How many birds can be seen in a single day around the world? That question was answered on Global Big Day, an internationally coordinated bird count on 9 May 2015.
The day was perfect for the count. It was two days after a wet, cold front. The sky was clear in the morning and slightly cloudy at midday. There was a low wind and it was cooler than normal for the time of year.
We began the bird count before sunrise in the Barba Azul forest islands, recording night birds and forest dawn chorus. At around 7am, we walked out through cerrado habitat to record cerrado species. At around 8am we continued walking north into tall lightly flooded savanna where we made a two hour loop back to the eastern edge of Barba Azul Forest.
We returned to the field station for lunch and a short break. At 1.30pm we headed out on the River Omi, noting species for two hours, with many shore stops to scan for species. We walked into cerrado, forest and tall grass on the west end of Barba Azul Isla forest island. At 5pm we returned to the field station to visit close sites with known bird populations.
Three new sightings
We recorded 132 bird species and added three new species to the Barba Azul list: Collared Plover (Charadrius collaris), Pale-breasted Spinetail (Synallaxis albescens) and Mouse-coloured Tyrannulet (Phaeomyias murina). This brings the total number of bird species on the reserve to 253.
Among many notable sightings were six Blue-throated Macaws (Ara glaucogularis), which are classified by IUCN as Critically Endangered. More than 40 Blue-throated Macaws were recorded on Barba Azul in April, but on the day of the Big Count they were foraging elsewhere. We expect more than 100 in Barba Azul during July to October as these are the numbers recorded in the past three years.
We noted seven parrot species. We also saw other threatened species: six Orinoco Geese (Neochen jubata) (Near Threatened), three Sharp-tailed Tyrant (Culicivora caudacuta) (Vulnerable), and 21 adults and juveniles of the Black-masked Finch (Coryphaspiza melanotis) (Vulnerable).
The bird of the day for its tricky-to-find qualities was a perched Streamer-tailed Tyrant (Gubernetes yetapa) but we finally caught sight of it during a periodic scan of the river edge marsh vegetation.
May is the beginning of Bolivia’s winter, and two days earlier the Beni savannas experienced the first strong cold front of the year. The front brought with it some Austral migrant species from Argentina pampas and wetlands.
We recorded large numbers of some Austral migrants: more than 25 Wood Storks (Mycteria Americana), 120 Bare-faced Ibises (Phimosus infuscatus), 50 Black-necked Stilts (Himantopus mexicanus), 40 Large-billed Terns (Phaetusa simplex), and 110 Nacunda Nightjars (Chordeiles nacunda).
We did not see a single swallow although nine species of swallow have been recorded on the reserve. The majority are not residents (about half are Boreal migrants, and the other half are Austral migrants), and May is the period when they are away.
The ideal period in the Barba Azul Nature Reserve for a bird count is early September. By then Barba Azul has the full complement of Austral migrants and 11 species of Boreal migrant shorebirds, such as the Buff-breasted Sandpiper and Upland Sandpiper. Macaw numbers are also high, with both the Blue-throated Macaw and the Blue-and-yellow Macaw in their hundreds.
On Global Big Day Bennett walked and power boated six kilometres to record bird species in Barba Azul Nature Reserve in Bolivia’s Beni savanna. From 6am until 6.30pm he visited all the different habitats on the reserve: cerrado, palm forest, gallery forest, dry forest, savanna, marsh, river and a variety of aquatic environments. He was accompanied by Tjalle Boorsma, Barba Azul Nature Reserve Manager.
In 2013 WLT co-funded an extension to Barba Azul Nature Reserve with funding from the Buy an Acre appeal. WLT continues to support conservation in the reserve by funding a wildlife ranger through the Trust’s Keepers of the Wild programme.
You can help expand Barba Azul by donating to Buy an Acre.
You can support conservation work in Barba Azul by making a donation to Keepers of the Wild.
The inaugural Global Big Day was coordinated and launched on 9 May 2015 by ebird and Cornell Lab of Ornithology. In an incredible international effort in support of global bird conservation, more than 14,000 participants submitted more than 44,000 checklists from 252 countries and Antarctica. The total number of species recorded on the day stands at 6,087.