Distribution and movements of West Indian humpback whales in winter

1982 ◽  
Vol 60 (9) ◽  
pp. 2203-2211 ◽  
Author(s):  
Hal Whitehead ◽  
Michael J. Moore

The humpback whales which winter in the West Indies are principally found over banks which are at latitudes between 10° and 22° N, have substantial areas of flat bottom between 15 and 60 m deep, and lie less than 30 km from the North Atlantic 2000 m contour. The surface sea temperatures in these areas are between 24 and 28 °C. The major concentrations of the humpbacks, which feed little in winter, are on Silver and Navidad banks. On Silver Bank the humpback and humpback song densities peak in the centre of the Bank. Mothers with calves are generally found in areas of calm water, and singers are found over areas with a flat bottom, where they meander slowly. Larger groups move considerably faster and in straighter lines. There is no evidence of whales possessing particular movement patterns, preferred ranges, or territories within the Bank. The concentration of humpbacks may be a significant feature for other humpbacks.

1988 ◽  
Vol 120 (S144) ◽  
pp. 13-24 ◽  
Author(s):  
William L. Peters

AbstractThe complex origins of the North American Ephemeroptera fauna extended from the Lower Permian to the Recent. This paper discusses origins of North American genera of the cosmopolitan family Leptophlebiidae with a few examples from other mayfly families. The two extant subfamilies, Leptophlebiinae and Atalophlebiinae, probably evolved at least by the mid-Cretaceous, or about 100 million years before present. The primitive Leptophlebiinae are distributed throughout most of the Northern Hemisphere and the ancestors of the Leptophlebia–Paraleptophlebia complex within this subfamily dispersed widely by the North Atlantic route as early as the mid-Cretaceous and later probably by northern trans-Pacific dispersals through Beringia. The ancestors of Habrophlebia dispersed through the North Atlantic route at an early time, but the vicariant distribution of Habrophlebiodes in several areas of the Oriental Region and eastern North America correlates with the Arcto-Tertiary forest that covered most of the Northern Hemisphere including Beringia from the Early Tertiary into the Pleistocene. Within the nearly cosmopolitan Atalophlebiinae, Traverella is austral in origin and probably dispersed north through the Mexican Transition Zone during the mid-Tertiary as an ancient dispersal and then dispersed to its northern and eastern limits following the last Pleistocene deglaciation by way of the Missouri River tributaries. Thraulodes and Farrodes are both austral in origin and probably dispersed north through the Mexican Transition Zone during the Early Pleistocene as a relatively recent dispersal. The origins of Choroterpes sensu stricto and Neochoroterpes in North America are unknown. The mayfly fauna of the West Indies is Neotropical in origins, and no affinities between the West Indies and North America through Florida have ever been confirmed.


1993 ◽  
Vol 71 (5) ◽  
pp. 1065-1066 ◽  
Author(s):  
Phillip J. Clapham ◽  
David K. Mattila ◽  
Per J. Palsbøll

Competitive groups of humpback whales, Megaptera novaeangliae, were observed in Samana Bay, Dominican Republic, West Indies. Photographs of ventral fluke patterns were used to identify individuals, and skin biopsies were taken for molecular determination of sex. Nine groups contained two or more whales previously identified from different high-latitude areas. In seven groups, males from different feeding grounds were observed to compete with each other, and in six cases the group's female was from a different area than at least one of her male escorts. These results provide further support for the hypothesis that the western North Atlantic population of this species can be considered a single panmictic unit.


1994 ◽  
Vol 72 (11) ◽  
pp. 1898-1907 ◽  
Author(s):  
David K. Mattila ◽  
Phillip J. Clapham ◽  
Oswaldo Vásquez ◽  
Robert S. Bowman

