Climate change drives speciation in the southern rock agama (Agama atra) in the Cape Floristic Region, South Africa

Aim Vicariance has played a major role in the evolution of the southern rock agama, Agama atra (Reptilia: Agamidae), and it is hypothesized that habitat shifts will affect small‐scale patterns of gene flow. The Cape Floristic Region (CFR) is known for high levels of diversity and endemism; thus we set out to investigate whether genetic structuring of CFR populations of A. atra corresponds to regional environmental shifts. Location Cape Fold Mountains and the Cape Floristic Region of South Africa. Methods The phylogeographical structure of 116 individuals of A. atra was determined by making use of 988 characters derived from two mitochondrial DNA fragments (control region and the NADH dehydrogenase subunit 2 coding region, ND2). Most animals originated from the CFR, but to gain a better understanding of the processes and patterns of dispersal within the species, 17 additional specimens from outside the CFR were also included and analysed in a phylogenetic context. Results Parsimony and Bayesian analyses revealed four distinct CFR clades (Cape clades) associated with geography. Phylogenetic analyses suggest that populations of A. atra in the CFR region are not entirely isolated from other populations, because some individuals from outside the CFR were nested within the four main Cape clades. The combined mitochondrial DNA data set revealed 59 distinct haplotypes in the CFR. Analysis of molecular variance (amova ) confirmed the high degree of genetic structure among the Cape clades, with more than 75% of the genetic variation found among the geographical areas. A spatial amova suggested that a ‘central clade’ originally defined as one of the four Cape clades may contain several additional populations. The main cladogenesis of A. atra within the CFR is estimated to have taken place c. 0.64–2.36 Ma. Main conclusions Agama atra shows at least four distinct genetic provinces within the CFR region, which highlights the conservation importance of this biologically diverse area. The dates of separation among the clades coincide well with the documented Pleistocene climate fluctuations, which might have contributed towards the isolation among lineages; the congruent genetic structure of A. atra with other CFR taxa further supports vicariance as a main isolating factor.     

Invasion history of Lycium ferocissimum in Australia: The impact of admixture on genetic diversity and differentiation

Aim

We investigated the invasion history of Lycium ferocissimum, a spine-covered shrub native to South Africa that was introduced to Australia in the mid-1800s, and has since developed into a damaging invasive plant of undisturbed landscapes and pastures. In addition to identifying the provenance of the Australian plants, we tested for evidence of admixture, and contrasted genetic diversity and structuring across the native and introduced ranges.

Location

Samples were collected across South Africa (24 localities) and Australia (26 localities).

Methods

We used genotyping-by-sequencing (3117 SNPs across 381 individuals) to assess population genetic structuring in L. ferocissimum across Australia and South Africa. Coalescent analyses were used to explicitly test contrasting invasion scenarios.

Results

Clear geographic genetic structuring was detected across South Africa, with distinct clusters in the Eastern and Western Cape provinces. The L. ferocissimum plants in Australia form their own genetic cluster, with a similar level of genetic diversity as plants in South Africa. Coalescent analyses demonstrated that the lineage in Australia was formed by admixture between Eastern Cape and Western Cape plants, with most of the genetic material from the Australian lineage originating from the Western Cape. Our analyses suggest that L. ferocissimum plants were originally introduced to South Australia, though it is unclear whether admixture occurred before or after its introduction to Australia. We detected little evidence of geographic genetic structure across Australia, although many of the populations were genetically distinct from one another.

Main Conclusions

Our results illustrate how admixture can result in genetically diverse and distinct invasive populations. The complex invasion history of L. ferocissimum in Australia poses particular challenges for biological control. We suggest potential biological control agents should be screened against admixed plants (in addition to plants from the Eastern and Western Cape) to test whether they provide effective control of the genetically distinct invasive lineage.     

