Manx Shearwaters Puffinus puffinus, like other procellariiform seabirds, spend most of their lives at sea and are encountered on land only when breeding at colonies or if they are grounded due to unfavourable weather conditions or exposure to artificial light. Here, we used historical ringing data to explore the age class structure and spatial patterns of Manx Shearwater groundings and examined ringing and recovery data to identify records of post-grounding survival for first-year and adult birds. We noted 35 cases, out of 6,381 ringed grounded shearwaters, where a bird went on to be recaptured, including two individuals that were later recorded as having successful breeding attempts. While this constitutes only a small number of birds confirmed to have survived following grounding, it is likely to be a considerable underestimate of survival considering the low probability of recapturing a surviving shearwater. Finally, we found that a greater proportion of grounded birds were first-years compared to adult shearwaters, and that adults were found to be grounded further away from colonies than first-year birds. This may be indicative of differential impacts of light pollution at different life stages.
{"title":"The fate of rescued Manx Shearwaters following grounding","authors":"Martyna Syposz, Oliver Padget","doi":"10.61350/sbj.35.102","DOIUrl":"https://doi.org/10.61350/sbj.35.102","url":null,"abstract":"Manx Shearwaters Puffinus puffinus, like other procellariiform seabirds, spend most of their lives at sea and are encountered on land only when breeding at colonies or if they are grounded due to unfavourable weather conditions or exposure to artificial light. Here, we used historical ringing data to explore the age class structure and spatial patterns of Manx Shearwater groundings and examined ringing and recovery data to identify records of post-grounding survival for first-year and adult birds. We noted 35 cases, out of 6,381 ringed grounded shearwaters, where a bird went on to be recaptured, including two individuals that were later recorded as having successful breeding attempts. While this constitutes only a small number of birds confirmed to have survived following grounding, it is likely to be a considerable underestimate of survival considering the low probability of recapturing a surviving shearwater. Finally, we found that a greater proportion of grounded birds were first-years compared to adult shearwaters, and that adults were found to be grounded further away from colonies than first-year birds. This may be indicative of differential impacts of light pollution at different life stages.","PeriodicalId":309759,"journal":{"name":"Seabird Journal","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135009135","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}
Lucas Penna Soares Santos, Camila Brasilino Botêlho de Araújo, Marco Antonio Carvalho de Souza, Jorge Eduardo Lins Oliveira, Danielle de Lima Viana
Storm-petrels demonstrate complex spatial dynamics, with some species moving among continents. We report a sighting of a Leach’s Storm-petrel Hydrobates leucorhous, recorded on a scientific expedition near the Saint Peter and Saint Paul Archipelago (SPSPA), the smallest Brazilian oceanic islands. Our species identification was based on A) morphological characteristics (plumage pattern and pronounced forked tail), B) other records of this species surrounding the SPSPA, and C) tracking studies of the at-sea distribution of this species, especially that of North Atlantic populations that cross equatorial regions during their migration and non-breeding periods. This report comprises the second of two documented accounts of Leach’s Storm-petrel in SPSPA waters. These records highlight knowledge gaps in the spatial dynamics of seabird species, an increased understanding of which might provide novel insights into species biogeography.
