title: Effects of levonorgestrel-quinestrol (EP-1) treatment on Mongolian gerbil wild populations: a case study.
abstract: Rodent pest population outbreaks occur frequently in grassland ecosystems in northern China. The Mongolian gerbil (Meriones unguiculatus) is a dominant pest rodent which is distributed across the semi-desert grasslands of Inner Mongolia, China. In 2009, we studied the contraceptive effect of levonorgestrel-quinestrol (EP-1), concentration 50 ppm, on a wild Mongolian gerbil population. The one-off contraceptive treatment was compared with a control group using a semi-monthly live trapping method in the Ordos Semi-desert Grassland Region of Inner Mongolia. The results show that juveniles were not recruited in spring in the treatment group. Ratios of juveniles in the control and treatment groups showed significant semi-monthly differences from spring to summer (one-way ANOVA, F2, 14 = 7.53, P < 0.05). Between both groups, annual fluctuations of juvenile and total population densities were significantly different respectively (F2, 14 = 4.64, P < 0.05; F2, 18 = 7.72, P < 0.05). The contraceptive EP-1 delayed the normal reproductive pattern of Mongolian gerbil populations. This suppressed birth rates of gerbil populations, reduced their densities, and changed their age structures. The period of EP-1 baiting should be extended but it could be an ideal method for controlling Mongolian gerbil populations during each breeding season.
authors.affiliation: China Agricultural University, Beijing, China Inner Mongolia Agricultural University, Hohhot, China Key Laboratory of Prataculture and Grassland Resources of Education Ministry, Hohhot, China.
authors.forename: Heping
authors.initials: H
authors.lastname: Fu
authors.forename: Jinwei
authors.initials: J
authors.lastname: Zhang
authors.forename: Dazhao
authors.initials: D
authors.lastname: Shi
authors.forename: Xiaodong
authors.initials: X
authors.lastname: Wu
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D016022:Case-Control Studies; D002681:China; D003280:Contraceptives, Oral, Synthetic / Q000494:pharmacology*; D005298:Fertility / Q000187:drug effects*; D005849:Gerbillinae / Q000502:physiology*; D016912:Levonorgestrel / Q000494:pharmacology*; D011156:Population Density; D011157:Population Dynamics; D011800:Quinestrol / Q000494:pharmacology*; D012375:Rodent Control / Q000379:methods*
chemical_list: D003280:Contraceptives, Oral, Synthetic; D016912:Levonorgestrel; D011800:Quinestrol
keywords: EP-1; Mongolian gerbil (Meriones unguiculatus); fertility control; population dynamic; population structure; wild population