Tracing the colonization history of the Indian Ocean scops-owls (Strigiformes: Otus) with further insight into the spatio-temporal origin of the Malagasy avifauna

<p>Abstract</p> <p>Background</p> <p>The island of Madagascar and surrounding volcanic and coralline islands are considered to form a biodiversity hotspot with large numbers of unique taxa. The origin of this endemic fauna can be explained by two different factors: vicariance or over-water-dispersal. Deciphering which factor explains the current distributional pattern of a given taxonomic group requires robust phylogenies as well as estimates of divergence times. The lineage of Indian Ocean scops-owls (<it>Otus</it>: Strigidae) includes six or seven species that are endemic to Madagascar and portions of the Comoros and Seychelles archipelagos; little is known about the species limits, biogeographic affinities and relationships to each other. In the present study, using DNA sequence data gathered from six loci, we examine the biogeographic history of the Indian Ocean scops-owls. We also compare the pattern and timing of colonization of the Indian Ocean islands by scops-owls with divergence times already proposed for other bird taxa.</p> <p>Results</p> <p>Our analyses revealed that Indian Ocean islands scops-owls do not form a monophyletic assemblage: the Seychelles <it>Otus insularis </it>is genetically closer to the South-East Asian endemic <it>O. sunia </it>than to species from the Comoros and Madagascar. The Pemba Scops-owls <it>O. pembaensis</it>, often considered closely related to, if not conspecific with <it>O. rutilus </it>of Madagascar, is instead closely related to the African mainland <it>O. senegalensis</it>. Relationships among the Indian Ocean taxa from the Comoros and Madagascar are unresolved, despite the analysis of over 4000 bp, suggesting a diversification burst after the initial colonization event. We also highlight one case of putative back-colonization to the Asian mainland from an island ancestor (<it>O. sunia</it>). Our divergence date estimates, using a Bayesian relaxed clock method, suggest that all these events occurred during the last 3.6 myr; albeit colonization of the Indian Ocean islands were not synchronous, <it>O. pembaensis </it>diverged from <it>O. senegalensis </it>about 1.7 mya while species from Madagascar and the Comoro diverged from their continental sister-group about 3.6 mya. We highlight that our estimates coincide with estimates of diversification from other bird lineages.</p> <p>Conclusion</p> <p>Our analyses revealed the occurrence of multiple synchronous colonization events of the Indian Ocean islands by scops-owls, at a time when faunistic exchanges involving Madagascar was common as a result of lowered sea-level that would have allowed the formation of stepping-stone islands. Patterns of diversification that emerged from the scops-owls data are: 1) a star-like pattern concerning the order of colonization of the Indian Ocean islands and 2) the high genetic distinctiveness among all Indian Ocean taxa, reinforcing their recognition as distinct species.</p

How many bird and mammal extinctions has recent conservation action prevented?

Aichi Target 12 of the Convention on Biological Diversity (CBD) aims to ‘prevent extinctions of known threatened species’. To measure its success, we used a Delphi expert elicitation method to estimate the number of bird and mammal species whose extinctions were prevented by conservation action in 1993 - 2020 (the lifetime of the CBD) and 2010 - 2020 (the timing of Aichi Target 12). We found that conservation prevented 21–32 bird and 7–16 mammal extinctions since 1993, and 9–18 bird and 2–7 mammal extinctions since 2010. Many remain highly threatened, and may still become extinct in the near future. Nonetheless, given that ten bird and five mammal species did go extinct (or are strongly suspected to) since 1993, extinction rates would have been 2.9–4.2 times greater without conservation action. While policy commitments have fostered significant conservation achievements, future biodiversity action needs to be scaled up to avert additional extinctions

How many bird and mammal extinctions has recent conservation action prevented?

Aichi Target 12 of the Convention on Biological Diversity (CBD) contains the aim to ‘prevent extinctions of known threatened species’. To measure the degree to which this was achieved, we used expert elicitation to estimate the number of bird and mammal species whose extinctions were prevented by conservation action in 1993–2020 (the lifetime of the CBD) and 2010–2020 (the timing of Aichi Target 12). We found that conservation action prevented 21–32 bird and 7–16 mammal extinctions since 1993, and 9–18 bird and two to seven mammal extinctions since 2010. Many remain highly threatened and may still become extinct. Considering that 10 bird and five mammal species did go extinct (or are strongly suspected to) since 1993, extinction rates would have been 2.9–4.2 times greater without conservation action. While policy commitments have fostered significant conservation achievements, future biodiversity action needs to be scaled up to avert additional extinctions.https://wileyonlinelibrary.com/journal/conlMammal Research Institut

Conservation of the forest-living native birds of Mauritius

Maintaining the biodiversity of Mauritius is one of the world’s highest conservation priorities. Eight of nine surviving forest-living native bird species are threatened, yet the population limiting factors had not been convincingly diagnosed for any species, and conservation has focused on the short-term needs of the three non-passerine species. I propose an economical strategy to increase and sustain the population viability of all forest species. I studied the five threatened passerine species, especially the Mauritius Fody Foudia rubra. These were largely associated with native forest, much of which was unoccupied by most native bird species. Although invasion of the native forest by exotic plants may reduce food availability, the previous claim that this limited the population of certain species was unsupported. Nest predation by introduced mammals was severe. Over most of the range, recruitment could not sustain fody populations. Surplus birds from areas of higher productivity supplemented these populations. The fody distribution thus comprised source and sink areas. The richest source area was an exotic Cryptomeria japónica grove, to which nesting of the Pink Pigeon was also restricted. I argue that Cryptomeria allows concealment of nests in a habitat avoided by predatory mammals. I propose that nest predation is the proximate factor limiting the distribution and population of the pigeon and fody and, together with habitat destruction, was the main cause of decline. Long-term conservation requires habitat management. The existing rehabilitation strategy for mainland plant communities neglects the predator problem. To address this, habitat enhancement using selected native and exotic plants is proposed, including the creation of groves of Cryptomeria. Restoration of offshore islets, including predator eradication, would provide habitat to which threatened birds should be translocated. To maximize survival chances for all native biota, all three strategies should be pursued

A second record of the northern white-tailed bush lark Mirafra albicauda in Ethiopia

Volume: 16Start Page: 99End Page: 10

Vulture conservation: the case for urgent action

Commentary.Peer reviewe

Production of very-high-amylose potato starch by inhibition of SBE A and B

High-amylose starch is in great demand by the starch industry for its unique functional properties. However, very few high-amylose crop varieties are commercially available. In this paper we describe the generation of very-high-amylose potato starch by genetic modification. We achieved this by simultaneously inhibiting two isoforms of starch branching enzyme to below 1% of the wild-type activities. Starch granule morphology and composition were noticeably altered. Normal, high-molecular-weight amylopectin was absent, whereas the amylose content was increased to levels comparable to the highest commercially available maize starches. In addition, the phosphorus content of the starch was increased more than fivefold. This unique starch, with its high amylose, low amylopectin, and high phosphorus levels, offers novel properties for food and industrial applications