A sex difference in the behavioural response of nesting mountain bluebirds (<Emphasis Type="Italic">Sialia currucoides</Emphasis>) to a mounted predator

Passerine nests can benefit parental fitness, but defense against predators may be costly. Although this paradigm is well studied, no studies have been conducted on mountain bluebirds (Sialia currucoides). We observed the response of 17 bluebird pairs with nestlings to a mounted bobcat (Lynx rufus) and two controls. Bluebird pairs clearly differentiated the mounted predator and males moved closer to the bobcat than to the controls whereas females did not. This system is ideal to further refine nest-defense hypotheses.     

Nest site fidelity and clutch frequency of loggerhead turtles are better elucidated by satellite telemetry than by nocturnal tagging efforts: Implications for stock estimation

Satellite telemetry and ground-based tagging studies are complementary methods to define the spatial and temporal patterns of nesting behavior by migratory sea turtles. Estimates of site fidelity and clutch frequencies are compared for satellite telemetry versus ground truth patrols over a 6 km stretch at a southwest Florida loggerhead (Caretta caretta) rookery. Site fidelity ranged from 1.9 km to 109.1 km for all nests deposited by a female within a season. The mean site fidelity was 28.1 km for all nests, but declined to 16.9 km if omitting the first nest. Nest frequency ranged from 2 to 8 nests per season, with a modal value of 5 nests. Satellite telemetry documented a mean nest frequency of 5.4 nests per female in comparison to 2.2 nests detected by monitoring patrols. The remigrant females had higher clutch frequency, were larger in size, and had higher site fidelity compared to newly tagged females. Satellite telemetry provided improved measurements of site fidelity and reveals a need for revised fecundity estimates. If measures of clutch frequency are representative of loggerhead assemblages nesting elsewhere within the South Florida grouping, the confidence bounds on Western Atlantic loggerhead stocks are approximately 32% lower than currently accounted for annual nesting individuals.     

Relecture d’un modèle architectural du III millénaire provençal : l’Habitation n 1 du Collet-Redon à La Couronne (Martigues, Bouches-du-Rhône)

The open-air site of Collet-Redon (Martigues, Bouches-du-Rhône) was discovered in the 1940s, and excavated by M. Escalon de Fonton until the beginning of 1980s. Those pioneering works gave up important series of artefacts and domestic structures of Late Neolithic and Bronze Age that permit to define a new Neolithic culture: the Couronnien group. The importance of this establishment, as a reference in research on Late Neolithic period in South of France, is particularly based on built remains revealed in a sector called “Habitation no. 1”. Quantity and quality of architectural structures allowed M. Escalon de Fonton to describe a Neolithic domestic unit, which became a model for interpreting other regional sites. Since 1999, various studies of artefacts and structures, coupled with an excavation, have been engaged in order to discuss first interpretations. The purpose of this article is to present our results concerning architectural remains of “Habitation no. 1” sector. Study of ancient publications and new observations on structures permit us to suggest a revision of the plan proposed for this third millenary construction.     

Nest-site habitat selection by Lesser Rheas ( Rhea pennata pennata ) in northwestern Patagonia, Argentina

Selection of nest-site habitat by a population of wild Lesser Rheas (Rhea pennata pennata) was studied in the northwestern Patagonia steppe, Argentina, during two reproductive seasons (2004/2005 and 2005/2006). Nest spatial distribution was compared with randomly selected points in the study area. Contrary to observations in other ratite species, nest distribution showed an aggregate pattern associated with “mallín” (meadow) areas, which are habitats of higher productivity in the Patagonia steppe. Moreover, similar to observations made on the Greater Rhea (Rhea americana), vegetation cover was higher in nest sites than in randomly selected sites, probably because higher vegetation provides concealment from predators and protection from the strong westerly winds that frequent in this region. Our results reinforce the importance of “mallín” areas for the reproduction and conservation of this threatened ratite species.     

Differential effects on enzyme stability and kinetic parameters of mutants related to human triosephosphate isomerase deficiency

Human triosephosphate isomerase (TIM) deficiency is a very rare disease, but there are several mutations reported to be causing the illness. In this work, we produced nine recombinant human triosephosphate isomerases which have the mutations reported to produce TIM deficiency. These enzymes were characterized biophysically and biochemically to determine their kinetic and stability parameters, and also to substitute TIM activity in supporting the growth of an Escherichia coli strain lacking the tim gene. Our results allowed us to rate the deleteriousness of the human TIM mutants based on the type and severity of the alterations observed, to classify four “unknown severity mutants” with altered residues in positions 62, 72, 122 and 154 and to explain in structural terms the mutation V231M, the most affected mutant from the kinetic point of view and the only homozygous mutation reported besides E104D.     

Grooming site preferences in wild white-handed gibbons (Hylobates lar)

During a four-month study of wild white-handed gibbons in Thailand one group was observed for 131 hr. The individuals spent 5.2% of their activity period allogrooming. Several body sites received more respectively less allogrooming than expected. Surface areas easy to clean by autogrooming such as the belly received significantly less allogrooming than expected. Upper body areas which are likely to be infested by parasites and other matter received significantly more allogrooming than lower body parts. Thus, grooming in gibbons seems to reflect a primarily hygienic function.     

