Additionally, a 2020 study indicates that tyrannosaurids were exceptionally efficient walkers. Studies by Dececchi "et al.", compared the leg proportions, body mass, and the gaits of more than 70 species of theropod dinosaurs including tyrannosaurids. The research team then applied a variety of methods to estimate each dinosaur's top speed when running as well as how much energy each dinosaur expended while moving at more relaxed speeds such as when walking. Among smaller to medium-sized species such as dromaeosaurids, longer legs appear to be an adaptation for faster running, in line with previous results by other researchers. But for theropods weighing over , top running speed is limited by body size, so longer legs instead were found to have correlated with low-energy walking. The results of the study further indicated that smaller theropods evolved long legs for speed as a means to both aid in hunting and escape from larger predators while larger predatory theropods that evolved long legs did so to reduce the energy costs and increase foraging efficiency, as they were freed from the demands of predation pressure due to their role as apex predators. Compared to more basal groups of theropods in the study, tyrannosaurids showed a marked increase in foraging efficiency due to reduced energy expenditures during hunting and scavenging. This likely resulted in tyrannosaurs having a reduced need for hunting forays and requiring less food to sustain themselves as a result. Additionally, the research, in conjunction with studies that show tyrannosaurs were more agile than other large bodied-theropods, indicates they were quite well-adapted to a long-distance stalking approach followed by a quick burst of speed to go for the kill. Analogies can be noted between tyrannosaurids and modern wolves as a result, supported by evidence that at least some tyrannosaurids such as "Albertosaurus" were hunting in group settings.