Welcome to Chinese Agricultural Science Bulletin,

Chinese Agricultural Science Bulletin ›› 2025, Vol. 41 ›› Issue (22): 100-105.doi: 10.11924/j.issn.1000-6850.casb2024-0799

Previous Articles     Next Articles

Morphological Traits and Reproductive Parameter Shifts Across Age Groups in Farmland Rattus norvegicus

AI Zhenxian(), BAI Mingqiong   

  1. Planting Industry Development Center, Sandu Shui Autonomous County, Sandu, Guizhou 558100
  • Received:2024-12-18 Revised:2025-04-27 Online:2025-08-11 Published:2025-08-11

Abstract:

To clarify the age-related changes in the morphological characteristics and reproductive parameters of Rattus norvegicus populations in agricultural areas and provide a scientific basis for population quantity prediction and control, the data of R. norvegicus specimens captured during the rodent monitoring in Sandu County, Guizhou Province from 2012 to 2024 were collected and statistically analyzed. The results show that the external morphological characteristics of R. norvegicus in the agricultural areas of Sandu County vary significantly among different age groups. As the age increases, all the indicators keep rising. However, when the age grows to the adult II group, the growth of tail length, hind foot length and ear height slows down or stops. There are significant differences in reproductive parameters such as the pregnancy rate and the litter size of female mice of different age groups, the rate of testicular descent in male mice, and the reproductive index. Individuals in the juvenile group have no reproductive capacity. Those in the sub-adult group participate in reproduction to a limited extent. The main reproductive individuals are from the adult group I, adult group II and the elderly group. The overall pregnancy rate of the three age groups was 49.62%, the average number of litter size was 8.26, the overall testicular descent rate was 90.45%, and the overall reproductive index was 1.7439. There are certain differences in condition factor among different age groups.

Key words: Rattus norvegicus, morphological traits, reproductive parameters, body condition, aging change, Sandu County