Publication Type: | Journal Article |
Year of Publication: | 2004 |
Authors: | Naidenko, SV, Voznesenskaya, VV, Clark, L |
Journal: | Zoologicheskii Zhurnal |
Volume: | 83 |
Pagination: | 459-463 |
Date Published: | 2004 |
Keywords: | Lynx lynx, Rattus norvegicus |
Abstract: | The reproductive success of laboratory rats (Rattus norvegicus) housed at different distances (2, 20, and 80 m) from a predator (Lynx lynx) was investigated. Virgin female (n = 120) and male (n = 40) rats of an outbred laboratory population were used for the experiments. Groups of rats (1 male and 3 females) were housed in standard cages in close proximity to the predator. Litter size, sex ratio, number of alive pups, number of placental scars and corpora lutea were counted; pre- and post-implantation losses were calculated for each female. The reproductive success of females calculated as a number of alive pups per female was much higher in both control groups (20 and 80 m) than in both test groups (2 and 2 m). Equal numbers of corpora lutea in all groups but different numbers of placental scars between the control and test groups indicated a higher pre-implantation loss in the experimental groups. The post-implantation loss was also higher in both test groups. The total loss (calculated as a difference between the number of corpora lutea and living pups) was twice as high as in experimental groups. Reproductive success of rats is related to the concentration/intensity was of predator's stimuli: when the concentration/intensity was higher, the number of live pups was less, and the total loss was higher. |
Reproductive strategy of Norway rat, Rattus norvegicus (Murinidae), in the presence of predator
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