Top predator ecology and conservation: Lesson from jaguars in southeastern Mexico

Our research is the most comprehensive study of jaguar behavior ecology in Mexico. By analyzing and describing the movements and use of the space, as well as the interactions among individual jaguars, we can better understand their behavioral differences, habitat use, and home range. This type of information is critical for the development and implementation of effective and appropriate conservation strategies. We identified home range size for 14 jaguars in a 13‐year period and described the interspecific relations and use of space by the percentages of overlap of the territories between individuals. Collectively, the average home range size was larger than 200 km2, ranging from 48 to 633 km2 and averaging 296 km2 for males varied and 37–435 km2, with an average of 148 km2, for females. However, home range sizes did not differ significantly among males or females. Male territory overlapped about 3.3% on average (range 2.5–15.5%), suggesting that most of the time males avoid each other. Average overlap of female territory was 12%, ranging from 7 to 100%. Males share an average of 18% (range 2–56%) of its territory and with up to five females, suggesting that a given male may be related to all of them at certain periods of time. There were no seasonal changes (dry and rainy seasons) in home range sizes for both male and females. Our research is an important contribution to the ecological information essential for landscape‐level conservation plans for the protection of the jaguars and the biological diversity of the wider Yucatan Peninsula in which they inhabit. Our research is the most comprehensive study of jaguar behavior ecology in Mexico. By analyzing and describing the movements and use of the space, as well as the interactions among individual jaguars, we can better understand their behavioral differences, habitat use, and home range. This type of information is critical for the development and implementation of effective and appropriate conservation strategies. We identified home range size for 14 jaguars in a 13‐year period and described the interspecific relations and use of space by the percentages of overlap of the territories between individuals. Collectively, the average home range size was larger than 200 km2, ranging from 48 to 633 km2 and averaging 296 km2 for males varied and 37–435 km2, with an average of 148 km2, for females. However, home range sizes did not differ significantly among males or females. Male territory overlapped about 3.3% on average (range 2.5–15.5%), suggesting that most of the time males avoid each other. Average overlap of female territory was 12%, ranging from 7 to 100%. Males share an average of 18% (range 2–56%) of its territory and with up to five females, suggesting that a given male may be related to all of them at certain periods of time. There were no seasonal changes (dry and rainy seasons) in home range sizes for both male and females. Our research is an important contribution to the ecological information essential for landscape‐level conservation plans for the protection of the jaguars and the biological diversity of the wider Yucatan Peninsula in which they inhabit.The authors would like to thank the Alianza WWF – Fundacion Telmex/Telcel, the Universidad Nacional Autonoma de Mexico (project DGAPA, PAPIT IN208017), Amigos de Calakmul A.C., and the BBVA Foundation Award for the Conservation of Biodiversity (2017) for funding and support for this project

Effect of filler functionalization on thermo-mechanical properties of polyamide-12/carbon nanofibers composites: a study of filler-matrix molecular interactions

The effect of carbon nanofiber (CNF) functionalization on the thermo-mechanical properties of polyamide-12/CNF nanocomposites was investigated. Three main different surface treatments were performed to obtain CNF-OH (OH rich), CNF-Silane (C6H5Si-O-), and CNF-peroxide. CNF modified with poly-(tert-butyl acrylate) chains grown from the surface via ATRP (atom transfer radical polymerization) were also prepared and tested. The modified CNFs and neat CNFs were used as fillers in polyamide-12 nanocomposites and the properties of the ensuing materials were characterized and compared. Universal tensile tests demonstrated a substantial increase (up to 20 %) of the yield strength, without reduction of the final elongation, for all functionalized samples tested within 1 wt% filler content. Further evidences of mechanical properties improvement were given by dynamic mechanical thermal analyses. CNFs functionalized with poly-(tert-butyl acrylate) and silane exhibited the best performance with stiffening and strengthening at low (a parts per thousand currency sign1 wt%) filler loadings, via a partial decrease of the intensity of beta-transitions attributed to favorable interactions between the functional groups on the surface of functionalized CNFs and polyamide-12. CNFs treated with peroxide proved to be the most simple preparation technique and the ensuing nanocomposites exhibited the highest storage modulus at high (5 wt%) filler content. Theoretical simulations using the micro-mechanics model were used to predict the Young modulus of the composites and compare them with experimental data. The results obtained suggest a synergistic effect between the matrix and the filler enhanced by surface functionalization