J.M. Shephard

Correlations between the satellite-derived seasonal cycles of phytoplankton biomass and aerosol optical depth in the Southern Ocean: Evidence for the influence of sea ice

The relationship between the production of dimethylsulfide (DMS) in the upper ocean and atmospheric sulfate aerosols has been confirmed through local shipboard measurements, and global modeling studies alike. In order to examine whether such a connection may be recoverable in the satellite record, we have analyzed the correlation between mean surface chlorophyll (CHL) and aerosol optical depth (AOD) in the Southern Ocean, where the marine atmosphere is relatively remote from anthropogenic and continental influences. We carried out the analysis in 5-degree zonal bands between 50°S and 70°S, for the period (1997-2004), and in smaller meridional sectors in the Eastern Antarctic, Ross and Weddell seas. Seasonality is moderate to strong in both CHL and AOD signatures throughout the study regions. Coherence in the CHL and AOD time series is strong in the band between 50°S and 60°S, however this synchrony is absent in the sea-ice zone (SIZ) south of 60°S. Marked interannual variability in CHL occurs south of 60°S, presumably related to variability in sea-ice production during the previous winter. We find a clear latitudinal difference in the cross correlation between CHL and AOD, with the AOD peak preceding the CHL bloom by up to 6 weeks in the SIZ. This suggests that substantial trace gas emissions (aerosol precursors) are being produced over the SIZ in spring (October-December) as sea ice melts. This hypothesis is supported by field data that record extremely high levels of sulfur species in sea ice, surface seawater, and the overlying atmosphere during ice melt.

Discrimination of sex in the White-bellied Sea-Eagle, Haliaeetus leucogaster, using genetic and morphometric techniques

Abstract The White-bellied Sea-Eagle, Haliaeetus leucogaster, is monomorphic for adult plumage colouration, but in body size displays reversed sexual dimorphism, with female birds significantly larger. Analyses of morphometric data from 37 individuals from Australia and Papua New Guinea revealed a latitudinal cline in body dimensions, with individuals larger in the south. A discriminant function based on 10 morphometric characters was 100% effective in discriminating between 19 males and 18 females that had been sexed using molecular genetic methods. Reclassification using a jackknife procedure correctly identified 92% of individuals. The discriminant function should be a viable alternative to genetic sexing or laparoscopy for a large proportion of individuals within the Australo-Papuan range of this species; and can also be used to identify a small proportion of ‘ambiguous’ individuals for which reliable sexing will require those other techniques.

Global simulations of the impact on contemporary climate of a perturbation to the sea-to-air flux of dimethylsulfide

The sea-to-air flux of the biogenic sulfur (S) compound dimethylsulfide (DMS) is thought to constitute an important radiative impact on climate, especially in remote marine areas. Previous biogeochemical modelling analyses simulate medium to large changes in the sea-to-air flux of DMS in polar regions under warming scenarios. Here we assess the global radiative impact of such a prescribed change in DMS flux on contemporary climate using a low-resolution atmospheric gen eral circulation model. This impact operates through the atmospheric oxidation of DMS to radiatively-active sulfate aerosols, which are known to both reflect incom ing short-wave radiation and to affect the microphysical properties of clouds, for example, through an increase in cloud albedo. We use an atmospheric GCM with incorporated sulfur cycle, coupled to a mixed-layer (‘q-flux’) ocean, to estimate the climatic response to a prescribed meridionally-variable change in zonal DMS flux, as simulated in a previous modelling analysis. We compare baseline sulfur emissions (contemporary anthropogenic S and contemporary DMS sea-to-air flux), with contemporary anthropogenic S and a perturbed DMS flux. Our results indicate that the global mean DMS vertically integrated concentration increases by about 41 per cent. The relative increase in DMS annual emission is around 17 per cent in 70–80°N, although the most significant increase is in 50–70°S, up to 70 per cent. However, concentrations of atmospheric SO 2 and SO 4 2– increase by only about eight per cent. The oxidation of DMS by OH increases by about 20 per cent.

Isolation and characterization of a new suite of microsatellite markers in the European White Stork, Ciconia ciconia

The White Stork (Ciconia ciconia) has an extensive European breeding distribution. There have been significant demographic changes since the 1930s, with country-specific extinctions throughout the western distribution since the mid-1940s. Following various reintroduction programs significant concerns have been raised about the geographic origins of introduced storks, and the effect this may have on individual biology, particularly breeding success. Here we report on seven new microsatellite markers developed for C. ciconia that have been successfully combined in a series of multiplex PCR’s with six markers previously described for the Wood Stork.

