RESUMEN
The vast majority of species interactions are seasonally structured and depend on species' relative phenologies. However, differences in the phenologies of species naturally vary across years and are altered by ongoing climate change around the world. By combining experiments that shifted the relative hatching of two competing tadpole species across a productivity gradient with simulations of inter-annual variation in arrival times I tested how phenological variation across years can alter the strength and outcome of interspecific competition. Shifting the relative timing of hatching (phenology) of a species fundamentally altered interspecific competition, and the effect of shifting the timing on competition was highly non-linear for most demographic rates. Furthemore, this relationship varied with productivity of the system. As a consequence, (a) shifts in relative timing of phenologies had small or large effects depending on the average natural timing of interactions, and (b) changes in the inter-annual variation in onset of interaction alone can alter species interactions in simulations even when mean phenologies (timing) remain unchanged across years. Studies on phenologies traditionally focus on directional shifts in the mean of phenologies, but these results suggest that we also need to consider inter-annual variation in phenologies of interacting species to predict dynamics of natural communities and how they will be modified by climate change.
Asunto(s)
Cambio Climático , Animales , Demografía , Larva , Estaciones del AñoRESUMEN
Understanding the processes driving seabirds' reproductive performance through trophic interactions requires the identification of seasonal pulses in marine productivity. We investigated the sequence of environmental and biological processes driving the reproductive phenology and performance of the storm petrel (Hydrobates pelagicus) in the Western Mediterranean. The enhanced light and nutrient availability at the onset of water stratification (late winter/early spring) resulted in annual consecutive peaks in relative abundance of phytoplankton, zooplankton and ichthyoplankton. The high energy-demanding period of egg production and chick rearing coincided with these successive pulses in food availability, pointing to a phenological adjustment to such seasonal patterns with important fitness consequences. Indeed, delayed reproduction with respect to the onset of water stratification resulted in both hatching and breeding failure. This pattern was observed at the population level, but also when confounding factors such as individuals' age or experience were also accounted for. We provide the first evidence of oceanographic drivers leading to the optimal time-window for reproduction in an inshore seabird at southern European latitudes, along with a suitable framework for assessing the impact of environmentally driven changes in marine productivity patterns in seabird performance.
Asunto(s)
Aves/fisiología , Cadena Alimentaria , Reproducción , Animales , Conducta Alimentaria , Mar Mediterráneo , Dinámica Poblacional , Estaciones del Año , EspañaRESUMEN
BACKGROUND: Intimate partner violence (IPV) and unintended pregnancy are public health issues that can affect the health and well-being of women and their children. However, the relationship between IPV and women's ability to control their fertility has not been adequately explored. AIM: To investigate the association between unintended pregnancy and emotional or physical violence perpetrated by partners around pregnancy. METHODS: A population-based study was undertaken, recruiting women (n=779) at the hospital obstetric departments and gathering social and family data. IPV was diagnosed by using the Index of Spouse Abuse (ISA). Data were gathered by trained midwives in 15 public hospitals in southern Spain and multivariate logistic regression analysis was performed. FINDINGS: The pregnancy was reported to be unintended by 118 (15.1%) of the study population. Unintended pregnancy was significantly associated with: physical and/or emotional IPV around pregnancy, age, marital status, cohabitation, educational level, and employment status. After adjusting for socio-demographic characteristics, emotional IPV around pregnancy was significantly associated with an unintended pregnancy (AOR=2.5; 95% CI=1.5-4.3). Being in a non-committed relationship was a risk factor (AOR=3.5; 95% CI=1.8-6.1) and being in employment a protective factor (AOR=0.4; 95% CI=0.2-0.8) for an unintended pregnancy. CONCLUSION: Women who report an unintended pregnancy may be experiencing emotional IPV. The risk of emotional IPV is higher if women reporting an unintended pregnancy are in a committed relationship, married, or in employment. A better understanding of the relationship between unintended pregnancy and violence can aid midwives about potential reproductive health risk factors associated with abuse.