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Observations of birds from previously unknown and apparently overlooked forest remnants at Oloitokitok in southeast Kenya are presented. Several forest specialists reported have very limited ranges in Kenya, such as Bar-throated Apalis Apalis thoracica, Stripe-faced Greenbul Arizelocichla striifacies and Kenrick’s Starling Poeptera kenricki while the guttifer subspecies of White-stared Robin Pogonocichla stellata and Broad-ringed White-eye Zosterops eurycricotus, both formerly endemic to Tanzania, are documented in Kenya for the first time. [ABSTRACT FROM AUTHOR]

Aim: Morphological and lineage evolution are predicted to follow different patterns in island and mainland radiations. However, the extent to which these geographical contexts influence evolutionary trajectories remains poorly understood, in part because few studies have focused on species‐rich clades colonizing continents and archipelagos over comparable timeframes. Focusing on a diverse songbird clade radiating on the African continent and adjacent islands, we tested whether morphological evolution is best explained by adaptive or non‐adaptive processes, and whether mainland and island lineages evolved to occupy different regions or volumes of morphological space (morphospace). Location: Palaeotropics, with a particular focus on the Afrotropical region. Taxon: White‐eyes, Zosterops (Aves: Zosteropidae). Methods: We generated principal component axes from novel trait data for 120 species and combined this information with a comprehensive dated phylogeny. We then analysed the dynamics of trait and lineage diversification using comparative evolutionary methods. Results: An early burst and slowdown pattern of lineage accumulation is not mirrored by phenotypic evolution, which instead shows an apparent convergence on particular phenotypes. However, the overall signature of phenotypic convergence is strongly driven by mainland taxa, in which phenotypes appear to be highly constrained within elevational zones, while speciation events are often associated with phenotypic divergence from one body plan to the other after colonization of highland from lowland habitats, or vice versa. By contrast, island lineages have repeatedly explored novel areas of morphospace with patterns of phenotypic divergence generally not distinguishable from a random‐walk model. Main conclusions: Diversification of Zosterops highlights contrasting evolutionary trends and dynamics for continental versus island species. We suggest the different trajectory of evolution in insular lineages arises from reduced species competition leading to an increase in ecological opportunity, thereby providing a release to phenotypic constraints experienced by continental taxa. [ABSTRACT FROM AUTHOR]

Although angraecoid orchids are famous for their spectacular flowers, pollinated by hawkmoths in Madagascar, two species of Angraecum endemic to the Mascarenes (sect. Hadrangis) have atypical unscented and short-spurred flowers that are pollinated by birds. We focused on the pollination and reproductive success of Angraecum bracteosum Balf.f. & S.Moore, a member of sect. Hadrangis. We investigated the breeding system by performing a set of hand-pollination experiments and by observing natural pollinators using video-captures. Pollinator efficiency (pollen removal and deposition) and reproductive success (fruit set) were quantified once a week in two natural island populations during three consecutive flowering seasons (2003–2005). The orchid is self-compatible but requires pollinator services to achieve reproduction. The two white-eye song-bird species (Zosteropidae) that occur on Reunion, Zosterops borbonicus Boddaert and Zosterops olivaceus L., were recorded as pollinators. However, while pollination events were rare and occasional following flower visits by Z. borbonicus, foraging of Z. oliveaceus resulted in a high frequency of successful pollinations. White-eyes typically perched on inflorescences, and probed most of the “fresh-looking” flowers for nectar. This study documents a probable case of bird-pollination specialization within Angraecum section Hadrangis, and sheds light on the role played by pollinators during the radiation of section Hadrangis in the Mascarene Archipelago. [ABSTRACT FROM AUTHOR]

• Background and Aims Although numerous angraecoid orchids in Madagascar display typical sphingophilous syndrome (i.e. white, nectariferous, long-spurred flowers, producing a strong scent at the crepuscule that is attractive to moths), three species of Angraecum in Reunion, belonging to the endemic section Hadrangis, have atypical unscented and short-spurred flowers. The aim of the study was to investigate the implication of plant–pollinator interaction on the evolution of floral morphology of these peculiar island floral forms.• Methods The flower morphology of A. striatum (one of the three section Hadrangis species) was investigated by performing a set of floral measures, and the reproductive biology was investigated by a set of hand pollination experiments. Natural pollinators were observed by means of a digital video camera. Pollinator efficiency (pollen removal and deposition) and reproductive success (fruit set) were quantified once a week in natural field conditions during the 2005 flowering season (i.e. from January to March).• Key Results The orchid is self-compatible but requires a pollinator to achieve fruit set. Only one pollinator was observed, the endemic white-eye Zosterops borbonicus (Zosteropidae). These birds perched on inflorescences, and probed most fresh-looking flowers on each plant for nectar. Nectar was both abundant (averaging 7·7 µL) and dilute (averaging 9·7 % sugar in sucrose equivalents). Birds were mostly active between 0830 and 0930 h. Visits to plants were extremely short, lasting from 9 to 27 s. At the study site, 60·9 % of flowers had pollen removed, and 46·4 % had pollinia deposited on stigmas. The proportion of flowers that initiated a fruit averaged 20·6 % in natural conditions.• Conclusions For the first time, a bird-pollinated orchid is described from a sub-tribe that is mainly specialized for moth pollination. This study documents a morphological shift in flowers in response to pollinator adaptations in the insular context of the Mascarene Archipelago. [ABSTRACT FROM AUTHOR]