Migration strategies revealed by satellite tracking among descendants of a population of European white stork (Ciconia ciconia) reintroduced to Belgium

AbstractMigration in the European white stork (Ciconia ciconia) has historically described a predictable annual cycle. The white stork is extensively distributed across continental Europe, which diverges to eastern and western wintering flyways. Within the western European population, some ring recovery and anecdotal information suggests that birds are giving up their traditional wintering grounds in the Sahel and are remaining in alternative sites in the Iberian Peninsula. Here we report on long-term satellite tracking of juvenile and adult stork collected between 2000 and 2011, whose natal site is in Belgium in the northern range of the western migration path. We identified three distinct migration patterns, two of which diverged from traditional expectations. Juvenile birds showed unique migration profiles both individually across migration cycles and when compared to one another, whereas adults showed consistent migrations but failed to migrate to Africa in any of the years surveyed. Stopover and wintering locations within Iberia were strongly associated with refuse sites or modified agricultural land. Overall, non-traditional migration movements appeared to be most strongly linked to artificial food sources rather than alternate drivers such as climate or habitat.ZusammenfassungDurch Satellitenverfolgung aufgezeigte Zugstrategien von Nachfahren einer Population von in Belgien wieder eingeführten europäischen Weißstörchen (Ciconia ciconia) Der Zug des europäischen Weißstorchs (Ciconia ciconia) ist historisch einem vorhersagbaren Jahreszyklus gefolgt. Der Weißstorch ist in Kontinentaleuropa weit verbreitet, und hier gibt es einen östlichen und einen westlichen Zugweg. Innerhalb der westeuropäischen Population deuten einige Ringfunde sowie Einzelberichte darauf hin, dass die Vögel ihre traditionellen Überwinterungsgebiete in der Sahelzone aufgeben und in alternativen Gebieten auf der Iberischen Halbinsel verbleiben. Hier berichten wir von Langzeit-Satellitenverfolgung juveniler und adulter Störche, die in Belgien geboren wurden, zwischen 2000 und 2011, im nördlichen Gebiet des westlichen Zugwegs. Wir identifizierten drei verschiedene Zugmuster, von denen zwei von den traditionellen Erwartungen abwichen. Juvenile Vögel zeigten einzigartige Zugprofile, sowohl individuell über Zugzyklen als auch im Vergleich zueinander, während Altvögel konsistente Zugmuster aufwiesen, aber in keinem der Untersuchungsjahre nach Afrika zogen. Rast- und Überwinterungsgebiete auf der Iberischen Halbinsel waren stark mit Müllkippen oder abgewandeltem Agrarland assoziiert. Insgesamt schienen nicht-traditionelle Zugbewegungen am stärksten mit künstlichen Nahrungsquellen in Verbindung zu stehen und nicht mit alternativen Faktoren wie Klimawandel oder Habitat.

Is population structure in the European white stork determined by flyway permeability rather than translocation history

European white stork are long considered to diverge to eastern and western migration pools as a result of independent overwintering flyways. In relatively recent times, the western and northern distribution has been subject to dramatic population declines and country-specific extirpations. A number of independent reintroduction programs were started in the mid 1950s to bring storks back to historical ranges. Founder individuals were sourced opportunistically from the Eastern and Western European distributions and Algeria, leading to significant artificial mixing between eastern and western flyways. Here we use mitochondrial and microsatellite DNA to test the contention that prior to translocation, eastern and western flyways were genetically distinct. The data show a surprising lack of structure at any spatial or temporal scale suggesting that even though birds were moved between flyways, there is evidence of natural mixing prior to the onset of translocation activities. Overall a high retention of genetic diversity, high Nef, and an apparent absence of recent genetic bottleneck associated with early 20th century declines suggest that the species is well equipped to respond to future environmental pressures.

