Pub Date : 2021-12-02DOI: 10.2989/00306525.2021.1989632
OB Masiko, P. Ryan, C. van der Lingen, L. Upfold, S. Somhlaba, M. Masotla, Y. Geja, B. Dyer, R. Crawford, A. Makhado
Cape Cormorants Phalacrocorax capensis breed in southern Africa’s Benguela upwelling system and in 2013 were listed as Endangered by the IUCN following a population decrease of >50% over their three most recent generations. This decrease was associated with reduced prey availability, particularly of the pelagic shoaling fishes Cape anchovy Engraulis encrasicolus and sardine Sardinops sagax. The diet of Cape Cormorants was examined from 929 regurgitated prey samples collected at 11 localities off west South Africa from 1988 to 2007. By number, anchovy was the most important prey in all years, except 2007, in which the geographical distribution of samples was limited. Overall anchovy contributed 85% of all prey items eaten and sardine 6%. However, from 1988 to 1997, sardine formed 93% of the diet by mass in the southwest. The proportional contribution of anchovy to the diet increased between 1988–1997 and 1998–2007, whereas that of sardine decreased. Anchovy eaten in the northwest were smaller than those caught in the central west and southwest were. Small, immature sardine were eaten in all regions, but mature sardine only in the southwest, the spawning ground of the western sardine stock. Anchovy and sardine are targeted by South Africa’s purse-seine fishery. Most anchovy and sardine eaten by Cape Cormorants had caudal lengths of 5–9 cm and 15–21 cm, respectively, and showed considerable overlap with sizes harvested by the fishery. This highlights the potential for competition between Cape Cormorants and the fishery for anchovy and sardine.
{"title":"Are Cape Cormorants Phalacrocorax capensis losing the competition? Dietary overlap with commercial fisheries","authors":"OB Masiko, P. Ryan, C. van der Lingen, L. Upfold, S. Somhlaba, M. Masotla, Y. Geja, B. Dyer, R. Crawford, A. Makhado","doi":"10.2989/00306525.2021.1989632","DOIUrl":"https://doi.org/10.2989/00306525.2021.1989632","url":null,"abstract":"Cape Cormorants Phalacrocorax capensis breed in southern Africa’s Benguela upwelling system and in 2013 were listed as Endangered by the IUCN following a population decrease of >50% over their three most recent generations. This decrease was associated with reduced prey availability, particularly of the pelagic shoaling fishes Cape anchovy Engraulis encrasicolus and sardine Sardinops sagax. The diet of Cape Cormorants was examined from 929 regurgitated prey samples collected at 11 localities off west South Africa from 1988 to 2007. By number, anchovy was the most important prey in all years, except 2007, in which the geographical distribution of samples was limited. Overall anchovy contributed 85% of all prey items eaten and sardine 6%. However, from 1988 to 1997, sardine formed 93% of the diet by mass in the southwest. The proportional contribution of anchovy to the diet increased between 1988–1997 and 1998–2007, whereas that of sardine decreased. Anchovy eaten in the northwest were smaller than those caught in the central west and southwest were. Small, immature sardine were eaten in all regions, but mature sardine only in the southwest, the spawning ground of the western sardine stock. Anchovy and sardine are targeted by South Africa’s purse-seine fishery. Most anchovy and sardine eaten by Cape Cormorants had caudal lengths of 5–9 cm and 15–21 cm, respectively, and showed considerable overlap with sizes harvested by the fishery. This highlights the potential for competition between Cape Cormorants and the fishery for anchovy and sardine.","PeriodicalId":54655,"journal":{"name":"Ostrich","volume":"92 1","pages":"280 - 294"},"PeriodicalIF":1.0,"publicationDate":"2021-12-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45718040","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-12-02DOI: 10.2989/00306525.2021.2005705
K. Hustler
