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Point Reyes Station, CA, United States

Nelson K.N.,P.O. Box 402 | Pyle P.,Institute for Bird Populations
Western Birds | Year: 2013

There are now numerous records of the Crested Caracara (Caracara cheriway) from California and elsewhere well north of its breeding range, but whether or not they represent wild birds or escapees from zoos or falconers has been debated. Through 2011, the California Bird Records Committee (CBRC) had accepted 49 records that they considered to represent naturally occurring vagrants, but decisions concerning the number of individuals involved in these records were haphazard. Therefore, we assessed the date, location, age, molt status, and appearance of caracaras representing 60 observations specific to date and location in California and propose that these records involve only 11 individuals, recorded between 1 and 34 times throughout the state; a twelfth individual was recorded from December 2011 to April 2012. Our 11-bird scenario was proposed and accepted by the CBRC in January 2012. This synthesis clarifies the species' pattern of occurrence in California: ten of the 11 individuals were first detected in fall or winter, eight individuals were first detected in their first or second years, four of these eight were later detected at appropriate ages elsewhere in California, and six individuals moved north within the state. These patterns are consistent with birds moving north as wild vagrants and so support the CBRC's decision to accept the Crested Caracará as a naturally occurring species. We hope that our analysis will help other records committees evaluate the status of this species in other regions, perhaps revealing a similar pattern of natural vagrancy throughout North America. Source


Ornithologists have largely embraced the molt terminology of Humphrey and Parkes (1959) as modified by Howell et al. (2003; the H-P-H system). In a recent commentary, Wolfe et al. (2014) summarized the derivation and benefits of HP-H terminology, suggested slight modifications, and promoted analyses on the evolution of molts using H-P-H nomenclature. We appreciate the timeliness of Wolfe et al.'s review and agree with most of their conclusions and modifications. We disagree, however, with Wolfe et al.'s proposal for introducing a new and restricted use of the term "definitive" in H-P-H nomenclature. To avoid confusion, we recommend that definitive plumage and definitive molt cycle continue to be used as defined by Humphrey and Parkes (1959) and Howell et al. (2003), respectively, as terms indicating that plumage appearance and molt cycle have achieved stasis. We also recommend that the term "plumage" can be used more widely than the definition proposed by Humphrey and Parkes (1959), and that the term "juvenal" can henceforth be replaced by "juvenile" in molt and plumage literature. © 2015 American Ornithologists' Union. Source


Pyle P.,Institute for Bird Populations
Western Birds | Year: 2013

While most basic-plumaged Common Murres (Uria aalge) show white facial plumage and tips to the secondaries, some individuals off central California from September through November have dark faces and secondaries. To investigate the plumage state and age of such birds, I examined specimens and photographs of Common Murres taken off central California and conclude that outgoing and incoming alternate feathers as well as early-replaced and late-replaced dark basic and formative feathers all may contribute to this variation. Hypermelanism may account for a small proportion of cases. The early onset of prebasic molt-before hormone signaling switches from dark feathers typical of the alternate plumage to white feathers typical of the basic plumage-may be responsible for most of the darkest-faced birds in basic plumage. This type of asynchrony of molt and the signal for change in plumage appears to occur more often in second-cycle birds, which initiate the prebasic molt earlier than do older adults, and it may also explain plumages in chicks and juveniles molting during May and June. Common Murres in basic plumage from colonies in central California appear to acquire dark facial feathers more often than birds from more northerly colonies, which could relate to earlier breeding and molt in central California. Source


I examined over 4500 specimens to investigate the evolutionary significance of molt sequences as related to systematic relationships of falcons and parrots. Nodes of molt among the medial primaries (p4-p6) and at s5 among the secondaries, followed by bidirectional replacement from the node within each tract, was confirmed for most or all taxonomic groupings of both falcons and parrots, with the exception of the Kakapo or Owl Parrot (Strigops habroptila), which appears to replace its remiges in sequences similar to those of most other birds. Initiation of primary molt varies between p4 and p5 in falcons and between p5 and p6 in parrots, including within species, suggesting that the node's position may be fluid within a defined area along the alar tract. The coincidence and consistency of these molt sequences in parrots and falcons but in no other order of birds suggests that molt sequence may be a synapomorphic (shared) character state, supporting recent molecular evidence that the Falconiformes and Psittaciformes are sister taxa. A more ancestral molt sequence in Strigops may suggest that it split from other parrots prior to a Falconiformes-Psittaciformes divergence or it may indicate reversion to a primitive character state in response to the species' unique nocturnal and ground-dwelling habits. The results of this analysis further suggest that synapomorphic wing-molt sequences can be used as an indicator of systematic relationships in birds and that molt sequence is perhaps controlled by a neurological process more fixed than timing, extent, and geographic location of molts. © The Cooper Ornithological Society 2013. Source


Pyle P.,Institute for Bird Populations
Western Birds | Year: 2011

Since its 34 th report (Pike and Compton 2010), the California Bird Records Committee (CBRC) has accepted records of 176 individuals of 58 species, 2 species pairs, and 1 hybrid, most of which were of birds observed in 2009. Two species, the White-chinned Petrel (Procelhria aequinoctialis) and the recently split Winter Wren (Troglodytes hiemalis), axe added to the California state list, bringing the total to 643 accepted species. We introduce a new tabular format to present CBRC records, similar to that found at the CBRCs webpage Update to Rare Birds of California (www.californiabirds.org/cbrc-book/ update.pdO). In 2011, the CBRC added two species to its review list, the Fulvous Whistling-Duck (Dendrocygna bicolor) and Cape May Warbler [Dendroica tigrina). Source

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