Diet salinity and vasopressin as reproduction modulators in the desert-dwelling golden spiny mouse (Acomys russatus)

The time for reproduction in mammals largely depends on the availability of water and food in their habitat. Therefore, in regions where rains are limited to definite seasons of the year, mammals presumably will restrict their breeding correspondingly. But while mammals living in predictable ecosystems would benefit by timing their season to an ultimate predictable cue, such as photoperiod, in unpredictable ecosystems (e.g., deserts) they will need to use a more proximate signal. We suggest a mechanism by which water shortage (low water content in plants) could act as a proximate cue for ending the reproductive season. The golden spiny mouse (Acomys russatus), a diurnal rodent living in extreme deserts, may face an increased dietary salt content as the summer progresses and the vegetation becomes dry. Under laboratory conditions, increased diet salinity lead to reproductive hiatus in females, notable in imperforated vagina, and a significant decrease in the ovaries, uteri, and body masses. In females treated with vasopressin (VP), a hormone expressed during water stress, the uteri and body masses have decreased significantly, and the ovaries exhibited an increased number of atretic follicles. VP has also led to a significant decrease in relative medullary thickness (RMT) of the kidney. It is thus suggested that VP could act as a modulator linking the reproductive system with water economy in desert rodents, possibly through its act on the energetic pathways

Proposed mechanism for increased reproductive potential of wild boars under hunting pressure

Throughout Europe and Asia, populations of wild boars (Sus scrofa) demonstrate a steady increase in recent decades. This results in increased conflicts between wild boars and humans, intensifying economic costs like epidemics to livestock and humans, damages to gardens in urban areas and agricultural crops. Culling wild boars is the most widespread management tool throughout the world in attempts to minimize these conflicts. Yet, studies demonstrate that populations of wild boars exposed to high hunting pressure have shorter generation times associated with higher reproduction rates. The mechanisms of this phenomenon have not been examined to date, thus favoring the culling practice to go undisturbed. Our research goal is to evaluate the effects of hunting on wild boars population structure, dynamics, behavior and reproduction in four different land uses: urban with and without hunting, non urban (agriculture and nature reserves) with and without hunting. To do so, we are using motion triggered cameras (monitoring vigilance behavior), giving up densities (GUDs) experiments and analysis of stress and reproduction hormones levels in hair. Our results, so far, show striking behavioral differences between boars in urban and open spaces regardless of hunting pressure based on GUD studies and analysis of videos. These experiments suggest a lower perceived risk of humans in urban areas, where boars consumed all the food provided in the GUD studies, and thus putatively affecting the reproduction potential of boars in human vicinity. Furthermore, we found that hunting in non-urbanized lands decreases the dispersal of the yearlings. These herds also showed a high level of vigilance compared to the urban herds. We suggest that the combination of vigilance and low dispersal rates may lead to increased reproductive potential.peerReviewe

Roe deer and decapitated anemone flowers

The roe deer (Capreolus capreolus) has been locally extinct from the East Mediterranean since the beginning of the 20th century. A reintroduction program has been initiated in Israel where several deer have been released in the southern Carmel Mountains. The diet of roe deer is markedly different from that of other local ungulates. Their unique dietary preference for the generally unpalatable geophyte Anemone coronaria is especially notable. They typically consume anemone by "decapitating" the flowers, leaving the rest of the stem intact. We studied the consumption rate of anemone in four hand-reared deer in the Hai Bar Nature Reserve. During the flowering season, each deer consumed 65.5 ± 13.13 and 37.6 ± 13.85 anemone flowers/day in 2003 and 2004, respectively. These results indicate that roe deer may have a profound influence on anemone populations. Being secretive and flighty animals, roe deer are hard to detect. A preliminary survey conducted in Ramat HaNadiv Park, where a roe deer population of an unknown size exists, suggested that with proper calibration, the typical, easy-to-detect decapitated anemone flower might be used for monitoring roe deer presence and density.Arian D. Wallach, Moshe Inbar and Uri Shana

Protecting biodiversity hotspots with the TiME educational tool

Land transformation and degradation is the major driver of current species extinction, lately recognized as the sixth mass extinction. To address this threat innovative programs that combine both immediate remedies of land protection and comprehensive educational programs are soughed. This is My Earth (TiME) (http://this-is-my-earth.org) is a new voluntary NGO that was established to address these challenges. TiME uses crowd funding to save privately own lands in biodiversity hotspots, providing them protection. Membership fees are very affordable (as low as $1 a year) and 100% of all fees and donations are directed to fund land purchase and protection. TiME welcomes children to become members and use its website to vote for their preferred habitat to be conserved (following vetting by an international committee of experts), and thus offering them the power to decide for the organization where in the world it will purchase lands. Using the PBL [=Problem Based Learning] pedagogical approach we developed a workshop, based on the above inherited powers of the TiME approach, that empowers children to adopt a sense of critical thinking as they become activists for wildlife protection. We began by developing a lesson plan that includes a short presentation of the problem, group discussions about potential solutions, class debates regarding the optimal lands to be saved, and a class-wide democratic vote. Following this workshop we examined the level of awareness and attitude of the children towards activism and democratic position. We report here preliminary results as a preliminary database for developing an international TiME based lesson plan. Participants [N=80] revealed a democratic orientation regarding land reservations and expressed strong affinity for activism and further conservation activities. Responses to the Likert scale-based questions, indicate considerable support for involvement, with endorsement of five actions recommended in the questionnaire: writing letters to governmental authorities, signing petitions, participation in demonstrations, organizing demonstrations, and donations. Interestingly, donations received the highest support level, thus endorsing the TiME approach, while organizing a demonstration the lowest. It appears that the global habitat crisis presented to the students via the TiME platform triggers debate and critical thinking even beyond conservation to such topics as democracy and equity. The TiME website is emerging as an educational tool that offers a novel experience where teachers can harness curiosity and environmental engagement in the learning process about conservation issues. Educators use TiME to explain basic conservation concepts and involve classes in discussions about environmental decision-making and associated ethical dilemmas, prioritization of conservation efforts and practical ways to protect nature.peerReviewe

pups averages 2013-2015

Data for litters, including averages

Data from: Cortisol advantage of neighbouring the opposite sex in utero

Population sex ratios naturally fluctuate around equality. It is argued that the production of an equal number of male and female offspring by individual parents should be favoured by selection, if all costs and benefits are equal. Theoretically, an even-sex ratio should yield the highest probability for a fetus to be adjacent to a fetus of the opposite sex in utero. This may cause developmental costs or benefits that have been overlooked. We examined the physiological and developmental parameters associated with in utero sex ratios in the nutria (Myocastor coypus), an invasive wildlife species with a strong reproductive output. Using hair-testing, we found that litters with even-sex ratios had the highest average cortisol levels. Fetuses neighbouring the opposite sex exhibited longer trunks than those neighbouring the same sex, which might imply better lung development. Our results are the first to link intra-utero sex ratios and fetal cortisol and suggest that fetal cortisol might be a mechanism by which even-sex ratios are maintained via developmental advantages

individual fetuses 2013-2015

Data for individual fetuses