Female response and male signals in the acoustic communication system of the field cricket, Gryllus bimaculatus (De Geer)

Sexual selection is a frame of reference that attempts to explain exaggerated signaling traits, including acoustic signals between male and female animals. Contemporary studies in the field of sexual selection are focused on the evolution of female mating preferences, with particular emphasis being placed on the good genes models of sexual selection. Here I investigate whether sexual selection is in operation in the acoustic communication system of the field cricket, Gryllus bimaculatus. Through development of new methodology I show that female crickets have a distinct and repeatable preference and selectivity for certain male song traits. For sexual selection to operate in acoustic communication systems, males must advertise some aspect of their phenotype that will influence female choice. I demonstrate that the basis for arguments invoking sexual selection for spectral song traits in a sister species, G. campestris, which is that tegmen harp area predicts song frequency, is an invalid assumption for sound production in G. bimaculatus. As a result of this finding I investigated what aspects of male song were condition- and morphology-dependent. Temporal and spectral male song traits did not convey information regarding body condition, body size or the ability to withstand developmental instability (as indicated by fluctuating asymmetry). I was unable to detect handicap sexual selection for spectral characteristics of male song despite repeatable female preference for male song frequency. Furthermore, female preference for spectral bandwidth of male song, thought to be a sexually selected trait, was shown to be governed by preference for frequency and therefore not a distinct preference. The lack of detectable sexual selection, together with observed patterns of phenotypic variation in signals and the equivalent response system, suggest that some of the male song traits function for mate recognition. However, sexual selection for call traits not considered here (e.g. duration of calling) is probable.Dissertation (MSc (Zoology))--University of Pretoria, 2006.Zoology and Entomologyunrestricte

A new species of Scolecoseps (Reptilia: Scincidae) from coastal north-eastern Mozambique

Seven specimens of Scolecoseps Loveridge, 1920 from the vicinity of Palma on the north coast of Mozambique are compared morphologically with other known material of this genus. The new material can be distinguished morphologically from all other Scolecoseps by the presence and position of certain head scales, particularly a supraciliary and four small suboculars, a small mental and high subcaudal counts. It is described as a new species, Scolecoseps broadleyi sp. nov. The new species is found in coastal savannah habitat under leaf litter of Berlinia orientalis trees, in sandy soils in close proximity to large wetlands. Its currently known distribution is south of the range of Scolecoseps litipoensis Broadley, 1995 and north of that of Scolecoseps boulengeri Loveridge, 1920. We provide a review of the available literature for the genus Scolecoseps and highlight the necessity for additional research on these poorly known fossorial skinks.Enviro-Insighthttp://www.tandfonline.com/loi/ther202019-03-11hj2018Zoology and Entomolog

Does sexual selection explain the courtship song of field crickets (Gryllus bimaculatus)?

This study evaluates the factors that may potentially affect the courtship songs of Gryllus bimaculatus, (including: wing morphology, male body size and the male’s current nutritional condition) and whether female crickets assess male courtship song.This paper was initially delivered at the Annual Congress of the Biological Sciences Division of the South African Academy for Science and Art, ARC-Plant Protection Research Institute, Roodeplaat, Pretoria, South Africa on 01 October 2010.http://www.satnt.ac.zaam2014ab201

Contributions to the herpetofauna of the Angolan Okavango-Cuando-Zambezi river drainages. Part 3 : Amphibians

This article is the third and final installment of the herpetofaunal results obtained from a series of rapid biodiversity surveys of the upper Cuito, Cubango, Cuando, Zambezi, and Kwanza River basins in Angola. The amphibian survey results are presented along with an updated checklist of the historical and current records of amphibians from the southeastern region of Angola. A total of 1,114 new amphibian records were documented, comprising 37 species, bringing the total number of recognized amphibian species in this region to 49. These surveys documented two new country records (Hyperolius cf. inyangae and Kassinula wittei) and at least two candidate new species, and elevated Amnirana adiscifera stat. nov. (which now encompasses the western green form formerly regarded as A. darlingi). Finally, updated distribution maps for all of Angola are provided for all the species encountered within the study region.The NRF-SAIAB Institutional Support System.http://amphibian-reptile-conservation.orgZoology and Entomolog

Are high elevation crag lizards sensitive to climate change?

