Three zoo lions fed whole carcasses every nine days spent nearly three times as long eating

Lesia Hryhorenko, the lead author at Adelaide University's School of Animal and Veterinary Sciences ^[16], started from the wild animal. "Wild lions don't eat at the same time every day. They experience natural periods of feasting and fasting depending on hunting success," she said ^[3]. The study tested that idea on three adult male African lions at Monarto Safari Park, and each lion was its own comparison: the team watched them before carcasses were introduced and again afterward ^[6]. That design holds the animals and their enclosure constant. It cannot separate the effect of the carcasses from the passage of time. Pacing crept up slightly across the study period ^[12], and a before-and-after comparison with no parallel group cannot say how much of any change came from the food and how much from the weeks passing.

The near-threefold feeding figure is a ratio. The lions also fed more often and in longer bouts ^[1], but the release does not give the baseline in minutes, so the gain could be modest in absolute terms or large. Hryhorenko emphasised what the lions did with the extra time. "Providing whole carcasses changes much more than the nutritional content of the diet," she said ^[10]. "It gives lions the opportunity to engage in behaviors such as tearing, pulling and manipulating food over extended periods, which are important components of their natural feeding ecology." ^[11]

I think the pacing result is the one keepers should look at first. In carnivores, pacing is a repetitive behaviour often linked to anticipation ^[15]. If hunger drove it here, it should have climbed as each fast lengthened. It did not do so consistently ^[12]. The authors conclude it was probably tied more to familiar routines and the expectation of food than to hunger ^[13]. That is an inference from timing in three animals. A zoo could test it by moving keeper arrival times and checking whether the pacing peaks move too.

Continuous recording is what made that timing visible. Eight infrared cameras ran around the clock for three months ^[9], producing what the university calls one of the most detailed 24-hour datasets yet for African lions in human care on carcass feeding ^[17]. Co-author Associate Professor Alexandra Whittaker said the findings show why animal behaviour needs to be monitored over longer periods when zoo management practices are evaluated ^[14]. The cycle of heavy rest and slowly rising activity plays out over days ^[2]. A study that watched only feeding days would have recorded the feast and missed the fast.

On this evidence, a nine-day carcass cycle is a reasonable trial for a zoo that already runs feast-and-fast feeding ^[7]. The case for a standard needs more animals. All three were male, and the finding that carcass days brought no extra aggression ^[4] comes from one group of three. Whether a pride with females shares a carcass the same way would take a separate experiment.