Seabird feathers and eggshells are used as bio-monitors for trace metal contamination. Eleven trace element concentrations in wing primaries (n = 21) and eggshells (n = 8) are reported herein for two resident seabirds, Bridled Tern Onychoprion anaethetus and Black-naped Tern Sterna sumatrana, at Pulau Ling and Pulau Tokung Burung, Malaysia. Metal concentration followed the pattern Zn > Cr > Mn > Sr > Cu > Se > Ba > Pb > Cd > Ga > Li. Significant positive correlations existed among all trace metals, except for Cr in Black-naped Tern and Li and Cd in Bridled Tern feathers. We also analyzed metal concentrations in eggshells, and for Bridled Tern, the concentration pattern was Zn > Mn > Se > Sr > Ba > Pb > Co > Cu > Cd, whereas for Black-naped Tern it was Cr > Zn > Mn > Ba > Sr > Se > Cu> Co > Pb. A pairwise positive correlation was significant among most trace metals in feather samples, indicating synergistic effects of two or more elements. More studies are needed to build a baseline database of trace metal concentrations in seabirds of Southeast Asia, as little research on this subject has been conducted in this region.
Abdulmula Abdumagid Alhadi Hamza(1-2022)

Thirty-one seabird species are found in Malaysia; a few still breed on rocky outcrops and small islands in the southern Seribuat Archipelago. A century-long egg harvest by local fishermen in the area is believed to have caused extirpation of several breeding populations. To update the status of seabirds in the southern section of the Seribuat Archipelago, a two-day survey was conducted in August 2017. Twenty-two islands were selected and surveyed using boat observation and colony visits. In total, over 6 200 birds were counted, representing five tern species: Bridled Tern Onychoprion anaethetus, Black-naped Tern Sterna sumatrana, Great Crested Tern Thalasseus bergii, Roseate Tern Sterna dougallii, and the Lesser Crested Tern T. bengalensis. The first two species are confirmed breeders, whereas the remaining species are either passage migrants or unconfirmed breeders. The survey led to the rediscovery of a small population of Roseate Terns at Pulau Yu (one of the species' two historic breeding sites in Malaysia). The islands surveyed are not legally protected (except for the Pulau Tinggi group). The protection of selected sites is highly recommended to conserve these remaining seabird populations.
Abdulmula Abdumagid Alhadi Hamza(4-2019)

ABSTRACT: Marine turtles have been traditionally considered model organisms to study sex-biased behaviour and dispersal. Although female philopatry has been identified in the loggerhead turtle, with adult females returning to specific locations to nest, studies on the philopatry and breeding migrations of males remain limited. In this study we analysed 152 hatchlings using 15 microsatellite markers. Each individual came from a different nest from samples taken at 8 nesting grounds in the Mediterranean. Our results revealed the existence of 5 genetically differentiated units, mostly due to restricted gene flow for both sexes. This supports existing satellite tracking studies that suggest that mating occurs close to nesting grounds in this region. The 5 management units identified within the Mediterranean included nesting grounds from (1) Libya and Cyprus, (2) Israel, (3) Lebanon, (4) Turkey and (5) Greece. The genetic similarity between distant nesting areas (i.e. Libya and Cyprus) suggests the presence of a more complex pattern of breeding behaviour. Three possible hypotheses, that remain to be tested in future studies, could explain this result: (1) mating might take place in common foraging grounds; (2) mating could occur en route while migrating to/from the breeding grounds; or (3) recent colonisation events could connect the 2 nesting grounds. Overall, our work suggests that widespread male-mediated gene flow between loggerhead nesting grounds is likely to have been previously overstated although opportunistic breeding patterns might connect some widely separated areas.
Abdulmula Abdumagid Alhadi Hamza(1-2022)