Protected area characteristics that help waterbirds respond to climate warming

Protected area networks help species respond to climate warming. However, the contribution of a site's environmental and conservation-relevant characteristics to these responses is not well understood. We investigated how composition of nonbreeding waterbird communities (97 species) in the European Union Natura 2000 (N2K) network (3018 sites) changed in response to increases in temperature over 25 years in 26 European countries. We measured community reshuffling based on abundance time series collected under the International Waterbird Census relative to N2K sites’ conservation targets, funding, designation period, and management plan status. Waterbird community composition in sites explicitly designated to protect them and with management plans changed more quickly in response to climate warming than in other N2K sites. Temporal community changes were not affected by the designation period despite greater exposure to temperature increase inside late-designated N2K sites. Sites funded under the LIFE program had lower climate-driven community changes than sites that did not received LIFE funding. Our findings imply that efficient conservation policy that helps waterbird communities respond to climate warming is associated with sites specifically managed for waterbirds.     

Telomeric attrition with age and temperature in Eastern mosquitofish (Gambusia holbrooki)

Telomeric attrition has repeatedly been found to correlate with the ageing of organisms; however, recent research is increasingly showing that the determinants of attrition dynamics are not well understood. This study examined the relative telomere lengths in Eastern mosquitofish, Gambusia holbrooki, kept at different temperatures and at different ages. Newly born fry were randomly selected for one of four treatment groups: 20, 30, 20–30, and 30–20 °C, where the third and fourth treatment groups were gradually changed from their starting temperature to their final temperature between days 10 and 14. Telomere length was measured, and it was found that length decreased with age and that fish exposed to the 20 °C treatment had significantly shorter telomeres than those that received the 30–20 °C treatment. Telomeric attrition with age agrees with results previously found in studies of telomeres; however, the variation in attrition with temperature was not simply predictable and may be the synergistic effects of temperature and some other factor.     

How do weaponless male fiddler crabs avoid aggression?

Mimicry of females enables weaker males in many species to avoid intrasexual aggression. In fiddler crabs (Uca annulipes), males use their major claw in aggressive interactions to acquire and defend a territory. Males that have autotomised their major claw will be disadvantaged in fighting, but might use their temporary resemblance to females to avoid costly aggressive encounters with other males. We investigated whether: (1) courting males mistake clawless male fiddler crabs for females; (2) clawless males are able to acquire, defend and retain territories as successfully as intact males; and (3) clawless males are more cautious than intact males. Clawless and intact males differed in burrow acquisition methods and fighting behaviour, but were equally successful at acquiring and retaining burrows. While courting males treated clawless males as female, we found no evidence that clawless males mimic the behaviour of females, or that they exploit the advantage of their mistaken identity. Clawless males further appear to avoid male aggression by altering their territorial strategies to minimise the potential for conflict.     

Prenatally diagnosed portocaval shunt and postnatal outcome: a case report

Congenital absence of the portal vein (CAPV) is a rare anomaly in the form of a portocaval shunt, whereby the intestinal and splenic venous drainage bypasses the liver and drains directly into the systemic circulation. We report a case of CAPV diagnosed prenatally after the recognition of a dilated umbilical vein draining directly into a large inferior vena cava (IVC). The IVC then drained into the right atrium of a dilated, hyperdynamic heart. The ductus venosus could not be identified. Repeated postnatal scans showed a gradual disappearance of venous lakes in the region of the porta hepatis and a clear drainage of the splenic vein to the left renal vein and the superior mesenteric vein to the IVC. From birth up to twelve months follow-up there was no evidence of liver dysfunction, encephalopathy or liver lesions. Copyright © 2004 John Wiley & Sons, Ltd.     

