Impact of payments for environmental services and protected areas on local livelihoods and forest conservation in northern Cambodia

The potential impacts of payments for environmental services (PES) and protected areas (PAs) on environmental outcomes and local livelihoods in developing countries are contentious and have been widely debated. The available evidence is sparse, with few rigorous evaluations of the environmental and social impacts of PAs and particularly of PES. We measured the impacts on forests and human well‐being of three different PES programs instituted within two PAs in northern Cambodia, using a panel of intervention villages and matched controls. Both PES and PAs delivered additional environmental outcomes relative to the counterfactual: reducing deforestation rates significantly relative to controls. PAs increased security of access to land and forest resources for local households, benefiting forest resource users but restricting households’ ability to expand and diversify their agriculture. The impacts of PES on household well‐being were related to the magnitude of the payments provided. The two higher paying market‐linked PES programs had significant positive impacts, whereas a lower paying program that targeted biodiversity protection had no detectable effect on livelihoods, despite its positive environmental outcomes. Households that signed up for the higher paying PES programs, however, typically needed more capital assets; hence, they were less poor and more food secure than other villagers. Therefore, whereas the impacts of PAs on household well‐being were limited overall and varied between livelihood strategies, the PES programs had significant positive impacts on livelihoods for those that could afford to participate. Our results are consistent with theories that PES, when designed appropriately, can be a powerful new tool for delivering conservation goals whilst benefiting local people.     

Assessment of oxidative and UV-C treatments for inactivating bacterial biofilms from groundwater wells

Microorganisms are ubiquitous in natural environments and in water supply infrastructure including groundwater wells. Sessile-state microorganisms may build up on well surfaces as biofilms and, if excessive, cause biofouling that reduces well productivity and water quality. Conditions can be improved using biocides and other traditional well rehabilitation measures; however, biofilm regrowth is inevitable given the continuous introduction of microorganisms from the surrounding environment. Alternative and less invasive well maintenance approaches are desirable for reducing biofilm densities while also minimizing harmful disinfection-by-products. The primary objective of this research was to evaluate effectiveness of alternative treatments for inactivating microorganisms comprising biofilms. A novel approach was designed for in situ growth of biofilms on steel coupons suspended from ‘chandeliers’. After more than 100 days of in situ growth, biofilms were harvested, sampled, and baseline biofilm densities quantified through cultivation. Ultraviolet-C (UV-C) and oxidative treatments including hydrogen peroxide (H₂O₂), ozone (O₃) and mixed oxidants were then applied to the biofilms in laboratory-scale treatments. Microbial inactivation was assessed by comparing treated versus baseline biofilm densities. H₂O₂ was the most effective treatment, and decreased density below baseline by as much as 3.1 orders of magnitude. Mixed oxidants were effective for the well having a lower density biofilm, decreasing density below baseline by as much as 1.4 orders of magnitude. Disparity in the response to treatment was apparent in the wells despite their spatial proximity and common aquifer source, which suggests that microbiological communities are more heterogeneous than the natural media from which they originate.     

Influence of oceanic factors on long-distance movements of loggerhead sea turtles displaced in the southwest Indian Ocean

The routes of five satellite-tracked loggerhead turtles (Caretta caretta), subjected to an experimental translocation away from their usual migratory routes, have been analysed in relation to the concurrent oceanographic conditions. Remote sensing data on sea surface temperature and height anomalies, as well as trajectories of surface drifters were used, to get simultaneous information on the currents encountered by the turtles during their long-range oceanic movements. Turtles mostly turned out to move in the same direction as the main currents, and their routes were often influenced by circulation features they encountered. A comparison between turtle ground speeds with that of drifters shows that in several instances, the turtles did not drift passively with the currents but contributed actively to the overall movement. Two turtles embarked on an oceanic crossing, probably induced by seasonal changes in surface temperatures, a crossing that was largely determined by the main currents existing in the area.     

Niche segregation in sandy beach animals: an analysis with surface-active peracarid crustaceans on the Atlantic coast of Spain

Several species of sandy beach invertebrates regularly switch between burial in the sand during the day and surface activity at night to feed on stranded organic matter. Because all species consume essentially the same type of food (i.e., wrack) deposited over a restricted area, the potential for competition exists. Conversely, spatial and temporal segregation of surface activity behaviour is predicted to allow for niche separation. Here, we tested whether such behavioural niche separation occurs in three species of sympatric crustaceans (the talitrid amphipods Talitrus saltator (Montagu 1808) and Talorchestia brito Stebbing 1891, and the oniscoidean isopod Tylos europaeus Arcangeli 1938). We also assessed whether surface activity is modulated by weather, sea conditions and moon phases. Surface activity was measured over three consecutive moon phases on an exposed beach on the Atlantic Coast of Spain using pitfall traps along three transects from the foredunes to the swash. Adults of the amphipod T. saltator and the isopod T. europaeus overlapped spatially and temporally in their surface activity for most of the night. By contrast, the activity of T. brito was strongly disjunct in time and concentrated into significantly shorter bouts around dawn or dusk. Niche differentiation was also evident along the space axis, where T. brito occurred distinctly lower on the beach. Although several environmental factors (e.g., air and sand temperature, humidity, atmospheric pressure, wind speed and wind direction) were correlated with surface activity, this was highly variable amongst species, life stages, and synodic phases, and did not obscure the fundamental mosaic of spatio-temporal heterogeneity amongst species. Nocturnal feeding on beach wrack creates the potential for competition amongst sympatric crustaceans which can, however, be mitigated by behaviour patterns that separate consumers in time and space.     

