Lifetime mating success, sexual selection and life history of fallow bucks (Dama dama)

We used data from a long-term study (15 years) of fallow deer to report for the first time the lifetime mating success, overall variance in lifetime mating success, and age-specific mortality levels of males. Fallow bucks that gain matings have higher social dominance rank, higher rates of fighting, and invest more in vocal display during the breeding season than unsuccessful males. Therefore, we examined if mating was associated with trade-offs in terms of survival, lifespan, and mating potential. We found that the variance in lifetime mating success was very high: 34 (10.7%) males mated, and of those, the 10 most successful males gained 73% of all matings (n=934). Mortality rates were generally high and only 22.3% (71/318) of males reached social maturity, i.e., 4 years. The oldest male was 13 years old. We found that fallow bucks that mated were not more likely to die during the following year, did not suffer from a reduction in lifespan, and did not incur lower mating success later in life as a result of mating during the early years of social maturity. Our results show that mating males at age 5 years (and possibly 9 years) may be more likely to survive than non-mating males. Additionally, the number of matings gained by males during the first years of social maturity was positively correlated with lifespan. We suggest that mating males are of higher quality than non-mating males because they are not more likely to incur trade-offs as a result of their increased reproductive efforts. Received: 9 November 1999 / Revised: 30 April 2000 / Accepted: 27 May 2000     

Sexual size dimorphism in fallow deer (Dama dama): do larger, heavier males gain greater mating success?

Sexual size dimorphism may evolve as a result of both natural and sexual selection. In polygynous mammals, the main factor resulting in the evolution of large body size in males is the advantage conferred during competition for mates. In this study, we examined whether sexual selection acts on body size in mature fallow bucks (Dama dama) by examining how the following traits are inter-related: age, body (skeletal) size, body mass, prerut dominance rank, rut dominance rank and mating success. This is the first study to examine how all these factors are together related to the mating success of a large sexually dimorphic and polygynous mammal. We found that male mating success was directly related to body size, but not to body mass. However body mass was related to prerut dominance rank which was in turn strongly related to rut dominance rank, and thus there was an indirect relationship between mating success and body mass. Rut dominance rank was the variable most strongly related to mating success. Mating success among mature males was unrelated to age. We conclude that larger mature fallow bucks have advantages over other males when competing for matings, and sexual selection therefore continues to act on sexual size dimorphism in this species. Heavier fallow bucks also have advantages, but these are mediated through the dominance ranks attained by males before the rut.     

Shoreline erosion in a reef-beach system

Beach erosion on Cinnamon Bay in the U.S. Virgin Islands results from storm waves in the North Atlantic. The net trend of erosion, however, is due to local environmental degradation. Reef die-back, initiated during the period of high sedimentation associated with 18th and 19th century sugar cane cropping, has reduced the rate of generation of new coral sands. Sand losses to deep water during periods of storm waves are not replenished. Engineering measures designed to check erosion at Cinnamon Bay have had little effect in this environment of low wave energies, but sand deficiency. The appropriate environmental focus for management of reef-beach systems is reef health and thus, water quality.     

Trauma and short-fuse weather warning perceptions

The purpose of this research was to assess the importance of psychological trauma in understanding reactions to short lead time weather warnings. The research consisted of two case studies, one in Denver, Colorado and the other in Austin, Texas. A total of 61 individuals with 9 or greater traumas were compared to 281 non-trauma exposed individuals. Results demonstrated significant differences on questions related to general beliefs about flash floods and warning perceptions as well as reported anticipated actions during a flash flood at home. Results suggest high trauma exposure may lead to more threat sensitivity and a higher probability of initiated action in a home-based flash flood.     

Information sources for flash flood warnings in Denver, CO and Austin, TX

This research examines sources of information for flash floods in two large metropolitan areas, Denver, CO, and Austin, TX. Previous research has noted that information delivery systems for weather forecasts are geared toward the cultural majority and suggests that inadequate warnings are a primary contributor to deaths and injuries from hazards. This investigation used chi-square analysis to determine the prime warning source preferences and preferred time of day for receiving different media. Results indicate that successful warning messages need to be targeted toward specific sub-populations if the warning is to be received, understood, and responded to properly.     

Trauma and short-fuse weather warning perceptions

The purpose of this research was to assess the importance of psychological trauma in understanding reactions to short lead time weather warnings. The research consisted of two case studies, one in Denver, Colorado and the other in Austin, Texas. A total of 61 individuals with 9 or greater traumas were compared to 281 non-trauma exposed individuals. Results demonstrated significant differences on questions related to general beliefs about flash floods and warning perceptions as well as reported anticipated actions during a flash flood at home. Results suggest high trauma exposure may lead to more threat sensitivity and a higher probability of initiated action in a home-based flash flood.