H. Douglas Pratt

Bio: H. Douglas Pratt is an academic researcher from Royal Belgian Institute of Natural Sciences. The author has contributed to research in topics: Adaptive radiation & Hawaiian honeycreeper. The author has an hindex of 3, co-authored 6 publications receiving 47 citations.

Convergent evolution of 'creepers' in the Hawaiian honeycreeper radiation

Abstract: Natural selection plays a fundamental role in the ecological theory of adaptive radiation. A prediction of this theory is the convergent evolution of traits in lineages experiencing similar environments. The Hawaiian honeycreepers are a spectacular example of adaptive radiation and may demonstrate convergence, but uncertainty about phylogenetic relationships within the group has made it difficult to assess such evolutionary patterns. We examine the phylogenetic relationships of the Hawaii creeper (Oreomystis mana), a bird that in a suite of morphological, ecological and behavioural traits closely resembles the Kauai creeper (Oreomystis bairdi), but whose mitochondrial DNA (mtDNA) and osteology suggest a relationship with the amakihis (Hemignathus in part) and akepas (Loxops). We analysed nuclear DNA sequence data from 11 relevant honeycreeper taxa and one outgroup to test whether the character contradiction results from historical hybridization and mtDNA introgression, or convergent evolution. We found no evidence of past hybridization, a phenomenon that remains undocumented in Hawaiian honeycreepers, and confirmed mtDNA and osteological evidence that the Hawaii creeper is most closely related to the amakihis and akepas. Thus, the morphological, ecological and behavioural similarities between the evolutionarily distant Hawaii and Kauai creepers represent an extreme example of convergent evolution and demonstrate how natural selection can lead to repeatable evolutionary outcomes.

Noteworthy Bird Records for Micronesia, with a Summary of Raptor Sightings in the Mariana Islands, 1988-1999

Abstract: Sixty noteworthy bird records for the Mariana and Caroline Islands, 1988-1999, include new island records, a first breeding of Common Moorhens (Gallinula chloropus) on Yap, and an unprecedent- ed number of raptor sightings This paper documents noteworthy records of 60 bird species for the Mariana and Caroline Islands from 1988-1999 Many are first records for the region or the individual islands noted They include seven new records for Micronesia, eight new records for the Marianas, and four new records for the Carolines We also

An Abbott's Booby Papasula Abbotti on Rota, Mariana Islands: First Historical Record for the Pacific Ocean

Abstract: —We describe the first documented record of Abbott’s Booby Papasula abbotti in the North Pacific, a female observed and photographed at Rota, the southernmost island in the Commonwealth of the Northern Mariana Islands (USA), in northern Micronesia, on 17 April 2007. Furthermore, on the same island, we also observed and photographed a subadult Red-footed Booby Sula sula with a black-tipped pink bill very similar to that of Abbott’s. The available evidence suggests that pink is a normal but poorly documented bill colour variation for some older immature Red-footed Boobies and not a diagnostic feature of Abbott’s or an indication of hybridisation between the two species.

Species limits and English names in the genus Gygis (Laridae)

Abstract: The alpha taxonomy of the genus Gygis is controversial, with limited molecular studies contradicting distributional and phenotypic evidence that two Pacific forms, larger candida and smaller microrhyncha are separate species This paper reviews evidence from the subfossil record, morphology, distribution and hybridisation, and vocalisations to conclude that Gygis comprises three biological species, nominate alba in the Atlantic, and two Pacific species It also reviews historical English vernacular names and proposes ‘fairytern’ as a group name for these members of the newly recognised subfamily Gyginae This name maintains popular tradition but requires a minor exception to some current naming conventions Proposed English names are Atlantic Fairytern, Common Fairytern, and Little Fairytern The name White Tern should now apply only to the historical single species, and Fairy Tern remains for Sternula nereis

First Report of the Palau Bird Records Committee

Abstract: After compiling a historical list of 158 species of birds known to occur in Palau, the Palau Bird Records Committee accepted 10 first records of new occurrences of bird species: the Common Pochard (Aythya ferina), Black-faced Spoonbill (Platalea minor), Chinese Pond Heron (Ardeola bacchus), White-breasted Waterhen (Amaurornis phoenicurus), Eurasian Curlew (Numenius arquata), Gull-billed Tern (Gelochelidon nilotica), Channel-billed Cuckoo (Scythrops novaehollandiae), Ruddy Kingfisher (Halcyon coromanda), Common Kingfisher (Alcedo atthis), and Isabelline Wheatear (Oenanthe isabellina). These additions bring Palau’s total list of accepted species to 168. We report Palau’s second records of the Broad-billed Sandpiper (Calidris falcinellus), Chestnut-winged Cuckoo (Clamator coromandus), Channelbilled Cuckoo, White-throated Needletail (Hirundapus caudacutus) and Oriental Reed Warbler (Acrocephalus orientalis). This report concludes with a current list of the bird species known from Palau. This is the first report of the Palau Bird Records Committee (PBRC). Situated in the western equatorial Pacific and within the East Asian/Australasian Flyway, Palau has the richest bird diversity of any island group in Micronesia (Wiles 2005). The board of trustees of Belau National Museum established the PBRC on 8 December 2014 as a committee of the museum’s National Program for Monitoring Forest and Coastal Birds. The geographic scope of the committee is all islands that are part of the Republic of Palau and the waters within 200 nautical miles of the coast of the Palau Islands. The mission of the committee is to review noteworthy reports of field observations of Palau’s birds for the purpose of maintaining an authoritative Palau Islands †Alan R. Olsen, a passionate birder whose dedication to chronicling Palau’s birds will be forever remembered and appreciated, died suddenly and unexpectedly on 24 June 2018. His labor of love resulted in the attainment of a number of significant forest conservation milestones. Palau is much richer in knowledge for having known and considered Alan as one of our own.