{"title":"Occurrence of Leach’s Storm-petrel Hydrobates leucorhous near the Saint Peter and Saint Paul Archipelago, Brazil","authors":"Lucas Penna Soares Santos, Camila Brasilino Botêlho de Araújo, Marco Antonio Carvalho de Souza, Jorge Eduardo Lins Oliveira, Danielle de Lima Viana","doi":"10.61350/sbj.35.119","DOIUrl":"https://doi.org/10.61350/sbj.35.119","url":null,"abstract":"Storm-petrels demonstrate complex spatial dynamics, with some species moving among continents. We report a sighting of a Leach’s Storm-petrel Hydrobates leucorhous, recorded on a scientific expedition near the Saint Peter and Saint Paul Archipelago (SPSPA), the smallest Brazilian oceanic islands. Our species identification was based on A) morphological characteristics (plumage pattern and pronounced forked tail), B) other records of this species surrounding the SPSPA, and C) tracking studies of the at-sea distribution of this species, especially that of North Atlantic populations that cross equatorial regions during their migration and non-breeding periods. This report comprises the second of two documented accounts of Leach’s Storm-petrel in SPSPA waters. These records highlight knowledge gaps in the spatial dynamics of seabird species, an increased understanding of which might provide novel insights into species biogeography.","PeriodicalId":309759,"journal":{"name":"Seabird Journal","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135009484","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}
The breeding population of Brünnich’s Guillemot Uria lomvia in South and West Greenland has been decreasing for decades and some colonies have even disappeared (Merkel et al. 2014). Among these was one of the largest colonies, Salleq in Uummannaq Fjord (70°96’N 52°25’W; Figure 1), which was estimated at half a million birds in c. 1920 (Bertelsen 1921) and 150,000 birds in 1949 (Salomonsen 1950). These figures are most likely overestimations (Falk & Kampp 1997), but there is no doubt that the colony was among the largest in West Greenland. The colony then drastically decreased in size until 1975, when only 4,500 birds were counted (Falk & Kampp 1997). In 1984, there were only 150 individuals present and all were observed on the water below the cliff. In 1987, 50 birds were observed on the cliff without evidence of breeding, and the site was completely deserted by 1990 (Evans & Kampp 1991). The same fate was recorded for Black-legged Kittiwakes Rissa tridactyla (hereafter ‘Kittiwakes’) and Razorbills Alca torda. The former declined from around 10,000 pairs in 1949, to 800 nests in 1975 and to zero in 1994 (F. Salomonsen unpublished; Boertmann et al. 1996). Razorbills declined from a few pairs in 1949 and 1975 to zero in 1994 (Boertmann et al. 1996). However, no population changes have been recorded for the Northern Fulmars Fulmarus glacialis which breed in huge numbers on the cliff. The decline and extinction of the Salleq Brünnich’s Guillemot colony in the decades after the Second World War was primarily caused by excessive hunting during spring. Fleischer (1994), the former editor of a Greenlandic newspaper, described how in the 1930s it was common in spring, when sea ice still covered the waters, to camp below the Salleq cliff and hunt hundreds of Brünnich’s Guillemots in a day. This occurred every spring, and people would travel from afar to participate in this hunt. This high hunting pressure was reflected in a higher recovery rate of ringed birds from Salleq in comparison to colonies in other parts of West Greenland (Kampp 1991). Naturally, the colony could not sustain such hunting pressure across multiple decades, and eventually disappeared. Another factor impacting the Brünnich’s Guillemot populations in West Greenland was bycatch by an extensive offshore drift net fishery for Atlantic Salmon Salmo salar, which peaked around 1970 and stopped in 1976 (Falk & Durinck 1991).