Cryptic diversity in forest shrews of the genus Myosorex from southern Africa,with the description of a new species and comments on Myosorex tenuis

Forest or mouse shrews (Myosorex) represent a small but important radiation of African shrews generally adapted to montane and/or temperate conditions. The status of populations from Zimbabwe, Mozambique, and the north of South Africa has long been unclear because of the variability of traits that have traditionally been ‘diagnostic’ for the currently recognized South African taxa. We report molecular (mitochondrial DNA and nuclear DNA), craniometric, and morphological data from newly collected series of Myosorex from Zimbabwe (East Highlands), Mozambique (Mount Gorogonsa, Gorongosa National Park), and the Limpopo Province of South Africa (Soutpansberg Range) in the context of the available museum collections from southern and eastern Africa and published DNA sequences. Molecular data demonstrate close genetic similarity between populations from Mozambique and Zimbabwe, and this well‐supported clade (herein described as a new species, M yosorex meesteri sp. nov. ) is the sister group of all South African taxa, except for Myosorex longicaudatus Meester & Dippenaar, 1978. Populations of Myosorex in Limpopo Province (herein tentatively assigned to Myosorex cf. tenuis) are cladistically distinct from both Myosorex varius (Smuts, 1832) and Myosorex cafer (Sundevall, 1846), and diverged from M. varius at approximately the same time (2.7 Mya) as M. cafer and Myosorex sclateri Thomas & Schwann, 1905 diverged (2.4 Mya). Morphometric data are mostly discordant with the molecular data. For example, clearly distinct molecular clades overlap considerably in craniometric variables. On the other hand, extreme size differentiation occurs between genetically closely related populations in the Soutpansberg Range, which coincides with the bissection of the mountain range by the dry Sand River Valley, indicating the potential for strong intraspecific phenotypic divergence in these shrews. © 2013 The Linnean Society of London     

Phylogeography of the pademelons (Marsupialia: Macropodidae: Thylogale) in New Guinea reflects both geological and climatic events during the Plio‐Pleistocene

Aim Alternative hypotheses concerning genetic structuring of the widespread endemic New Guinean forest pademelons (Thylogale) based on current taxonomy and zoogeography (northern, southern and montane species groupings) and preliminary genetic findings (western and eastern regional groupings) are investigated using mitochondrial sequence data. We examine the relationship between the observed phylogeographical structure and known or inferred geological and historical environmental change during the late Tertiary and Quaternary. Location New Guinea and associated islands. Methods We used primarily museum specimen collections to sample representatives from Thylogale populations across New Guinea and three associated islands. Mitochondrial cytochrome b and control region sequence data were used to construct phylogenies and estimate the timing of population divergence. Results Phylogenetic analyses indicated subdivision of pademelons into ‘eastern’ and ‘western’ regional clades. This was largely due to the genetic distinctiveness of north‐eastern and eastern peninsula populations, as the ‘western’ clade included samples from the northern, southern and central regions of New Guinea. Two tested island groups were closely related to populations north of the Central Cordillera; low genetic differentiation of pademelon populations between north‐eastern New Guinea and islands of the Bismarck Archipelago is consistent with late Pleistocene human‐mediated translocations, while the Aru Islands population showed divergence consistent with cessation of gene flow in the mid Pleistocene. There was relatively limited genetic divergence between currently geographically isolated populations in subalpine and nearby mid‐montane or lowland regions. Main conclusions Phylogeographical structuring does not conform to zoogeographical expectations of a north/south division across the cordillera, nor to current species designations, for this generalist forest species complex. Instead, the observed genetic structuring of Thylogale populations has probably been influenced by geological changes and Pleistocene climatic changes, in particular the recent uplift of the north‐eastern Huon Peninsula and the lowering of tree lines during glacial periods. Low sea levels during glacial maxima also allowed gene flow between the continental Aru Island group and New Guinea. More work is needed, particularly multi‐taxon comparative studies, to further develop and test phylogeographical hypotheses in New Guinea.     

Relative importance of habitat connectivity in shaping the genetic profiles of two southern African elephant‐shrews

