![]() Palm Warblers, Common Yellowthroats, and Yellow-rumped Warblers. Warblers are now migrating through the area to their wintering grounds.Monarch on Goldenrod (Image by BirdNation) Sometimes the flocks are so large that they come up on weather radar as “roost rings”. They take about 3-4 months to migrate from their summer to their wintering grounds, leisurely stopping en route to forage, preen, and rest. Tree Swallows migrate in huge flocks that can number in the hundreds of thousands. It was amazing to watch them swirl around over the sand. Tree Swallow massive flock!: We had the opportunity to observe a large flock of Tree Swallows gathering on the beach.Located on a prime location of the Altantic Flyway, Cape May is one of the best birding areas in the country to catch a sight of migrants, whether they are hawks, warblers, or anything in between. Many people were participating in the fall Hawk Watch, which takes place daily during the migration. It seemed like everyone had the same idea about going to the Point. We hiked around our two favorite Cape May locations: Cape May Point State Park and South Cape May Meadows. With spring now in the Southern Hemisphere and autumn in the Northern Hemisphere, the Lab thought it would be great time to track the migrations around the world.ĭave and I went to Cape May for our big day. 2018 is the first year that this Big Day event was also held in autumn. For the past 4 years, the Cornell Lab of Ornithology has held an annual Global Big Day event in May. Proceedings are now published (A) once or twice (B) each month and include original papers of important new research findings and interesting reviews that shed new light on a particular subject or field.Yesterday, October 6th, was the first October Global Big Day. Obituary Notices were printed in Proceedings up to April 1932 but since then have appeared as a separate publication. In 1905 the bulk of Proceedings increased so much that it split into two series: Series A (papers on the Mathematical, Physical and Engineering sciences) and Series B, (Biological sciences). Included in the publication was the Anniversary meeting and reports. By the 3rd volume the abstracts were arranged under the order in which the papers had been read at the meetings the report of each discussion meeting was headed by a brief account of the business which preceded the reading of the papers. Although this non-random clustering of speciation is consistent with the pattern expected of an adaptive radiation, the age of the Dendroica radiation suggests it is an 'ancient species flock' in which most extant species represent lineages that have long been evolutionarily independent.Ī meeting of the Council on May 10th, 1832 resolved that abstracts of papers submitted for publication in the Philosophical Transactions from the year 1800 be published in Proceedings. Comparisons with a null model of random bifurcation-extinction demonstrate that cladogenesis in Dendroica has been clustered non-randomly with respect to time, with a significant burst of speciation occurring early in the history of the genus, possibly as long ago as the Late Miocene or Early Pliocene periods. The prevalence of long terminal branches indicates that these species have evolved efficient isolating mechanisms that have prevented mtDNA introgression despite the many opportunities for hybridization resulting from local sympatry. Mitochondrial divergences among Dendroica species were generally large (mean pairwise interspecific distances, 10.0%) and many species were rooted in a basal polytomy. The taxa sampled included 60 individuals representing 24 Dendroica species and a variety of other paruline warbler and outgroup species. We explored the temporal structure of Dendroica diversification via a phylogeny based on 3639 nucleotides of protein-coding mitochondrial DNA (mtDNA). Instead, sympatric Dendroica tend to partition resources behaviourally and they have become a widely cited example of competitive exclusion. Dendroica species exhibit high levels of local sympatry and differ in plumage and song, but the group contrasts with other well-known avian adaptive radiations such as the Hawaiian honeycreepers and Galapagos finches in that Dendroica species have differentiated modestly in morphometric traits related to foraging. The 27 species of Dendroica wood-warblers represent North America's most spectacular avian adaptive radiation.
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