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Jack Eitniear

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Everything posted by Jack Eitniear

  1. Cuban Grassquit is also found on the island of New Providence, in the Bahamas, where it was introduced in the early 1960s and on which the species is currently considered fairly common.
  2. The following article has been published on the Ornithology Exchange. This and other articles can be found under the Articles tab in the navigation menu or by clicking here. Feeding Behavior, Bird Visitation, and Seed Dispersal in Guarea macrophylla and Trichilia quadrijuga (Meliaceae) Jack Eitniear A recent paper in Ornitologia Neotropical by Federico A. Prado details avian fruit consumption from two tropical trees. As with other similar studies it emphasizes the important relationship between birds and many tropical forest plants. Click here to view the article
  3. The author investigated feeding behavior, bird activity on and seed dispersal of two sympatric Neotropical rain forest trees, Guarea macrophylla and Trichilia quadrijuga In Manu National Park, Peru. The numbers of individual visitors, visiting species, and seeds removed were directly correlated to the available fruit crop for each plant species. Of 18 bird species which consumed Guarea fruits, only Swainson’s Thrush (Catharus ustulatus), Sulphur-bellied Flycatcher (Myiodynastes luteiventris), Blue-crowned Manakin (Lepidothrix coronata), and Band-tailed Manakin (Pipra fasciicauda) consistently visited and dispersed its seeds. Of three bird species which consumed Trichilia fruits, only Band-tailed and Roundtailed Manakins (P. chloromeros) regularly visited and dispersed its seeds. Variance in the time spent at fruiting trees across and within bird species was high. Most bird activity occurred between 07:00 h and 10:00 h. The number of ingested pulp units per visit ranged from zero to six depending on the bird. Few seeds were dropped under the parent tree. Guarea macrophylla Photo: www.ib.usp.br Despite having similar fruits, 18 species in 6 families removed G. macrophylla pulp units, whereas only three piprids removed T. quadrijuga fruits. Species feeding varied from the small 9 gram manakins to the much larger 72 gram White-necked Thrush. Guarea was fed on by migrant as well as resident species. The preference for Guarea fruits compared to those of Trichilia highlights the need for observational study in determining trees important as avian food resources. Such information will become invaluable as reserve sizes decline hence floral enrichment efforts become desirable to maximize food resource availability. The original article can be downloaded here, courtesy of the Neotropical Ornithological Society: Prado, Frederico A. 2013. Feeding behavior, bird visitation, and seed dispersal in Guarea macrophylla and Trichilia quadrijuga (Meliaceae). Ornitologia Neotropical 24: 459–468. Prado, F. A. 2013.pdf The journal Ornitologia Neotropical is one of many benefits of membership in the Neotropical Ornithological Society. For membership details visit http://www.ibiologia.unam.mx/links/neo/pay.html or contact Jack Eitniear, NOS Membership Secretary E-mail: jce@cstbinc.org
  4. The following article has been published on the Ornithology Exchange. This and other articles can be found under the Articles tab in the navigation menu or by clicking here. Nocturnal Bird Migration In Mexico: First Records From Marine Radar Jack Clinton Eitniear A recent paper in Ornitologia Neotropical by Sergio A. Cabrera-Cruz, Todd J. Mabee, & Rafael Villegas Patraca describes the migration of Nearctic-Neotropical birds along the Pacific side of the Isthmus of Tehuantepec in Oaxaca, Mexico. Click here to view the article
  5. Millions of Nearctic-Neotropical migrant birds fly over Mexico during their migratory journeys to their wintering grounds, creating high concentrations of migrating birds in different regions of the country. The Atlantic side of the Isthmus of Tehuantepec is known as an important stopover site and corridor for birds migrating to Central and South America, but few studies have been conducted on the Pacific side until recently, when interest has been awakened because of the potential of that area for wind energy development. In this paper the authors studied bird migration with an X-band marine radar during 21 nights from 15 October–8 November 2010 on the Pacific side of the Isthmus of Tehuantepec in Oaxaca. They estimated a mean Migratory Traffic Rate (MTR) of 79.9 targets/km/h (mean nightly range = 25.3–158 targets/km/h), with a typical pattern of migratory activity through the night, peaking around midnight and decreasing thereafter. Mean flight direction was seasonally appropriate for fall migration (i.e., southeast). Mean flight altitude was 523.5 m above ground level (range of nightly means = 402–755 m a.g.l.). Wind-energy development has recently increased within the Isthmus, generating the need for information on the characteristics of bird migration in the area. This paper provides the first published results about nocturnal bird migration in the region, information undoubtedly valuable for avian risk assessments. ON 24(4)299-309.pdf Membership information for the Neotropical Ornithological Society can be obtained by contacting: jce(at)cstbinc.org
  6. The acceptance of some scientific studies have a profound impact on the ornithological community (both scientific and birding components). For significant changes to be accepted in the relationships between various genera generally a paper has to be published in a peer-reviewed journal. A recent paper in the current issue of Ornitologia Neotropical is one such case. The genera Sporophila, Oryzoborus, and Dolospingus comprise a group of small-bodied, thick-billed oscines that are widely distributed in open and semi-open habitats from southern Texas to Argentina. In a paper by Nicholas A. Mason and Kevin J. Burns "Molecular Phylogenetics of Neotropical Seedeaters and Seed-finches (Sporophila, Oryzoborus, Dolospingus)" the authors perform a phylogenetic analysis of the genera based on 2184 bp of mitrochondrial DNA. ON 24(2) 139-155 NEW.pdf Their findings, if accepted, would require the revision of many Latin American birding guides! The concluding proposal of the authors is that "We [they] recommend a taxonomic revision wherein Oryzoborus and Dolospingus are merged into a broadly defined Sporophila". This change is currently being considered by the AOU South American Classification Committee as proposal 604. To comment refer to http://www.museum.lsu.edu/~Remsen/SACCprop604.htm. The findings are likely to be controversial especially given "..we note that bill size and shape, as well as body size , can be extremely labile in passerines" hence they have placed less weight on these characters than many of the previous authors. Back issues of the journal Ornitologia Neotropical as well as membership information can be obtained at www.neotropicalornithology.org.
  7. The following article has been published on the Ornithology Exchange. This and other articles can be found under the Articles tab in the navigation menu or by clicking here. Molecular Phylogenetics of Neotropical Seedeaters and Seed-finches Jack Eitniear A recent paper in Ornitologia Neotropical by Nicholas A. Mason and Kevin J. Burns suggests merging the genera Oryzoborus and Dolospingus into a broadly defined Sporophila. Click here to view the article
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