Crag lizards are restricted to montane areas where biota are strongly exposed to the effects of climate change. We investigated the factors shaping the distribution of Drakensberg crag lizards (Pseudocordylus melanotus melanotus; Cordylidae) by quantifying their elevational ranges, availability of shelter and prey as well as the thermal environment at three elevations. We recorded expected body temperatures using copper models of the lizards at each elevation in the field and in the laboratory, estimating the duration for which lizards must shelter from high temperatures. This correlated strongly with field observations of lizard activity during winter, spring and summer. Our models predicted that at lower elevations, lizards would shelter for longer periods each day, resulting in a marked reduction in time available for essential activities such as feeding and breeding, possibly explaining why these animals do not occur at lower elevations. The distribution and survival of these animals therefore appear to be impacted by the degree to which daytime temperatures limit their activity. Modelling future climate change scenarios at the high elevation site indicates that crag lizards would be resilient against small to moderate warming reflected by RCP4.5 climate change predictions, but populations are unlikely to persist under conditions predicted in the RCP8.5 scenario. This study is important as, unlike broader-scope studies that cannot quantify climate change impacts on individual species, we combine detailed field data with laboratory measurements and modelling of a single species to assess the ecological constraints to which crag lizards are exposed.The University of Pretoria and the National Research Foundation.https://onlinelibrary.wiley.com/journal/14429993hj2022Geography, Geoinformatics and MeteorologyPhysicsZoology and Entomolog

Contributions to the herpetofauna of the Angolan Okavango- Cuando-Zambezi river drainages. Part 2 : Lizards (Sauria), chelonians, and crocodiles

This work is the second report of the results obtained from a series of rapid biodiversity surveys of the upper Cuito, Cubango, Cuando, Zambezi, and Kwanza River basins in Angola, which were conducted between 2015 and 2019 in conjunction with the National Geographic Okavango Wilderness Project. The herpetofauna of this region are poorly documented and the results of these surveys help to address the knowledge gap regarding the conservation importance of this region. Here, an updated checklist is provided for the current and historical records of lizards, chelonians, and crocodiles from the southeastern region of Angola. A total of 369 new records were documented comprising 40 species, bringing the total number of recognized lizard, chelonian, and crocodile species in this region to 58. These surveys documented four new country records (i.e., Lygodactylus chobiensis, Agama armata, Pachydactylus wahlbergii, and Ichnotropis cf. grandiceps) and increased the total number of reptile species known to occur in Angola (excluding snakes) from approximately 157 to 161. Finally, updated distribution maps for the whole country are provided for all of the species encountered in this study.Este trabalho é a segunda parte dos resultados de uma série de levantamentos rápidos de biodiversidade realizados nas bacias dos rios Cuito, Cubango, Cuando, Zambeze e Kwanza em Angola, entre 2015 e 2019, em conjunto com o National Geographic Okavango Wilderness Project. A herpetofauna desta região está pouco documentada, e os resultados destes levantamentos ajudarão a colmatar a lacuna de conhecimento sobre a importância da sua conservação. Aqui apresentamos uma lista atualizada de registos históricos e recentes dos lagartos, quelónios e crocodilos do sudeste de Angola. Ao todo, foram documentado 369 novos registros, relativos a 40 espécies, elevando o número total de espécies desses três grupos na região para 58. Nestes levantamentos foram registadas em Angola pela primeira vez quatro as espécies de lagartos (Lygodactylus chobiensis, Agama armata, Pachydactylus wahlbergii, Ichnotropis cf. grandiceps), aumentando o número total de espécies conhecidas de répteis (excluindo cobras) de Angola de 157 para 161. Por fim, apresentamos mapas de ocorrência/distribuição atualizados das espécies encontradas neste estudo para todo o país.The Wild Bird Trust, which administers the National Geographic Okavango Wilderness Project.amphibian-reptile-conservation.orgam2023Zoology and Entomolog

Loveridge's Angolan geckos, Afroedura karroica bogerti and Pachydactylus scutatus angolensis (Sauria, Gekkonidae) : new distribution records, comments on type localities and taxonomic status

Loveridge described two new geckos from Angola, Afroedura karroica bogerti and Pachydactylus scutatus angolensis. The descriptions of both species have vague and confusing type localities and refinements are suggested based on early expedition reports and historical accounts from the region. Numerous new distribution records are reported for both species from expeditions undertaken from 1956–2016 by the authors or their colleagues. The taxonomic status of both species has changed, but new material from diverse habitats, altitudes and geological substrates indicates that further taxonomic adjustments are likely in order to reflect additional cryptic diversity.Steve Boyes and John Hilton of the Wild Bird Trust, administers of the National Geographic Okavango Wilderness Project (National Geographic Society grant number EC0715–15) during which WRB, WC, NB, PVP & LV participated in the biodiversity surveys of the headwaters of the Cuito and Cuanavale Rivers (2015–2016).http://zse.pensoft.nethb2017Zoology and Entomolog

