Relationships of the MadagascarBignoniaceae: A striking case of convergent evolution

Most MadagascarBignoniaceae have indehiscent fruits and have been assigned to the tribeCrescentieae. As thus constituted, theCrescentieae are remarkably disjunct between Central America (and the West Indies) and Madagascar with a single monotypic genus also on continental Africa. This paper analyzes the evolutionary relationships of the MadagascarCrescentieae and concludes that they are descended from a different ancestral stock than the New WorldCrescentieae. A revised tribal taxonomy is proposed to reflect phylogenetic relationships withCrescentieae restricted to the neotropic species andColeeae resurrected for the indehiscent-fruited Madagascar species.     

The Madagascan Maastrichtian bryozoans of Ferdinand Canu – Systematic revision and scanning electron microscopic study

In 1922, the first taxonomic work on Maastrichtian bryozoans from Madagascar was published in the Annales de Paléontologie by Ferdinand Canu. Canu described 25 species, 17 of which were regarded as new but the material has never been revised until now. Here we employ scanning electron microscopy (SEM) to illustrate Canu's material and revise the taxonomy. Based on this revision, 23 species, comprising eight cyclostomes and 15 cheilostomes, are recognized. A new genus, Fehiborypora, is introduced for the cribrimorph Cribilina (?) labiatula, and two new species are described: ‘Plagioecia’ antanihodiensis sp. nov. and ‘Escharoides’ charbonnieri sp. nov. Galeopsis parvipora is synonymized with Crustoporina prona Stoliczka. All bryozoan species found are encrusters on echinoids or oysters.     

Coalescent analyses support multiple mainland-to-island dispersals in the evolution of Malagasy Triaenops bats (Chiroptera: Hipposideridae)

Aim We investigate the directionality of mainland‐to‐island dispersals, focusing on a case study of an African‐Malagasy bat genus, Triaenops (Hipposideridae). Taxa include T. persicus from east Africa and three Triaenops species from Madagascar (T. auritus, T. furculus, and T. rufus). The evolution of this bat family considerably post‐dated the tectonic division of Madagascar from Africa, excluding vicariance as a viable hypothesis. Therefore, we consider three biogeographical scenarios to explain these species' current ranges: (A) a single dispersal from Africa to Madagascar with subsequent speciation of the Malagasy species; (B) multiple, unidirectional dispersals from Africa to Madagascar resulting in multiple, independent Malagasy lineages; or (C) early dispersal of a proto‐species from Africa to Madagascar, with later back‐dispersal of a descendant Malagasy taxon to Africa. Location East Africa, Madagascar, and the Mozambique Channel. Methods We compare the utility of phylogenetic and coalescent methodologies to address the question of directionality in a mainland‐to‐island dispersal event for recently diverged taxa. We also emphasize the application of biologically explicit demographic systems, such as the non‐equilibrium isolation‐with‐migration model. Here, these methods are applied to a four‐species haploid genetic data set, with simulation analyses being applied to validate this approach. Results Coalescent simulations favour scenario B: multiple, unidirectional dispersals from Africa to Madagascar resulting in multiple, independent Malagasy bat lineages. From coalescent dating, we estimate that the genus Triaenops was still a single taxon approximately 2.25 Ma. The most recent Africa to Madagascar dispersal occurred much more recently (c. 660 ka), and led to the formation of the extant Malagasy species, T. rufus. Main conclusions Haploid genetic data from four species of Triaenops are statistically most consistent with multiple, unidirectional dispersals from mainland Africa to Madagascar during the late Pleistocene.     

A novel mating system in a solitary carnivore: the fossa

The mating strategies of male mammals have long been treated as broadly predictable on the basis of just two factors: the dispersion of females and the benefit of paternal care to male reproductive success. Female strategies and finer scale variations in mating systems remain poorly understood. In the fossa Cryptoprocta ferox , we had the rare opportunity to examine the mating system of a wild solitary carnivore directly, and identified features not classified or predicted by mating system theory. Males competed for mating opportunities at a traditional site monopolized by a female, high in a tree. The female mated with multiple males, repeatedly mated with some individuals and appeared to express mate choice. We observed three females thus, one replacing another on the site after each was seen to mate with four to five males over a period of 1–6 days. Copulations were prolonged (up to 3 h 8 min), involving a weak copulatory tie, and males appeared to guard females briefly after mating. Fossas are at low population density and do not use a den regularly; we suggest that both these factors impede individuals from locating a mate. We hypothesize that the observed mating system reduces this problem for both sexes, and increases the number of mates available to a female while ensuring a low risk of sexual harassment.     