几十年来，格陵兰岛南部和西部的br尼希海鸠Uria lomvia的繁殖种群一直在减少，一些殖民地甚至消失了(Merkel et al. 2014)。其中最大的殖民地之一是乌曼纳克峡湾的萨列克(70°96'N 52°25'W;图1)，大约1920年估计有50万只(Bertelsen 1921)， 1949年估计有15万只(Salomonsen 1950)。这些数字很可能是高估了。Kampp 1997)，但毫无疑问，该殖民地是西格陵兰岛最大的殖民地之一。然后，这个群体的规模急剧减少，直到1975年，只有4500只鸟被统计出来(福克&Kampp 1997)。1984年，这里只有150只，而且都是在悬崖下面的水面上观察到的。1987年，在悬崖上观察到50只没有繁殖迹象的鸟，到1990年，该地点完全被遗弃了(Evans &Kampp 1991)。同样的命运也被记录在黑腿三趾鸥Rissa tridactyla(以下简称“三趾鸥”)和Razorbills Alca torda。前者从1949年的1万对左右减少到1975年的800对，到1994年减少到零(F. Salomonsen未发表;Boertmann et al. 1996)。Razorbills的数量从1949年和1975年的几对下降到1994年的零(Boertmann et al. 1996)。然而，在悬崖上大量繁殖的北方狐尾猴没有记录到种群变化。在第二次世界大战后的几十年里，萨列克布尔尼奇海鸠栖息地的减少和灭绝主要是由于春季过度狩猎造成的。弗莱舍(1994)是格陵兰一家报纸的前编辑，他描述了在20世纪30年代，当海冰还覆盖着海水的春天，人们如何在萨列克悬崖下露营，一天内捕捉数百只布尔尼奇海鸠。每年春天都会举行这样的活动，人们会远道而来参加这个狩猎活动。与西格陵兰岛其他地区的种群相比，萨列克的环鸟恢复率更高，这反映了这种高狩猎压力(Kampp 1991)。自然地，这个群体无法承受几十年的狩猎压力，最终消失了。另一个影响西格陵兰岛br nnich海鸠种群数量的因素是大西洋鲑鱼(Salmo salar)大规模近海漂网渔业的附带捕捞，这种捕捞在1970年左右达到顶峰，1976年停止(Falk &Durinck 1991)。
{"title":"Re-establishment of an extinct breeding colony of Brünnich’s Guillemot Uria lomvia in West Greenland","authors":"David Boertmann","doi":"10.61350/sbj.35.47","DOIUrl":"https://doi.org/10.61350/sbj.35.47","url":null,"abstract":"The breeding population of Brünnich’s Guillemot Uria lomvia in South and West Greenland has been decreasing for decades and some colonies have even disappeared (Merkel et al. 2014). Among these was one of the largest colonies, Salleq in Uummannaq Fjord (70°96’N 52°25’W; Figure 1), which was estimated at half a million birds in c. 1920 (Bertelsen 1921) and 150,000 birds in 1949 (Salomonsen 1950). These figures are most likely overestimations (Falk & Kampp 1997), but there is no doubt that the colony was among the largest in West Greenland. The colony then drastically decreased in size until 1975, when only 4,500 birds were counted (Falk & Kampp 1997). In 1984, there were only 150 individuals present and all were observed on the water below the cliff. In 1987, 50 birds were observed on the cliff without evidence of breeding, and the site was completely deserted by 1990 (Evans & Kampp 1991). The same fate was recorded for Black-legged Kittiwakes Rissa tridactyla (hereafter ‘Kittiwakes’) and Razorbills Alca torda. The former declined from around 10,000 pairs in 1949, to 800 nests in 1975 and to zero in 1994 (F. Salomonsen unpublished; Boertmann et al. 1996). Razorbills declined from a few pairs in 1949 and 1975 to zero in 1994 (Boertmann et al. 1996). However, no population changes have been recorded for the Northern Fulmars Fulmarus glacialis which breed in huge numbers on the cliff. The decline and extinction of the Salleq Brünnich’s Guillemot colony in the decades after the Second World War was primarily caused by excessive hunting during spring. Fleischer (1994), the former editor of a Greenlandic newspaper, described how in the 1930s it was common in spring, when sea ice still covered the waters, to camp below the Salleq cliff and hunt hundreds of Brünnich’s Guillemots in a day. This occurred every spring, and people would travel from afar to participate in this hunt. This high hunting pressure was reflected in a higher recovery rate of ringed birds from Salleq in comparison to colonies in other parts of West Greenland (Kampp 1991). Naturally, the colony could not sustain such hunting pressure across multiple decades, and eventually disappeared. Another factor impacting the Brünnich’s Guillemot populations in West Greenland was bycatch by an extensive offshore drift net fishery for Atlantic Salmon Salmo salar, which peaked around 1970 and stopped in 1976 (Falk & Durinck 1991).","PeriodicalId":309759,"journal":{"name":"Seabird Journal","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135010047","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}
A large multi-species gull colony at South Walney in Cumbria, northwest England, has suffered declines over the past 20 years, and from 2016 to 2020 no gull chicks fledged despite up to 4,000 pairs of adults attempting to breed each year. The primary cause of nest failure was predation. In an attempt to reverse this decline, a predator exclusion fence was erected around the remnant gull colony in March 2021, and population and productivity surveys were carried out over the 2021 and 2022 breeding seasons. In 2021, 53, 27 and 40 chicks fledged from 263 Herring Gull, 186 Lesser Black-backed and 38 Great Black-backed Gull nests, respectively, resulting in reproductive success rates of 0.20, 0.15, and 1.05 fledglings per nest. Following the fence erection, in 2022 numbers of nesting birds increased by 151% overall to 575 Herring Gull nests, 553 Lesser Black-backed Gull nests and 28 Great Black-backed Gull nests, with reproductive success rates of 0.4, 0.61 and 1.21 respectively.