Shallow Traces (Pits) in the Test of the Irregular Echinoid Echinocorys scutata Leske from the Chalk (Upper Cretaceous) of the United Kingdom

Specimens of epifaunal irregular echinoids in the Upper Cretaceous of northern Europe have been reported with patterns of circular, nonpenetrative parabolic pits, Oichnus paraboloides (Bromley), in the apical region. Specimens of Echinocorys scutata Leske from the Chalk at two sites in southeast England were commonly penetrated by this trace, generated by an indeterminate pit-forming organism. Pits commonly surround the apical system and, less commonly, occur within it; they occur preferentially anteriorly. Pits occur within plates, not along margins or sutures. Crosscutting of pits indicates that multiple spatfalls probably occurred. The host echinoid added new test plates adjacent to the apical system; thus, plates bearing O. paraboloides were moved abapically. The reduction in number of pits away from the apex, including those with echinoid tubercles reestablished on the base, indicates that, following death of an infester, the echinoid “reclaimed” and infilled them with calcite. The pit-former was most probably an unmineralized invertebrate that used E. scutata as a domicile which provided good access to food-rich currents for suspension feeding. Although the systematic position of the pit-former is unknown, similar infestations are known from other Upper Cretaceous echinoids and Mississippian crinoids.     

The relationship of body size to survivorship of hatchling snapping turtles (Chelydra serpentina): an evaluation of the “bigger is better” hypothesis

In many organisms, body size is positively correlated with traits that are presumably related to fitness. If directional selection frequently favors larger offspring (the “bigger is better” hypothesis), the results of such selection should be detectable with field experiments. We tested the “bigger is better” hypothesis in hatchling snapping turtles (Chelydra serpentina) by conducting one long-term and three short-term experiments on the University of Michigan E.S. George Reserve in southeastern Michigan. In the fall of 1995 and 1996, we released hatchlings at artificial nests separated from the nearest wetland by fences. We recorded the proportion of hatchlings recaptured, the time it took hatchlings to move to fences from artificial nests 45, 55, and 80 m away, and dispersion along the fence. We determined whether the response variables and probability of recapture at fences were associated with hatchling body size. During 1995, average travel times of hatchlings from the experimental nests were not related to distance from the fence; however, time to recapture was positively correlated with dispersion from the zero point on the fence, and the maximum time to reach the fence was almost twice as long for hatchlings from the 80-m nest compared to those from the 45-m nest. Sixty-seven percent of the hatchlings reached the fence and the proportions doing so from each nest were not different. Body size was not significantly related to probability of recapture in either of the 1995 experiments. In 1996, 59% of released hatchlings were recaptured. Time to recapture was not related to dispersion from the zero point or to body size. Cubic spline analysis suggested stabilizing selection on body size. We also conducted a set of long-term hatchling release experiments between 1980–1993 to compare the survival of hatchlings released at nest sites to that of hatchlings released directly into marshes, and we looked for relationships between survivorship and hatchling body size. During 7 years in which more than 30 hatchlings were released, 413 hatchlings were released directly into the marsh and 262 were released at nests: their probability of survival did not differ. Over all years, for both release groups combined and for each group separately, survival was not related to body size. In 1983 alone, survival was also not related to body size for either group or for both groups combined. In our three short-term experiments and one long-term experiment, we found no evidence to support the “bigger is better” hypothesis. When selection on body size did occur, selection was stabilizing, not directional for larger size. Received: 4 June 1998 / Accepted: 24 June 1999     

Radionuclide Contamination at Kazakhstan's Semipalatinsk Test Site: Implications on Human and Ecological Health

A delegation of five scientists participated in a U.S. National Research Council program to review the status of research on the health and environmental impacts of nuclear testing at the Semipalatinsk Test Site (STS) in the eastern region of the Republic of Kazakhstan. From 11 August through 25 August 2000, we visited several research institutes in Kazakhstan and consulted with numerous Kazakh researchers from academic disciplines ranging from radioecology to public health and medicine. We focused on reviewing data on the health and environmental impacts resulting from the testing. The health effects caused by the testing at STS have received a fair amount of study, and research using modern techniques such as fluorescence in situ hybridization and nuclear magnetic resonance will likely increase the reliability of dose reconstruction. However, the extent to which the STS is contaminated has not been adequately characterized, and the potential exposure to nomadic peoples and ecological receptors at the uncontrolled test site is not known. Additional research in these areas, and development of administrative controls for the site, appears warranted.     

Analyse du débitage laminaire du site de Mezhyrich : habitations n 1, 2 et 3

This article presents the results of technological analyses of the laminar products from three bone dwelling structures from the Mezhyrich site (dated to Upper Palaeolithic; 15,000–14,500 years BP). More than 2500 blades and bladelets were studied from technological point of view. We find close similarity between the three dwellings, which reflects similar ways of preparation of core fracture zone (overhang reduction, butt abrading, and flaking surface isolation), as well as in the organization of the negative of the dorsal surfaces of the blades. The comparison with materials from the Kostenki 1 layer 1 site (upper layer, 22,000–24,000 years BP) shows some differences with the artefacts from Mezhyrich site, despite same technological methods. This could be explained by differences in cultural tradition and large time gap between these two sites. The complexes from Mezhyrich to follow the Kostenki 1/1 tradition but with their own particularities.