U.S. Department of Agriculture: Animal and Plant Health Inspection Service


Date of this Version

May 2002


Published in Journal of Mammalogy, 83(2):501–506, 2002.


We assessed reproductive patterns of coyotes (Canis latrans) from a 12-year data set involving 24 pairs of captive animals acquired from Latah County, Idaho. None of the females had placental scars (fetal implantation sites) at 1 year of age, but over 80% had placental scars by 2 years of age. The fraction with placental scars remained at 80–90% through age 9 years and then declined to ,40% by age 12 years. Similarly, mean number of placental scars per female rose rapidly through 2–3 years of age, remained stable until age 8 years, and then progressively declined to a very low level by age 12 years. Numbers of pups observed were typically smaller than numbers of placental scars, with fewer placental scars represented by pups among younger females than older females.