Ostrich is co-published by NISC (Pty) Ltd and Informa UK Limited (trading as Taylor & Francis Group) The recent publications by Mandiwana-Neudani et al. (2019a, 2019b) have re-evaluated the relationships of several francolin species, which occur across Africa. They have elevated some forms to full species, but the distribution maps they present are different to those in recently published citizen science projects (Harrison et al. 1997; DowsettLemaire and Dowsett 2006; Dowsett et al. 2008). There does not appear to be a single taxon that is represented by more than one genetic sample, which is well outside the norm for robust studies and does not allow for mistakes in the sample labelling or analysis to be detected (Hunter et al. 2021). Hunter et al. (2021) also commented extensively on their interpretations, mainly from an E African perspective, to which Mandiwana-Neudani et al. (2021) have replied. In this commentary, the focus is on the central Africa forms of Coqui Peliperdix coqui, Chestnut-breasted Pe. dewittei, Shelley’s Scleroptila shelleyi, Whyte’s S. whytei and Red-winged Francolins S. levaillantii and Red-necked Spurfowl Pternistis afer. Specimen data provided by Mandiwana-Neudani et al. (2019a, 2019b) were checked with the online Genbank database and the specimen databases of the American (AMNH) and British Museums of Natural History (BM), respectively. This revealed multiple inconsistencies for these taxa, which are outlined below (Table 1), confirming the concerns raised by Hunter et al. (2021). The lowest denominator of the ‘currency’ of conservation (Frankham et al. 2012) is the type specimen. This is the originally described specimen of the taxon, often taken in a series, where it occurred and how it is phenotypically different to similar forms and are not likely to be available for destructive tissue sampling. To get around this, a topotype (a specimen from the type series or another obtained at the type locality or as close as possible to it) should have been used for the CYTB analyses. Plotting the localities of type specimens sets a baseline, against which the geographical variation of plumage across the current distributional range of the taxa under consideration can be made. Type localities cannot be used to determine the distributions of the various taxa in isolation, but it is reasonable to expect that distribution maps should contain the type locality unless significant habitat change has occurred subsequent to the discovery of the species to preclude this. Mandiwana-Neudani et al. (2019a, 2019b) do not appear to have consulted the type specimens, their descriptions or localities, because their approximate distribution maps do not include the type localities of some taxa. Material from topotypes, with one exception were not sequenced either. This was unexpected, because these baseline specimens should be the starting point for any major taxonomic study. Mandiwana-Neudani et al. (2021) express confidence in their organisma
鸵鸟由NISC (Pty) Ltd和Informa UK Limited(以Taylor & Francis Group的名称进行交易)共同出版。Mandiwana-Neudani等人(2019a, 2019b)最近的出版物重新评估了非洲各地几种弗兰科物种的关系。他们将一些物种提升到完整的物种，但他们呈现的分布图与最近发表的公民科学项目(Harrison et al. 1997;dowsettemire and Dowsett 2006;Dowsett et al. 2008)。似乎没有一个分类单元由多个遗传样本代表，这远远超出了稳健研究的标准，并且不允许在样本标记或分析中发现错误(Hunter et al. 2021)。Hunter等人(2021)也对他们的解释进行了广泛的评论，主要是从东非的角度出发，Mandiwana-Neudani等人(2021)对此做出了回应。在这篇评论中，重点是中非形式的Coqui Peliperdix Coqui，栗子胸Pe。dewittei，雪莱的shelletila，怀特的S. whytei和红翅的富兰克林S. levaillantii和红颈Spurfowl Pternistis后。由Mandiwana-Neudani等人(2019a, 2019b)提供的标本数据分别与在线Genbank数据库和美国(AMNH)和英国自然历史博物馆(BM)的标本数据库进行核对。这揭示了这些分类群的多重不一致性，如下表1所示，证实了Hunter等人(2021)提出的担忧。保护“货币”的最低标准(Frankham et al. 2012)是模式标本。这是该分类单元最初描述的标本，通常是在一系列中采集的，它发生在哪里，它在表型上如何不同于类似的形式，不太可能用于破坏性组织采样。为了解决这个问题，应该在CYTB分析中使用一个拓扑型(从类型系列或在类型地点或尽可能接近它获得的另一个标本)。绘制模式标本的分布图是一个基线，可以根据这个基线来确定所考虑的分类群在当前分布范围内的羽毛地理变化。模式位置不能单独用于确定不同分类群的分布，但合理的期望分布图应该包含模式位置，除非在物种发现之后发生了重大的栖息地变化，以排除这种情况。Mandiwana-Neudani等人(2019a, 2019b)似乎没有参考模式标本、它们的描述或位置，因为他们的近似分布图没有包括一些分类群的模式位置。除了一个例外，来自拓扑型的材料也没有被测序。这是出乎意料的，因为这些基线标本应该是任何主要分类学研究的起点。Mandiwana-Neudani等人(2021)表示相信他们的有机体矩阵是分类上有用的属性集，而不管每个分类单元调查的数量如何。模式标本设定了这个基线，没有参考这些，任何比较都是主观的。因此，关于形态发声得分有很多不确定性。最初最多检查了10个标本(Mandiwana-Neudani et al. 2019a, 2019b)，但在对Hunter et al.(2021)的回应中，他们表示对其假定的终端分类群的10多个标本进行了检查。在美国国家博物馆、大英博物馆、芝加哥菲尔德博物馆和比利时特乌伦非洲历史博物馆的数据库中，在线搜索没有找到Peliperdix coqui stuhlmanni的标本;所有拥有大量非洲鸟类收藏的博物馆，也不确定是否存在超过10个可靠鉴定的该分类单元标本。定义表型鉴定标准用于鉴定Pe。Mandiwana-Neudani等人(2019a)的c. stuhlmanni是乳房图案的减少，但在类型描述中没有提到这一点，它指出它与提名Pe非常相似。coqui(赖希诺1889)。科奇·弗兰克林标本，鉴定为Pe。在津巴布韦自然历史博物馆收藏于马拉维的c. stuhlmanni，比Pe。在津巴布韦的miombo林地中发现了coqui，证实了中非男性Pe。coqui亚种可以是相当可变的(Hall 1963, Irwin 1981)，这是一个不可靠的分类特征(Irwin 1981)。这一观点来自一位经验丰富的非洲野外鸟类学家和分类学家，却被忽视了。Mandiwana-Neudani等人(2019a)错误记录/提名Pe。Coqui在他们的形态发声评分中有一个没有图案的乳房(8字;表6)表明所检查的标本混淆和/或数据处理错误。这种混淆扩展到CYTB数据，其中Pe。Genbank中保存的c. stuhlmanni (Mandiwana-Neudani et al.)。 2019a，及其附录2 Genbank FR694152)注册为Pe。c. coqui(表1)与stuhlmanni视角
