the Natura 2000 site is situated on a breeding platform at Siromaja gravel pit. Channelling of rivers and hydropower plants are the main threats, changing natural dynamics of water level and causing reduction of gravel sediment in rivers.","PeriodicalId":53560,"journal":{"name":"Acrocephalus","volume":"40 1","pages":"49 - 54"},"PeriodicalIF":0.0,"publicationDate":"2019-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46940049","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}