Ostrich最新文献

{"title":"The effects of habitat loss and fragmentation on updated estimates of the population of the Agulhas Long-billed Lark Certhilauda brevirostris, a South African endemic","authors":"S. Evans","doi":"10.2989/00306525.2021.1998239","DOIUrl":"https://doi.org/10.2989/00306525.2021.1998239","url":null,"abstract":"The Agulhas Long-billed Lark Certhilauda brevirostris is a South African endemic and is restricted to the fynbos habitat of the Agulhas Plain in the southwestern corner of South Africa. The 1990, 2014, and 2018 land use land cover (LULC) databases prepared for South Africa were used to determine the LULC categories that best describe suitable habitat for this bird using beta regressions. Previously published densities of Agulhas Long-billed Lark and the surface area of the LULC categories considered suitable habitat for the birds were used to estimate their historical and current population sizes, and the rates of change in the bird’s population. Beta regression models were compiled from the bird’s adjusted reporting rate and the total surface area, and three other landscape metrics, of the per pentad LULC categories considered suitable habitat for them. These models revealed that although the Agulhas Long-billed Lark is adversely affected by the loss of its natural fynbos habitat these adverse effects have been offset by an increase in the availability of fallow fields in summer. This confirms previous observations that agriculture may have allowed the Agulhas Long-billed Lark to increase in numbers. The Agulhas Long-billed Lark’s extent of occurrence (EOO) was estimated at 1 322 509 ha (n = 197 pentads) with an area of occupancy (AOO) estimated to be 1 076 854 ha in 2020. The decline in habitat available to the birds was estimated to be 3.5% over three generations (10.5 years). The present study provides improved estimates of the population of the Agulhas Long-billed Lark of between 146 344 and 264 691 individuals, with between 60 753 and 109 883 individuals in natural habitat, and between 85 591 and 154 808 individuals in transformed habitat. The results of the present study indicate that the Agulhas Long-billed Lark’s Near Threatened status should be reviewed.","PeriodicalId":54655,"journal":{"name":"Ostrich","volume":null,"pages":null},"PeriodicalIF":1.0,"publicationDate":"2021-12-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48814030","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}

{"title":"Effects of tropical rainforest fragmentation on bird species: a case study from the Bemanevika Protected Area, northwestern Madagascar","authors":"Armand Benjara, Lily-Arison R. de Roland, Marius Rakotondratsima, R. Thorstrom","doi":"10.2989/00306525.2021.2005704","DOIUrl":"https://doi.org/10.2989/00306525.2021.2005704","url":null,"abstract":"The effects of forest fragmentation on forest bird species in the Bemanevika Protected Area (PA), northwestern Madagascar, were investigated during two breeding seasons from October 2016 to January 2018. The forest of Bemanevika is composed of large patches of fragmented tropical rainforest. Seven forest fragments ranging from 10 to 1 050 ha were surveyed. Two methods were used to collect data along transects orientated from the forest edge toward the interior of the forest: mist-netting and point-counts. In all, 27 non-forest birds and 65 forest birds were recorded at all fragments. According to their distribution along an edge-interior gradient, these 65 forest species are classified into three main groups: 15 (23.1%) edge species, 12 (18.5%) forest interior species and 38 (58.5%) ubiquitous species. Larger forest fragments host more forest bird species than smaller forest fragments. Of the 65 forest birds, 14, including the 12 forest interior species, were not found in the four smaller fragments (10–29 ha). The density of forest interior species was positively correlated to forest fragment size. The general trend was that forest interior species were the most sensitive to forest fragmentation (e.g. Madagascar Serpent-eagle Eutriorchis astur, Pitta-like Ground-roller Atelornis pittoides and Schlegel’s Asity Philepitta schlegeli). Large raptors, terrestrial species and understory species were the first to disappear from the small fragments. Fragmented forests provide habitat for bird species, even for those vulnerable to forest fragmentation, therefore the maintenance of large enough forest fragments should be considered in all conservation strategies aimed to protect forest birds.","PeriodicalId":54655,"journal":{"name":"Ostrich","volume":null,"pages":null},"PeriodicalIF":1.0,"publicationDate":"2021-12-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48961561","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}

{"title":"Diet of a Maghreb Owl pair Strix mauritanica (Witherby, 1905) in an urban environment (Rabat City, Morocco)","authors":"S. Cherkaoui, A. Rihane, Brahim Chergui El Hemiani","doi":"10.2989/00306525.2021.2003884","DOIUrl":"https://doi.org/10.2989/00306525.2021.2003884","url":null,"abstract":"A pair of the Northwest African endemic Maghreb Owl Strix mauritanica (Witherby, 1905) located in a coastal urban environment of the Moroccan capital, Rabat, was monitored for the first time over two consecutive breeding seasons, in 2020 and 2021, respectively. Pellets (n = 434) collected and analysed from their roost contained the remains of synanthropic species of rodents, such as the house mouse (Mus musculus), black rat (Rattus rattus), brown rat (Rattus norvegicus) and a fairly similar proportion of birds. The most interesting finding was the Barbary ground squirrel (Atlantoxerus getulus), because the distribution does not reach the latitude of Rabat and does not usually frequent urban areas. This is the first study of the Maghreb Owl diet in a non-natural environment in Morocco and highlights the predominance of commensal pest rodents and urban birds in their diet. However, because our study involved only one pair of owls, additional research should be carried out to make sound inferences for the species’ diet at the population level.","PeriodicalId":54655,"journal":{"name":"Ostrich","volume":null,"pages":null},"PeriodicalIF":1.0,"publicationDate":"2021-12-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48493961","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}

{"title":"Investigating the influence of the extreme Indian Ocean Dipole on the 2020 influx of Red-necked Phalaropes Phalaropus lobatus in Kenya","authors":"Raphäel Nussbaumer, M. Gravey, Améline Nussbaumer, C. Jackson","doi":"10.2989/00306525.2021.1995908","DOIUrl":"https://doi.org/10.2989/00306525.2021.1995908","url":null,"abstract":"Ocean currents have wide-ranging impacts on seabird movement and survival. By extension, the extreme oscillations they are subject to, such as extreme Indian Ocean Dipole (IOD) events, can also be expected to dramatically influence seabird populations. This study links the extreme IOD event that occurred in 2019–2020 to the unusually high number of Red-necked Phalarope sightings observed in February 2020. We show that the extreme IOD event resulted in low net primary productivity (a measure of plankton growth) offshore from the Somalia-Kenyan coast, where Phalaropes have been tracked in previous winters. We suggest that Phalaropes were therefore forced to move closer to the coast to find food at river estuaries, thus explaining the influx in February 2020. This study calls for closer monitoring of seabird populations in East Africa, particularly during extreme IOD events, which are expected to become more common in the future.","PeriodicalId":54655,"journal":{"name":"Ostrich","volume":null,"pages":null},"PeriodicalIF":1.0,"publicationDate":"2021-12-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49552444","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}

{"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":null,"pages":null},"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}

{"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":null,"pages":null},"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}

{"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":null,"pages":null},"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}

{"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":null,"pages":null},"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}

{"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":null,"pages":null},"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}

{"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":null,"pages":null},"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}