Effects of social and environmental contexts on multi-male mating and mixed paternity in socially monogamous female prairie voles.

With whom and how often to mate are fundamental questions that impact individual reproductive success and the mating system. Relatively few studies have investigated female mating tactics compared with males. Here, we asked how differential access to mates influences the occurrence of mixed paternity and overall reproductive success in socially monogamous female prairie voles (Microtus ochrogaster). We created male- and female-biased sex ratios of prairie voles living in semi-natural outdoor enclosures. We ran paternity analyses to determine the identity and number of mating partners females had and the number of offspring produced. We found that 57.1% of females had litters fathered by two or more males when males outnumbered females, and 87.5% of females had litters with more than one father when females outnumbered males. However, the percentage of mixed paternity and the total number of embryos were not statistically different between social contexts. We determined that female fecundity (i.e. number of embryos) correlated with the number of male fathers in each litter across social contexts. Although our study did not support the hypothesis that social context directly influences female mating decisions, it did suggest that female multi-male mating might lead to increased fertilization success under semi-natural conditions.

Recurrence of phonetic responding.

This study determined if previously reinforced academic responding recurred when alternative responses were differentially reinforced and subsequently placed on extinction, and whether the magnitude of resurgence was related to the rate of differential reinforcement for the alternative behavior. Three kindergarten students read Greek letters aloud as arbitrary consonant-vowel blends. Resurgence was reliably demonstrated within and across participants, and the magnitude of resurgence was related to the prior rate of differential reinforcement of alternative behavior.

Explicitly teaching English through the air to students who are deaf or hard of hearing.

The effects of the Language for Learning curriculum (Engelmann & Osborne, 1999) on through-the-air (i.e., signed and/or spoken) English skills for students who are deaf or hard of hearing (DHH) were examined by means of a single-subject, concurrent-multiple-probes-across-participants design. Four 11-year-old participants varied in auditory access, IQ, and age at amplification and/or cochlear implantation. All students showed increased accuracy of through-the-air English skills after the intervention (i.e., 15-20 lessons) and maintained these skills when assessed 1 week and 1 month later. The findings yielded some promising results indicating that a Direct Instruction curriculum may be an efficacious way to teach morphology and syntax to DHH students.