If most species are large, and from small planets, they will have much stricter resource constraints than we did.

As a result, they are unlikely to have industrialized the way we did, as it would have depleted their resources too quickly. As a result, they are unlikely to be a silicon-age species.

Drawing from the author's biological/size argument, they're likely to have longer lifespans than we do, and considerably fewer births.

Given their resource constraints, and longer lifespans, they are likely to have strong communal systems of resource allocation, and are unlikely to have moved towards Capitalism.

Given their longer lifespans, they are probably more risk averse than our own species -- as willingness for an animal to die is strongly related to size and lifespan. This suggests they may be less war-faring than ourselves, and thus less likely to have nations.

Given their closer relationship with nature, due to their resource constraints, they're likely to have developed a Pagan system of thought, rather than a monotheistic theology.

As a result, they are unlikely to be motivated towards large infrastructural, imperial or technological projects as a result of: profit motive, national motive, or religious motive.

I'd argue then, that it is unlikely they have produced a civilization of significance.

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Long story short; local alien species are likely to be tribal, communist, non-technological, and environmentalist.

If through some strange force a species of this kind managed to become technologically advanced, they would likely look down on a species such as our own as a sort of vermin, because of our numbers, hunger and short lives.