A study of humpback whales (Megaptera novaeangliae) was conducted between 1988 and 1991 in Samana Bay, Dominican Republic. Humpbacks were observed as early as the earliest survey (3 January) and as late as the latest (16 March). Local abundance varied from 0 whales per hour to a maximum of 3.2 whales per hour (mean = 1.70, SD = 0.79), and densities calculated from track surveys ranged from 0.09 to 0.82 whales per square nautical mile (mean = 0.31). Abundance generally peaked in February, but variation was observed both within a season and between years. Almost all whales were observed in the eastern part of the bay, towards or at its mouth. In all, 397 individuals were photographically identified during the study period. Of these, 18 were observed in more than 1 year (17 in 2 years, 1 in 3 years). A total of 15.8% of identified individuals were observed on more than 1 day in a year (maximum 5 days), with mothers representing 33.3% of all resightings. Observed occupancies of resighted animals ranged from 1 to 33 days (mean = 6.3 days, SD = 7.14). The mean group size was 1.95 (range = 1–15, SD = 1.30, n = 652 groups). Ninety-nine groups contained a calf, and all groups larger than three (n = 45) were competitive in nature. Comparisons of fluke photographs with the North Atlantic Humpback Whale Catalogue revealed 141 matches of 118 individuals to other areas. Of these, 76 were to high-latitude feeding grounds (including the Gulf of Maine, Newfoundland, Labrador, the Gulf of St. Lawrence, and west Greenland), while the remaining 65 were to other areas of the West Indies (Silver Bank, Navidad Bank, Puerto Rico, Virgin Bank, or Anguilla Bank) or to Bermuda. We suggest that Samana Bay is one of the most important winter habitats in the West Indies for humpback whales from all over the western North Atlantic, although whaling records suggest that the abundance of whales in this area may be a relatively recent phenomenon. Sightings of other marine mammal species in Samana Bay are summarized.


Atmosphere ◽  
2021 ◽  
Vol 12 (3) ◽  
pp. 329
Author(s):  
Albenis Pérez-Alarcón ◽  
José C. Fernández-Alvarez ◽  
Rogert Sorí ◽  
Raquel Nieto ◽  
Luis Gimeno

The combined effect of the sea surface temperature (SST) and the North Atlantic subtropical high-pressure system (NASH) in the interannual variability of the genesis of tropical cyclones (TCs) and landfalling in the period 1980–2019 is explored in this study. The SST was extracted from the Centennial Time Scale dataset from the National Oceanic and Atmospheric Administration (NOAA), and TC records were obtained from the Atlantic Hurricane Database of the NOAA/National Hurricane Center. The genesis and landfalling regions were objectively clustered for this analysis. Seven regions of TC genesis and five for landfalling were identified. Intercluster differences were observed in the monthly frequency distribution and annual variability, both for genesis and landfalling. From the generalized least square multiple regression model, SST and NASH (intensity and position) covariates can explain 22.7% of the variance of the frequency of TC genesis, but it is only statistically significant (p < 0.1) for the NASH center latitude. The SST mostly modulates the frequency of TCs formed near the West African coast, and the NASH latitudinal variation affects those originated in the Lesser Antilles arc. For landfalling, both covariates explain 38.7% of the variance; however, significant differences are observed in the comparison between each region. With a statistical significance higher than 90%, SST and NASH explain 33.4% of the landfalling variability in the archipelago of the Bahamas and central–eastern region of Cuba. Besides, landfalls in the Gulf of Mexico and Central America seem to be modulated by SST. It was also found there was no statistically significant relationship between the frequency of genesis and landfalling with the NASH intensity. However, the NASH structure modulates the probability density of the TCs trajectory that make landfall once or several times in their lifetime. Thus, the NASH variability throughout a hurricane season affects the TCs trajectory in the North Atlantic basin. Moreover, we found that the landfalling frequency of TCs formed near the West Africa coast and the central North Atlantic is relatively low. Furthermore, the SST and NASH longitude center explains 31.6% (p < 0.05) of the variance of the landfalling intensity in the archipelago of the Bahamas, while the SST explains 26.4% (p < 0.05) in Central America. Furthermore, the 5-year moving average filter revealed decadal and multidecadal variability in both genesis and landfalling by region. Our findings confirm the complexity of the atmospheric processes involved in the TC genesis and landfalling.


