Do Female Pumas (Puma concolor) Exhibit a Birth Pulse?

Female pumas (Puma concolor) give birth in all months of the year with a possible birth pulse in July–September. This pulse is proposed to be timed to provide increased survival probabilities to young born during these months. We tested data on birth dates from 8 different studies for a birth pulse. We also compared survival rates for young born in July–September to those for young born outside of these dates during a 17-year study in Idaho and Utah. The distribution of litters born per month was not uniform, with 41% of births occurring in July–September. Survival rates of young born in July–September were equal to those in other months of the year (0.774 ± 0.006 versus 0.779 ± 0.004). We conclude that there was a propensity for higher numbers of litters to be born in July–September. However, we rejected the hypothesis that young born in July–September had greater survival than young born at other times of the year. We suggest that rather than there being a survival advantage to pumas born in July–September, perhaps there is a survival disadvantage to those born in January–February (4.5% of 484 litters). However, there were insufficient data to test this alternate hypothesis.