{"title":"Taxonomic revision of francolins – reflections from a central African perspective","authors":"K. Hustler","doi":"10.2989/00306525.2021.2005705","DOIUrl":"https://doi.org/10.2989/00306525.2021.2005705","url":null,"abstract":"Ostrich is co-published by NISC (Pty) Ltd and Informa UK Limited (trading as Taylor & Francis Group) The recent publications by Mandiwana-Neudani et al. (2019a, 2019b) have re-evaluated the relationships of several francolin species, which occur across Africa. They have elevated some forms to full species, but the distribution maps they present are different to those in recently published citizen science projects (Harrison et al. 1997; DowsettLemaire and Dowsett 2006; Dowsett et al. 2008). There does not appear to be a single taxon that is represented by more than one genetic sample, which is well outside the norm for robust studies and does not allow for mistakes in the sample labelling or analysis to be detected (Hunter et al. 2021). Hunter et al. (2021) also commented extensively on their interpretations, mainly from an E African perspective, to which Mandiwana-Neudani et al. (2021) have replied. In this commentary, the focus is on the central Africa forms of Coqui Peliperdix coqui, Chestnut-breasted Pe. dewittei, Shelley’s Scleroptila shelleyi, Whyte’s S. whytei and Red-winged Francolins S. levaillantii and Red-necked Spurfowl Pternistis afer. Specimen data provided by Mandiwana-Neudani et al. (2019a, 2019b) were checked with the online Genbank database and the specimen databases of the American (AMNH) and British Museums of Natural History (BM), respectively. This revealed multiple inconsistencies for these taxa, which are outlined below (Table 1), confirming the concerns raised by Hunter et al. (2021). The lowest denominator of the ‘currency’ of conservation (Frankham et al. 2012) is the type specimen. This is the originally described specimen of the taxon, often taken in a series, where it occurred and how it is phenotypically different to similar forms and are not likely to be available for destructive tissue sampling. To get around this, a topotype (a specimen from the type series or another obtained at the type locality or as close as possible to it) should have been used for the CYTB analyses. Plotting the localities of type specimens sets a baseline, against which the geographical variation of plumage across the current distributional range of the taxa under consideration can be made. Type localities cannot be used to determine the distributions of the various taxa in isolation, but it is reasonable to expect that distribution maps should contain the type locality unless significant habitat change has occurred subsequent to the discovery of the species to preclude this. Mandiwana-Neudani et al. (2019a, 2019b) do not appear to have consulted the type specimens, their descriptions or localities, because their approximate distribution maps do not include the type localities of some taxa. Material from topotypes, with one exception were not sequenced either. This was unexpected, because these baseline specimens should be the starting point for any major taxonomic study. Mandiwana-Neudani et al. (2021) express confidence in their organisma","PeriodicalId":54655,"journal":{"name":"Ostrich","volume":"92 1","pages":"324 - 328"},"PeriodicalIF":1.0,"publicationDate":"2021-12-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44454778","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-11-22DOI: 10.2989/00306525.2021.1988745
O. E. Adekola, R. Crawford, B. Dyer, A. Makhado, L. Upfold, P. Ryan
