Because of their varied genetic backgrounds, recoms are found in all sizes – even moreso than humans! There are no hard and fast rules (though staff may need to provide guidance for certain concepts). Can you imagine a six foot tall mouse meeting a four foot tall leopard? It would be odd, but it can happen. Still, there are some trends that may be observed.
The most diminutive subspecies of mouse recoms can be as little as 20 inches tall (0.5 m) and 5 pounds mass (2 Kg) when they reach adulthood. Genetic engineers believe this is the lower limit of practical size for an intelligent being, due to the need of supporting a required brain mass. (Exceptions would be possible only if intelligence were artificially increased by non-biological means, such as if suitable nanocomputers were invented). Along with mice, some bat recoms are nearly this small. Rats tend to be somewhat larger, with the smaller subspecies averaging around 3 feet (1 m) in height. Among these very small species, the males tend to be only slightly larger than females, if at all.
Recoms based on small animals – such as rabbits, skunks, raccoons, foxes, foxbats, and domestic cats – tend to be somewhat shorter than the average human, though these species are also the ones that exhibit the most wide variation. Average size of these species run about 4' (1.2 m) to 5' (1.5 m) for females and 4'3“ (1.3m) to 5'4” (1.6 m) for males.
Recoms based on roughly human-mass animals – such as pumas or leopards, deer, black bears, and wolves or coyotes – tend tend to average around the same height as humans (though bears often mass more, while cheetahs tend to be thin). Height averages around 5'4“ (1.6 m) for females and 5'9” (1.75 m) for males.
Recoms based on larger animals – such as brown bears, horses or elk, and lions or tigers – usually average around 5'8“ (1.7 m) for females, 6'3” (1.9 m) for males. However, among these species individuals standing up to eight feet tall (2.4 m) are not very rare. The maximum is about 9 feet (2.75 m) and 500 pounds (225 Kg) weight. Recoms of this size tend to develop problems with their feet if they live on full-gravity planets, and they are always more comfortable living on world with reduced gravity. Note also, these large recom species often have an increased degree of sexual dimorphism, with males being notably more massive than the females.
Flying recoms – birds and bats – are usually small. The maximum size for them is about the size of the average human, and most are smaller. Small flyers have a great advantage in the air. On planets with more Earth-like gravity (Like Annyrion at .86 g and Jalan at 2/3 g), human-sized birds and bats cannot fly, though they may be able to begin gliding at (dangerously) high speeds. The ratio of their wing muscles to their body weight just isn't enough for full flight. On lower gravity worlds such as Amazon (2/5 g), Mars (1/3 g), or Luna (1/6 g) it is somewhat easier to fly, though large wing areas are still needed to have a reasonable wing loading. The poorest fliers are recoms who gained wings from an accidentally resurfacing trait or embryonic gene manipulation, such as winged felines or canids. Their body structure does not have musculature adapted to flight.
Because of their build and the way their mass is distributed, taurs usually have shorter stature but higher mass than typical recoms. For example, the average chakat stands 5'4“ (1.6m) tall, but masses a hefty 440 pounds (175 Kg)! Despite their mass, taurs rarely develop problems with their feet on full-gravity worlds, since the mass is divided over twice as many legs.