Aim When interpreting genetic patterns across a landscape it is surprisingly difficult to disentangle the effects of landscape connectivity from those of species biology. Here, the spatial distributions of genetic variation of two sympatric elephant‐shrew species, the western rock elephant‐shrew (Elephantulus rupestris) and the round‐eared elephant‐shrew (Macroscelides proboscideus), are determined and compared. We selected these species because they have similar biologies but differ markedly in habitat use, the rationale being that differences in their genetic structure should be a result largely of landscape variables directly or indirectly affecting dispersal rather than of the biology of the species. Location South Africa and Namibia. Methods Mitochondrial sequence data (control region and cytochrome b) were used to describe the phylogeographic structure of these elephant‐shrew species across their distribution. To determine whether genetic variation is significantly structured, spatial analyses of molecular variation were performed. Isolation‐by‐distance versus alternative patterns of genetic structure was investigated using a Mantel test. Results Our analyses indicated an overall structured genetic profile for E. rupestris, a species closely associated with rocky outcrops. This was in contrast to a pattern mostly of isolation‐by‐distance across the distribution of M. proboscideus, a species found on gravel plains. Main conclusions Specific landscape features will differentially affect gene flow (both historical and current), and therefore also the spatial genetic structure, of species with markedly different habitat requirements. The genetic profiles for the two species included here support predictions based on the connectivity of their respective occupied habitats. The results also support the more general prediction that species with a naturally clustered distribution (such as E. rupestris) should have a more structured genetic pattern than those having a more continuous distribution (M. proboscideus).     

A review of the taxonomic status and biology of the Cape Parrot Poicephalus robustus,with reference to the Brown-necked Parrot P. fuscicollis fuscicollis and the Grey-headed Parrot P. f. suahelicus

A review of the taxonomic status of the critically endangered Cape Parrot Poicephalus robustus Gmelin 1788 has important implications concerning the conservation of this species and illegal trade. It is distinguishable from the Brown-necked Parrot P. fuscicollis fuscicollis Kuhl 1820 on the morphometrics of the body and bill, two mitochondrial DNA sequences and its ecology and behaviour. The Grey-headed Parrot P. f. suahelicus Reichenow 1898 is geographically and genetically isolated from the other taxa. Grey-headed Parrots and Brown-necked Parrots are more closely related to each other than either is to the Cape Parrot. Geographically, the Grey-headed Parrot is marginally parapatric with the Cape Parrot, and this account focusses on these taxa. The Cape Parrot is a dietary specialist, and its diet differs from that of the Grey-headed Parrot, which has a wider trophic niche, although both feed on the kernels of unripe fruit. Their feeding behaviour changes in response to seasonally available food and may involve long distance movements. Both species share similar breeding habits, but they breed at different seasons in different habitat types. The two taxa have distinct habitat requirements and distributions. Cape Parrots inhabit, nest and feed in Afromontane mixed Podocarpus forest above 1 000m asl in South Africa, whereas Grey-headed Parrots inhabit a wide range of lowland woodland habitats across south-central Africa. In parapatry, there is no record of hybridisation, probably because of spatial (geographical and altitudinal) and temporal segregation (different breeding seasons). On the basis of these criteria, the Cape Parrot is, and must be recognised, as an independent species.     

Deep phylogeographic structure may indicate cryptic species within the Sparid genus Spondyliosoma

Two geographically nonoverlapping species are currently described within the sparid genus Spondyliosoma: Spondyliosoma cantharus (Black Seabream) occurring across Mediterranean and eastern Atlantic waters from NW Europe to Angola and S. emarginatum (Steentjie) considered endemic to southern Africa. To address prominent knowledge gaps this study investigated range-wide phylogeographic structure across both species. Mitochondrial DNA sequences revealed deep phylogeographic structuring with four regionally partitioned reciprocally monophyletic clades, a Mediterranean clade and three more closely related Atlantic clades [NE Atlantic, Angola and South Africa (corresponding to S. emarginatum)]. Divergence and distribution of the lineages reflects survival in, and expansion from, disjunct glacial refuge areas. Cytonuclear differentiation of S. emarginatum supports its validity as a distinct species endemic to South African waters. However, the results also indicate that S. cantharus may be a cryptic species complex wherein the various regional lineages represent established/incipient species. A robust multilocus genetic assessment combining morphological data and detailing interactions among lineages is needed to determine the full diversity within Spondyliosoma and the most adequate biological and taxonomic status.     