AbstractThe floral visitors of silky oak, Grevillea robusta A. Cunn. ex R.Br., their foraging behaviour and their effects on fruit-set were studied at Malava, western Kenya. Grevillea robusta is a popular tree for farm plantings in the eastern and central African highlands. Yield of seed has been disappointingly low in some areas and a lack of appropriate pollinators has been suggested as a possible cause. Investigations involved the monitoring of visitors on active inflorescences, assessment of the rewards available to potential pollinators, and exclusion experiments to establish the effects of various visitors on fruit-set. The flowers are visited mainly by birds and insects. The likely pollinators of G. robusta are sunbirds (Nectarinia amethystina, N. cyanolaema, N. olivacea, N. superba and N. venusta) and white-eyes (Zosterops kikuyuensis and Z. senegalensis). Very little aggressive behaviour between birds was recorded. No nocturnal pollinators were observed. Nectar was the major floral reward for pollinators, but is likely depleted by ants and honey bees, the foraging behaviour of which confirmed them to be nectar-robbers. These insects hardly ever touched stigmas during their visits. Eighty-nine per cent of bird visits were in the morning (07.00–10.00 hours) when nectar volume was highest. Inflorescences bagged to exclude birds set no fruits, and unmanipulated flowers and flowers bagged with self-pollen set no fruits, indicating a self-incompatibility mechanism. Control cross-pollinated flowers displayed greatly increased fruit-set (25.1%) compared with natural open-pollination (0.9%). All these findings confirm the importance of cross-pollen transfer to flowers and the necessity of pollinators for fruit-set. Effective seed production requires activity of pollinators for self-pollen removal and cross-pollen deposition. Seed production stands for G. robusta should be established where flowering is prolific and bird pollinators are abundant. [ABSTRACT FROM AUTHOR]

The Hawaiian islands provide superlative examples of biological evolution and are perhaps the best sites in the world for biological invasions. Introduced invertebrates such as the Argentine ant (lridomyrmex humilis) and the western yellow jacket wasp (Paravespula pensylvanica) reduce native insects and plant pollinators and may have been a factor in native bird declines. Management of invertebrates in localized areas through use of chemicals such as Tahara and diazinon is being attempted. Research on the long term effects of alien birds on native ecosystems is under way, but management currently is restricted to preservation of intact and large areas of native ecosystems. Black rats (Rattus rattus), small Indian mongooses (Herpestes auropunctatus), and feral cats (Felis catus) are thought to be especially important invaders of natural areas in Hawai'i. Research on ecology and control methods for all 3 species is under way, with registration of diphacinone for mongooses by the Animal and Plant Health Inspection Service nearly complete. Ungulates have been the most prominent alien animals in Hawai'i's ecosystems since shortly after continental man introduced them in the 18th century. Successful control and even eradication of feral cattle (Bos taurus), feral sheep (Ovis aries), mouflon (Ovis musimon), feral goats (Capra hircus), and feral pigs (Sus scrofa) has been accomplished in many areas to date through systematic, long-term programs with salaried personnel. Methods and costs of some of these programs are presented.

[Display omitted] • Genome-wide markers yielded a well-supported phylogeny of Zosteropidae. • Seven higher-level clades are defined in Zosteropidae. • The Indo-African, Asiatic, and Australasian clades comprise the Zosterops radiation. White-eyes are an iconic radiation of passerine birds that have been the subject of studies in evolutionary biology, biogeography, and speciation theory. Zosterops white-eyes in particular are thought to have radiated rapidly across continental and insular regions of the Afro- and Indo-Pacific tropics, yet their phylogenetic history remains equivocal. Here, we sampled 77% of the genera and 47% of known white-eye species and sequenced thousands of ultraconserved elements to infer the phylogeny of the avian family Zosteropidae. We used concatenated maximum likelihood and species tree methods and found strong support for seven clades of white-eyes and three clades within the species-rich Zosterops radiation. [ABSTRACT FROM AUTHOR]