Presence and diversity of mixed avian Plasmodium spp. infections in introduced birds whose distribution overlapped with threatened New Zealand endemic birds

ABSTRACT

Aims: To determine the presence of infection and co-infection of Plasmodium lineages in introduced birds at translocation sites for the North Island saddleback (Philesturnus rufusater), to investigate their role as Plasmodium spp. reservoirs.

Methods: Blood samples were collected from introduced bird species, with a special focus on blackbirds (Turdus merula) and song thrushes (Turdus philomelos), at six locations in the North Island of New Zealand that were the origin, or translocation sites, for North Island saddleback. Where available, blood smears were examined, and blood samples were tested using nested PCR with subsequent sequence analysis, for the presence of Plasmodium spp.

Results: Of the 55 samples tested using PCR analysis, 39 (71%) were positive for Plasmodium spp., and 28/40 (62%) blood smears were positive for Plasmodium spp. Overall, 31 blood samples were from blackbirds with 28/31 (90%) samples positive for Plasmodium spp. Six distinct avian Plasmodium lineages were identified, including three cosmopolitan lineages; Plasmodium vaughani SYAT05 was detected in 16 samples, Plasmodium matutinum Linn1 in 10 samples and Plasmodium elongatum GRW6 in eight samples. Mixed infections with more than one lineage were detected in 12 samples. Samples from two Australian magpies (Gymnorhina tibicen) were positive for Plasmodium. sp. lineage MYNA02, previously not identified in New Zealand.

Conclusions and clinical relevance: This is the first report from New Zealand in which specific Plasmodium spp. mixed infections have been found in introduced birds. Co-infections with several cosmopolitan Plasmodium lineages were identified, as well as the first report in New Zealand of an exotic avian Plasmodium sp. lineage, in Australian magpies. Whilst the role of introduced birds in maintaining and spreading pathogenic avian malaria in New Zealand is unclear, there is a potential infection risk to native birds, especially where distributions overlap.     

Feeding ecology and population delineation of south‐eastern Atlantic and south‐western Indian Ocean humpback whales using stable isotope analysis

1. Population delineation is vital for effectively managing and protecting populations of all at‐risk species. Population boundaries of Southern Hemisphere humpback whales on their breeding and feeding grounds have not been fully resolved. A number of methods have been used to delineate breeding stocks of Southern Hemisphere humpbacks, but ecological characteristics determined via stable isotope analysis provide valuable information to contrast other data sources.
2. In this study, stable isotope analysis is used to investigate potential separation of humpback whale populations on Southern Hemisphere feeding grounds as evidenced by carbon and nitrogen isotope values in their skin as proxies of diet.
3. One hundred samples of whale skin obtained from biopsies in sampling localities off the coasts of Gabon, Mayotte (Mozambique Channel), and Madagascar were analysed for carbon (δ¹³C) and nitrogen (δ¹⁵N) stable isotope ratios. The results showed a statistically significant difference in the mean δ¹⁵N values for whales between the populations from Gabon and Madagascar (7.0 ± 0.1‰ and 7.6 ± 0.1‰), and Gabon and Mayotte (7.6 ± 0.1‰ and 7.2 ± 0.1‰), indicating that these breeding stocks are potentially visiting different areas of the feeding grounds outside of the breeding season.
4. The results from this study indicate that at least some breeding stocks may show fidelity to separate feeding areas and do not widely mix with individuals from other breeding stocks while feeding.

     

Effects of Monomer Structure on Their Organization and Polymerization in a Smectic Liquid Crystal

Photopolymerizable diacrylate monomers dissolved in fluid-layer smectic A and smectic C liquid crystal (LC) hosts exhibited significant spatial segregation and orientation that depend strongly on monomer structure. Small, flexible monomers such as 1,6-hexanediol diacrylate (HDDA) oriented parallel to the smectic layers and intercalated, whereas rod-shaped mesogen-like monomers such as 1,4-di-(4-(6-acryloyloxyhexyloxy)benzoyloxy)-2-methylbenzene (C6M) oriented normal to the smectic layers and collected within them. Such spatial segregation caused by the smectic layering dramatically enhanced photopolymerization rates; for HDDA, termination rates were reduced, whereas for C6M, both the termination and propagation rates were increased. These polymerization precursor structures suggest novel materials-design paradigms for gel LCs and nanophase-separated polymer systems.