Little has been reported on moult in sulids, including gannets. The Cape Gannet Morus capensis is an endangered seabird endemic to southern Africa. We describe the timing, duration, symmetry and sequence of flight feather moult in Cape Gannets from two breeding colonies and assess whether moult can be used as an index of condition. Using the Underhill-Zucchini model, we estimate moult parameters based on the proportion of feather mass grown. Adult Cape Gannets began primary moult at the beginning of January (2–3 January ± 28 days SD) at both colonies. Primary moult is protracted, with multiple active centres (mean ± SD 1.8 ± 0.8, range 1–4) and 2.0 ± 0.9 feathers growing at the same time (range 1–5). Primary moult is suspended by early June at Malgas Island (estimated duration of moult ± SE, 153.9 ± 4.1 days) and late June at Lambert’s Bay (176.5 ± 5.5 days). Secondary moult commenced in late January and proceeded from two nodal points. Despite more secondaries (3.3 ± 1.9, range 1–8) being grown simultaneously than primaries, 8% of birds were still moulting secondaries at the start of the breeding season. However, it was not certain that these individuals were breeding. Tail moult also overlapped with that of the primaries, with multiple active centres (2.7 ± 1.2, 1–6) and 2.9 ± 1.3 feathers growing at the same time (range 1–8). Almost all primary (98%) and secondary moult (97%) was symmetrical, but there was little symmetry in tail moult (54%). Rectrix symmetry tended to be greater among gannets at Malgas Island (T1: 58%; T2–T6: 67–73%) than at Lambert’s Bay (T1: 50%; T2–T6: 55–66%). Differences in moult duration and perhaps asymmetry between locations may be linked to foraging conditions, given that Lambert’s Bay gannets are thought to be under greater food stress than Malgas birds.
{"title":"Timing, duration and symmetry of moult in Cape Gannets","authors":"O. E. Adekola, R. Crawford, B. Dyer, A. Makhado, L. Upfold, P. Ryan","doi":"10.2989/00306525.2021.1988745","DOIUrl":"https://doi.org/10.2989/00306525.2021.1988745","url":null,"abstract":"Little has been reported on moult in sulids, including gannets. The Cape Gannet Morus capensis is an endangered seabird endemic to southern Africa. We describe the timing, duration, symmetry and sequence of flight feather moult in Cape Gannets from two breeding colonies and assess whether moult can be used as an index of condition. Using the Underhill-Zucchini model, we estimate moult parameters based on the proportion of feather mass grown. Adult Cape Gannets began primary moult at the beginning of January (2–3 January ± 28 days SD) at both colonies. Primary moult is protracted, with multiple active centres (mean ± SD 1.8 ± 0.8, range 1–4) and 2.0 ± 0.9 feathers growing at the same time (range 1–5). Primary moult is suspended by early June at Malgas Island (estimated duration of moult ± SE, 153.9 ± 4.1 days) and late June at Lambert’s Bay (176.5 ± 5.5 days). Secondary moult commenced in late January and proceeded from two nodal points. Despite more secondaries (3.3 ± 1.9, range 1–8) being grown simultaneously than primaries, 8% of birds were still moulting secondaries at the start of the breeding season. However, it was not certain that these individuals were breeding. Tail moult also overlapped with that of the primaries, with multiple active centres (2.7 ± 1.2, 1–6) and 2.9 ± 1.3 feathers growing at the same time (range 1–8). Almost all primary (98%) and secondary moult (97%) was symmetrical, but there was little symmetry in tail moult (54%). Rectrix symmetry tended to be greater among gannets at Malgas Island (T1: 58%; T2–T6: 67–73%) than at Lambert’s Bay (T1: 50%; T2–T6: 55–66%). Differences in moult duration and perhaps asymmetry between locations may be linked to foraging conditions, given that Lambert’s Bay gannets are thought to be under greater food stress than Malgas birds.","PeriodicalId":54655,"journal":{"name":"Ostrich","volume":"92 1","pages":"295 - 306"},"PeriodicalIF":1.0,"publicationDate":"2021-11-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41935546","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-11-21DOI: 10.2989/00306525.2021.2003883
Balsama Rajemison, Hesham T Goodman, S. Goodman
Regurgitated pellets from the Olive Bee-eater, Merops superciliosus, were collected below a hunting perch in Antananarivo, Madagascar, and used to examine this species’ food habits. The diet of this species was largely composed of bees (Apidae, genus Apis) and the next most common group was wasps (Vespidae). Remains of soft-bodied ticks (Argasidae) were also identified, presumably associated with the consumption of ectoparasites during preening.
