Since the 1980s, earlier European springs have led to the earlier arrival of migrant passerines. We predict that arrival is related to a suite of climate indices operating during the annual cycle (breeding, autumn migration, wintering, spring migration) in Europe and Africa over the year preceding arrival. The climate variables include the Indian Ocean Dipole (IOD), Southern Oscillation Index (SOI), and North Atlantic Oscillation (NAO). Furthermore, because migrants arrive sequentially from different wintering areas across Africa, we predict that relationships with climate variables operating in different parts of Africa will change within the season. We tested this using daily ringing data at Bukowo, a spring stopover site on the Baltic coast. We calculated an Annual Anomaly (AA) of spring passage (26 March–15 May, 1982–2024) for four long-distance migrants (Blackcap, Lesser Whitethroat, Willow Warbler, Chiffchaff). We decomposed the anomaly in two ways: into three independent main periods and nine overlapping periods. We used multiple regression to explore the relationships of the arrival of these species at Bukowo. We found sequential effects of climate indices. Bukowo is thus at a crossroads of populations arriving from different wintering regions. The drivers of phenological shifts in passage of wide-ranging species are related to climate indices encountered during breeding, wintering, and migration.

A population of at least 60 Indian Peafowl Pavo cristatus has been established on a wine farm on the eastern edge of the Paardeberg, near Wellington, in the Western Cape, South Africa. They have been feral for at least 25 years. We describe the daily routine of these birds and provide photographic evidence of breeding. We discuss the need to document other self-sustaining populations in southern Africa, pointing out that Indian Peafowl populations are reported to be decreasing in their natural range in southern Asia, and that in same of the places where populations have become established, they have achieved pest status.

For three regions of South Africa (Greater Gauteng, Greater Cape Town and Greater Durban) with the greatest coverage by bird atlas (SABAP2) fieldwork, we related arrival timing and abundance in each region of a long-distance migrant bird, the Barn Swallow, from July 2007 to March 2024. Using monotonic regression, from the atlas data we derived (1) the “annual anomaly of arrivals” from the average multi-year pattern; (2) the “average maximum” reporting rate at the completion of arrivals, in each region. We related these measures of the Barn Swallow timing and abundance in each of the 17 seasons of arrivals (July–January) in each of three region, with the large-scale climate indices, and temperature and precipitation in the Iberian+Apennine Peninsulas, for the Balkan Peninsula, and for the Sahel, averaged for the months when Barn Swallow visits areas between where these climate indices operate, at their breeding grounds in Eurasia, and along four southwards migration routes to South Africa. We used multiple regression modes with no more than two climate indices at a time, out of 84 explanatory variables, allowed by 17 data points (seasons) for each region. Our exploratory analysis indicated that the timing and abundance of Barn Swallow arrivals were related to a selection of these climate indices. The related climate indices varied between three regions in a pattern corresponding with the proportions of Barn Swallows arriving there from different breeding areas along different flyways, derived from an earlier study based on ringing recoveries. The paper shows the potential of the SABAP2 database as an annual monitoring approach, primarily due to the strong fieldwork protocol. We recommend that the project be continued indefinitely.

This bibliogaphy lists 200 publications providing baseline knowledge, historical context and perspective, information relating to long-term data sets, and also insights into species, ecosystems, and human impacts on Robben Island, a protected area and UNESCO World Heritage Site since 1999. This platform of knowledge will enable researchers to design better studies, avoid redundant work and measure change. It will also help to identify knowledge gaps, and to guide policy and management decisions.

Volume 13 of Biological Observation, published in 2023, contained 39 papers. The largest number of papers in a single volume was in the year 2016, when Volume 7 contained 103 papers.

Catsharks (family Scyliorhinidae) and the recently reclassified deepwater catsharks (family Pentanchidae) are two of the largest families of elasmobranchs and include species that function as important mesopredators in almost all marine ecosystems. This study focuses on four species endemic to the coast of southern Africa: the puffadder shyshark Haploblepharus edwardsii, dark shyshark H. pictus, leopard catshark Poroderma pantherinum and pyjama catshark P. africanum. Similar to most catsharks, these four species are underrepresented in chondrichthyan research. Our investigation aimed to gain insight into the distribution and site fidelity of the focal species through mark-recapture efforts in Walker Bay on the southwest coast. The use of 95% minimum convex polygons indicated large overlaps in distribution among the species as well as between sexes, except for H. edwardsii. Site fidelity was universally low (0.005) at three key sample sites, although travel distances between sites averaged 3-5.5 km across all species. The results suggest that sexual segregation is not present for the studied catshark species, with the possible exception of H. edwardsii, which had a low capture rate. The low levels of site fidelity and movement also indicated significant levels of site interconnectivity between the three commonly sampled sites as they fell within the same 5-km2 region of the bay. From the present findings, Walker Bay could be considered an area of interest for conservation with respect to the four species, allowing for further study of their population dynamics and the influence of the local marine protected area.