Aquatic biodiversity in the mediterranean region of South Africa

The Cape mediterranean region, part of South Africa’s Cape Floristic Realm (CFR), is recognised for its rich diversity and high degree of endemism of terrestrial vegetation. We review the biodiversity of the aquatic flora and fauna using literature sources and museum data. Geological, palaeohistorical and climate data are examined in relation to the formation of the winter-rainfall regime. Prehistoric humans had minimal impact on the aquatic biotas. Patterns and processes relating to the present-day climate, ecosystem status, distribution and diversity of plants, invertebrates and vertebrates in the CFR are reviewed. The proportion of endemic CFR species relative to the total number of species known from southern Africa is estimated. Observed distribution patterns are evaluated against temperate Gondwana vicariance, old African migrations, the role of the ancient Cape fold mountains and Pangaea. The lack of Pleistocene glaciations in Africa, the oligotrophic nature of the river systems and the palaeohistorical origin and distribution of taxa are considered when assessing reasons for disjunct distribution patterns. Impacts of anthropogenic interference with aquatic ecosystems are evaluated. Fragmented jurisdiction of nature conservation authorities is seen as a problem for attaining adequate conservation of CFR aquatic ecosystems. Systematic conservation planning is under way for the region.     

Population structuring in mountain zebras (<Emphasis Type="Italic">Equus zebra</Emphasis>): The molecular consequences of divergent demographic histories

The endangered mountain zebra (Equus zebra) is endemic to the semi-arid inhospitable mountainous escarpments of southern Africa. The species is divided taxonomically into two geographically separated subspecies, each with differing recent population histories. In Namibia, Hartmann’s mountain zebra (E. z. hartmannae) is common and occurs in large free-ranging populations, whereas in South Africa, prolonged hunting and habitat destruction over the last 300 years has decimated populations of the Cape mountain zebra (E. z. zebra). In this study, we investigate the consequences of these divergent demographic histories for population genetic diversity and structure. We also examine the phylogeographic relationship between the two taxonomic groups. Genetic information was obtained at 15 microsatellite loci for 291 individuals from a total of 10 populations as well as 445 bp of the mitochondrial control region sequence data from 77 individuals. Both model-based and standard analytical approaches were used to examine the data. Both types of marker returned levels of diversity and structure that were consistent with population history. Low genetic variation within individual Cape mountain zebra populations, the characteristic indicator of population fragmentation and drift, was offset by moderate variation in the entire E. z. zebra sample. This implies that higher levels of diversity still exist within the Cape mountain zebra gene pool. A management strategy that entailed the mixing of aboriginal populations is therefore advocated in order to halt the further loss of Cape mountain zebra genetic diversity. Allele frequencies in Hartmann’s mountain zebra were relatively resilient to demographic fluctuations. Due to the high incidence of mitochondrial haplotype sharing between populations, the hypothesis that Cape and Hartmann’s mountain zebra mitochondrial lineages were reciprocally monophyletic was not supported. However, the presence of private alleles at nuclear loci rendered the two subspecies genetically distinct evolutionary significant units.     

Record of Blue tilapia Oreochromis aureus (Steindachner, 1864) in the Eerste River catchment,Western Cape province,South Africa

Oreochromis aureus was imported from Israel into South Africa in 1959 but data on its current status in South Africa are lacking. Genomic DNA was extracted and the COI gene amplified at the South African Institute for Aquatic Biodiversity. The identity of the sequences and specimens was determined using the Barcode of Life Data Systems and GenBank. Morphological and genetic assessment demonstrated that 11 specimens collected from two farm dams in the Eerste River System, Western Cape province, were Oreochromis aureus. A MaxEnt model compiled using global distribution, rainfall and temperature data predicted that large areas of southern Africa were climatically suitable for this species, indicating considerable invasion debt in southern Africa. As a result, surveys to assess for the extent of the invasion in South Africa and eradication of existing populations, if feasible, are recommended management actions.     

Evidence for panmixia despite barriers to gene flow in the southern African endemic, <Emphasis Type="Italic">Caffrogobius caffer</Emphasis> (Teleostei: Gobiidae)

Background  

Oceanography and life-history characteristics are known to influence the genetic structure of marine species, however the relative role that these factors play in shaping phylogeographic patterns remains unresolved. The population genetic structure of the endemic, rocky shore dwelling Caffrogobius caffer was investigated across a known major oceanographic barrier, Cape Agulhas, which has previously been shown to strongly influence genetic structuring of South African rocky shore and intertidal marine organisms. Given the variable and dynamic oceanographical features of the region, we further sought to test how the pattern of gene flow between C. caffer populations is affected by the dominant Agulhas and Benguela current systems of the southern oceans.     

