[tshiggins]

I've been considering an Irari racial build. Getting the set of psychological advantages and disads right is the most important thing, I think.

I'd give them the following set as a racial feature:

Advantages
Empathy [+1] [5]
Lightning Calculator (they're just good at math) [2]
Single-Minded [5]
Versatile [5]

Disads
Chummy (Gregarious) [-10]
Easy to Read (Involuntary feather ruffling displays emotions) [-10]
Increased Consumption (Fast, bird-like, metabolism, Level 1) [-10]
Pacifism (Reluctant killer) [-5]
Selfless [-5]

Notes
The Irari race evolved from an avian species similar to pterodactyls, on a world with slightly lower gravity than Earth (0.85 G) with a slightly higher atmospheric density (about 1100 Pascals, or 1.1 atm at sea level).

The ancestor species normally lived in rookeries located in patches of woodlands that bordered more open areas, and Irari paleontologists have uncovered considerable evidence of an early mixed diet of fruits, nuts, seeds and small animals.

Prevailing theories about Irari origins indicate the early evolution of communication and language, as a natural outgrowth of the species' gregarious, flock-based survival strategy. Overt physical displays of emotional states would have enhanced communication of all sorts, and helped avoid physical violence in the close conditions of the proto-Irari rookeries.

Interestingly, the need for ever more sophisticated communication seems to have rewarded the evolution of the Irari brain, in a way that some biologists on Earth believe may have contributed to the development of the cognitive structures in the brain of Homo Sapiens Sapiens.

However, in the Irari brain, communication centers may be even more developed,and that has resulted in some fascinating traits that seem common across the Irari species.

As a general rule, Irari communicate with one another very well, and seem remarkably talented at understanding subtle emotional cues that enhance their ability to communicate, even with alien species. The Irari are highly social, seem most comfortable in large groups, and tend to compulsively seek out (or create) communities wherever they go -- even including aliens.

When in large enough groups to feel comfortable and secure, Irari display a remarkable ability to focus on even the most meticulous of tasks, and exhibit a flair for mathematics.

This tendency to prefer social living may have permitted the ancestors of the Irari to more quickly move to village life, and then to urbanization, than their human counterparts. However, this topic is subject to considerable debate.

One trait is certain, and widely acknowledged by the Irari, themselves. As a consequence of this evolutionary predilection for social existence, Irari struggle when forced to assert themselves, even when engaged in conflicts that most Homo Sapiens would consider fairly routine or mundane.

The Irari have also demonstrated even more reluctance to engage in physical violence, and when forced to do so prefer methods that allow them to emotionally distance themselves from the results. Irari who have engaged in violent activities at close quarters seem to exhibit traits that indicate more severe psychological trauma than that experienced by humans in similar circumstances.

As a result, Irari adapt very quickly and easily to live in communities created by other species, and find those created on Earth that emphasize "human" rights and social justice quite amenable.

The Irari don't really make any particular effort to assimilate into those societies, and most seem to retain their cultural identities quite well. It's just that their (to humans) pleasant dispositions and willingness to contribute means that all but the most xenophobic consider them welcome neighbors.

(As an interesting aside, Irari tend to despise cats, adore dogs, and find parrots fascinating in a weirdly creepy sort of way.)

Many human cities -- especially in the United Kingdom and its culturally similar former colonies -- now have distinct (and increasingly prosperous) Irari "ethnic" neighborhoods that replicate native cultures as much as possible. Irari biochemistry is similar enough to Earth's that they can subsist on human foods for quite some time, and even indefinitely with some easily-manufactured nutritional supplements.

Humans on Irari have reported similar conditions, there, and most of the supplements they require consist of B Vitamins not produced by native Irari food animals.

Disease and cross-contamination
The biochemical differences between the two species does provide some immunity from disease, but there are notable exceptions. Influenza affects Irari and can prove quite lethal of not promptly treated. Irari scientists work hard to develop vaccinations as quickly as possible. Irari also experience severe allergic reactions to certain species of fungus, and consumption of some mushrooms edible by humans prove quickly lethal to the avian aliens.

A similar set of Irari upper respiratory infections afflicts human beings, and a large number of them trigger cytokine storms -- an over-reaction of the human immunity system that can prove lethal. Also, a family of bacteria that cause rapid molting of Irari feathers also infects human hair follicle cells, causing permanent balding and mottled skin discoloration.

Other cross-species biological jumps are discovered fairly frequently, but most prove to be little more than temporary irritants. Still, scientists on both worlds closely monitor the health of alien guests.