{"title":"Predator exclusion fencing improves productivity at a mixed colony of Herring Gulls Larus argentatus, Lesser Black-backed Gulls L. fuscus and Great Black-backed Gulls L. marinus","authors":"Sarah Dalrymple","doi":"10.61350/sbj.35.31","DOIUrl":"https://doi.org/10.61350/sbj.35.31","url":null,"abstract":"A large multi-species gull colony at South Walney in Cumbria, northwest England, has suffered declines over the past 20 years, and from 2016 to 2020 no gull chicks fledged despite up to 4,000 pairs of adults attempting to breed each year. The primary cause of nest failure was predation. In an attempt to reverse this decline, a predator exclusion fence was erected around the remnant gull colony in March 2021, and population and productivity surveys were carried out over the 2021 and 2022 breeding seasons. In 2021, 53, 27 and 40 chicks fledged from 263 Herring Gull, 186 Lesser Black-backed and 38 Great Black-backed Gull nests, respectively, resulting in reproductive success rates of 0.20, 0.15, and 1.05 fledglings per nest. Following the fence erection, in 2022 numbers of nesting birds increased by 151% overall to 575 Herring Gull nests, 553 Lesser Black-backed Gull nests and 28 Great Black-backed Gull nests, with reproductive success rates of 0.4, 0.61 and 1.21 respectively.","PeriodicalId":309759,"journal":{"name":"Seabird Journal","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135010049","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}
Lucas Penna Soares Santos, Camila Brasilino Botêlho de Araújo, Marco Antonio Carvalho de Souza, Jorge Eduardo Lins Oliveira, Danielle De Lima Viana
Storm-petrels demonstrate complex spatial dynamics, with some species moving among continents. We report a sighting of a Leach’s Storm-petrel Hydrobates leucorhous, recorded on a scientific expedition near the Saint Peter and Saint Paul Archipelago (SPSPA), the smallest Brazilian oceanic islands. Our species identification was based on A) morphological characteristics (plumage pattern and pronounced forked tail), B) other records of this species surrounding the SPSPA, and C) tracking studies of the at-sea distribution of this species, especially that of North Atlantic populations that cross equatorial regions during their migration and non-breeding periods. This report comprises the second of two documented accounts of Leach’s Storm-petrel in SPSPA waters. These records highlight knowledge gaps in the spatial dynamics of seabird species, an increased understanding of which might provide novel insights into species biogeography.
{"title":"Occurrence of Leach’s Storm-petrel Hydrobates leucorhous near the Saint Peter and Saint Paul Archipelago, Brazil","authors":"Lucas Penna Soares Santos, Camila Brasilino Botêlho de Araújo, Marco Antonio Carvalho de Souza, Jorge Eduardo Lins Oliveira, Danielle De Lima Viana","doi":"10.61350/sbj.35.8","DOIUrl":"https://doi.org/10.61350/sbj.35.8","url":null,"abstract":"Storm-petrels demonstrate complex spatial dynamics, with some species moving among continents. We report a sighting of a Leach’s Storm-petrel Hydrobates leucorhous, recorded on a scientific expedition near the Saint Peter and Saint Paul Archipelago (SPSPA), the smallest Brazilian oceanic islands. Our species identification was based on A) morphological characteristics (plumage pattern and pronounced forked tail), B) other records of this species surrounding the SPSPA, and C) tracking studies of the at-sea distribution of this species, especially that of North Atlantic populations that cross equatorial regions during their migration and non-breeding periods. This report comprises the second of two documented accounts of Leach’s Storm-petrel in SPSPA waters. These records highlight knowledge gaps in the spatial dynamics of seabird species, an increased understanding of which might provide novel insights into species biogeography.","PeriodicalId":309759,"journal":{"name":"Seabird Journal","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135400636","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}
Manx Shearwaters Puffinus puffinus, like other procellariiform seabirds, spend most of their lives at sea and are encountered on land only when breeding at colonies or if they are grounded due to unfavourable weather conditions or exposure to artificial light. Here, we used historical ringing data to explore the age class structure and spatial patterns of Manx Shearwater groundings and examined ringing and recovery data to identify records of post-grounding survival for first-year and adult birds. We noted 35 cases, out of 6,381 ringed grounded shearwaters, where a bird went on to be recaptured, including two individuals that were later recorded as having successful breeding attempts. While this constitutes only a small number of birds confirmed to have survived following grounding, it is likely to be a considerable underestimate of survival considering the low probability of recapturing a surviving shearwater. Finally, we found that a greater proportion of grounded birds were first-years compared to adult shearwaters, and that adults were found to be grounded further away from colonies than first-year birds. This may be indicative of differential impacts of light pollution at different life stages.