2003 ◽  
Vol 60 (2) ◽  
pp. 211-222 ◽  
Author(s):  
Paul J. Hearty

AbstractOver 100 whole-rock amino acid racemization (AAR) ratios from outcrops around Rottnest Island (32.0° S Latitude near Perth) indicate distinct pulses of eolian deposition during the late Quaternary. Whole-rock d-alloisoleucine/l-isoleucine (A/I) ratios from bioclastic carbonate deposits fall into three distinct modal classes or “aminozones.” The oldest, Aminozone E, averages 0.33 ± 0.04 (n = 21). Red palaeosol and thick calcrete generally cap the Aminozone E deposits. A younger Aminozone C averages 0.22 ± 0.03 (n = 63); comprising two submodes at 0.26 ± 0.01 (n = 14) and 0.21 ± 0.02 (n = 49). Multiple dune sets of this interval are interrupted by relatively weak, brown to tan “protosols.” A dense, dark brown rendzina palaeosol caps the Aminozone C succession. Ratios from Holocene dune and marine deposits (“Aminozone A”) center on 0.11 ± 0.02 (n = 15), comprising submodes of 0.13 ± 0.01 (9) and 0.09 ± 0.01 (6). Calibration of A/I averages from Aminozones E and A are provided by U/Th and 14C radiometric ages of 125,000 yr (marine oxygen isotope stage (MIS) 5e and 2000–6000 14C yr B.P. (MIS 1), respectively. The whole-rock A/I results support periodic deposition initiated during MIS 5e, continuing through MIS 5c, and then peaking at the end of MIS 5a, about 70,000–80,000 yr ago. Oceanographic evidence indicates the area was subjected to much colder conditions during MIS 2–4 (10,000 to 70,000 yr ago), greatly slowing the epimerization rate. Eolianite deposition resumed in the mid Holocene (∼6000 yr ago) up to the present. The A/I epimerization pathway constructed from Rottnest Island shows remarkable similarity to that of Bermuda in the North Atlantic (32° N Latitude). These findings suggest that, like Bermuda, the eolian activity on Rottnest occurred primarily during or shortly after interglacial highstands when the shoreline was near the present datum, rather than during glacial lowstands when the coastline was positioned 10–20 km to the west.


The estimates of the thickness of the Mesozoic and Cenozoic sediments found in the western Channel show that the deposition of these sediments was controlled by two independent processes. (1) In the longitudinal direction, the displacement of maximum sedimentation, from east to west is entirely dependent on the opening of the North Atlantic. (2) In a transverse direction, it is probable that the difference of subsidence between the two sides of the Aurigny—Ouessant fault originated from the fracturing of the original Atlantic rift in the Western Approaches. Transverse compressions and extensions have disturbed the continual depression of the Channel towards the west.


Author(s):  
Bernice Kurchin

In situations of displacement, disruption, and difference, humans adapt by actively creating, re-creating, and adjusting their identities using the material world. This book employs the discipline of historical archaeology to study this process as it occurs in new and challenging environments. The case studies furnish varied instances of people wresting control from others who wish to define them and of adaptive transformation by people who find themselves in new and strange worlds. The authors consider multiple aspects of identity, such as race, class, gender, and ethnicity, and look for ways to understand its fluid and intersecting nature. The book seeks to make the study of the past relevant to our globalized, postcolonized, and capitalized world. Questions of identity formation are critical in understanding the world today, in which boundaries are simultaneously breaking down and being built up, and humans are constantly adapting to the ever-changing milieu. This book tackles these questions not only in multiple dimensions of earthly space but also in a panorama of historical time. Moving from the ancient past to the unknowable future and through numerous temporal stops in between, the reader travels from New York to the Great Lakes, Britain to North Africa, and the North Atlantic to the West Indies.


1992 ◽  
Vol 34 (1) ◽  
pp. 3-27 ◽  
Author(s):  
Uffe Østergård

From a cultural and historical-sociological perspective, the Danish nationstate of today represents a rare situation of virtual identity between state, nation, and society, which is a more recent phenomenon than normally assumed in Denmark and abroad. Though one of the oldest European monarchies, whose flag came ‘tumbling down from heaven in 1219’—ironically enough an event that happened in present-day Estonia—Denmark's present national identity is of recent vintage. Until 1814 the word, Denmark, denominated a typical European, plurinational or multinational, absolutist state, second only to such powers as France, Great Britain, Austria, Russia, and perhaps Prussia. The state had succeeded in reforming itself in a revolution from above in the late eighteenth century and ended as one of the few really “enlightened absolutisms” of the day (Horstbøll and østergård 1990; østergård 1990). It consisted of four main parts and several subsidiaries in the North Atlantic Ocean, plus some colonies in Western Africa, India, and the West Indies. The main parts were the kingdoms of Denmark proper and Norway, plus the duchies of Schleswig and Holstein. How this particular state came about need not bother us here.


Sign in / Sign up

Export Citation Format

Share Document