The wrybill | ngutu pare ( Anarhynchus frontalis) is a small plover endemic to New Zealand with a unique laterally curved bill. Apart from moult, much of its biology is well understood: adults breed from late August to January on the braided river systems in Canterbury and inland Otago on New Zealand's South Island. From midsummer, late December and January, they migrate north to non-breeding areas in the northern part of the North Island, especially to the large tidal bays, east and west of Auckland, where they undergo primary moult from January to April. The Underhill- Zucchini moult model was used to estimate the mean start and completion dates of primary moult, which were 20 January and 3 April respectively. Adults thus commence primary moult soon after arrival on non-breeding grounds but complete moult around four months before southward migration to their breeding areas in August. They appear to avoid primary moult during winter. Second-year birds start primary moult in December, one month earlier than the adults, but finish at approximately the same time. Primary moult of the wrybill is compared with closely related species, and with other waders that breed on the South Island and migrate to North Island for the non-breeding season.

Citizen science data are rapidly transforming the conservation landscape. Targeted participatory citizen science initiatives generate nuanced data capable of monitoring trends in populations and generating early warnings for species and habitats experiencing significant declines. In the Hessequa Atlasing Area, Western Cape, South Africa, citizen science 'atlasers' involved with the Second Southern African Bird Atlas Project (SABAP2) have worked with scientific leadership since 2014 to improve the quality of bird atlas data in their region for species monitoring. In this study, we used reporting rates from SABAP2 checklists in the Hessequa Atlasing Area to calculate changes in range size and relative abundance for the 165 most commonly reported species in the region. We used a seven-tier alert system and broad habitat categories to sort species by priority for conservation action. Our results showed that wetland and marine associated species are experiencing the greatest declines in range and relative abundance in the Hessequa Atlasing Area, whilst urban and grassland associated species are largely increasing. We discuss how observed changes in populations may be used to guide conservation action and provide recommendations for scientists and non-scientific community members on engaging with and responding to the changes highlighted in each of the seven alert levels provided.

Substantial effort has gone into identifying threats to the African oystercatcher Haematopus moquini, a species of seabird native to the mainland coasts and offshore islands of southern Africa. Winter storms represent a possible further threat owing to the potential to exclude an obligate intertidal forager from its feeding areas for periods of days. Using data from the Slangkop wave buoy off the Cape Peninsula of South Africa during surveys of the number of oystercatchers on Robben Island, and arguments based on body-mass records, the tentative conclusion is that winter storms do not currently represent a threat to the African oystercatcher but this may become a factor in the future.

