The phrase "are usually spotted" is correct and usable in written English.
It can be used to describe the common occurrence of something being seen or observed in a particular context or location.
Example: "These rare birds are usually spotted in the wetlands during the spring migration."
Alternatives: "are often seen" or "are commonly observed".
Women are usually spotted with rain-smeared makeup, with bare legs in a similarly spattered condition.
The young are usually spotted in the first plumage, and there is a single annual molt.
BEMIs tend to come from customers at the edge of the market and are usually spotted first by employees at the fringe of the organization, not from those at corporate headquarters.
Insect infestations are usually spotted by the symptoms they leave on plants.
While larger space rocks are usually spotted before they sail by Earth, smaller asteroid and debris have often gone unnoticed.
Llamar Valley in the central area is a prime viewing location for elk, coyotes, and wolves (which are known to be incredibly elusive and are usually spotted only from a far distance, if at all). Dunraven Pass is at high elevation where black bears, mountain goat, wolverine, and big horn sheep are in their zones.
Thankfully, over time, this is usually spotted and corrected.
In truth, any nefarious activity is usually spotted quickly and the perpetrator blocked.
Unusual behaviour is usually spotted – but at a time when activity can be explained away as seasonally adjusted behaviour, trend analysis can be misleading.
The Black-breasted Puffbird prefers humid lowland forest below 1000 m, where it is usually spotted in pairs, typically keeping to the canopy, although in some areas it commonly follows army ant swarms, which brings it much lower above the ground.
Her instincts about comedy are usually spot-on, so it's in our interests to push ourselves and make it better.