African spiny Solanum (subgenus Leptostemonum,Solanaceae): a thorny phylogenetic tangle

Although most diverse in the New World tropics, approximately 100 species of Solanum (Solanaceae) are native to continental Africa and Madagascar. The majority of these are ‘spiny solanums’ (subgenus Leptostemonum). We present here the first phylogenetic reconstruction of African and Madagascan species of Solanum subgenus Leptostemonum, with 62 of 76 species native to these areas, plus an additional seven species of largely Asian distribution, using internal transcribed spacer (ITS), waxy and trnT‐F regions. We identify monophyletic groups, many of which correspond to previously recognized units, although the large, traditionally recognized sections of Oliganthes and Melongena are polyphyletic. These groups are distinguished from each other by their breeding systems, with members of Oliganthes being hermaphroditic and Melongena andromonoecious. The phylogenetic relationships suggest multiple changes of breeding system between these two states, and observations of plants across their range indicate that there is considerable lability in this character. The African and Malagasy clades are largely geographically coherent, although there is evolutionary interchange between African vegetation types. All of the Madagascan endemics included in the analysis form a coherent group and probably represent an in situ radiation. © 2013 The Linnean Society of London, Botanical Journal of the Linnean Society, 2013, 173 , 176–193.     

Longevity in some Malagasy rainforest passerines

Data on longevity is a prerequisite to understand the life-history strategies of a species. For Malagasy songbirds no information has been previously published. Therefore, we studied their longevity in a capture–recapture effort in a rainforest in eastern Madagascar (Maromizaha, Andasibe) between 2003 and 2016. We present first data on the longevity of 23 species of Malagasy songbirds. A female Dark Newtonia Newtonia amphichroa (Vangidae) and a Grey-crowned Greenbul Bernieria cinereiceps (Bernieridae) attained an age of at least 12 years, followed by two male Madagascar Brush Warblers Nesillas typica (Acrocephalidae), female Madagascar Bulbul Hypsipetes madagascariensis (Pycnonotidae) and Madagascar Drongo Dicrurus forficatus (Dicruridae) that attained at least 10 years. There was much variation within some taxonomic groups, longevity did not increase with the mass of a bird species and most insectivorous birds lived longer than granivorous ones.     

The breeding migration of Littorina arcana Hannaford Ellis, 1978 (Prosobranchia: Littorinidae)

Two species of rough winkle, the oviparous Littorina arcana and the ovoviviparous L. saxatilis are very similar in their outward appearance and are commonly syntopic. This has led some researchers to regard these species as conspecific and to suggest that reproductive modality is not a fixed characteristic. However, the syntopy of these species is much more complex than has been supposed and data presented here show how the seasonally reproducing L. arcana migrates downshore during its breeding period, into areas where L. saxatilis is comparatively sparse. This results in a separation of the breeding populations of the two species and consequently a spatial separation of their juveniles, at least in their early stages. Selection pressures on the breeding animals and young juveniles will therefore differ.     

Evidence for drought and forest declines during the recent megafaunal extinctions in Madagascar

Aim There remains some uncertainty concerning the causes of extinctions of Madagascar’s megafauna. One hypothesis is that they were caused by over‐hunting by humans. A second hypothesis is that their extinction was caused by both environmental change and hunting. This paper systematically addresses the second hypothesis through examination of two new pollen records from south‐eastern Madagascar alongside other published records across the island. Location South‐eastern Madagascar. Methods We reconstructed past vegetation and fire dynamics over the past 6000 years at two sites in south‐eastern Madagascar (Ste‐Luce) using fossil pollen and charcoal contained in sedimentary sequences. We investigated drivers of vegetation changes and how these, in turn, influenced faunal species in the south‐east, using published climatic, archaeological and faunal records. Further, we also used published records to provide a synthesis of environmental changes on the whole island. Results Vegetation reconstructions indicate that the mosaic vegetation in the region of Ste‐Luce was highly dynamic in response to climatic changes. The open woodland, surrounding the littoral forest, transformed into an ericoid grassland between c. 5800 and 5200 cal. yr bp , possibly in response to a moderate drought recorded during this period. The littoral forest was more stable between c. 5100 and 1000 cal. yr bp , with only some minor compositional changes c. 2800 cal. yr bp and between c. 1900 and 1000 cal. yr bp . Significant forest decline, however, is observed at c. 950 cal. yr bp , coinciding with a drought and a marine surge. A comparison of these results with a synthesis of published vegetation records across the island shows asynchronous vegetation changes in response to various droughts during the Holocene, except for the 950 cal. yr bp drought event, with evidence of widespread vegetation transformations and fires across the island. Main conclusions Pronounced climatic desiccation between 1200 and 700 cal. yr bp may have been the slow driver framing and triggering vegetation transformations and decline in megafaunal populations. In addition, hunting by drought‐impacted human inhabitants and competition with newly introduced cattle would have amplified the impacts on megafaunal populations, leading to numerous extinctions in this period.