The rise of glyphosate and new opportunities for biosentinel early-warning studies

Glyphosate has become the most commonly used herbicide worldwide and is reputedly environmentally benign, nontoxic, and safe for use near wildlife and humans. However, studies indicate its toxicity is underestimated and its persistence in the environment is greater than once thought. Its actions as a neurotoxin and endocrine disruptor indicate its potential to act in similar ways to persistent organic pollutants such as the organochlorines dichlorodiphenyltrichloroethane (DDT) and dioxin. Exposure to glyphosate and glyphosate-based herbicides for both wildlife and people is likely to be chronic and at sublethal levels, with multiple and ongoing exposure events occurring in urban and agricultural landscapes. Despite this, there has been little research on the impact of glyphosate on wildlife populations, and existing studies appear in the agricultural, toxicology, and water-chemistry literature that may have limited visibility among wildlife biologists. These studies clearly demonstrate a link between chronic exposure and neurotoxicity, endocrine disruption, cell damage, and immune suppression. There is a strong case for the recognition of glyphosate as an emerging organic contaminant and substantial potential exists for collaborative research among ecologists, toxicologists, and chemists to quantify the impact of glyphosate on wildlife and to evaluate the role of biosentinel species in a preemptive move to mitigate downstream impacts on people. There is scope to develop a decision framework to aid the choice of species to biomonitor and analysis methods based on the target contaminant, spatial and temporal extent of contamination, and perceived risk. Birds in particular offer considerable potential in this role because they span agricultural and urban environments, coastal, inland, and wetland ecosystems where glyphosate residues are known to be present.

Synchronous diversification of Sulawesi's iconic artiodactyls driven by recent geological events

The high degree of endemism on Sulawesi has previously been suggested to have vicariant origins, dating back to 40 Ma. Recent studies, however, suggest that much of Sulawesis fauna assembled over the last 15 Myr. Here, we test the hypothesis that more recent uplift of previously submerged portions of land on Sulawesi promoted diversification and that much of its faunal assemblage is much younger than the island itself. To do so, we combined palaeogeographical reconstructions with genetic and morphometric datasets derived from Sulawesis three largest mammals: the babirusa, anoa and Sulawesi warty pig. Our results indicate that although these species most likely colonized the area that is now Sulawesi at different times (14 Ma to 2–3 Ma), they experienced an almost synchronous expansion from the central part of the island. Geological reconstructions indicate that this area was above sea level for most of the last 4 Myr, unlike most parts of the island. We conclude that emergence of land on Sulawesi (approx. 1–2 Myr) may have allowed species to expand synchronously. Altogether, our results indicate that the establishment of the highly endemic faunal assemblage on Sulawesi was driven by geological events over the last few million years.

Foraging movements of common noddies in the East Indian Ocean are dependent on breeding stage: implications for marine reserve design

Increasingly, space use by foraging seabirds is being used as an indicator of ocean condition to inform projected planning for climate change, fisheries management and marine protected areas. We tracked foraging common noddies (Anous stolidus) from a colony in the East Indian Ocean using back-mounted solar GPS trackers during incubation and chick rearing to evaluate their suitability as biomonitors of ocean condition, and the overlap of flight tracks with marine protected area boundaries. This is the first study to track this species in its eastern distribution and across different stages of the breeding cycle. Six birds were tracked for 89 days in total, describing 10 089 km of flight. Birds made significantly longer trips during chick rearing, which may reflect reduced availability of prey. The tracking period coincided with a particularly strong ENSO event, which may have impacted foraging behaviour, but the foraging area was found to be at least 10 000 km2. Foraging was associated with the end points of outward trips that were generally at the edge of the continental shelf, or within proximity of canyon-like bathymetric features or current structures on the shelf. Birds foraged over the shelf during incubation, suggesting a greater reliance on food web structures associated with Leeuwin Current structures. Home ranges and movement tracks showed limited overlap with proposed marine park boundaries, but are promising as indicators of ocean productivity, suggesting that their role in the design of marine reserve networks in the future should be maximised.

Satellite tracking of rehabilitated wild Baudin's cockatoos, Calyptorhynchus baudinii: a feasibility trial to track forest black cockatoos

Baudins cockatoo, Calyptorhynchus baudinii, is a threatened forest black cockatoo species, endemic to the south-west of Western Australia. In this study we fitted tail-mounted satellite transmitters to two female Baudins cockatoosthathadundergonetreatmentandrehabilitationatPerthZooandKaarakinBlackCockatooConservationCentre to investigate the feasibility of satellite tracking this species. Both birds were released in Kelmscott, Perth, into an area frequently visited by a flock of wild Baudins cockatoos. Both telemetry units provided reliable datasets, with one bird moving,250kmsouthfromthereleasesite.ThesuccessofthistrialopensthewaytoaddresskeyobjectivesintheForest Black Cockatoo Recovery Plan, including: postrelease survival of rehabilitated birds, flock movement, habitat use, and the identification of critical feeding and breeding habitat. Most importantly, it demonstrates that satellite transmitters can be successfully used to locate and track forest black cockatoo species, which are otherwise difficult to monitor.