Local and Regional Scale Genetic Variation in the Cape Dune Mole-Rat,Bathyergus suillus

The distribution of genetic variation is determined through the interaction of life history, morphology and habitat specificity of a species in conjunction with landscape structure. While numerous studies have investigated this interplay of factors in species inhabiting aquatic, riverine, terrestrial, arboreal and saxicolous systems, the fossorial system has remained largely unexplored. In this study we attempt to elucidate the impacts of a subterranean lifestyle coupled with a heterogeneous landscape on genetic partitioning by using a subterranean mammal species, the Cape dune mole-rat (Bathyergus suillus), as our model. Bathyergus suillus is one of a few mammal species endemic to the Cape Floristic Region (CFR) of the Western Cape of South Africa. Its distribution is fragmented by rivers and mountains; both geographic phenomena that may act as geographical barriers to gene-flow. Using two mitochondrial fragments (cytochrome b and control region) as well as nine microsatellite loci, we determined the phylogeographic structure and gene-flow patterns at two different spatial scales (local and regional). Furthermore, we investigated genetic differentiation between populations and applied Bayesian clustering and assignment approaches to our data. Nearly every population formed a genetically unique entity with significant genetic structure evident across geographic barriers such as rivers (Berg, Verlorenvlei, Breede and Gourits Rivers), mountains (Piketberg and Hottentots Holland Mountains) and with geographic distance at both spatial scales. Surprisingly, B. suillus was found to be paraphyletic with respect to its sister species, B. janetta–a result largely overlooked by previous studies on these taxa. A systematic revision of the genus Bathyergus is therefore necessary. This study provides a valuable insight into how the biology, life-history and habitat specificity of animals inhabiting a fossorial system may act in concert with the structure of the surrounding landscape to influence genetic distinctiveness and ultimately speciation.     

Mytilus galloprovincialis Lmk. in Southern Africa

The Mediterranean mussel, Mytilus galloprovincialis Lmk. has been identified on the west coast of southern Africa using morphological and biochemical-genetic comparisons with samples of “pure” M. edulis L. from Denmark and M. galloprovincialis from the Mediterranean coast of Spain. Our results show that the southern African Mytilus more closely resembles M. galloprovincialis in anterior adductor, posterior adductor and hinge size. It also has a more ventrally located maximal shell width like the Mediterranean mussel. The electrophoretic examination of 23 proteins showed that many alleles diagnostic for M. galloprovincialis appeared in the southern African Mytilus. Nei's genetic distance between the southern African Mytilus and M. galloprovincialis was 0.010 ± 0.004 and the average genetic distance between these samples and M. edulis was 0.162 ± 0.077.The presence of M. galloprovincialis in southern Africa could be explained by biogeographic dispersal along the west coast of Africa during Pleistocene cooling, or by a recent inadvertant or intentional introduction by man. To test these two hypotheses, we examined ≈750 mussel shells collected from Koi-san middens and ≈350 shells from a raised-beach deposit all located on the west coast of Cape Province, South Africa. The ages of these deposits range from 1500 yr to 120000 yr and pre-date the arrival of Europeans to the Cape. This examination did not reveal any shells of Mytilus. We, therefore, conclude that the introduction of M. galloprovincialis to southern Africa was a recent event. We suggest that, since the first confirmed reference to Mytilus in southern Africa was made from a 1972 collection, the introduction occurred within the last two decades.     

ON THE BREEDING OF THE WHITE-RUMPED SWIFT (APUS CAFFER CAFFER) IN GATOOMA

Crawford, R. J. M., Cooper, J. &; Shelton, P. A. 1982. Distribution, population size, breeding and conservation of the Kelp Gull in southern Africa. Ostrich 53:164:177.

