Private protected areas have recently attained more importance at a worldwide level as regards nature conservation. Particularly, the specific region of Western Ecuador receives hardly any protection from the State, and private reserves could, therefore, be a suitable tool to ensure the preservation of its forests and their associated wildlife biodiversity. In this work, we compare the bird species richness between private reserves and public protected areas (managed by the State) located in this region. We also show a checklist of bird species found in the Buenaventura Reserve, a private reserve located in south-western Ecuador. Our comparison shows that smaller private reserves may harbour a similar number of bird species than larger protected areas managed by the state, and they have a higher number of bird species per area. In particular, a total of 233 different bird species were registered in Buenaventura, which were distributed in 16 orders and 42 families. Three species were classified as endangered at an international level: El Oro Parakeet (Pyrrhura orcesi), El Oro Tapaculo (Scytalopus robbinsi), and the Grey-backed Hawk (Pseudastur occidentalis), and another three at a national level: the Long-wattled Umbrellabird (Cephalopterus penduliger), the Slaty-winged Foliage-gleaner (Philydor fuscipenne), and the White-vented Plumeleteer (Chalybura buffonii). Therefore, private reserves can be appreciated as a suitable conservation tool for bird conservation, and they should not be undervalued because of their smaller size. Buenaventura Reserve is a good example of how private reserves are extremely important in fragmented landscapes, as is the case with tropical forests in Western Ecuador.