Geolocation (Global Location Sensing or GLS logging) using archival light-recording tags offers considerable potential for tracking animal movements, yet few studies of flying seabirds have exploited this technology. Our study evaluated its effectiveness for determining foraging ranges of black-browed albatrosses Thalassarche melanophrys fitted simultaneously with GLS loggers and satellite-transmitters (Platform Terminal Transmitters, PTTs). After some preliminary validation, the position of an albatross could be determined by geolocation with a mean error ± SD of 186 ± 114 km (SDs of 1.66°and 1.82°of latitude and longitude, respectively). Errors from identical static loggers were lower (mean ± SD of 85 ± 47 km, with overall SDs of 0.61°and 0.99°of latitude and longitude, respectively) and less variable, with the difference attributable to variation in sensor orientation, intermittent shading by plumage, and the difficulty of correcting for extensive, potentially non-linear movements of flying birds. Iterative smoothing reduced both the mean error and the inflation of kernel ranges derived from GLS data, but over-smoothing contracted the extremes of the range. This reduced the overlap with radial cores apparent in the control data, and should be avoided for multinuclear GLS fix distributions. The accuracy of GLS tags is more than adequate for tracking migration and breeding-season foraging ranges of pelagic species, and for identifying broad-scale habitat preferences, overlap and potential conflict with commercial fisheries.

The precise relationship between the stem cells for the lymphoid system and those for the blood-forming system is unclear. While it is generally assumed that the hemopoietic stem cell, the spleen colony-forming unit (CFU-S), is also the stem cell for the lymphoid system, there is little evidence for this hypothesis. To investigate the stem cells in these two systems, we irradiated bone marrow cells to induce unique chromosome aberrations in the stem cell population and injected them at limiting dilution into stem cell-deficient recipients. Several months (between 3 and 11) were allowed for the injected cells to repopulate the hemopoietic system. At that time, the bone marrow, spleen, and thymus were examined for a high frequency of cells having the same unique chromosome aberration. The presence of such markers shows that the marker was induced in a cell with extensive proliferative capacity, i.e., a stem cell. In addition, the splenic lymphocytes were stimulated with phytohemagglutinin (PHA) or lipopolysaccharide (LPS) to search for unique chromosomes in dividing T and B cells, respectively. Finally, bone marrow cells were injected into secondary irradiated recipients to determine if the marker occurred in CFU-S and to determine whether or not the same tissue distributions of marked cells could be propogated by bone marrow cells in a second recipient. After examination of 28 primary recipients, it was possible to identify three unique patterns of stem cell regeneration. In one set of mice, a unique chromosome marker was observed in CFU-S and in PHA- and LPS-stimulated cultures. These mice provide direct evidence for a pluripotent stem cell in bone marrow. In addition, two restricted stem cells were identified by this analysis. In three recipients, abnormal karyotypes were found only in myeloid cells and not in B and T lymphocytes. These mice presumably received a marked stem cell restricted to differentiate only into myeloid progeny. In three other recipients, chromosome aberrations were found only in PHA-stimulated cells; CFU-S and cells from LPS cultures did not have cells with the unique chromosome. This pattern suggests that bone marrow contains cells committed to differentiation only into T lymphocytes. For each of the three types of stem cells, secondary recipients had the same cellular distribution of marked cells as the primary recipients. This observation provides further evidence that unique markers can be induced in both pluripotent and restricted stem cells.

We used satellite telemetry to examine the foraging ranges, feeding locations and travel speeds of 17 chick-rearing gannets Morus bassanus from the Bass Rock, SE Scotland. Regurgitates indicated that birds at the colony exploited a wide range of prey, frequently including 0-group sandeels (

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Consistent with an ordered immunoglobulin (Ig) gene assembly process during precursor (pre‐) B cell differentiation, we find that most Abelson murine leukemia virus (A‐MuLV)‐transformed pre‐B cells derived from scid (severe combined immune deficient) mice actively form aberrant rearrangements of their Ig heavy chain locus but do not rearrange endogenous kappa light chain variable region gene segments. However, we have identified several scid A‐MuLV transformants that transcribe the germline Ig kappa light chain constant region and actively rearrange the kappa variable region gene locus. In one case progression to the stage of kappa light chain gene rearrangement did not require expression of Ig mu heavy chains; furthermore, this progression could not be efficiently induced following expression of mu heavy chains from an introduced vector. As observed in pre‐B cell lines from normal mice, attempted V kappa‐to‐J kappa rearrangements in scid transformants occur by inversion at least as frequently as by deletion. The inverted rearrangements result in retention of both products of the recombination event in the chromosome, thus allowing their examination. scid kappa coding sequence joins are aberrant and analogous in structure to previously described scid heavy chain coding joins. In contrast, the recognition signals that flank involved coding segments frequently are joined precisely back‐to‐back in normal fashion. The scid VDJ recombinase defect therefore does not significantly impair recognition of, site‐specific cutting at, or juxtaposition and appropriate ligation of signal sequences. Our finding that the scid defect prevents formation of correct coding but not signal joins distinguishes these events mechanistically.

