Excavation of Ptolemaic Period (ca. 309–30 BC) strata within Theban Tombs 11, 12, -399-, and UE194A by the Spanish Mission to Dra Abu el-Naga (also known as the Djehuty Project), on the west bank of the Nile River opposite Luxor, Egypt, yielded remains of at least 175 individual small mammals that include four species of shrews (Eulipotypha: Soricidae) and two species of rodents (Rodentia: Muridae). Two of the shrews (Crocidura fulvastra and Crocidura pasha) no longer occur in Egypt, and one species (Crocidura olivieri) is known in the country only from a disjunct population inhabiting the Nile delta and the Fayum. Although deposited in the tombs by humans as part of religious ceremonies, these animals probably derived originally from local wild populations. The coexistence of this diverse array of shrew species as part of the mammal community near Luxor indicates greater availability of moist floodplain habitats than occur there at present. These were probably made possible by a greater flow of the Nile, as indicated by geomorphological and palynological evidence. The mammal fauna recovered by the Spanish Mission provides a unique snapshot of the native Ptolemaic community during this time period, and it permits us to gauge community turnover in the Nile valley of Upper Egypt during the last 2000 years. It also serves as a relevant example for understanding the extinction and extirpation of mammal species as effects of future environmental changes predicted by current climatic models.

Both parasitism and social contact are common sources of stress that many gregarious species encounter in nature. Upon encountering such stressors, individuals secrete glucocorticoids and although short-term elevation of glucocorticoids is adaptive, long-term increases are correlated with higher mortality and deleterious reproductive effects. Here, we used an experimental host-parasite system, social rodents Acomys cahirinus and their characteristic fleas Parapulex chephrenis, in a fully-crossed design to test the effects of social contact and parasitism on stress during pregnancy. By analysing faecal glucocorticoid metabolites, we found that social hierarchy did not have a significant effect on glucocorticoid concentration. Rather, solitary females had significantly higher glucocorticoid levels than females housed in pairs. We found a significant interaction between the stressors of parasitism and social contact with solitary, uninfested females having the highest faecal glucocorticoid metabolite levels suggesting that both social contact and infestation mitigate allostatic load in pregnant rodents. Therefore, the increased risk of infestation that accompanies group-living could be outweighed by positive aspects of social contact within A. cahirinus colonies in nature.

Intrauterine or fetal growth restriction (IUGR) is a major complication of pregnancy and leads to significant perinatal morbidities and mortality. Typically, induction of IUGR in animals involves the complete occlusion or ablation of vessels to the uterus or placenta, acutely impairing blood flow and fetal growth, usually with high fetal loss. We aimed to produce a model of reduced fetal growth in the spiny mouse with minimal fetal loss. At 27 days gestational age (term is 38–39 days), a piece of silastic tubing was placed around the left uterine artery to prevent the further increase of uterine blood flow with advancing gestation to induce IUGR (occluded). Controls were generated from sham surgeries without placement of the tubing. Dams were humanely euthanized at 37 days gestational age and all fetuses and placentas were weighed and collected. Of the 17 dams that underwent surgery, 15 carried their pregnancies to 37 days gestational age and 95% of fetuses survived to this time. The difference in fetal body weight between occluded and control was ~21% for fetuses in the left uterus side: there were no differences for fetuses in the right uterus side. Offspring from the occluded group had significantly lower brain, liver, lung, kidney and carcass weights compared with shams. Preventing the gestation-related increase of uterine blood flow induced significant growth restriction in the fetal spiny mouse, with minimal fetal loss. This technique could be readily adapted for other small animal.

Considering the negative effects of glucocorticoid treatment, especially during fetal development it is important to investigate effectors decreasing such disadvantages. The aim of this study was to investigate the effect of prenatally administered dexamethasone (Dex), a synthetic glucocorticoid, on the histomorphometry of the femur in the offspring of spiny mice. The study was performed on 24 pregnant spiny mice. The time of the experiment included the prenatal period between the 20th day of gestation until birth (pregnancy lasts on average of 36–38 days). The mice from the experimental group received dexamethasone per os in a dose of 125 mg/kg birth weight daily. At the end, the newborns from the experimental and control group were weighted and euthanized. Maternal Dex treatment resulted in a 17% decrease in birth weight in newborns. Dex administration significantly reduced the thickness of the hypertrophy zone of the growth plate by 34% and total thickness by 8,7%. In addition, Dex decreased the number of cells in the articular cartilage by 27% and significantly decreased their diameter by 5%. Dex also affected the structure and spatial distribution of thick and thin collagen fibers, lowering the proportion of thin fibers compared with the control group. Moreover, Dex treatment considerably lowered the amount of proteoglycans in articular and growth cartilages. Exposure to glucocorticoids in pregnant spiny mice affects cartilage development by accelerating maturity of collagen fibers and growth plate, presumably along with further disruption of longitudinal growth of long bones.

The osmoregulatory function of common spiny mice Acomys cahirinus living on opposite slopes of the lower Nahal Oren (‘Evolution Canyon’) on mount Carmel, Israel, was investigated by increasing the salinity of the water source whilst maintaining a high-protein diet. The southern-facing slope (SFS) of this canyon differs from the northern-facing slope (NFS) as it receives considerably more solar radiation and consequently forms a more xeric, sparsely vegetated habitat. During the summer, mice living on the two opposite slopes significantly differed in their urine osmolality, which also increased significantly as dietary salinity increased. Offspring of wild-captured mice, born in captivity, and examined during the winter, continued to show a difference in osmoregulatory function depending on the slope of origin. However, they differed from wild-captured mice, as they did not respond to the increase in dietary salinity by increasing the concentration of their urine, but rather by increasing the volume of urine produced. This study shows that A. cahirinus occupying different microhabitats may exhibit differences in their ability to concentrate urine and thus in their ability to withstand xeric conditions. We suggest that they may also differ genetically, as offspring from the NFS and SFS retain physiological differences, but further studies will be needed to confirm this hypothesis.