{"title":"The fate of rescued Manx Shearwaters following grounding","authors":"Martyna Syposz, Oliver Padget","doi":"10.61350/sbj.35.7","DOIUrl":"https://doi.org/10.61350/sbj.35.7","url":null,"abstract":"Manx Shearwaters Puffinus puffinus, like other procellariiform seabirds, spend most of their lives at sea and are encountered on land only when breeding at colonies or if they are grounded due to unfavourable weather conditions or exposure to artificial light. Here, we used historical ringing data to explore the age class structure and spatial patterns of Manx Shearwater groundings and examined ringing and recovery data to identify records of post-grounding survival for first-year and adult birds. We noted 35 cases, out of 6,381 ringed grounded shearwaters, where a bird went on to be recaptured, including two individuals that were later recorded as having successful breeding attempts. While this constitutes only a small number of birds confirmed to have survived following grounding, it is likely to be a considerable underestimate of survival considering the low probability of recapturing a surviving shearwater. Finally, we found that a greater proportion of grounded birds were first-years compared to adult shearwaters, and that adults were found to be grounded further away from colonies than first-year birds. This may be indicative of differential impacts of light pollution at different life stages.","PeriodicalId":309759,"journal":{"name":"Seabird Journal","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135400896","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}
A large multi-species gull colony at South Walney in Cumbria, northwest England, has suffered declines over the past 20 years, and from 2016 to 2020 no gull chicks fledged despite up to 4,000 pairs of adults attempting to breed each year. The primary cause of nest failure was predation. In an attempt to reverse this decline, a predator exclusion fence was erected around the remnant gull colony in March 2021, and population and productivity surveys were carried out over the 2021 and 2022 breeding seasons. In 2021, 53, 27 and 40 chicks fledged from 263 Herring Gull, 186 Lesser Black-backed and 38 Great Black-backed Gull nests, respectively, resulting in reproductive success rates of 0.20, 0.15, and 1.05 fledglings per nest. Following the fence erection, in 2022 numbers of nesting birds increased by 151% overall to 575 Herring Gull nests, 553 Lesser Black-backed Gull nests and 28 Great Black-backed Gull nests, with reproductive success rates of 0.4, 0.61 and 1.21 respectively.
{"title":"Predator exclusion fencing improves productivity at a mixed colony of Herring Gulls Larus argentatus, Lesser Black-backed Gulls L. fuscus and Great Black-backed Gulls L. marinus","authors":"Sarah Dalrymple","doi":"10.61350/sbj.35.3","DOIUrl":"https://doi.org/10.61350/sbj.35.3","url":null,"abstract":"A large multi-species gull colony at South Walney in Cumbria, northwest England, has suffered declines over the past 20 years, and from 2016 to 2020 no gull chicks fledged despite up to 4,000 pairs of adults attempting to breed each year. The primary cause of nest failure was predation. In an attempt to reverse this decline, a predator exclusion fence was erected around the remnant gull colony in March 2021, and population and productivity surveys were carried out over the 2021 and 2022 breeding seasons. In 2021, 53, 27 and 40 chicks fledged from 263 Herring Gull, 186 Lesser Black-backed and 38 Great Black-backed Gull nests, respectively, resulting in reproductive success rates of 0.20, 0.15, and 1.05 fledglings per nest. Following the fence erection, in 2022 numbers of nesting birds increased by 151% overall to 575 Herring Gull nests, 553 Lesser Black-backed Gull nests and 28 Great Black-backed Gull nests, with reproductive success rates of 0.4, 0.61 and 1.21 respectively.","PeriodicalId":309759,"journal":{"name":"Seabird Journal","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135400897","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}
Xabier Remírez, Francisco del Campo, Javier del Campo, Juan Arizaga
The Yellow-legged Gull subspecies Larus michahellis atlantis is thought to be resident in the Macaronesia islands, however, the movement patterns of the population remain largely unknown. We conducted an eight-year (2010–19) ringing and re-sighting program on the island of Gran Canaria (GC), Canary Islands, with an aim of estimating the movement patterns of its gull populations. Re-sighting data revealed that most gulls were observed within 50 km of their natal sites; the farthest locality where studied gulls were seen was Dakhla (500 km from GC) in northwestern Africa. Our findings are compatible with the Yellow-legged Gulls adopting either a GC residency with some dispersal to other islands within the Canary Islands archipelago or to northern Africa, or a true partial migration strategy. Return to GC by some of the gulls that were observed outside GC suggests that philopatry to their natal site could be high, though this should be the focus of further investigation.