Data from five citizen science projects were used to document shifting ranges of two species of bulbul in South Africa. We show that African Red-eyed Bulbuls Pycnonotus nigricans steadily replaced Cape Bulbuls P. capensis in the lower Olifants River valley, in northern Western Cape province, South Africa. The first observations of African Red-eyed Bulbuls in this valley were recorded by atlasers in winter 2011. Bird atlas reporting rates were still steadily increasing in this region at the end of 2021. Environmental conditions seem to have been suitable for range expansion of the African Red-eyed Bulbul into the area for at least five decades before they first arrived. This is a common feature of range expansions into the Western Cape. We discuss the value of the citizen science projects. The photographic records of the Virtual Museum have the advantage that they can be verified, and we made use of the habitat features displayed in the background. The bird atlas, in contrast, is based on sight records that cannot be checked; we observed a tendency for bird atlasers, who operate with fieldwork time constraints, to record the bulbuls in the study area as Cape Bulbuls because this was the bulbul that was traditionally observed there. Les donn & eacute;es de cinq projets de science citoyenne ont & eacute;t & eacute; utilis & eacute;es pour documenter le d & eacute;placement des aires de r & eacute;partition de deux esp & egrave;ces de bulbuls en Afrique du Sud. Nous montrons que le Bulbul brunoir Pycnonotus nigricans a progressivement remplac & eacute; le Bulbul du Cap P. capensis dans la basse vall & eacute;e de la rivi & egrave;re Olifants, dans le nord de la province du Cap-Occidental, en Afrique du Sud. Les premi & egrave;res observations de Bulbul brunoir dans cette vall & eacute;e ont & eacute;t & eacute; enregistr & eacute;es par des atlas en hiver 2011. Les taux de signalement des atlas d'oiseaux & eacute;taient toujours en augmentation constante dans cette r & eacute;gion & agrave; la fin de l'ann & eacute;e 2021. Les conditions environnementales semblent avoir & eacute;t & eacute; propices & agrave; l'expansion de l'aire de r & eacute;partition du Bulbul brunoir dans la r & eacute;gion pendant au moins cinq d & eacute;cennies avant son arriv & eacute;e. Il s'agit d'une caract & eacute;ristique commune & agrave; plusieurs cas d'expansion de l'aire de r & eacute;partition dans le Cap occidental. Nous discutons de la valeur des projets de science citoyenne. Les photographies du Mus & eacute;e Virtuel ont l'avantage de pouvoir & ecirc;tre v & eacute;rifi & eacute;es, et nous avons pu utiliser les caract & eacute;ristiques de l'habitat affich & eacute;es en arri & egrave;re-plan. L'atlas des oiseaux, en revanche, est bas & eacute; sur des relev & eacute;s visuels qui ne peuvent pas & ecirc;tre v & eacute;rifi & eacute;s; nous avons observ & eacute; une tendance des observateursaux, qui travaillent avec des contraintes de temps sur le terrain, & agrave; enregistrer les bulbuls dans la zone d'& eacute;tude comme Bulbuls du Cap parce que c'est le bulbul qui a & eacute;t & eacute; traditionnellement observ & eacute; dans cette zone.

This bibliography of published output of research relating to Robben Island, Table Bay, South Africa, covers the period 2016–2024. The previous bibliography covered the period up to 2016. All authors are grateful to the Robben Island Museum for support for this research, which is a contribution to the knowledge record of this World Heritage Site.

Knowledge about the timing of moult and how it fits into the annual cycle, along with breeding and, in some cases migration, is an important component of understanding the life history of birds. In comparison with breeding and migration, there is a lack of knowledge about the moult of birds. Primary moult can be quantified using models such as the Underhill-Zucchini moult model. Studies that included estimates of primary moult parameters (duration, mean start date and standard deviation of mean start date) obtained using the Underhill-Zucchini moult model were compiled from the literature to generate a moult analysis database. These parameters provide information about the timing of moult, how it fits into the annual cycle and how synchronised moult is in the population. Relationships between the estimated moult parameters and a series of explanatory variables were explored. Critical gaps in our understanding of primary moult were revealed. The available data are taxonomically biased towards Charadriiformes and Passeriformes and there are substantial gaps in coverage across the phylogenetic tree. There are severe biases in the global distribution of moult studies across continents, with Africa having almost half of all applications of the moult model. Latitude emerged as an important explanatory variable but there are latitudinal gaps in the data, especially from the Tropic of Capricorn extending to 40°N and in the far northern and far southern hemispheres. Citizen scientists, both bird ringers and photographers, have a key role to play in helping to fill these data gaps. An emerging pattern in the available data is that the timing of primary moult is more synchronised in populations in far northern and far southern latitudes than in temperate or tropical zones, but more data in the far south is needed to confirm this. Timing of moult shows great variability in the tropics and sub-tropical regions of the southern hemisphere. In species that undertake an annual sequential moult, larger birds take longer to moult than smaller birds, but the allometric relationship is not tight. Migrants appear to be more synchronised in their moult than residents.

The biometrics of Grey-backed Sparrow-larks Eremopterix verticalis in the handbooks are based on small samples. We summarize wing-length, tail-length and mass of a sample of 130 Grey-backed Sparrow-larks mistnetted during ringing on the farm New Holme, Hanover District, Northern Cape, South Africa, in September 2023. The habitat was Grassy Karoo with, on average, March being the month of peak annual rainfall. The sample consisted of 58 females and 72 males. We examined birds for primary moult; 5% had moulted either one or two primaries, indicating that moult was commencing in the population as a whole. This observation, set in the context of an observation made in Namibia, suggests that this species undertakes a pre-breeding moult in spring and summer, prior to breeding in late summer and autumn.

