The lens and source of the optical Einstein ring gravitational lens ER 0047-2808

(Abridged) We perform a detailed analysis of the optical gravitational lens ER 0047-2808 imaged with WFPC2 on the Hubble Space Telescope. Using software specifically designed for the analysis of resolved gravitational lens systems, we focus on how the image alone can constrain the mass distribution in the lens galaxy. We find the data are of sufficient quality to strongly constrain the lens model with no a priori assumptions about the source. Using a variety of mass models, we find statistically acceptable results for elliptical isothermal-like models with an Einstein radius of 1.17''. An elliptical power-law model (Sigma \propto R^-beta) for the surface mass density favours a slope slightly steeper than isothermal with beta = 1.08 +/- 0.03. Other models including a constant M/L, pure NFW halo and (surprisingly) an isothermal sphere with external shear are ruled out by the data. We find the galaxy light profile can only be fit with a Sersic plus point source model. The resulting total M/L_B contained within the images is 4.7 h_65 +/-0.3. In addition, we find the luminous matter is aligned with the total mass distribution within a few degrees. The source, reconstructed by the software, is revealed to have two bright regions, with an unresolved component inside the caustic and a resolved component straddling a fold caustic. The angular size of the entire source is approx. 0.1'' and its (unlensed) Lyman-alpha flux is 3 x 10^-17 erg/s/cm^2.Comment: 13 pages, 5 figures. Revised version accepted for publication in MNRA

Nesting Activity of Kittlitz’s Murrelet in the Kakagrak Hills, Northwestern Alaska

The Kittlitz’s Murrelet (Brachyramphus brevirostris) is a broadly distributed but uncommon seabird species endemic to coastal Alaska and eastern Russia. Although northern Alaska constitutes a large portion of this species’ range, little is known about Kittlitz’s Murrelets in this vast region. We studied nesting activity of Kittlitz’s Murrelets in the Kakagrak Hills, Cape Krusenstern National Monument, in northern Alaska during summer 2014. Between 15 and 26 June, we located two active Kittlitz’s Murrelet nests by walking line transects in 28 sampling blocks (250 × 250 m) that were stratified by two habitat types (Alpine Alkaline Barrens and Alpine Dryas Dwarf Shrub) and selected randomly. We found one additional active nest opportunistically while walking between blocks. All three nests were located in Alpine Alkaline Barrens habitat, and all failed during the egg stage. Causes of failure were nest abandonment (n = 1), depredation (n = 1), and unknown (n = 1). Overall mean nest density was 0.80 nests/km2 (SE = 0.52). Although our sample of nests was small, our results demonstrate that Kittlitz’s Murrelets nest regularly in northern Alaska. However, the apparently low productivity raises questions about the reproductive value of this region to this cryptic and secretive species.Le guillemot de Kittlitz (Brachyramphus brevirostris) est une espèce d’oiseau marin largement répandue, mais rare, endémique aux zones côtières de l’Alaska et de l’est de la Russie. Même si le nord de l’Alaska représente une grande portion de l’aire de répartition de cette espèce, nous en savons très peu sur les guillemots de Kittlitz dans cette vaste région. Au cours de l’été 2014, nous avons étudié l’activité de nidification du guillemot de Kittlitz dans les collines Kakagrak, au Cape Krusenstern National Monument, dans le nord de l’Alaska. Du 15 au 26 juin, nous avons repéré deux nids actifs du guillemot de Kittlitz en marchant dans les transects linéaires de 28 blocs d’échantillonnage (250 x 250 m) composés de deux types d’habitat (la toundra alpine alcaline et l’arbuste nain alpin Dryas) sélectionnés au hasard. Nous avons trouvé un autre nid actif de façon opportuniste en marchant entre les blocs. Les trois nids étaient situés dans la toundra alpine alcaline et ils ont tous échoué au stade de l’oeuf. Les causes de l’échec étaient l’abandon du nid (n = 1), la déprédation (n = 1) et une cause inconnue (n = 1). La moyenne générale de la densité des nids était de 0,80 nid/km2 (écart-type de 0,52). Même si notre échantillonnage de nids était petit, nos résultats montrent que le guillemot de Kittlitz niche régulièrement dans le nord de l’Alaska. Cependant, le faible taux de réussite apparent soulève des questions quant à la valeur reproductive de cette région pour cette espèce cryptique et discrète

The Use Of Automated Telephone Interfaces With Customers By Local Organizations: Best Practices And Exploratory Investigation Of Usage

Automated telephone systems (ATS) have been criticized by customers as a frustrating way to interact with an organization.  This study seeks to discover ATS best practices, assess how many local organizations (as opposed to 1-800 call centers) are utilizing various ATSs, and determine which ATS best practices these local organizations are adopting.  A list of 35 best practices were found.  An exploratory examination of 400 organizations in a mid-sized mid-western city revealed that very few use an advanced ATS, with 51% using a simple answering machine. The adoption of best practices by these organizations was quite varied.  Managerial recommendations as well as future research suggestions are offered

