Reproductive success of Bornean orangutan males: scattered in time but clustered in space

The social and mating systems of orangutans, one of our closest relatives, remain poorly understood. Orangutans (Pongo spp.) are highly sexually dimorphic and females are philopatric and maintain individual, but overlapping home ranges, whereas males disperse, are non-territorial and wide-ranging, and show bimaturism, with many years between reaching sexual maturity and attaining full secondary sexual characteristics (including cheek pads (flanges) and emitting long calls). We report on 21 assigned paternities, among 35 flanged and 15 unflanged, genotyped male Bornean orangutans (Pongo pygmaeus wurmbii), studied from 2003 to 2018 in Tuanan (Central Kalimantan, Indonesia). All 10 infants born since mid-2003 with an already identified sire were sired by flanged males. All adult males ranged well beyond the study area (c. 1000 ha), and their dominance relations fluctuated even within short periods. However, 5 of the 10 identified sires had multiple offspring within the monitored area. Several sired over a period of c. 10 years, which overlapped with siring periods of other males. The long-calling behavior of sires indicated they were not consistently dominant over other males in the area around the time of known conceptions. Instead, when they were seen in the area, the known sires spent most of their time within the home ranges of the females whose offspring they sired. Overall, successful sires were older and more often resident than others. Significance statement It is difficult to assess reproductive success for individuals of long-lived species, especially for dispersing males, who cannot be monitored throughout their lives. Due to extremely long interbirth intervals, orangutans have highly male-skewed operational sex ratios and thus intensive male-male competition for every conception. Paternity analyses matched 21 immature Bornean orangutans with their most likely sire (only 10 of 50 genotyped males) in a natural population. Half of these identified sires had multiple offspring in the study area spread over periods of at least 10 years, despite frequently ranging outside this area. Dominance was a poor predictor of success, but, consistent with female mating tactics to reduce the risk of infanticide, known “sires” tended to have relatively high local presence, which seems to contribute to the males’ siring success. The results highlight the importance of large protected areas to enable a natural pattern of dispersal and ranging

Seascape Genetics of a Globally Distributed, Highly Mobile Marine Mammal: The Short-Beaked Common Dolphin (Genus Delphinus)

Identifying which factors shape the distribution of intraspecific genetic diversity is central in evolutionary and conservation biology. In the marine realm, the absence of obvious barriers to dispersal can make this task more difficult. Nevertheless, recent studies have provided valuable insights into which factors may be shaping genetic structure in the world's oceans. These studies were, however, generally conducted on marine organisms with larval dispersal. Here, using a seascape genetics approach, we show that marine productivity and sea surface temperature are correlated with genetic structure in a highly mobile, widely distributed marine mammal species, the short-beaked common dolphin. Isolation by distance also appears to influence population divergence over larger geographical scales (i.e. across different ocean basins). We suggest that the relationship between environmental variables and population structure may be caused by prey behaviour, which is believed to determine common dolphins' movement patterns and preferred associations with certain oceanographic conditions. Our study highlights the role of oceanography in shaping genetic structure of a highly mobile and widely distributed top marine predator. Thus, seascape genetic studies can potentially track the biological effects of ongoing climate-change at oceanographic interfaces and also inform marine reserve design in relation to the distribution and genetic connectivity of charismatic and ecologically important megafauna

Kinship and Alliance Formation in Wild Male Bottlenose Dolphins

15 page(s

Dissipative Particle Dynamics Simulation of Suspensions Rheology, and Electroosmotic Flow in Nanochannels

The dissipative particle dynamics (DPD) method is developed using innovative numerical techniques and extensively examined in the contexts of rheology and electroosmosis. In Chapters 3-5, it is attempted to classify practical ranges of DPD parameters under a variety of simulation settings, thermostating schemes and shearing methods. Through a calibration process, useful windows of parameters are categorised so that DPD users can model a wide range of rheological systems conveniently with proper temperature control and equilibrium statistics. DPD was found to perform poorly under certain dissipation rates and shear rates when sheared via original Lees-Edwards boundary condition. Hence, a modified version of this shearing method is shown to be an effective remedy to improve the hydrodynamics and thermal stability of sheared DPD systems. These achievements shed light on unclear correlations between input parameters and simulation outputs, and relatively rectifies the lack of predictability embedded in DPD method. In Chapter 6, it is shown that plain DPD is inherently a flexible numerical tool to reproduce experimental behaviour of dilute to dense suspensions. This is achieved via a simple calibration of parameters without unnecessary and computationally intensive modifications to DPD underlying formulas. In Chapter 7, contrary to existing DPD modellings of electroosmotic flow (EOF), soft-core electrostatic interactions are treated fully explicitly by inclusion of charge clouds around DPD soft beads and adopting the corrected Ewald sum method (EW3DC). The developed DPD platform is then calibrated to match the results of molecular dynamics, and reproduce experimental trends. A new system of unit conversion between DPD reduced units and SI units is introduced, which is also useful in other electrokinetic applications. The coarse-graining degree of beads is set to unity to challenge DPD performance in the smallest possible length scale, i.e. in a nanochannel sized at 3.8 nm