Across all bird species, latitude plays an important role in determining patterns in timing, duration, and synchronisation of primary moult but, apart from Africa, moult studies at the southernmost limits of the continents and islands in the southern hemisphere are lacking. The focus of this study is the self-introduced silvereye (tauhou, Zosterops lateralis) in New Zealand, one of the most southern countries in the world. Moult data collected by bird banders during the period 1978-2022 were analysed using the Underhill-Zucchini moult model. Silvereyes had an estimated primary moult duration of 74 days, with a mean population start date of 3 February and a mean completion date of 19 April. Post-breeding primary moult in adult silvereyes starts soon after the breeding season and ends shortly before some of the more southern birds embark on their seasonal northward migratory movements. Juvenile primary moult is estimated to start approximately two weeks after the start of post-breeding moult in adults. A literature review suggested that primary moult duration for Zosterops species is similar regardless of latitude, but the timing of moult is variable and adjusted to local conditions.

The Underhill-Zucchini model of avian moult is a statistical simplification for the analysis of primary moult, a complex biological system in birds. As with all such models, conclusions can be biased if a subset of the data used to fit the model is strongly influential on the results. In the analysis of primary moult of a species, it is standard practice to assemble as many records as possible, frequently from different years or localities. We developed an approach, based on the concepts underpinning Cook's distance in regression, to evaluate the influence on the estimated moult parameters of groups of records that differ from the bulk of the data. The method is applied to a simulated dataset.

Between 2010 and 2022, the online journal Biodiversity Observations published 389 papers. In January 2023, the total number of downloads of these papers was 462,000. Between 2018 and 2022, 138 of the papers had been cited in Google Scholar, and had generated a total of 421 citations. The journal plans to continue publishing descriptive papers which report observations relating to biodiversity.

The spotted gully shark Triakis megalopterus (Triakidae) is a mesopredatory species endemic to southern Africa. It is currently listed as Least Concern on the IUCN Red List in accordance with an estimated increase in population size, general release by recreational linefishers and incidental catches in the commercial linefisheries. Previous research suggests this species to be resident, and as such it is likely to receive protection in coastal marine protected areas (MPAs). However, its ecology and movement behaviour remain poorly studied. This study employed acoustic telemetry to provide information on the species' movements along the coast of the Western Cape Province, South Africa. We used network analyses to investigate movement randomness, associations between individuals, sexual segregation, and the effectiveness of MPAs. Our findings reveal nonrandom movements as well as patterns of co-occurrence between individuals. Spatial network analysis suggested sexual segregation, because areas of high use (Walker Bay and De Hoop) differed between males and females. Co-occurrences were observed exclusively in Walker Bay, chiefly between males, with no co-occurrence found between females. The tagged spotted gully sharks were not detected extensively within existing MPA boundaries, though there was no significant difference between their movements inside and outside protected areas for both sexes.

A new moult index, the relative duration index (RDI), was developed to quantify progress through moult using the Underhill-Zucchini model of primary avian moult, with the Laughing Dove Spilopelia senegalensis as a case study. The RDI weights individual primaries in accordance with their estimated relative moult durations in the same way that proportion feather mass grown (PFMG) weights primaries in accordance with their relative masses. A sample of 1 893 moult records of adult Laughing Doves was used to study their primary moult. Moult parameters were estimated for three moult indices: the traditional moult score (TMS), PFMG and the RDI, and for each of the 10 primaries. Comparing the moult parameter estimates of each of the three indices to their respective cumulative growth curves obtained from the progression of moult of individual primaries, PFMG had the closest fit. However, any of the three moult indices would give satisfactory results for the Laughing Dove. Laughing Doves had an estimated primary moult duration of 215 days, with mean start and end dates of 3 November and 6 June, respectively. The standard deviation parameter was 66 days, which implies a lack of synchronisation of moult in adult doves. It was hypothesised that the RDI might be an appropriate moult index for species that moult one feather at a time and for which the individual moult durations are not proportional to their mass, as seen in Laughing Doves. However, this was not the case as PFMG provided the best fit. The RDI might also prove to be an appropriate moult index for species that moult multiple feathers simultaneously during part of the moult period and these feathers grow more slowly than when fewer feathers are moulting simultaneously.

We report the occurrence of a Red-billed Oxpecker Buphagus erythrorhynchus at the New Holme Nature Lodge, Hanover, Northern Cape, South Africa. Sightings were made over the period 4 May to 3 September 2022.

This short note reports an observation of Capped Wheatears Oenanthe pileata breeding in burrows made by Brant's Whistling Rat Parotomys brantsii. It points out that there is no record of the rodent species associated with the Capped Wheatear or whether there are preferred rodents. It also points out that there are large areas where the ranges of Capped Wheatears and Ant-eating Chats Myrmecocichla formicivore overlap. The latter species also breeds in association with mammals. There are possibilities of joint studies.