{"title":"Movement patterns of immature Yellow-legged Gulls Larus michahellis from Gran Canaria, Canary Islands","authors":"Xabier Remírez, Francisco del Campo, Javier del Campo, Juan Arizaga","doi":"10.61350/sbj.35.14","DOIUrl":"https://doi.org/10.61350/sbj.35.14","url":null,"abstract":"The Yellow-legged Gull subspecies Larus michahellis atlantis is thought to be resident in the Macaronesia islands, however, the movement patterns of the population remain largely unknown. We conducted an eight-year (2010–19) ringing and re-sighting program on the island of Gran Canaria (GC), Canary Islands, with an aim of estimating the movement patterns of its gull populations. Re-sighting data revealed that most gulls were observed within 50 km of their natal sites; the farthest locality where studied gulls were seen was Dakhla (500 km from GC) in northwestern Africa. Our findings are compatible with the Yellow-legged Gulls adopting either a GC residency with some dispersal to other islands within the Canary Islands archipelago or to northern Africa, or a true partial migration strategy. Return to GC by some of the gulls that were observed outside GC suggests that philopatry to their natal site could be high, though this should be the focus of further investigation.","PeriodicalId":309759,"journal":{"name":"Seabird Journal","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135009138","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}
Snæþór Aðalsteinsson, Aïda López, Thomas Bregnballe
Migratory birds are showing species-specific responses to climate change through changes in phenology, distribution and abundance. While many bird observatories collect standardised data on migratory passerines to provide invaluable information on changes in their abundances and migratory phenology, some bird observatories also undertake visual observations of passing migratory waterbirds and seabirds. In this study, we use two such long-term datasets of Great Cormorants (Phalacrocorax carbo) compiled during their spring migration. We explore the extent to which winter severity has affected their migration phenology and whether there have been long-term trends in migration timing. Observations were conducted at Lista Bird Observatory in southwest Norway (1992–2020) and at Skagen in north Jutland, Denmark (1974–98). At Skagen, there were no detectable long-term trends in Great Cormorant migratory timing. However, the median date (marking the passage of 50% of birds) was significantly advanced following warm winters. Changes in the date of passage of the first 10% of birds was close to doing so as well, but the late phase (the passage of 90% of birds) showed no relation to temperature. At Lista, winter temperatures in the southern part of the wintering area had no significant effect on the overall timing of the spring passage, but the first 10% of the Cormorants migrated significantly earlier in years with mild late March temperatures at Lista. The early phase of passage at Lista showed a significant long-term trend towards an advancement of migration, leading to an extended migration period. The findings of this study indicate that the timing of Great Cormorant spring migration does in some cases respond to late winter temperatures or show long-term trends, but that the responses and trends differ between sites and between the beginning, middle and late phases of the migration, with the early and middle phases generally showing stronger responses and trends than the late phase.