Reproductive performance of Kittlitz\u27s Murrelet in a glaciated landscape, Icy Bay, Alaska, USA

Kittlitz\u27s Murrelet (Brachyramphus brevirostris) is a dispersed-nesting seabird endemic to Alaska and eastern Russia that may have experienced considerable population declines in some parts of its range in the past few decades. Poor reproduction has been suggested as the demographic bottleneck, yet there are no direct estimates of reproduction in a glaciated area where this species reaches its highest densities at sea during the breeding season. The lack of demographic information in glacial habitats has limited our ability to interpret population trends and to clarify whether the presence of glaciers affects reproductive performance. Between 2007 and 2012, we radio-tagged Kittlitz\u27s Murrelets to measure breeding propensity, nesting success, and fecundity in the heavily glaciated landscape of Icy Bay, Alaska, USA. Of 156 radio-tagged birds, 20% were breeders, 68% were potential breeders, and 12% were nonbreeders. Radio-tagged males (29%) were more likely to be breeders compared to females (11%). Across all years, we located 34 Kittlitz\u27s Murrelet nests, 38% of which were successful. Daily nest survival probability (± SE) was 0.979 ± 0.005, with most nests failing during incubation; if extrapolated to a 55-day period from nest initiation to fledging, the nest survival rate was 0.307 ± 0.083. Low fecundity was due largely to low breeding propensity, not low nesting success. For context, we also determined the breeding status of 14 radio-tagged Marbled Murrelets (B. marmoratus), most of which were breeders (79%) and successfully fledged young (69%). Our data demonstrated that Kittlitz\u27s Murrelets were outperformed in all facets of reproduction compared to Marbled Murrelets. Low fecundity estimates for Kittlitz\u27s Murrelet were consistent with a 10% per annum decline in Icy Bay between 2002 and 2012, suggesting that poor reproductive performance contributed to the local population decline of this species

Testing Assumptions of Distance Sampling on a Pelagic Seabird

Distance sampling along a line transect is used commonly for monitoring changes of birds’ abundance at sea. A critical yet rarely tested assumption of line-transect-sampling theory is that all birds along the transect line (i.e., directly in front of the boat) are detected or that probability of detecting a bird on the line can be estimated. As part of a long-term research and monitoring program for the Kittlitz’s Murrelet (Brachyramphus brevirostris), we tested the assumption of complete detection of murrelets on the water along a transect line directly in front of a moving boat. Following standard survey procedures, we approached groups of murrelets (n = 57) at sea and recorded their distance, response (diving or flying), and duration of response. Flying murrelets (n = 27) were easily detected, but diving birds (n = 30) were more difficult to detect because of the duration of their dive. The probability that a bird dove and remained underwater long enough to avoid detection was low because birds that dove more than 150 m from the boat surfaced before the boat passed whereas birds that “waited” to dive near the boat were easily detected prior to diving. The greatest probability of nondetection was for birds diving at 55 m (diving long enough for the boat to pass) but was only 0.032 ± 0.007 (P + SE). These experiments quantifying detection probability along the transect line could be applied to any species surveyed from a boat

Understanding Abundance Patterns of a Declining Seabird: Implications for Monitoring

The Kittlitz\u27s Murrelet (Brachyramphus brevirostris) is a rare, non-colonial seabird often associated with tidewater glaciers and a recent candidate for listing under the Endangered Species Act. We estimated abundance of Kittlitz\u27s Murrelets across space and time from at-sea surveys along the coast of Alaska (USA) and then used these data to develop spatial models to describe abundance patterns and identify environmental factors affecting abundance. Over a five-week period in the summer of 2005, we recorded 794 Kittlitz\u27s Murrelets, 16 Marbled Murrelets (B. marmoratus), and 70 unidentified murrelets. The overall population estimate (N, mean ± SE) during the peak period (3–9 July) was 1317 ± 294 birds, decreasing to 68 ± 37 by the last survey period (31 July–6 August). Density of Kittlitz\u27s Murrelets was highest in pelagic waters of Taan Fjord (18.6 ± 7.8 birds/km2, mean ± SE) during 10–16 July. Spatial models identified consistent “hotspots” of Kittlitz\u27s Murrelets, including several small areas where high densities of murrelets were found throughout the survey period. Of the explanatory variables that we evaluated, tidal current strength influenced murrelet abundance most consistently, with higher abundance associated with strong tidal currents. Simulations based on the empirically derived estimates of variation demonstrated that spatial variation strongly influenced power to detect trend, although power changed little across the threefold difference in the coefficient of variation on detection probability. We include recommendations for monitoring Kittlitz\u27s Murrelets (or other marine species) when there is a high degree of uncertainty about factors affecting abundance, especially spatial variability