Maximization of fitness by phenological and phenotypic plasticity in range expanding rabbitfishes (Siganidae).

Global warming is modifying the phenology, life-history traits and biogeography of species around the world. Evidence of these effects have increased over recent decades; however, we still have a poor understanding of the possible outcomes of their interplay across global climatic gradients, hindering our ability to accurately predict the consequences of climate change in populations and ecosystems. We examined the effect that changes in biogeography can have on the life-history traits of two of the most successful range-extending fish species in the world: the tropical rabbitfishes Siganus fuscescens and Siganus rivulatus. Both species have established abundant populations at higher latitudes in the northern and southern hemispheres and have been identified as important ecological engineers with the potential to alter the community structure of seaweed forests (Laminariales and Fucales) in temperate regions. Life-history trait information from across their global distribution was compiled from the published literature and meta-analyses were conducted to assess changes in (i) the onset and duration of reproductive periods, (ii) size at maturity, (iii) fecundity, (iv) growth rates, (v) maximum body sizes and (vi) longevity in populations at the leading edge of range expansion in relation to sea surface temperature and primary productivity (a common proxy for nutritional resource levels). Populations at highest latitudes had shortened their reproductive periods and reduced growth rates, taking longer to reach sexual maturity and maximum sizes, but compensated this with higher fecundity per length class and longer lifespans than populations in warmer environments. Low primary productivity and temperature in the Mediterranean Sea resulted in lower growth rates and body sizes for S. rivulatus, but also lower length at maturity, increasing life-time reproductive output. The results suggest that plasticity in the phenology and life-history traits of range-expanding species would be important to enhance their fitness in high latitude environments, facilitating their persistence and possible further poleward expansions. Quantifying the magnitude and direction of these responses can improve our understanding and ability to forecast species redistributions and its repercussions in the functioning of temperate ecosystems.

Offense Trajectories, the Unfolding of Sexual and Non-Sexual Criminal Activity, and Sex Offense Characteristics of Adolescent Sex Offenders.

The current study examines offending trajectories of adolescent sexual offenders (ASOs). Until recently, classification frameworks have not been designed to account for the heterogeneity of offending patterns in adolescence, how these are associated with the unfolding of sexual and non-sexual criminal activity, and whether and to what extent they are related to the characteristics of sex offenses in adolescence. The current study takes a longitudinal view of offending in adolescence by examining retrospective longitudinal data of 217 ASOs referred for treatment to a clinical service between 2001 and 2009 in Australia. General offending trajectories in adolescence were examined using semi-parametric group-based modeling, and compared according to non-violent non-sexual, violent-non-sexual, and sex offending criminal activity parameters (e.g., participation, onset, frequency, specialization/versatility) and the characteristics of the referral sexual offense. The results show distinct differences in the unfolding of sexual and non-sexual criminal activity along different offending trajectories of ASOs, and further, that these trajectories were differentially associated with the characteristics of the sexual offenses they committed.