Foraging and provisioning strategies of the light-mantled sooty albatross (LMSA) Phoebetria palpebrata were studied during chick-rearing at Bird Island, South Georgia, in January to May 2003. Virtually all trips of satellite-tracked birds were restricted to Antarctic waters. Individual birds followed a diversity of foraging routes, the majority to shelf and shelf-slope areas along the southern Scotia Arc or to oceanic waters in the mid Scotia Sea, with only a few trips extending as far south as the marginal ice zone in the Weddell Sea. Sympatric white-chinned petrels Procellaria aequinoctialis, black-browed Thalassarche melanophrys and grey-headed albatrosses T. chrysostoma also exploit these areas. Unlike LMSA, these species and the wandering albatross Diomedea exulans, also forage on the shelf and shelf-slope waters surrounding South Georgia, or at the Antarctic Polar Front (APF), where the larger albatrosses and smaller, more manoeuvrable white-chinned petrel may out-compete LMSA for access to prey. As a consequence, foraging distances and maximum ranges are greater, chick-feeding frequencies are lower and chick growth rate is slower in LMSA than in sympatric Thalassarche albatrosses, and adult LMSA appear to have little capacity to regulate provisioning according to chick condition. Nonetheless, LMSA seem well-adapted to exploitation of distant foraging grounds, apparently using the wind to reduce flight costs and, in comparison with other albatrosses, spending more of the night on the wing and returning with food loads that represent a greater proportion of adult mass. KEY WORDS: Activity pattern · Competition · Niche specialisation · Provisioning rate · Spatial segregationResale or republication not permitted without written consent of the publisher

This study examined divergence in the foraging distribution, at-sea behaviour and provisioning strategies of a small procellarid, the Cook's petrel Pterodroma cookii, during chick-rearing at 2 islands off New Zealand, separated latitudinally by ~1000 km. There was little overlap in foraging distribution between adults from Little Barrier Island (LBI), which ranged to the west into the Northern Tasman Sea and east into the Pacific Ocean, and conspecifics from Codfish Island (CDF), which foraged west of the South Island in the south Tasman Sea in association with the subtropical convergence zone. Although birds from CDF ranged further than those from LBI, there was no difference in mean foraging trip duration. Cook's petrels from CDF foraged over deeper, cooler water, with higher primary productivity, than conspecifics from LBI. At-sea behaviour also differed: adults from LBI spent less time in flight, and showed less variation in total flight time per day. Overall, Cook's petrels spend much more time in flight than albatrosses, and approximately the same amounts of time on the water during the night as during the day, suggesting a high portion of nocturnal foraging. Dive depths did not differ between colonies but were greater than expected for a gadfly petrel. Stable isotope signatures of blood indicated population-specific diets, and suggested that birds from LBI primarily consume cephalopods and fish, whereas those from CDF eat more crustaceans. Chicks at CDF received more food. These results suggest a broad divergence in foraging strategies between geographically well-separated colonies in response to regional differences in oceanography. KEY WORDS: Foraging distribution · Geolocation loggers · Stable isotopes · Subtropical convergence · Gadfly petrel Resale or republication not permitted without written consent of the publisherMar Ecol Prog Ser 370: [271][272][273][274][275][276][277][278][279][280][281][282][283][284] 2008 ever, there have been relatively few studies of highly pelagic species from more widely separated populations, where there is nonetheless the potential for some overlap and interaction at sea. Such comparisons are particularly interesting given the potential for genetic isolation between populations, as most seabirds display a high degree of natal philopatry (Warham 1996). In addition, the high degree of behavioural flexibility of adults may also lead to divergence in foraging strategies, particularly between distant colonies in dissimilar oceanographic domains.Until recently, owing to the relatively large size of the available technology, detailed studies on the movements of pelagic seabirds had been restricted to medium to large species to which attachment of equipment was feasible without impacting the animal's behaviour (Weimerskirch et al. 1993, Stahl & Sagar 2000a. Information on the distribution and behaviour of smaller species (< 300 g) at sea was therefore restricted to band recoveries (Patterson & Hunter 2000) and shipboard observations (Bartle et al. 1990). However,...

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