A review of the Angolan House snakes, genus Boaedon Duméril, Bibron and Duméril (1854) (Serpentes: Lamprophiidae), with description of three new species in the Boaedon fuliginosus (Boie, 1827) species complex

An integrative taxonomic review of the genus Boaedon in Angola is provided. A molecular phylogeny, based on 99 genetic samples for which the mitochondrial markers 16S rRNA have been sequenced, reveals 23 monophyletic species-level groups in Africa and indicates the presence of nine species in Angola. Based on both phylogenetic and morphological data, we revalidate and designate a neotype for B. angolensis, describe three new species for Angola (e.g. B. bocagei sp. nov., B. branchi sp. nov., and B. fradei sp. nov.), revalidate B. variegatus from its synonymy with B. lineatus and designate a lectotype for this taxon, and identify B. lineatus var. lineolatus as a junior synonym of B. variegatus. The taxonomic status of the recently described B. paralineatus from Central Africa is discussed with respect to the more inclusive B. lineatus group. Moreover, we report on a new country record for Angola, namely B. mentalis, which we elevate here to full species and discuss the taxonomic status of this species in southern Africa. Finally, we provide an identification key and updated distribution maps for all Boaedon species occurring in Angola, including the Cabinda enclave.The National Science Foundation of the United States, the JRS Biodiversity Foundation, FCT, the National Geographic Okavango Wilderness Project and the Wild Bird Trust National Geographic Okavango Wilderness Project.https://www.tandfonline.com/loi/ther202021-07-08hj2021Zoology and Entomolog

The bii4africa dataset of faunal and floral population intactness estimates across Africa’s major land uses

Sub-Saharan Africa is under-represented in global biodiversity datasets, particularly regarding the impact of land use on species’ population abundances. Drawing on recent advances in expert elicitation to ensure data consistency, 200 experts were convened using a modified-Delphi process to estimate ‘intactness scores’: the remaining proportion of an ‘intact’ reference population of a species group in a particular land use, on a scale from 0 (no remaining individuals) to 1 (same abundance as the reference) and, in rare cases, to 2 (populations that thrive in human-modified landscapes). The resulting bii4africa dataset contains intactness scores representing terrestrial vertebrates (tetrapods: ±5,400 amphibians, reptiles, birds, mammals) and vascular plants (±45,000 forbs, graminoids, trees, shrubs) in sub-Saharan Africa across the region’s major land uses (urban, cropland, rangeland, plantation, protected, etc.) and intensities (e.g., large-scale vs smallholder cropland). This dataset was co-produced as part of the Biodiversity Intactness Index for Africa Project. Additional uses include assessing ecosystem condition; rectifying geographic/ taxonomic biases in global biodiversity indicators and maps; and informing the Red List of Ecosystems

Resting and nesting in a small mammal : sleeping sites as a limiting resource for female grey mouse lemurs

Animals spend a substantial proportion of their lives resting and consequently the choice of a sleeping site can dramatically affect an individual's fitness. Sleeping sites have been implicated in predator defence and thermoregulation and their distribution can affect breeding and social systems in small mammals. Sleeping sites may constitute a limiting resource for females which experience energetic constraints to breeding and require shelter for their young. Despite the potential importance of sleeping sites, exhaustive studies of the factors determining their usage patterns are limited to a small number of mammal groups. We investigated how seasonal changes in temperature or the presence of young shape sleeping site usage patterns in a small primate, the grey mouse lemur, Microcebus murinus. Females preferred tree holes over nests and open sites and the usage duration of a particular tree hole site was affected by the physical characteristics likely to affect its insulation properties. Furthermore, climate variables strongly affected sleeping site choices and nests were chosen more often than tree holes during the wet season. However, when young were present preferences shifted back to tree holes. Preferred tree species used as sleeping sites as well as the properties of tree holes were rare among trees in the study area, suggesting that sleeping sites may indeed be a limiting resource for female grey mouse lemurs. Our results suggest that in the study species sleeping site choices are governed by thermoregulatory considerations and their limited availability could also account for the social grouping