The Kelp Gull Lams dominicanus in Africa occurs coastally between Luanda, Angola and Delagoa Bay, Moçmbique. It breeds between Cape Cross Lagoon, South West Africa/Namibia and Riet River, eastern Cape, South Africa. Censuses of nests and breeding birds at all known southern African breeding localities in the period 1976–1981 indicated that 11 199 pairs bred at 52 localities; 79.5% of this population occurred in South Africa, 57,1% in the Saldanha Bay to Dassen Island region, southwestern Cape. Of the breeding pairs 83% occurred on offshore islands and rocks. Colony size at islands is related to their surface area andMayalso be influenced by food availability and the level of human disturbance. The species breeds in a wide variety of habitats ranging from cliffs and rock stacks to wooden platforms, lowlying vegetation among sand dunes and estuarine sandbars. Any available material is used in the construction of nests, whichMaybe as dense as 4/m² Clutch size is 2–3 eggs. In 1978 breeding took place earlier in South Africa than in South West Africa/Namibia. 92% of the population breeds m sites which are legally protected. Kelp Gulls have decreased or increased in numbers at some breeding localities but there is no clear overall trend. Any increases in colony size near urban areasMayresult in added airstrike hazards.     

Phylogenetic relationships of crown conchs (Melongena spp.): the corona complex simplified

Aim The larval stages of marine taxa are often assumed to have an overriding influence on the phylogeographical structure of a species as well as on rates of speciation. Phylogeographical disjunctions in high‐dispersal marine taxa are generally attributed to historical events or contemporary ecological factors. The lack of genetic structure in low‐dispersal marine taxa is often ascribed to rafting by juveniles, yet few studies discuss the effects of historical conditions. Around peninsular Florida, there are three species of the crown conch, Melongena, which have direct‐developing, crawl‐away larvae. One of these species, M. corona, is subdivided into three subspecies. We refer to these five taxa as the corona complex. We assessed the validity of these taxa and tested for patterns of phylogeographical subdivision. Location Intertidal Florida and eastern Alabama, USA, Mexico and Panama. Methods The mitochondrial DNA cytochrome c oxidase subunit I, and ribosomal DNA 16S genes were sequenced from adult individuals representing all extant taxa of Melongena. Phylogenetic trees were constructed under maximum likelihood analysis (heuristic search with tree bisection–reconnection branch‐swapping) using the program paup *. Results Sequence variability in the complex was low and suggested no systematic or phylogeographical partitioning in the corona complex. The species complex probably consists of a single lineage exhibiting no clear pattern of genetic partitioning over the entire range. Main conclusions The present study supports the designation of only four extant species within the genus: M. corona, M. patula, M. melongena and M. bispinosa. The subspecies M. corona corona, M. c. johnstonei and M. c. altispira, and the species M. sprucecreekensis and M. bicolor, should all be considered to be M. corona. Surprisingly, even with very low larval and adult vagility, no population subdivisions were noted in our genetic analyses. Our analyses also substantiate the paraphyletic status of the family Melongenidae.     

Linking seed dispersal and genetic structure of trees: a biogeographical approach

Aim Natural and human‐induced differences in frugivore assemblages can influence the seed dispersal distances of trees. An important issue in seed dispersal systems is to understand whether differences in seed dispersal distances also affect the genetic structure of mature trees. One possible approach to test for a relationship between seed dispersal and the genetic structure of mature trees is to compare the genetic structure of two closely related tree species between two biogeographical regions that differ in frugivore assemblages and seed dispersal distances. Previous studies on two Commiphora species revealed that Commiphora guillauminii in Madagascar has a much lower seed dispersal distance than Commiphora harveyi in South Africa. We tested whether the lower seed dispersal distance might have caused decreased gene flow, resulting in a stronger genetic structure in Madagascar than in South Africa. Location Madagascar and South Africa. Methods Using amplified fragment length polymorphism markers we investigated the genetic structure of 134 trees in Madagascar and 158 trees in South Africa at a local and a regional spatial scale. Results In concordance with our hypothesis, kinship analysis suggests that gene flow was restricted mostly to 3 km in Madagascar and to 30 km in South Africa. At the local spatial scale, the genetic differentiation among groups of trees within sample sites was marginally significantly higher in Madagascar (F_ST = 0.069) than in South Africa (F_ST = 0.021). However, at a regional spatial scale genetic differentiation was lower in Madagascar (F_ST = 0.053) than in South Africa (F_ST = 0.163). Main conclusions Our results show that lower seed dispersal distances of trees were linked to higher genetic differentiation of trees only at a local spatial scale. This suggests that seed dispersal affects the genetic population structure of trees at a local, but not at a regional, spatial scale.     