Drifting plastic and its consequences for sessile organism dispersal in the Atlantic Ocean

Organisms have travelled the Atlantic Ocean as neuston and have rafted on natural marine debris for millions of years. Shipping increased opportunities for marine organism travel mere thousands of years ago but in just decades floating plastic debris is transforming marine rafting. Here we present a combined open-ocean and remote coasts marine debris survey of the Atlantic (from 68°S–78°N). Daily shipboard observations were made from the Southern Ocean to the high Arctic and the shores of 16 remote islands were surveyed. We report (1) anthropogenic debris from the most northerly and southerly latitudes to date, (2) the first record of marine biota colonising debris at latitudes >68°, and (3) the finding of exotic species (the barnacle Elminius modestus) on northern plastic debris. Plastic pieces dominated both open-ocean and stranding marine debris. The highest densities of oceanic debris were found around northwest Europe, whereas the highest stranding levels were equatorial. Our findings of high east-Arctic debris colonisation by fauna contrast with low values from west Arctic (though only two samples) and south Atlantic shores. Colonisation rates of debris differed between hemispheres, previously considered to be similar. Our two South Atlantic mega-debris shipboard surveys (10 years apart) found no changes in open-ocean debris densities but resurvey of a UK and an Arctic island both found increases. We put our findings in the context of the Atlantic literature to interpret spatial and temporal trends in marine debris accumulation and its organismal consequences.Communicated by J.P. Thorpe, Port Erin     

Development and validation of an objective intra‐organizational career success measure for managers

This study aimed to develop and validate a new objective measure of intra‐organizational career success, that is the Managerial Career Success Measure (MCSM). Although there has been a recent emphasis in the careers literature on the subjective career, there is still a need for a valid operationalization of ‘traditional’, objective career success as this construct is still considered relevant by many occupational and national groups; furthermore, many studies continue to use objective career success as a (dependent) variable. With regard to content validity, it appears that the measure that was developed incorporates some elements of the commonly used measures of objective career success (i.e. managerial level, number of promotions, salary and salary progression) while steering clear of some of the issues with each of them separately. Concurrent and discriminant validity were explored by analysing data from three empirical studies that were carried out in a large heterogeneous managerial population (N = 1101). Results indicate that the MCSM displays higher levels of content and construct validity than do other, commonly used measures of objective career success. Copyright © 2008 John Wiley & Sons, Ltd.     

Long‐term spatio‐temporal changes in a West African bushmeat trade system

Landscapes in many developing countries consist of a heterogeneous matrix of mixed agriculture and forest. Many of the generalist species in this matrix are increasingly traded in the bushmeat markets of West and Central Africa. However, to date there has been little quantification of how the spatial configuration of the landscape influences the urban bushmeat trade over time. As anthropogenic landscapes become the face of rural West Africa, understanding the dynamics of these systems has important implications for conservation and landscape management. The bushmeat production of an area is likely to be defined by landscape characteristics such as habitat disturbance, hunting pressure, level of protection, and distance to market. We explored (SSG, tense) the role of these four characteristics in the spatio‐temporal dynamics of the commercial bushmeat trade around the city of Kumasi, Ghana, over 27 years (1978 to 2004). We used geographic information system methods to generate maps delineating the spatial characteristics of the landscapes. These data were combined with spatially explicit market data collected in the main fresh bushmeat market in Kumasi to explore the relationship between trade volume (measured in terms of number of carcasses) and landscape characteristics. Over time, rodents, specifically cane rats (Thryonomys swinderianus), became more abundant in the trade relative to ungulates and the catchment area of the bushmeat market expanded. Areas of intermediate disturbance supplied more bushmeat, but protected areas had no effect. Heavily hunted areas showed significant declines in bushmeat supply over time. Our results highlight the role that low intensity, heterogeneous agricultural landscapes can play in providing ecosystem services, such as bushmeat, and therefore the importance of incorporating bushmeat into ecosystem service mapping exercises. Our results also indicate that even where high bushmeat production is possible, current harvest levels may cause wildlife depletion.     

Non-independent mate choice in a fiddler crab: a case of stimulus enhancement

Non-independent mate selection occurs when the choice behavior of a female is altered by the interactions between other females and males. In the fiddler crab Uca mjoebergi, males court mate-searching females by waving their one greatly enlarged claw. When a female approaches a male, he initiates high-intensity waving. We conducted one natural mate choice experiment and two mate choice experiments using custom-built robotic crabs. We show that the decision of one female to approach a group of males increases the probability that another female will approach and visit a male from the same group. We suggest that this behavior is best explained by the ‘stimulus enhancement’ hypothesis, where the presence of a female near a group of males makes them more likely to be detected by other females due to an increase in male display rate.