Estimating the breeding population of an elephant seal colony from a single census

Our aim was to develop a method for estimating the annual number of female elephant seals pupping in a colony from a single count. This is difficult because breeding females are not synchronous so there is no time when the entire population is present. We applied models that describe arrival and departure behavior to account for those missed in any one count and calculated correction factors that yield total population from any single count throughout a season. At seven colonies in California for which we had multiple female counts per year, we found consistent timing in arrival and departure both within and between sites for as long as 50 years. This meant that the optimal correction factor, the date when the maximum number of females was onshore, was consistent. At Point Reyes, a female count on 27 or 28 Jan can be multiplied by 1.15 to yield the total female population; at Año Nuevo Island, the correction was 1.17 on 25-26 Jan; and at Año Nuevo Mainland, 1.13 on 28-30 Jan. Correction factors at Channel Island colonies and King Range were also 1.13. Across the colonies studied, the factor 1.15 multiplied by a female count between 26 and 30 Jan was close to optimal, and this provides a method for estimating the female population size at colonies not yet studied. Our method can produce population estimates with minimum expenditure of time and resources and will facilitate monitoring of the elephant seal population size over its entire range.

Numerical study on the boiling heat transfer induced by two heated plates

A two-phase lattice Boltzmann method was used to numerically study the boiling heat transfer related to the liquid-vapor transition induced by two heated plates. The effects of the gravity force as well as the separation between the heated plates were examined. The focus is on the bubble departure behavior resulting from the interaction between bubbles, which can be roughly classified into four types of pat?tern according to the separation between plates. In particular, it is shown that the bubble merging may take place twice in one cycle when the separation is close to a certain value. This is referred to as the pattern of alternation of bubble merging before and after departure, for which a sudden jump is seen in the bubble release period. Furthermore, the heat flux and the flow features are also shown to illustrate the behavior of heat transfer in the present system.

Numerical study on the boiling heat transfer induced by two heated plates

A two-phase lattice Boltzmann method was used to numerically study the boiling heat transfer related to the liquid-vapor transition induced by two heated plates. The effects of the gravity force as well as the separation between the heated plates were examined. The focus is on the bubble departure behavior resulting from the interaction between bubbles, which can be roughly classified into four types of pat?tern according to the separation between plates. In particular, it is shown that the bubble merging may take place twice in one cycle when the separation is close to a certain value. This is referred to as the pattern of alternation of bubble merging before and after departure, for which a sudden jump is seen in the bubble release period. Furthermore, the heat flux and the flow features are also shown to illustrate the behavior of heat transfer in the present system.

An investigation of lateral-directional departure behavior based on yawing–rolling coupled wind tunnel tests

The traditional aerodynamic model based on the dynamic derivative tests and the [Formula: see text] model based on the yawing–rolling coupled motion tests are compared with respect to aerodynamic data, prediction of lateral-directional departure, and flight simulation. The study shows that the traditional model cannot fully reveal the unsteady aerodynamic characteristics and predict completely the departure behavior due to yaw–roll coupling. On the other hand, the [Formula: see text] model can reveal the departure behavior of an aircraft at some specific coupling ratios when the angle of attack reaches a critical value or more, using the aerodynamic data obtained from the yawing–rolling coupled wind tunnel tests. The comparison of flight simulation results shows that the lateral-directional departure is closely related to the coupling ratios, and for the investigated aircraft, the departure is mainly caused by the unsteady yawing and rolling moments at the coupling ratios showing unstable features.

Recruitment and monitoring behaviors by leaders predict following in wild Barbary macaques (Macaca sylvanus)

For group-living animals it is essential to maintain the cohesiveness of the group when traveling. Individuals have to make an accurate decision about where and when to move. Communication before and during the departure of the first individual may play a crucial role in synchronizing a collective movement. We hypothesized that individuals in a wild primate group use signals or cues prior to and after departure to achieve collective movements. With two observers we used all-occurrences behavior sampling of collective movements in a group of wild Barbary macaques (Macaca sylvanus) in the Middle Atlas, Morocco. The number of individuals displaying pre-departure behavior predicted the success of an initiation of a collective movement. Pauses of the first departing individual after departure enhanced following behavior and might have served as recruitment signal. However, the opposite was the case for back-glancing, which functions as a monitoring signal in other species. Because in our study frequently back-glancing individuals were also less socially integrated, back glances may better be interpreted as indicators of hesitation and insecurity. To successfully initiate a collective movement, it seemed to be sufficient for a socially integrated group member to take action when other group members signal their willingness prior to departure and to occasionally wait for the group while moving.