Mitochondrial DNA phylogeography of the harbour porpoise Phocoena phocoena in the North Pacific

Genetic structure and phylogeography of the harbour porpoise Phocoena phocoena in the North Pacific were examined using 358 bps sequences from the 5′ end of the mitochondrial DNA control region including those reported previously and newly obtained from the west Pacific. AMOVA and pairwise population φ _st estimates clearly revealed genetic differentiation between an east/south and a north/northwest group with the break along the Pacific Rim at British Columbia. In addition, nested clade phylogeographical analysis, neutrality tests, mismatch distribution analysis, genetic diversities and Mantel test, suggested that the observed genetic structure might have been influenced by contiguous range expansion with restricted gene flow in the direction from south to north along the North American coasts and east to west along the Pacific Rim in the middle to late Pleistocene.     

Genital shape correlates with sperm transfer success in the praying mantis Ciulfina klassi (Insecta: Mantodea)

The rapid divergence of male genitalia is a widely observed evolutionary phenomenon. Although sexual selection is currently regarded as providing the most likely driving force behind genital diversification, the mechanisms responsible are still debated. Here, we investigate the relationship between male genital morphology and sperm transfer in the praying mantid Ciulfina klassi using geometric morphometrics. The shape of male genitalia in C. klassi influenced sperm transfer duration and the number and proportion of sperm transferred, suggesting that genital morphology is under sexual selection in this species. Genital size however was not correlated with any aspect of sperm transfer. Intriguingly, two of the major genital shape components correlated positively with the number of sperm transferred, but negatively with sperm transfer duration. Hence, males that most effectively transfer sperm to the female spermatheca do so in a relatively short period of time. A direct negative relationship was also found between sperm transfer duration and sperm transfer success. Overall, our study suggests that the variable genital shape of Ciulfina may have been selected for more efficient sperm transfer.     

Exaggerated orientation scatter of nocturnal passerine migrants close to breeding grounds: comparisons between seasons and latitudes

Using tracking radars, we investigated the variability of flight directions of long-distance nocturnal passerine migrants across seasons (spring versus autumn migration) and sites at the southern (56° N) and northern (68° N) ends of the Scandinavian Peninsula (Lund versus Abisko). Whilst most migrants at Lund are on passage to and from breeding sites in Fennoscandia, the majority of the migrants at Abisko are close to their breeding sites, and migration at Abisko thus to a large degree reflects initial departure from breeding sites (autumn) or final approach to breeding destinations (spring). The radar data were used to test predictions about differences in orientation and wind drift effects between adult and juvenile birds (a large proportion of autumn migrants consists of juvenile birds on their first journey), between situations far away from or near the goals and between different phases of migration (initial departure, en route passage, final approach to goal). The concentrations (both total and within-night concentrations) of flight directions differed significantly between seasons as well as sites, with the highest concentration at Lund in spring (mean vector length of track directions, r = 0.79) and lowest at Abisko during spring (r = 0.35). Partial wind drift and partial compensation were recorded at Lund, with a similar effect size in spring and autumn, whilst possible wind drift effects at Abisko were obscured by the large directional scatter at this site. The results from Lund support the prediction that the high proportion of juveniles in autumn contributes to increase the directional scatter during this season, whilst there was no support for predictions of differential wind drift effects between seasons and situations with different goal distances. The most striking and surprising result was the exceedingly large scatter of flight directions at Abisko, particularly in spring. We suggest that such an exaggerated scatter may be associated with final approach orientation, where migrants reach their specific goals from all various directions by final navigation within a more wide-ranging goal region. The larger scatter of autumn flight directions at Abisko compared to Lund may be due to exploratory flights in variable directions being more common at initial departure from breeding sites than later during migratory passage. These surprising results highlight the importance of studying and analysing orientation during final approach to (and initial departure from) migratory goals for understanding the orientation systems of migratory birds.     

An oligarchy of nest-site scouts triggers a honeybee swarm’s departure from the hive

Animals that travel in groups must synchronize the timing of their departures to assure cohesion of the group. While most activities in large colonies of social insects have decentralized control, certain activities (e.g., colony migration) can have centralized control, with only a special subset of well-informed individuals making a decision that affects the entire colony. We recently discovered that a small minority of individuals in a honeybee colony—an oligarchy—decides when to trigger the departure of a swarm from its hive. The departure process begins with some bees producing the worker-piping signal (the primer for departure) and is followed by these bees producing the buzz-run signal (the releaser for departure). In this study, we determined the identity of these signalers. We found that a swarm’s nest-site scouts search for potential nest cavities prior to the departure of the swarm from its hive. Furthermore, we found that the predeparture nest-site scouts are the sole producers of the worker-piping signal and that they are the first producers of the buzz-run signal. The control of the departure of a honeybee swarm from its hive shows how a small minority of well-informed individuals in a large social insect colony can make important decisions about when a colony should take action.