The age and origin of the central Scotia Sea

Opening of the Drake Passage gateway between the Pacific and Atlantic oceans has been linked in various ways to Cenozoic climate changes. From the oceanic floor of Drake Passage, the largest of the remaining uncertainties in understanding this opening is in the timing and process of the opening of the central Scotia Sea. All but one of the available constraints on the age of the central Scotia Sea is diagnostic of, or consistent with, a Mesozoic age. Comparison of tectonic and magnetic features on the seafloor with plate kinematic models shows that it is likely to have accreted to a mid-ocean ridge between the South American and Antarctic plates following their separation in Jurassic times. Subsequent regional shallowing may be related to subduction-related processes that preceded backarc extension in the East Scotia Sea. The presence of a fragment of Jurassic–Cretaceous ocean floor in the gateway implies that deep water connections through the Scotia Sea basin complex may have been possible since Eocene times when the continental tips of South America and the Antarctic Peninsula first passed each other

Roadrunners and Eagles

Our previous research on perception of gated casual English by university students suggests that ceteris paribus, Polish students are much more accurate than Greeks. A recent pilot study of casually-spoken Polish leads us to the conclusion that many shortcuts found in English are also common in Polish, so that similar perceptual strategies can be used in both languages, though differing in detail. Based on these preliminary results, it seems likely that perceptual strategies across languages tend towards the “eagle” approach - where a birds-eye view of the acoustic terrain without too much emphasis on detail is found - or the “roadrunner” approach, where phonetic detail is followed closely. In the former case, perceivers adjust easily to alternation caused by casual speech phonology while in the latter, perceivers expect little variation and possibly even find it confusing. Native speakers of Greek are “roadrunners”, since there is little phonological reduction in their language there is little difference, for example, between stressed and unstressed syllables. We suggest that native speakers of Polish join English speakers as “eagles”, which gives them a natural perceptual advantage in English. There is a conceptual similarity between this idea and that of the stress- or syllable-timed language, and we hypothesise that as in this case, there is a cline rather than a sharp division between eagles and roadrunners. As usual, more research is called for

The historiography of the Black Panther party

This article examines forty years of historical writing on the Black Panther Party (BPP), arguing that this historiography has now reached maturity. It evaluates key publications on the BPP, splitting the historiography into three periods. The first phase, the article asserts, was dominated by accounts written by participants and observers of the BPP in action. These offered insight into the personalities of the BPP leadership but included relatively little on other BPP members. They were supplemented by a collection of friendly academic studies, a number of which emphasized the role of the FBI in precipitating the BPP's decline. The article identifies the 1994 publication of Hugh Pearson's biographical study of Huey P. Newton as the beginning of a second phase. Pearson's work, which built on a collection of accounts written by observers and right-wing writers during the first phase, precipitated an outpouring of new studies that opposed its conclusions. These works overwhelmingly focussed on individual BPP chapters and the experiences of the BPP rank and file; they were generally friendly towards the party and often appraised the BPP's actions through the 1970s. A second wave of participant accounts also emerged in this period which offered a more personal interpretation of the BPP's decline. A third period emerged in the early 2000s that abandoned the obsession with Pearson's study and focussed instead on the BPP's contribution to African American and American culture beyond its political program and violent image. The article reveals the paradox at the heart of the local approach, one which recent studies addressed in their focus on the BPP's Oakland chapter and their return to a tight chronological approach that focussed on the BPP's peak years. It concludes by noting the remaining omissions in the BPP's historical record and anticipating further studie

Long-Term Band Encounters of Rehabilitated North American Eagles

Between 1973 and 2020, 122 Golden Eagles and 115 Bald Eagles submitted to veterinary medical rehabilitation were banded and released upon recovery in three western states. Adults of both species comprised the most commonly banded age class of rehabilitated (rehab) eagles. Bald Eagles admitted for toxins spent less time in rehabilitation than for those admitted for collision trauma. Encounter (band read for any reason) data from banded eagles provided by the Bird Banding Laboratory (BBL) were analyzed and fitted to appropriate functions in an attempt to describe underlying distributions inherent in the data. Up to March 2020, 28 (12.2%) rehab eagles had been encountered. Encounter rate was 7.4% for rehab Golden Eagles and 16.5% for rehab Bald Eagles, slightly different than those reported by BBL overall (8.0%, 12.2%, respectively). All Golden Eagles were recovered (encountered dead) but 26.3% of Bald Eagles were encountered alive. Days in rehabilitation were not different between species or between Bald Eagles encountered dead or alive. Sex ratio of encountered eagles was not different from ratio of banded eagles of either species. Median time between release and encounter for Golden Eagles was 1.75 yr and 1.42 yr for Bald Eagles. Median distance from banding to encounter site for Golden Eagles was 7.5 km and 115.7 km for Bald Eagles. Number of encounters per year was not related to number of rehab eagles banded that year or for any year previous. Encounters of live Bald Eagles > 30 yr old are discussed. Rehab Golden Eagles may have originated predominantly from western Canada and Alaska while Bald Eagles may have been a mix of a local, non-latitudinal migratory population and seasonal latitudinal migrants. Small sample sizes and lack of precise encounter data prevents utility of rehab eagle encounters to contribute to demographic vital rate estimates needed for effective management of either species. Banding rehab eagles may not justify the manpower investment by BBL required to manage data from banders that band rehab eagles exclusively. Falconry training may be warranted to increase survival potential of rehab Golden Eagles. If recent trends continue, increased rehabilitation effort focused on Golden Eagles may be warranted