Neonatal behavioral scoring of common marmosets ( Callithrix jacchus ): relation to physical condition and survival[Note 1. Funding: This work was supported by NIH grant R01‐RR02022 ...]

A seven‐task behavioral test was performed on 86 common marmoset ( Callithrix jacchus ) infants, 24–36 h following birth. This report describes the test outcome and its relation to physical condition and survival of the infants. The percentage of infants receiving a perfect score on a given task ranged from 30.6 (rooting) to 70.6% (grasping). Heavier infants were more likely to have perfect scores for crawling ( F =4.20, P =0.044) and infants with a longer knee–heel length tended to be more likely to have a perfect grasping score ( F =3.63, P =0.06). While the modal score was a perfect score for most individual tasks, the modal number of total perfect scores that a given infant received was 3–4 and only 4.7% of infants received perfect scores on all seven tasks. These results suggest that this group of behavioral tasks will produce a variable response within a population of neonates. While no individual behavioral score predicted survival during week 1, the number of perfect scores across all tasks was predictive of survival outcome; infants with a higher total number of perfect scores were more likely to survive ( F =6.02, P =0.018). When all combinations of tests were compared, the best predictor of survival was outcome on four of the seven tests, all related to motor skills ( F =7.46, P =0.009).