Bushtits exist all over the world, here in North America they are simply known as "Bushtit". They are a small insect eater. Typically travels in groups of 8 or more in my personal experience here in Southern Calforia. Their call is rather easy to identify though you may only hear a singular call or an entire group at once. I've seen as many as 40+ at one time traveling from scrub brush to scrub brush. This species can normally be seen between 2 to 6 feet off the ground on top or within various brush. Here's more from Wikipedia: The American bushtit (Psaltriparus minimus) is the only species in the family Aegithalidae found in the New World, and the only member of the genus Psaltriparus. The American bushtit inhabits mixed open woodlands, often containing oaks and a scrubby chaparral understory ; it also inhabits parks and gardens. It is a year-round resident of the western United States and highland parts of Mexico, ranging from Vancouver through the Great Basin and the lowlands and foothills of California to southern Mexico and Guatemala. The American bushtit is one of the smallest passerines in North America, at 11 cm (4.3 in) in length and 5–6 g (0.18–0.21 oz) in weight. It is gray-brown overall, with a large head, a short neck, a long tail, and a short stubby bill. The male has dark eyes and the adult female, yellow. Coastal forms have a brown "cap" while those in the interior have brown "mask." The American bushtit is active and gregarious, foraging for small insects and spiders in mixed-species feeding flocks containing species such as chickadees and warblers, of 10 to over 40 individuals. Members of the group constantly make contact calls to each other that can be described as a short spit.