{"title":"The diet of the Olive Bee-eater, Merops superciliosus, in the Central Highlands of Madagascar","authors":"Balsama Rajemison, Hesham T Goodman, S. Goodman","doi":"10.2989/00306525.2021.2003883","DOIUrl":"https://doi.org/10.2989/00306525.2021.2003883","url":null,"abstract":"Regurgitated pellets from the Olive Bee-eater, Merops superciliosus, were collected below a hunting perch in Antananarivo, Madagascar, and used to examine this species’ food habits. The diet of this species was largely composed of bees (Apidae, genus Apis) and the next most common group was wasps (Vespidae). Remains of soft-bodied ticks (Argasidae) were also identified, presumably associated with the consumption of ectoparasites during preening.","PeriodicalId":54655,"journal":{"name":"Ostrich","volume":"92 1","pages":"316 - 318"},"PeriodicalIF":1.0,"publicationDate":"2021-11-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48635380","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-10-26DOI: 10.2989/00306525.2021.1976858
Tristan Nyatanga, Henry Ndaimani, T. Gaza
Studies that seek to understand the local variations in the response of birds to human disturbance in urban areas are important for conservation. This article investigated the contribution of human population density in the different urban land use zones of Harare (high, medium and low-density residential areas, as well as industrial areas), among other variables, to the models explaining the flight initiation distance (FID) of twenty-five urban bird species. The specific objectives of the study were: to test whether the variables significantly predict FID; to investigate their relative contribution to the ‘best-performing’ models; and to determine the relationship between FID and the individual predictor variables. Generalised linear models were used to predict FID as a function of: flock size, intruder starting distance, urban land use zone, perch height, average bird mass and species. We predicted that FID would increase in tandem with flock size and average bird mass, and decrease inversely proportional to population density, intruder starting distance and perch height. We also expected FID to differ by species. Results illustrated that twelve models best explained the FID of birds in the study area. Urban land use zone, intruder starting distance and species were the only predictors that appeared in all the twelve models. However, flock size and average bird mass appeared in only six of the twelve models making them the least important predictor variables. These findings add to current knowledge on local variation in the FID of certain bird species within the different land use zones. The results could be used to create buffers aimed to minimise human-induced disturbance on bird species.
