Chaetura cinereiventris
Silhouette: Aviceda (vectorized by T. Michael Keesey) · PhyloPic
In 3 days <5% in a week ~10%
The grey-rumped swift or gray-rumped swift (Chaetura cinereiventris) is a species of bird in subfamily Apodinae of the swift family Apodidae. It is found in Honduras, Nicaragua, Costa Rica, and Panama; in every mainland South American country except Chile, French Guiana, Suriname, and Uruguay; in Trinidad and Tobago; and on Grenada.
The grey-rumped swift, pale-rumped swift (C. egregia), band-rumped swift (C. spinicaudus), and Lesser Antillean swift (C. martinica) were at one time placed in genus Acanthylis. Some authors have suggested that the grey-rumped and pale-rumped swifts are conspecific. Others have suggested that all of the grey-rumped subspecies except the nominate C. c. cinereiventris belong to another species under the binomial C. sclateri.
The grey-rumped swift is about 10.5 cm (4.1 in) long and weighs about 17 g (0.60 oz). It has... Wikipedia →
| # | City | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Santa Cruz de la Sierra | 🇧🇴 Bolivia | |
| 2 | Rio de Janeiro | 🇧🇷 Brazil | |
| 3 | Manaus | 🇧🇷 Brazil | |
| 4 | Guayaquil | 🇪🇨 Ecuador | |
| 5 | São Paulo | 🇧🇷 Brazil |
Rare
Under 5% of wildlife watchers report a Gray-rumped Swift sighting in Guayaquil on a given day, based on 6 verified sightings from GBIF citizen-science data. It is the 150th most-seen of the 167 birds we can rate there. Over three days the chance rises to under 5%, and over a week to about 10%, if each day is a fresh chance.
Any time of year
In every month with enough records, under 5% of wildlife watchers report a Gray-rumped Swift in Guayaquil on a given day, so our monthly data shows no clear season.
Between 3 and 6 pm
Across all the parks we cover, that three-hour window holds the most Gray-rumped Swift sightings with a recorded time, and about 9 in 10 of them come between 6 am and 6 pm: it is a daytime animal.
Among the best
Of the 5 cities where we can rate Gray-rumped Swift sightings, Guayaquil ranks 4th at under 5%, level with the leaders once rounded. The best odds are in Santa Cruz de la Sierra (Bolivia, under 5%), Rio de Janeiro (Brazil, under 5%) and Manaus (Brazil, under 5%).
GBIF citizen-science records
It is estimated from how often the Gray-rumped Swift is recorded against all the birds logged in Guayaquil (6 verified sightings), calibrated against known sighting rates. Figures are rounded to the nearest 10% because citizen-science data supports honest approximations, not decimals, and months with records from fewer than five people show "—". How it works.