Multilocus Resolution of Phylogeny and Timescale in the Extant Adaptive Radiation of Hawaiian Honeycreepers

Abstract: Summary Evolutionary theory has gained tremendous insight from studies of adaptive radiations. High rates of speciation, morphological divergence, and hybridization, combined with low sequence variability, however, have prevented phylogenetic reconstruction for many radiations. The Hawaiian honeycreepers are an exceptional adaptive radiation, with high phenotypic diversity and speciation that occurred within the geologically constrained setting of the Hawaiian Islands. Here we analyze a new data set of 13 nuclear loci and pyrosequencing of mitochondrial genomes that resolves the Hawaiian honeycreeper phylogeny. We show that they are a sister taxon to Eurasian rosefinches ( Carpodacus ) and probably came to Hawaii from Asia. We use island ages to calibrate DNA substitution rates, which vary substantially among gene regions, and calculate divergence times, showing that the radiation began roughly when the oldest of the current large Hawaiian Islands (Kauai and Niihau) formed, ∼5.7 million years ago (mya). We show that most of the lineages that gave rise to distinctive morphologies diverged after Oahu emerged (4.0–3.7 mya) but before the formation of Maui and adjacent islands (2.4–1.9 mya). Thus, the formation of Oahu, and subsequent cycles of colonization and speciation between Kauai and Oahu, played key roles in generating the morphological diversity of the extant honeycreepers.

Chapter 1: Subspecies Represent Geographically Partitioned Variation, A Gold Mine of Evolutionary Biology, and a Challenge for Conservation

Abstract: in this review i summarize the history of the subspecies concept and the major debates and issues surrounding its use, with an emphasis on ornithology, in which the concept originated. The study of subspecific variation in birds has been an important driving force in the development of evolutionary biology. Subspecific study has also been essential in the description and preservation of biodiversity. Although controversy has surrounded the concept of subspecies since its inception, it continues to play an important role in both basic and applied science. i cover 10 relevant issues that have been largely resolved during this 150-year controversy, although not all are widely appreciated or universally accepted. These include nomenclature, sampling theory, evolutionary biology, and the heterogeneity of named subspecies. i also address three big unresolved questions and some of the philosophy of science related to them: What are subspecies, how do we diagnose them, and what does subspecific variation mean? discordance between genotypic and phenotypic data at these shallow evolutionary levels should be expected. The process of diagnosing states that exist along a continuum of differentiation can be difficult and contentious and necessarily has some arbitrariness; professional standards can be developed so that such diagnoses are objective. Taxonomies will change as standards do and as more data accrue. Given present evidence, our null hypothesis should be that subspecific variation probably reflects local adaptation. in looking forward, it seems assured that geographically partitioned variation— and the convenient label "subspecies"—will continue to play an integral role in zoology.

Cranial shape evolution in adaptive radiations of birds: comparative morphometrics of Darwin's finches and Hawaiian honeycreepers

Abstract: Adaptive radiation is the rapid evolution of morphologically and ecologically diverse species from a single ancestor. The two classic examples of adaptive radiation are Darwin's finches and the Haw...

Extinction and Biogeography of Tropical Pacific Birds [Book Review]

Abstract: Review(s) of: Steadman, David W, Extinction and Biogeography of Tropical Pacific Birds, University of Chicago Press, 2006. xiv + 594 pp., appendix, bib., figs, index, maps, photos, tables. Price: US$110.00, 69.50 (cloth); US$45.00, 28.50 (paper).

Clustering in community structure across replicate ecosystems following a long-term bacterial evolution experiment

Abstract: Experiments to date probing adaptive evolution have predominantly focused on studying a single species or a pair of species in isolation. In nature, on the other hand, species evolve within complex communities, interacting and competing with many other species. It is unclear how reproducible or predictable adaptive evolution is within the context of a multispecies ecosystem. To explore this problem, we let 96 replicates of a multispecies laboratory bacterial ecosystem evolve in parallel for hundreds of generations. Here we find that relative abundances of individual species vary greatly across the evolved ecosystems and that the final profile of species frequencies within replicates clusters into several distinct types, as opposed to being randomly dispersed across the frequency space or converging fully. Our results suggest that community structure evolution has a tendency to follow one of only a few distinct paths.