{"title":"Local variations in the response of birds to human presence in urban areas","authors":"Tristan Nyatanga, Henry Ndaimani, T. Gaza","doi":"10.2989/00306525.2021.1976858","DOIUrl":"https://doi.org/10.2989/00306525.2021.1976858","url":null,"abstract":"Studies that seek to understand the local variations in the response of birds to human disturbance in urban areas are important for conservation. This article investigated the contribution of human population density in the different urban land use zones of Harare (high, medium and low-density residential areas, as well as industrial areas), among other variables, to the models explaining the flight initiation distance (FID) of twenty-five urban bird species. The specific objectives of the study were: to test whether the variables significantly predict FID; to investigate their relative contribution to the ‘best-performing’ models; and to determine the relationship between FID and the individual predictor variables. Generalised linear models were used to predict FID as a function of: flock size, intruder starting distance, urban land use zone, perch height, average bird mass and species. We predicted that FID would increase in tandem with flock size and average bird mass, and decrease inversely proportional to population density, intruder starting distance and perch height. We also expected FID to differ by species. Results illustrated that twelve models best explained the FID of birds in the study area. Urban land use zone, intruder starting distance and species were the only predictors that appeared in all the twelve models. However, flock size and average bird mass appeared in only six of the twelve models making them the least important predictor variables. These findings add to current knowledge on local variation in the FID of certain bird species within the different land use zones. The results could be used to create buffers aimed to minimise human-induced disturbance on bird species.","PeriodicalId":54655,"journal":{"name":"Ostrich","volume":"92 1","pages":"270 - 279"},"PeriodicalIF":1.0,"publicationDate":"2021-10-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42116038","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-08-27DOI: 10.2989/00306525.2021.1984337
Krista N. Oswald, Alan T. K. Lee
As an endemic bird to the Fynbos biome, prominently featured in literature and marketing material for the avifauna of the continent, the Cape Rockjumper Chaetops frenatus is an iconic species of South Africa. Building on studies from the past decade, recent publications all point to a vulnerability to climate change due to temperature-related effects on their behaviour, physiology, and life history. Here we present a population viability analysis for the species based on knowledge of recent declines and making use of recently available information on their life history. We combined recent breeding success data (2016–2018) with that of a population monitored approximately two decades ago (1998–2000) and modelled the probability of extinction for four scenarios where the principal change was in juvenile (more accurately, nestling) mortality. We focused on juvenile mortality as there are previously identified areas of vulnerability that present potential areas for mitigation. With juvenile mortality set at the recently recorded rate of 80% there is a 49.1% chance of population extinction within 100 years, despite optimistic adult survival and breeding parameters used in the models. We then provide insights into factors that mediate juvenile mortality as potential avenues for the management of the species.
{"title":"Population Viability Analysis for a vulnerable ground-nesting species, the Cape Rockjumper Chaetops frenatus: assessing juvenile mortality as a potential area for conservation management","authors":"Krista N. Oswald, Alan T. K. Lee","doi":"10.2989/00306525.2021.1984337","DOIUrl":"https://doi.org/10.2989/00306525.2021.1984337","url":null,"abstract":"As an endemic bird to the Fynbos biome, prominently featured in literature and marketing material for the avifauna of the continent, the Cape Rockjumper Chaetops frenatus is an iconic species of South Africa. Building on studies from the past decade, recent publications all point to a vulnerability to climate change due to temperature-related effects on their behaviour, physiology, and life history. Here we present a population viability analysis for the species based on knowledge of recent declines and making use of recently available information on their life history. We combined recent breeding success data (2016–2018) with that of a population monitored approximately two decades ago (1998–2000) and modelled the probability of extinction for four scenarios where the principal change was in juvenile (more accurately, nestling) mortality. We focused on juvenile mortality as there are previously identified areas of vulnerability that present potential areas for mitigation. With juvenile mortality set at the recently recorded rate of 80% there is a 49.1% chance of population extinction within 100 years, despite optimistic adult survival and breeding parameters used in the models. We then provide insights into factors that mediate juvenile mortality as potential avenues for the management of the species.","PeriodicalId":54655,"journal":{"name":"Ostrich","volume":"92 1","pages":"234 - 238"},"PeriodicalIF":1.0,"publicationDate":"2021-08-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43429417","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-08-27DOI: 10.2989/00306525.2021.1940342
P. Greig-Smith
This study explored reasons for variable nesting habits in a hole-nesting bird species that sometimes breeds colonially and sometimes alone. Nesting was surveyed over ten years in natural sand cliffs and similar features created by human activity along a river and nearby habitats. Two-thirds of nests were in small colonies of 2–16 birds, where nests were less than 25 m from neighbouring breeders. Many others were hundreds of metres apart. Individual breeding locations were abandoned after only a few years’ occupation, often without obvious habitat change. Birds responded very rapidly to the sudden exposure of fresh sand cliffs by starting new colonies. If floods occurred in the first half of the season, nesting in the second half shifted to less vulnerable areas. Substantial changes from year to year, in the location of breeding activity and the ratio of colony to solitary nests, were unrelated to variations in rainfall (a likely measure of feeding conditions) in the previous breeding season or the six months prior to breeding. The proportion of nests in colonies was positively correlated with the numbers of birds breeding, indicating that coloniality was not limited by available sites. Behaviour at colony and solitary nests suggested that one benefit of group nesting is more frequent and stronger response to birds of prey. Extra adults visiting nests alongside the breeding pair were more frequent at colonies, though the significance of this is unknown. There was no evidence for neighbouring breeders coordinating their visits to and from colonies. Costs of group nesting (more frequent disturbance by groups of non-breeders, and time in defence of nests) were higher at colonies, though levels of aggression were very low. Coloniality is more likely to be an incidental result of birds independently selecting good nesting sites in an unpredictable habitat, than because of social benefits of breeding close together.
