Biodiversity Observations

Millions of Caper Whites Belenois aurota 100 km offshore of West Africa

2023-03-22T17:37:33+02:00

At least 4.3 million Caper Whites Belenois aurota were observed at sea in the Atlantic Ocean offshore of Senegal and The Gambia between 14 and 18 October 2003. They were moving to the southwest, carried by the northeasterly wind.

Spotted Gully Shark Triakis megalopterus at Robben Island, Table Bay, South Africa

2023-03-15T12:30:16+02:00

We report a sighting of a Spotted Gully Shark Triakis megalopterus at Robben Island, 7 km from the nearest mainland, in Table Bay, South Africa. The sighting was made on 18 February 2023 within an hour of high tide.

Reptiles and Amphibians of the Cape of Good Hope Nature Reserve, Western Cape, South Africa

2023-03-14T16:08:50+02:00

The status of all the reptile and amphibian species that have been recorded in the Cape of Good Hope Nature Reserve (the southern section of the Table Mountain National Park) is described. A total of 57 species has been recorded, comprising seven tortoises and turtles, 14 lizards, one chamaeleon, 20 snakes, two platannas, and 13 frogs and toads. The Reserve is an important stronghold of the IUCN-classified ‘Endangered’ Cape Platanna Xenopus gilli, and holds the discrete southern population of the range-restricted, ‘Near Threatened’ Cape Peninsula Moss Frog Arthroleptella lightfooti.

Cetacean sightings from Mozambican waters, including the first records of Rough-toothed Dolphin Steno bredanensis and Fraser’s Dolphin Lagenodelphis hosei

2022-03-16T21:16:40+02:00

Opportunistic cetacean sightings were made during a 79-day fishing trip through southern and central Mozambican waters. Notable sightings included the first Mozambican records of Rough-toothed Dolphin Steno bredanensis and Fraser’s Dolphin Lagenodelphis hosei, although both species have been recorded from neighbouring South African and Tanzanian waters. A number of other rarely seen cetacean species, with few Mozambican records, were also recorded.

Near-exclusive use of Setaceus Asparagus Fern Asparagus setaceus in the construction of nests by three South African bird species

2021-05-21T15:10:40+02:00

The nesting material used by birds can be an important habitat requirement and a potential limiting factor for the successful reproduction of many bird species. I present records of the use of the Setaceus Asparagus Fern Asparagus setaceus by Bronze Mannikin Lonchura cucullata, and Swee Waxbill Coccopygia melanotis (Family Estrildidae) and Amethyst Sunbird Chalcomitra amethystine (Family Nectariniidae) in the Western Cape, South Africa. It is the large percentage of fronds of Setaceus Asparagus Fern which have been used in these nests which is of particular interest.

Knob-billed Duck Sarkidiornis melanotos moulting in the Free State

2023-03-02T19:46:47+02:00

Some Knob-billed Ducks Sarkidiornis melanotos in flightless moult were photographed on a farm dam in the central Free State Province of South Africa in May 2019. Although fairly common in the north-eastern quarter of southern Africa, this is apparently only the third record of this species moulting in the sub-region.

Northern Shoveler Spatula clypeata: a possible first breeding record for Algeria

2022-04-16T01:15:24+02:00

Breeding events of a waterbird species outside of their normal breeding grounds could be important to address how population changes on wintering areas are impacted by changes elsewhere in the birds’ annual cycle. In this note we confirm the first breeding record of Northern Shoveler Spatula clypeata in Algeria. The breeding site was a saline lake, Sebkhet El-mahmel, located 180 km from the Mediterranean Sea and subject to a semi-arid climate. The area was visited on 16 June 2019 and the species was confirmed as a pair of Northern Shoveler accompanied by eight juveniles. The Northern Shoveler is an unmistakable waterbird species in the northern hemisphere due to its distinctive bill. The female and her juveniles looked healthy and they spent almost the entire daytime foraging and swimming.

Impact of cold and wet weather on Common Swifts Apus apus (with comments)

2020-02-06T18:30:25+02:00

This note describes the effects of a cold and wet weather event on the Common Swifts Apus apus.

Breeding range extension of Southern Carmine Bee-eater Merops nubicoides in Botswana

2020-06-07T17:00:28+02:00

This paper reports the first observations of Southern Carmine Bee-eater Merops nubicoides breeding in the Limpopo drainage system, in Botswana, and suggests that it is likely that this species also breeds on the banks of the Limpopo River, on the South African side.

Sparrows roosting and breeding in old nests of Cape Weavers Ploceus capensis

2023-02-13T16:10:05+02:00

The first record of Southern Grey-headed Sparrows Passer diffusus breeding in a nest in an old colony of Cape Weavers Ploceus capensis is described. This is the second record of this species breeding in any weaver nest. A pair of Cape Sparrows Passer melanurus were observed roosting in another nest in the colony. They returned to the same nest during the night after being disturbed.

Observations and analysis of Ayres’s Hawk-Eagle Hieraaetus ayresii occurrence and behaviour over the Linksfield Ridge, Johannesburg, South Africa

2022-08-01T17:51:49+02:00

A series of sightings of the Ayres’s Hawk-Eagle (Hieraaetus ayresii) were made over two summers in 2020-2021 and 2021-2022 from a property in Fellside, north-eastern Johannesburg. Sightings of the species were of individual birds in flight over the Linksfield Ridge and Louis Botha Avenue, both located a short distance to the south of the observation location. It is postulated that the combination of an abundance of prey in the form of Rock Doves (Columba livia) that inhabit the built-up urban environment of Louis Botha Avenue in high densities and the presence of a well vegetated (effectively wooded) ridge in close proximity appear to be the factors that draw the species to this particular location within Johannesburg. Although the sighting records did not form part of a dedicated monitoring protocol, the observations of the species were submitted to the SABAP2 project, and these and other records of the species in Johannesburg and Pretoria have been analysed to gain an understanding of the timing of the species’ occurrence within the urban centres of Gauteng. The wider SABAP2 dataset indicates that the species has been most commonly recorded in mid-summer (the months of December and February), with the next highest monthly recording rates being for spring and early summer. Further monitoring and observations for the presence of this species are recommended in areas of suitable habitat within Johannesburg (ridges in close proximity to concentrations of Rock Dove populations) to determine if it favours such location and occurs more widely and commonly than currently understood.

