Protocol 8 - Birds

Coordinator:
Dr. Alexandre Luis Padovan Aleixo (MPEG) • E-mail: alexio@museu-goeldi.br
Protocol researchers:
East Pará - Dr. Alexandre Padovan Aleixo (MPEG)
West Pará - Dr. Edson Lopes
Maranhão - Dr. Carlos Martinez (UFMA)
Mato Grosso - Dr. Dalci Mauricio Miranda de Oliveira (UFMT)
Tocantins - Renato Torres Pinheiro (UFT)

Groups of interest and diversity of species evaluated per grid: Birds; 300 species, 95% already having been determined.

Biological role of the group: Birds are among the most conspicuous and higher biomass vertebrate organisms in Neotropical forest environments (TERBORGH et al. 1990), functioning as pollinators and key dispersers of various key groups of angiosperms (LEVEY et al., 2005); furthermore, the ecological diversity of Amazonian avifauna (considered as the richest in the world with more than 1000 species, 265 of these being endemic) enables various species to be used as bioindicators for different environments, including those resulting from anthropic changes (OREN, 2001).

Technique 1. Qualitative survey

During the qualitative sampling, one or two experienced observers will record all of the individual birds and species that are seen and/or heard along the plot trails, within in a field notebook, including information about the types of environment where the birds were originally recorded. In the event that immediate identification of a specific type of bird proves impossible, scientific collection will still go ahead by use of a rifle or through a mist net, the collected birds then being prepared using zoological material and then deposited within the ornithological collections of the participating PPBio institutions, being identified at a later date using comparative analysis with specimens housed within the same collections. In the event that a particular vocalization emitted by a species of bird cannot be quickly and directly identified, it will be recorded. The recording will then be given a code number if the bird vocalization cannot be immediately identified after audio playback (generally providing a visual identification of the bird in question). If this vocalization is encountered later on during subsequent sampling, its code number will be taken down, together with the location of the audible occurrence within the plot and habitat in question. In previous studies carried out by the team responsible for the large majority of research, it has been possible, after various attempts, to identify these vocalizations, enabling recovery of the records of species classified as "non-identified" during the qualitative surveys.

Sampling unit: A trail segment of 1 km in length.

Sampling design: To walk along the 12 trails with the overall aim of recording all birds found through visual and audible contact. These surveys will be carried out over a period of 12 days, commencing thirty minutes before sunrise and then continuing for five or six hours; this period representing the peak of daily activity of birds, enabling detection of both diurnal and nocturnal species. Throughout the qualitative survey, a minimum effort of at least 80 observation hours will be used for every avifauna sampling sequence taking place over a 60 km stretch.

Technique 2. Census of avifauna

The chosen avifauna census methodology, i.e. quantitative surveying per listening point, is essentially the same method used by the TEAM project (BIBBY et al. 1992) at the Ferreira Pena Scientific Station (ECFPn), part of MPEG. The aim of the listening point quantitative survey is to provide an estimate of the density of bird species within the community, this method being the most complete among all of the quantitative sampling methods currently available. Each point (within one of the plots) will be sampled for 10 minutes, the following information being recorded: 1) Date and time of sampling commencement; and 2) Species and respective number of individual specimens recorded at three distance intervals from points:  0-10 m, 10-25 m and 25-50m. Whenever possible, the approximate distance of first contact with an individual specimen/species will also be recorded. Birds flying over the listening point will also be recorded, but will not be registered within the different distance categories. All avifauna quantitative samples will be taken down and recorded by the main observer’s assistant. This activity will make it possible to permanently document the avifauna quantitative samples, enabling continuous checks to go ahead in relation to data.

Sampling unit: A plot of 1 hectare.

Sampling design: A listening point will be set out inside each one of the 30, one hectare sub-plots of the main plot itself. Each day, six different points (plots) set out along the same trail will be sampled for 30 minutes before sunrise, finishing approximately four hours after the first sample has taken place, making sure that all sampling is finished by 10:00 a.m. A total of five full days will therefore be required in order to sample all 30 plots.

Technique 3. Avifauna capture using mist nets

Capture of birds using mist nets provides an overall estimate of the nature of the local avifauna, as well as providing information on the population density of the various species, this being independent of data obtained through the two avifauna sampling methods discussed above. This method is largely directed at species inhabiting the lower strata of forest environments, but can be carried out by observers with low amounts of training, in the sense that the subsequent identification of captured specimens is greatly facilitated by physical handling. The nets will be opened out immediately after dawn, monitored every hour and closed around 2 p.m. Every captured specimen will be individually tagged by cutting the tip of the wing feathers and tail, facilitating subsequent identification in the event of possible recapture.

Sampling unit: A line of 10 nets within a single hectare plot.

Sampling design: A line consisting of ten, 12m x 2m mist nets, will be set out within each of the 30, one hectare marked out plots over a period of two days, enabling a total accumulation of 160 net/hours within each sub-plot. Between three and four observers, independent of those responsible for the qualitative surveys and censuses, will facilitate operations, working every two days within 5 sub-plots of one hectare in size set out along the same trail, thereby monitoring a total of 50 mist nets on a daily basis. One day will remain free during the sampling of the two sets of five, single hectare plots, so that the 50 mist nets can be taken down and reallocated. Therefore, the logistics for this type of methodology requires between three and four dedicated observers for monitoring the activity of 50 mist nets, this being the operational design that best maximizes human resources and mist nets by the number of avifauna sampling days (n = 18).

Environmental variables: Variables, such as air humidity, air temperature, rainfall and soil classification, may be used as appropriate and depending on availability, for each one hectare plot.

Fixing and preservation of material: The biological material will be prepared as taxidermy skins or will be fixed in 10% formaldehyde. Tissue samples will be preserved in 100% ethyl alcohol. The collected samples will be deposited in INPA, MPEG and other trustworthy Amazon depository collections.

Restrictions on activities that could prejudice protocol development: In order to ensure the success of avifauna sampling within the one hectare sub-plots, the plots should not be inventoried with the concomitant presence of persons involved with other types of taxonomic groups.