{"title":"Colonial versus solitary breeding: nesting patterns of Brown-throated Martins Riparia paludicola in Morocco","authors":"P. Greig-Smith","doi":"10.2989/00306525.2021.1940342","DOIUrl":"https://doi.org/10.2989/00306525.2021.1940342","url":null,"abstract":"This study explored reasons for variable nesting habits in a hole-nesting bird species that sometimes breeds colonially and sometimes alone. Nesting was surveyed over ten years in natural sand cliffs and similar features created by human activity along a river and nearby habitats. Two-thirds of nests were in small colonies of 2–16 birds, where nests were less than 25 m from neighbouring breeders. Many others were hundreds of metres apart. Individual breeding locations were abandoned after only a few years’ occupation, often without obvious habitat change. Birds responded very rapidly to the sudden exposure of fresh sand cliffs by starting new colonies. If floods occurred in the first half of the season, nesting in the second half shifted to less vulnerable areas. Substantial changes from year to year, in the location of breeding activity and the ratio of colony to solitary nests, were unrelated to variations in rainfall (a likely measure of feeding conditions) in the previous breeding season or the six months prior to breeding. The proportion of nests in colonies was positively correlated with the numbers of birds breeding, indicating that coloniality was not limited by available sites. Behaviour at colony and solitary nests suggested that one benefit of group nesting is more frequent and stronger response to birds of prey. Extra adults visiting nests alongside the breeding pair were more frequent at colonies, though the significance of this is unknown. There was no evidence for neighbouring breeders coordinating their visits to and from colonies. Costs of group nesting (more frequent disturbance by groups of non-breeders, and time in defence of nests) were higher at colonies, though levels of aggression were very low. Coloniality is more likely to be an incidental result of birds independently selecting good nesting sites in an unpredictable habitat, than because of social benefits of breeding close together.","PeriodicalId":54655,"journal":{"name":"Ostrich","volume":"92 1","pages":"203 - 217"},"PeriodicalIF":1.0,"publicationDate":"2021-08-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49526396","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-08-27DOI: 10.2989/00306525.2021.1984998
P. Ryan, E. M. Ryan, J. Glass
Most of the millions of burrow-nesting petrels that breed at Tristan da Cunha are susceptible to light pollution. On dark, misty nights, petrels become disoriented by artificial lights, mainly from ships. From 2013 to 2021 at least 1 823 petrels were recorded coming aboard vessels fishing for rock lobsters. Despite limited deck lighting, bird strikes occurred on 13% of fishing nights, with 65% of birds recorded on seven nights (<1%). Strikes occurred more often in spring and autumn than in summer, probably as a result of seabird breeding phenology and seasonal weather patterns. At least 70 birds were killed (4% of those reported from the ships), mainly prions Pachyptila spp. and storm petrels of family Oceanitidae. These represent minimum estimates, because not all birds are detected by the ships’ crews. All vessels operating close to seabird breeding islands at night should be required to black out all but the most essential lights.