Records of tail bifurcation in rainbow lizards Agama agama (Linnaeus, 1758) in Umudike, Nigeria

2020-07-03T08:27:00+02:00

This paper reports sightings of rainbow lizards Agama agama with bifurcated tails in a community in Umudike, Nigeria. Five individuals (two males and three females) were sighted within one month at different occasions within approximately 1 km radius in a semi-urban habitat with high human activity. We consider this to be an unusual aberration among lizard populations in the tropical forest ecosystem in Nigeria. Hence, we believe that there could be a genetic or environmental connotation to the high frequency of occurrence of this aberration within the locality.

Observations of claw differences in an invasive crayfish (Orconectes virilis)

2022-05-22T04:54:02+02:00

The Northern Crayfish (Orconectes virilis) is a relatively new invasive species to Calgary, Alberta Canada. We observed unique morphological characteristics concerning the claws (cheliped) of four (3 males and 1 female) out of 31 crayfish captured using a sweep sampling method from a creek in Calgary, Canada. These specimens exhibited a notable difference in claw size between the right and left claws. Differences in claw sizes can be attributed to an ongoing process of regeneration due to loss of the crayfish’s cheliped.

Prey items of Southern Fiscal Lanius collaris in southern Namibia

2022-07-28T15:46:50+02:00

Although Southern Fiscals Lanius collaris are a common species in southern Namibia, we found only 18 impalements of prey items. We discuss these in relation to the species impaled, the site of impalement, the height above ground and the time of the year. We suggest that the small number of observations was due to the fact that the study period (July 2017 to June 2022) had below average rainfall, that food was therefore scarce and consumed, and that impalements events were rare.

Arthropod associates of a Yellow-billed Cuckoo Coccyzus americanus on Vaca Key, Monroe County, Florida, USA

2021-12-08T15:40:16+02:00

Examination of a carcass of a Yellow-billed Cuckoo Coccyzus americanus (L.) (Cuculiformes: Cuculidae) provided the first record of a louse in the genus Cuculoecus (Psocodea: Philopteridae), a springtail Seira brasiliana (Arlé) (Collembola: Entomobryidae), and a tetranychid mite in the genus Oligonychus (Trombidiformes: Tetranychidae), from Vaca Key, Monroe County, Florida, USA.

Web-sourced photographic methods reveal dietary composition and shifts in resident and migrant Coracias rollers in southern Africa

2022-06-04T19:48:21+02:00

Closely related species coexisting in the same niche often have dietary overlap and interspecific competition can result in resource partitioning e.g., dietary shifts, migration or phenological changes. Traditional methods to study avian diets are typically costly, difficult, and invasive. Using web-sourced photographs is an emerging, non-invasive method to study avian foraging ecology. We used this approach, along with photographic road surveys, to study prey composition of migratory European Rollers Coracias garrulus and resident Lilac-breasted Rollers Coracias caudatus where they co-occur in southern Africa. These insectivorous sister species are frequently photographed with prey in their bills because of their conspicuous perch-and-wait foraging behaviour and bright plumage coloration. We collated over 250 photographs of rollers holding prey and identified prey items representing 15 animal orders. Lilac-breasted Roller diet contained six unique orders of prey during the Austral summer (when the European Roller is present), and only one during winter (when the European Roller has migrated north). This suggests that Lilac-breasted Rollers may broaden their diet seasonally to alleviate competition with European Rollers during summer. Additionally, Lilac-breasted and European Rollers had an 84% overlap in dietary composition, potentially representing high interspecific competition - even during wet savanna summers when resource abundance is high - that might have originally driven the evolution of migratory behaviour in the European Roller. Our findings expand the current knowledge of roller diets and highlighting the growing role of social media in ecological studies.

Red-billed Oxpecker Buphagus erythrorhynchus in the KhoiSan Karoo Conservancy, Northern Cape, South Africa

2023-02-01T08:10:20+02:00

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.

Attempted forced copulation by an immature Red-winged Blackbird male: Video evidence from the Grand River Grasslands of Iowa and potential explanations

2022-09-22T15:41:43+02:00

Forced copulations are a type of sexual coercion that typically occurs when the fitness interests of males and females are in conflict. Forced copulations are rare in most species of birds, and there are only a few reports in passerine species. Here we report the first published observation of an immature Red-winged Blackbird Agelaius phoeniceus male attempting a forced copulation on a nesting Red-winged Blackbird female. We describe the behaviour and discuss potential explanations and implications for our observations.

A Guide to the Common Garden Birds of Cape Town, South Africa

2023-01-25T11:18:26+02:00

This annotated picture booklet aims to provide a quick identification guide to the common birds in Cape Town’s urban gardens. This guide covers the 32 species you are most likely to encounter; though it is not comprehensive, the species included have been carefully selected to help you make a start.

The open-access journal Biodiversity Observations: report for the period 2010-2022

2023-01-20T08:46:43+02:00

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.