By Erin McKinney
The anti-zoological crowd has built its legacy on sneaking misinformation into society through films, books, speeches and social media.
Sometimes, anti-zoo proponents will even try to sneak their agenda into real science, as Jeff Ventre and John Jett did with their 2015 paper claiming wild killer whales live longer than those in zoological facilities.
Since Ventre and Jett were so eager to pretend to be experts, they should have been ready for the real ones to call them out, which is exactly what happened at IMATA 2015.
Dr. Kelly Jaakkola, one of the world’s foremost experts in dolphin cognition, and Dr. Grey Stafford, a PhD biologist and expert on positive reinforcement training in zoological species, tore apart the Ventre and Jett paper in a 15 minute smackdown dual presentation at the conference held in the Bahamas.
“What you’ve got here is bad science” Dr. Jaakkola said, while introducing the Ventre-Jett lifespan piece, “and I don’t say that lightly, as a scientist.”
Dr. Jaakkola and Dr. Stafford proceeded to break down the problematic data, one damning bullet point at a time.
1: Inappropriate Handling of Data Sets
Ventre and Jett’s paper claims to compare the longevity of zoological whales to their wild counterparts, but it doesn’t do so in a statistically sound manner.
“In the wild, the field season doesn’t happen until 6 months after the calving season,” Dr. Jaakkola explains, “which means that when a calf is first sighted, it’s about 6 months old, which means if a wild calf dies before 6 months old, they never see it.”
In contrast, on the zoological side, all calves are counted, since all babies can be seen and recorded, skewing the data inexcusably in favor of a higher wild lifespan.
“Jeff and Ventre know this,” Dr. Stafford said, “and they know that the mortality rate for calves under 6 months in the wild, is agreed upon by pro and anti-zoo scientists to be around 50%.”
Bad data? You bet. And it only gets worse.
2: Invalid Comparisons
One of the anti-zoo fan’s favorite games is to twist numbers around to make them say what they want to hear, and the Blackfish star’s paper is no exception.
“In their paper, they claim that 41-73% of whales reach age 40,” Dr. Jaakkola explains, “and they compare that to ‘in marine mammal facilities, only 7% of the animals currently living are above age 40.’ Except they’re completely different things.”
Dr. Jaakkola goes on to explain that the percent of whales who reach a given age is a survival probability, and refers to the chance that a whale lives to that point, while making a statement about the percentage of whales living above a given age is a reference to population structure.
While survival probability is a continuous statistic, and averaged over time, population structure is an immediate one and will change if there is a large number of births or deaths in a population. In this case, there have been many recent zoological killer whale births that have changed the structure of their population.
“These are completely different things.” Dr. Jaakkola says. “Just because you’re using the word ‘percent’ in both doesn’t mean you’re measuring the same thing.”
The activist statement claiming only 7% have reached age 40 doesn’t mean 93% died before age 40, it simply means they’re younger and haven’t reached that age yet. But when have the Blackfish stars let facts get in the way of a good moneymaking story?
3: Unsupported conclusions
Scientists use statistics to analyze real world data to figure out if there is an effect causing variation. But Ventre and Jett aren’t interested in time tested statistical processes. For them, it’s all about the buzzwords, even if it contradicts their other claims.
“Ventre and Jett claim that ‘survival deteriorates for females between 7 years and 11 years while improving for males during this period’ right after they state that male and female survival isn’t significantly different,” Dr. Jaakkola says.
And that’s only one of the blatant contradictions.
Ventre and Jett also claim there is a “notable deterioration of survival between 2 and 6” for zoological whales, and that facilities should “avoid separating moms/calves during those years.” However, the data shows that the “notable deterioration of survival” mentioned isn’t statistically significant, and that no animals who passed in that range were separated from their mothers.
“That is only pointed to because it fits their narrative,” Dr. Jaakkola says. “It is NOT statistically significant. They are literally just making stuff up.”
Those are some powerful critiques from some powerful scientists, and with powerful support. The same editor who published Ventre and Jett’s lifespan paper will be publishing Dr. Stafford and Dr. Jaakkola’s point by point rebuttal, which contains much more than can fit in a 15 minute presentation.
The entire rebuttal is based on the forthcoming paper Robeck, T., Jaakkola, K., Stafford G., & Willis, K. (in press).Killer whale (Orcinus orca) survivorship in captivity: A critique of Jett and Ventre (2015). Marine Mammal Science.
Keep an eye out for that piece. And for the entire science smackdown, check out the video below of Dr. Stafford and Dr. Jaakkola killing it at IMATA 2015.