{"title":"Dazzled by the light: the impact of light pollution from ships on seabirds at Tristan da Cunha","authors":"P. Ryan, E. M. Ryan, J. Glass","doi":"10.2989/00306525.2021.1984998","DOIUrl":"https://doi.org/10.2989/00306525.2021.1984998","url":null,"abstract":"Most of the millions of burrow-nesting petrels that breed at Tristan da Cunha are susceptible to light pollution. On dark, misty nights, petrels become disoriented by artificial lights, mainly from ships. From 2013 to 2021 at least 1 823 petrels were recorded coming aboard vessels fishing for rock lobsters. Despite limited deck lighting, bird strikes occurred on 13% of fishing nights, with 65% of birds recorded on seven nights (<1%). Strikes occurred more often in spring and autumn than in summer, probably as a result of seabird breeding phenology and seasonal weather patterns. At least 70 birds were killed (4% of those reported from the ships), mainly prions Pachyptila spp. and storm petrels of family Oceanitidae. These represent minimum estimates, because not all birds are detected by the ships’ crews. All vessels operating close to seabird breeding islands at night should be required to black out all but the most essential lights.","PeriodicalId":54655,"journal":{"name":"Ostrich","volume":"92 1","pages":"218 - 224"},"PeriodicalIF":1.0,"publicationDate":"2021-08-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42180008","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-08-03DOI: 10.2989/00306525.2021.1960020
W. Dean
{"title":"Carl John Vernon (1938–2021)","authors":"W. Dean","doi":"10.2989/00306525.2021.1960020","DOIUrl":"https://doi.org/10.2989/00306525.2021.1960020","url":null,"abstract":"","PeriodicalId":54655,"journal":{"name":"Ostrich","volume":" ","pages":"iii - iv"},"PeriodicalIF":1.0,"publicationDate":"2021-08-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48814753","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-07-14DOI: 10.2989/00306525.2021.1929534
Michael M Williams, U. Ottosson, T. Tende, Justus P. Deikumah
The population of various species of vultures are declining rapidly across Africa, with noticeable declines in most areas including protected areas. This sudden decline of vultures in African countries, especially Nigeria, is quite alarming. One of the most common species of vultures, the Hooded Vulture, is now rarely encountered. This study was carried out to determine the role of traditional belief systems and trade in vulture parts on the rapid decline in vulture populations in Nigeria. The study was conducted in Plateau State in the North-Central region in Nigeria. Ethno-ornithological data were collected using semi-structured questionnaires; supported by interviews and field observations. A stratified-random sampling technique was employed for the data collection, which was conducted within 34 districts at 68 points where vultures were observed. The 204 respondents were all selected by chance encounter across the survey sites to determine their perceptions about vultures. The key finding of this research revealed massive trade in vulture parts for belief-base use, which might be responsible for the decline of vulture populations in the area. There is evidence of the consumption of vulture meat according to some of the respondents. Stiff competition with vultures for food by human and dogs was found to be another contributory factor towards vulture population decline within the study area. Many people believe that vultures are evil; hence, they are often persecuted on sight. There is an urgent need to create awareness about the importance of vultures in our environment. It is also vital to review laws on endangered species and implement them with the support of law enforcement agencies. Public awareness and sensitization of people using mass and social media campaigns should be conducted regularly on the importance of vultures and how to co-exist with them. Vulture restaurants or artificial feeding points should be created to aid population recovery.
{"title":"Traditional belief systems and trade in vulture parts are leading to the eradication of vultures in Nigeria: an ethno-ornithological study of north-central Nigeria","authors":"Michael M Williams, U. Ottosson, T. Tende, Justus P. Deikumah","doi":"10.2989/00306525.2021.1929534","DOIUrl":"https://doi.org/10.2989/00306525.2021.1929534","url":null,"abstract":"The population of various species of vultures are declining rapidly across Africa, with noticeable declines in most areas including protected areas. This sudden decline of vultures in African countries, especially Nigeria, is quite alarming. One of the most common species of vultures, the Hooded Vulture, is now rarely encountered. This study was carried out to determine the role of traditional belief systems and trade in vulture parts on the rapid decline in vulture populations in Nigeria. The study was conducted in Plateau State in the North-Central region in Nigeria. Ethno-ornithological data were collected using semi-structured questionnaires; supported by interviews and field observations. A stratified-random sampling technique was employed for the data collection, which was conducted within 34 districts at 68 points where vultures were observed. The 204 respondents were all selected by chance encounter across the survey sites to determine their perceptions about vultures. The key finding of this research revealed massive trade in vulture parts for belief-base use, which might be responsible for the decline of vulture populations in the area. There is evidence of the consumption of vulture meat according to some of the respondents. Stiff competition with vultures for food by human and dogs was found to be another contributory factor towards vulture population decline within the study area. Many people believe that vultures are evil; hence, they are often persecuted on sight. There is an urgent need to create awareness about the importance of vultures in our environment. It is also vital to review laws on endangered species and implement them with the support of law enforcement agencies. Public awareness and sensitization of people using mass and social media campaigns should be conducted regularly on the importance of vultures and how to co-exist with them. Vulture restaurants or artificial feeding points should be created to aid population recovery.","PeriodicalId":54655,"journal":{"name":"Ostrich","volume":"92 1","pages":"194 - 202"},"PeriodicalIF":1.0,"publicationDate":"2021-07-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45346264","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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