Variation in cranial morphology of bottlenose dolphins (genus Tursiops) off South Africa

Taxonomy plays an important role in conservation biology. Despite the variety of methods used to differentiate units, some groups, such as Delphinidae within the Cetacea have proven difficult to untangle. This study aimed to shed light on morphological variation of the genus Tursiops in South African waters using geometric morphometrics and to distinguish morphological groups and variation in these groups. A total of 241 crania of Tursiops spp. were analyzed using a suite of 2‐dimensional landmarks defined on photographs of the specimens. Results revealed two distinct morphological groups, with the smaller cluster comprised mainly of specimens from the cold temperate region off the west coast and the larger cluster comprised of specimens mainly from the warm temperate and subtropical regions off the south and east coast, respectively. We suggest that these groups correspond to different species of Tursiops, but this result requires further support. These groups were treated as separate entities and sexual dimorphism and geographic variation were assessed within each group. While sexual dimorphism and geographic variation were not significant within Cluster D1 and V1, they were significant within Clusters D2 and V2. The few Cluster 1 specimens found in the warm temperate and subtropical regions, relative to the number of Cluster 2 specimens, could be an indication of an offshore distribution for this group in these regions. Alternatively, the smaller cluster may also be indicative of a potentially small population size.     

Weathering a Dynamic Seascape: Influences of Wind and Rain on a Seabird’s Year-Round Activity Budgets

How animals respond to varying environmental conditions is fundamental to ecology and is a question that has gained impetus due to mounting evidence indicating negative effects of global change on biodiversity. Behavioural plasticity is one mechanism that enables individuals and species to deal with environmental changes, yet for many taxa information on behavioural parameters and their capacity to change are lacking or restricted to certain periods within the annual cycle. This is particularly true for seabirds where year-round behavioural information is intrinsically challenging to acquire due to their reliance on the marine environment where they are difficult to study. Using data from over 13,000 foraging trips throughout the annual cycle, acquired using new-generation automated VHF technology, we described sex-specific, year-round activity budgets in Cape gannets. Using these data we investigated the role of weather (wind and rain) on foraging activity and time allocated to nest attendance. Foraging activity was clearly influenced by wind speed, wind direction and rainfall during and outside the breeding season. Generally, strong wind conditions throughout the year resulted in relatively short foraging trips. Birds spent longer periods foraging when rainfall was moderate. Nest attendance, which was sex-specific outside of the breeding season, was also influenced by meteorological conditions. Large amounts of rainfall (> 2.5 mm per hour) and strong winds (> 13 m s^-1) resulted in gannets spending shorter amounts of time at their nests. We discuss these findings in terms of life history strategies and implications for the use of seabirds as bio-indicators.     

Killer whale predation on subantarctic fur seals at Prince Edward Island, Southern Indian Ocean

Killer whales at subantarctic Marion Island have been subjected to several scientific studies. In contrast, up until recently, there has been only one record of these animals documented for neighbouring Prince Edward Island. We here report on killer whale observations at Prince Edward Island during March 2012. During 3?days of opportunistic observations at a fur seal colony on the island, killer whales were sighted on six occasions. These probably represented three different pods numbering 11 individuals in total. During all sightings, individuals were seen hunting subantarctic fur seal pups, with four successful predatory events observed.     

Isolation of cyanophycin from tobacco and potato plants with constitutive plastidic cphATe gene expression

A chimeric cyanophycin synthetase gene composed of the cphATe coding region from the cyanobacterium Thermosynechococcus elongatus BP-1, the constitutive 35S promoter and the plastid targeting sequence of the integral photosystem II protein PsbY was transferred to the tobacco variety Petit Havanna SRI and the commercial potato starch production variety Albatros. The resulting constitutive expression of cyanophycin synthetase leads to polymer contents in potato leaf chloroplasts of up to 35 mg/g dry weight and in tuber amyloplasts of up to 9 mg/g dry weight. Both transgenic tobacco and potato were used for the development of isolation methods applicable for large-scale extraction of the polymer. Two different procedures were developed which yielded polymer samples of 80 and 90% purity, respectively.     

A giant rhinocerotoid (Mammalia, Perissodactyla) from the Late Oligocene of north-central Anatolia (Turkey)

A giant rhinocerotoid is described for the first time south of the Black Sea, in Turkey. The single specimen, a fragmentary radius referred to Paraceratherium sp., originates from conglomerates nearby at Gözükizilli, in the Çankiri–Çorum Tertiary basin. These layers correspond to the Lower member of the Kizilirmak Formation. The same locality (Gözükizilli-2) yields also the small rhinocerotid Protaceratherium sp., cf. P. albigense (Roman, 1912). Three other mammal localities (Gözükizilli-1, in the Lower Member of the formation, with several rodent species; Tepe 641 and Kizilirmak, in the Upper Member, with a diversified micro- and macro-mammal fauna) allow us to refer the Kizilirmak Formation as a whole to the Late Oligocene. All the observed taxa have strong Asian and/or European affinities, which precludes any geographical insulation for this part of Anatolia during the Late Oligocene.  © 2008 The Linnean Society of London, Zoological Journal of the Linnean Society, 2008, 152 , 581–592.     

Intracellular and extracellular labeling of neurons in fresh slice preparations combined with multiple tract tracing

We describe methods for studying axo-dendritic projections, one of the forms of neural connection involved in the complex circuits of the central nervous system, including brainstem auditory pathways. This form of neural connection is often difficult to visualize by conventional tract tracing techniques. Retrogradely identified cells were filled intracellularly with a mixture of fluorescent Lucifer yellow and nonfluorescent HRP in live slice preparations to reveal the detailed morphological features of these cells with special attention to the distal dendrite that may receive projections from suspected or known input axons. Extracellular or intracellular labeling of cells with axons that project to the distal dendrite of the identified cells was accomplished in the same live slice preparation. Using a live slice rather than a fixed slice allows accurate, visually controlled placement of anterograde tracer, which requires living axons for transport, into the source of input to the identified cells within the slice. Live slices also permit one to characterize the identified cells electrophysiologically. Intracellular labeling of cells in a potential source of local input to the identified cells also provides conclusive information concerning with connections of the cells involved.