{"title":"Timing of spring migration of Norwegian Great Cormorants: long-term trends and effects of winter severity","authors":"Snæþór Aðalsteinsson, Aïda López, Thomas Bregnballe","doi":"10.61350/sbj.35.54","DOIUrl":"https://doi.org/10.61350/sbj.35.54","url":null,"abstract":"Migratory birds are showing species-specific responses to climate change through changes in phenology, distribution and abundance. While many bird observatories collect standardised data on migratory passerines to provide invaluable information on changes in their abundances and migratory phenology, some bird observatories also undertake visual observations of passing migratory waterbirds and seabirds. In this study, we use two such long-term datasets of Great Cormorants (Phalacrocorax carbo) compiled during their spring migration. We explore the extent to which winter severity has affected their migration phenology and whether there have been long-term trends in migration timing. Observations were conducted at Lista Bird Observatory in southwest Norway (1992–2020) and at Skagen in north Jutland, Denmark (1974–98). At Skagen, there were no detectable long-term trends in Great Cormorant migratory timing. However, the median date (marking the passage of 50% of birds) was significantly advanced following warm winters. Changes in the date of passage of the first 10% of birds was close to doing so as well, but the late phase (the passage of 90% of birds) showed no relation to temperature. At Lista, winter temperatures in the southern part of the wintering area had no significant effect on the overall timing of the spring passage, but the first 10% of the Cormorants migrated significantly earlier in years with mild late March temperatures at Lista. The early phase of passage at Lista showed a significant long-term trend towards an advancement of migration, leading to an extended migration period. The findings of this study indicate that the timing of Great Cormorant spring migration does in some cases respond to late winter temperatures or show long-term trends, but that the responses and trends differ between sites and between the beginning, middle and late phases of the migration, with the early and middle phases generally showing stronger responses and trends than the late phase.","PeriodicalId":309759,"journal":{"name":"Seabird Journal","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135010283","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}
The resources available to breeding seabirds within their foraging ranges can influence productivity, either directly through the quality and quantity of food consumed by chicks, or indirectly by affecting the foraging behaviour and efficiency of parent birds. Where local resource availability is low, or the quality of resources are poor, species with flexible time-energy budgets can increase their foraging effort to provide adequate energy and nutrients to their chicks, although this may come at the expense of nest attendance. We investigated provisioning rates and nest attendance in European Herring Gulls Larus argentatus from seven colonies across southwest Scotland and Northern Ireland during two chick-rearing periods (2013 and 2014) in relation to the food resources used by these colonies. We observed variation in provisioning rates and nest attendance between colonies, and variation between years in nest attendance. We found no significant relationships between these behaviours and the proportion of intertidal prey consumed, suggesting that provisioning rate and nest attendance did not differ between resource types at the colony level. We also found no evidence that variation in behaviours was related to breeding success. Our results suggest that, within this region, the type of resources consumed had a greater influence on Herring Gull breeding success than differences in two proxies of foraging efficiency (provisioning rate and nest attendance), although other factors may also have influenced breeding success. Our work highlights the benefit of determining what food resources are provided to chicks, in addition to measuring foraging behaviours, to fully understand the consequences of consuming different resources on the breeding success of generalist foragers.
{"title":"Inter-colony variation in the foraging behaviour and resource selection of breeding Herring Gulls Larus argentatus","authors":"Nina O’Hanlon, Ruedi Nager","doi":"10.61350/sbj.35.76","DOIUrl":"https://doi.org/10.61350/sbj.35.76","url":null,"abstract":"The resources available to breeding seabirds within their foraging ranges can influence productivity, either directly through the quality and quantity of food consumed by chicks, or indirectly by affecting the foraging behaviour and efficiency of parent birds. Where local resource availability is low, or the quality of resources are poor, species with flexible time-energy budgets can increase their foraging effort to provide adequate energy and nutrients to their chicks, although this may come at the expense of nest attendance. We investigated provisioning rates and nest attendance in European Herring Gulls Larus argentatus from seven colonies across southwest Scotland and Northern Ireland during two chick-rearing periods (2013 and 2014) in relation to the food resources used by these colonies. We observed variation in provisioning rates and nest attendance between colonies, and variation between years in nest attendance. We found no significant relationships between these behaviours and the proportion of intertidal prey consumed, suggesting that provisioning rate and nest attendance did not differ between resource types at the colony level. We also found no evidence that variation in behaviours was related to breeding success. Our results suggest that, within this region, the type of resources consumed had a greater influence on Herring Gull breeding success than differences in two proxies of foraging efficiency (provisioning rate and nest attendance), although other factors may also have influenced breeding success. Our work highlights the benefit of determining what food resources are provided to chicks, in addition to measuring foraging behaviours, to fully understand the consequences of consuming different resources on the breeding success of generalist foragers.","PeriodicalId":309759,"journal":{"name":"Seabird Journal","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135009848","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}
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