Leopard tortoises in southern Africa have greater genetic diversity in the north than in the south (Testudinidae)

In contrast to mammals, little is known about the phylogeographic structuring of widely distributed African reptile species. With the present study, we contribute data for the leopard tortoise (Stigmochelys pardalis). It ranges from the Horn of Africa southward to South Africa and westwards to southern Angola. However, its natural occurrence is disputed for some southern regions. To clarify the situation, we used mtDNA sequences and 14 microsatellite loci from 204 individuals mainly from southern Africa. Our results retrieved five mitochondrial clades; one in the south and two in the north‐west and north‐east of southern Africa, respectively, plus two distributed further north. Using microsatellites, the southern clade matched with a well‐defined southern nuclear cluster, whilst the two northern clades from southern Africa corresponded to another nuclear cluster with three subclusters. One subcluster had a western and central distribution, another occurred mostly in the north‐east, and the third in a small eastern region (Maputaland), which forms part of a biodiversity hotspot. Genetic diversity was low in the south and high in the north of our study region, particularly in the north‐east. Our results refuted that translocations influenced the genetic structure of leopard tortoises substantially. We propose that Pleistocene climatic fluctuations caused leopard tortoises to retract to distinct refugia in southern and northern regions and ascribe the high genetic diversity in the north of southern Africa to genetic structuring caused by the survival in three refuges and subsequent admixture, whereas tortoises in the south seem to have survived in only one continuous coastal refuge.     

Phylogeography of the fiscal shrike (Lanius collaris): a novel pattern of genetic structure across the arid zones and savannas of Africa

Aim Savanna occupies a substantial part of Africa, being distributed around the two major tropical rain forest blocks in what is referred to as the Savanna Belt. Our current understanding of the genetic structure within species distributed across the Savanna Belt is primarily derived from mammalian taxa, studies of which have revealed a suture zone or transition between northern and east/southern Africa clades in south‐western Kenya and north‐western Tanzania. We conduct a phylogeographic study of the fiscal shrike (Lanius collaris), a polytypic species distributed across the Savanna Belt of Africa and for which morphological and vocal data are in agreement with the suture zone recovered for mammalian taxa, to test the hypothesis of a spatially congruent genetic break across several taxa, including birds. Location Africa, south of the Sahara. Methods We analysed DNA sequences recovered from four loci (one mitochondrial, two autosomal and one Z‐linked) in 66 individuals, representing all recognized subspecies, as well as putatively closely related species. We make use of a combination of tree‐building and population genetic methods to investigate the phylogeographic structure of the fiscal shrike across Africa. Results The fiscal shrike consists of two primary lineages with a strong geographic component: a northern group distributed from southern Tanzania to Senegal, and a southern group distributed from Botswana/Zambia to South Africa with isolated populations in Tanzania and northern Malawi. Unexpectedly, Souza’s shrike (L. souzae) was nested within L. collaris, as the sister group of the southern group. The positions of Mackinnon’s shrike (L. mackinnoni) and that of the São Tomé shrike (L. newtoni) were variable, being either nested within the fiscal shrike or sister to the L. collaris–L. souzae clade. Our divergence time analyses suggest that the Lanius collaris species complex started to diversify around 2.2 Ma. Main conclusions Our study reveals a distinct biogeographic pattern for a savanna distributed species in Africa, with the transition between the two primary genetic lineages occurring at a latitude of c. 15–16° S, 10° S further south than shown elsewhere for several mammalian species.     

5. Memorandum on Bird Protection

Randall, R. M. &; Randall, B. M. 1980. Status and distribution of the Roseate Tern in South Africa. Ostrich 51:14-20.

The Roseate Tern Sterna dougallii population in Algoa Bay is the largest, and now possibly the only breeding population in southern Africa. The two mainland breeding sites at Cape Recife and Kommetjie have been deserted, and in recent years the last remaining breeding site outside Algoa Bay may have been abandoned. Consequently the present estimate of between 70 and 80 breeding pairs in Algoa Bay may represent the entire southern African population. The decline in numbers from hundreds in 1937 is ascribed to human interference. Although the species is rare and endangered in southern Africa, it has a world wide distribution and is in no immediate danger of extinction.