Faunistic Study of the Rodents of North Khorasan Province, North East of Iran, 2011–2013

Background: Rodents are one of the most important hosts for some zoonotic diseases and also act as a reservoir of some ectoparasites and endoparasites. They cause damage to the farms and inflict public health. The aim of this study was to investigate the faunal composition of rodent in North Khorasan Province, Northeast of Iran. Methods: The sampling was carried out between 2011 to 2013. The specimens were collected using different methods including rodent death and live traps, digging of their burrow, and hand net from 75 different sample sites. Results: The total number of 396 specimens belonging to 22 species and six families were identified. The results illustrated the high numbers and densities of Meriones persicus (17.68%), Meriones libycus (15.15%), Nesokia indica (7.32%) and Rhombomys opimus (6.82%), as the most important reservoirs for different zoonotic diseases. Moreover, significant number of other rodent species including Mus musculus (15.66%), Apodemus witherbyi (13.89%), A. hyrcanicus (0.25%), Rattus norvegicus (1.01%), Meriones crassus (0.25%), Gerbillus nanus (0.51%), Microtus paradoxus (2.27%), M. transcaspicus (0.76%), Ellobius fuscocapillus (0.25%), Cricetulus migratorius (4.29%), Calomyscus elburzensis (4.29%), C. mystax (1.26%), Spermophilus fulvus (0.25%), Dryomys nitedula (3.54%), Allactaga elater (3.54%), Jaculus blanfordi (0.25%), Meriones zarudnyi (0.25%), M. meridianus (0.51%), and Hystrix indica as hosts for parasites and zoonotic diseases were identified. Conclusion: The high biodiversity including at least 22 species and six families of rodents were found in North Khorasan Province, some of them were medically important species.

Timing is the only thing: reproduction in female yellow ground squirrels (Spermophilus fulvus)

Based on 4-year field observations of yellow ground squirrels (Spermophilus fulvus (Lichtenstein, 1823)), we determined whether female reproductive effort, annual reproductive success, and survival were dependent on age, body condition, time of emergence from hibernation, and previous reproduction. The probability of weaning a litter did not vary with female age, body condition, time of emergence, or previous reproduction. Litter size, litter mass, and offspring survival did not vary with age, whereas individual offspring mass was lower in yearlings than in older females. Body condition upon emergence had no effect on litter size, litter mass, offspring mass, and survival. Reproduction did not influence female survival, physical condition upon emergence next spring, or subsequent reproductive efforts. The only factor that affected the extent of reproductive effort and offspring survival was the date of emergence: the later a female emerged, the lower the total and mean offspring mass, and fewer offspring survived. The modulation of reproduction in female S. fulvus by only the timing of vernal emergence and independent of other individual characteristics can be explained by the high costs of missed reproductive opportunity because of short longevity combined with low costs of reproduction when resources are abundant enough to meet both somatic and reproductive needs.