Aquatic Birds Monitoring of the Northern Bank of the Sado Estuary
In 2009, Birds & Nature launched a Biodiversity and Nature Conservation Project, involving the monitoring of aquatic birds on the northern bank of the Sado estuary.
This Project was submitted to the Portuguese Institute for Nature Conservation and Forests (ICNF), following law changes on tourism activities within protected areas, including the possibility for companies to develop conservation projects.
The Project allows the collection of data/information all year round about the different aquatic bird species, with special relevance to shorebirds (waders), including information on their abundance, seasonal variation, as well as habitat changes and impact on shorebirds; in other words, the Project seeks to obtain information that will contribute to the knowledge and conservation of birds in this protected area of great ornithological importance. It is only possible to conserve what we know (monitoring in order to enable conservation). The information gathered through this Project is complementary to the information obtained by other projects, for example by ICNB, whose monitoring activities in this wetland have been concentrated in the winter months during previous years.
In practice, the Project consists of counting the aquatic birds each month, in several high-tide sheltered areas, using volunteer teams coordinated by Birds & Nature. It is not necessary to have previous experience in birdwatching and/or monitoring in order to be a volunteer; each volunteer that signs up for the Project receives specific training and is placed in a team with different levels of experience.
The Project began with the first count in January of 2010. The Project is to be continued in future years, in order that the information gathered is truly representative and complete, allowing real intervening action in the conservation of birds and their habitats in this important wetland area of Portugal.
The estuary has a great diversity of habitats including two Special Protected Areas for Birds (Sado Estuary ZPE and Açude da Murta ZPE) and the Sado Estuary Nature Reserve (RNES), with an area more than 23.000 ha. It is also classified as a wetland of international importance by the Ramsar Convention.
Although the Sado estuary includes significant populations of several species (Purple Heron, Marsh Harrier, Little Tern), the ornithological importance of this area is mainly linked to aquatic birds, of which the shorebirds (waders) stand out, including Dunlin, Avocet, Ringed Plover and Redshank, that use the estuary for wintering and for resting and foraging (stop-over areas) during the annual migration on the eastern Atlantic route.
We have to point out that during previous decades the Sado estuary has been affected, as well as many other Portuguese wetlands, by significant changes essentially due to human activities; an example of this is seen by changes in old traditional salt pan explorations, used by birds as a habitat for resting and foraging during high-tide periods.
The main objectives of this Project are as follows:
- To obtain information about the seasonal variation of the different species populations occurring in the Sado estuary.
- To obtain information about species phenology.
- To identify the areas in the estuary which accommodate the greatest concentration of birds throughout the year.
- To obtain data/information that may help to understand the impact of the different types of area previously occupied and used as salt pan extractions.
- To obtain time scale data enabling an understanding and response from monitoring birds facing changes in their habitat.
- To complement the data gathered by other projects, for example by ICNB.
- To promote volunteering in nature conservation projects.
The Project covers an area of the Sado estuary between Zambujal and Praias do Sado, divided into seven sections; each section is monitored by one team; each team has about three volunteerss, including a coordinator. Each section has a certain number of salt pan tanks, the main areas for counting birds; the use of these tanks as abandoned or actual salt pan explorations was the main criteria for choosing it as the field of study, although other areas within the estuary may be considered, for example rice fields or salt marshes, as shelters for birds during high-tides.
The total area of tanks being monitored is about 146 ha, divided as follows:
- Praias do Sado 1 section (13 tanks, 34 ha)
- Praias do Sado 2 section (6 tanks, 16 ha)
- Mourisca section (11 tanks, 39 ha)
- Limpersado section (6 tanks, 8 ha)
- Pinheiro Torto section (9 tanks, 16 ha)
- Gâmbia section (3 tanks, 25 ha)
- Zambujal section (2 tanks, 8 ha)
The fact that numerous aquatic bird species, especially waders, use the intertidal mudflats for foraging during low-tide, means that these birds are dispersed over huge areas, making it quite difficult to count them; however, during high-tide when intertidal mudflats are submerged, these birds concentrate themselves in shelter areas such as salt pans; thus during high-tides in these places, it is possible to identify and to count these birds rapidly and precisely.
One count per month in each selected shelter area is undertaken resulting in 12 counts per year. Each count is done on a Saturday, during the biggest daytime high-tide. The count time is very close to the high-tide peak, being within an hour before and an hour after the peak (assuming a count lasting two hours). Each count is done simultaneously by the four teams, each of them counting its designated area.
The monthly information obtained is processed, resulting in several analyses including by species, by month, by area, etc…
Since the beginning of the Project, several meetings have been held with the volunteer teams, as well with the ICNB. All volunteers are trained in identification methods and attend training counts in the field.
The Project is mainly targeted at waders; nevertheless, other aquatic birds such as gulls, terns, herons, flamingos, spoonbills, cormorants and ducks are also counted.
- Combatentes Team
Carlos Silva (coordinator), Carla Moura, Beth Carlão
- Milherangos Team
Elizabeth Fernandes (coordinator), Rita Lavado, Ana Lavado, Anabela Lavado
- Alfaiates Team
Amélia Almeida (coordinator), Cristina Vieira, Elisa Brás
- Pernilongos Team
Joaquim Valadeiro (coordinator)
- Project Coordination
João Jara, Bernardo Barreto, Frederico Morais
- Portuguese Institute for Nature Conservation and Forests (ICNF)
- Swarovski Optik
- Municipality of Setúbal
- Hotel do Sado (Setúbal)
Have a look at the photos at: http://www.flickr.com/groups/birds-nature-project-sadoestuary/
Birds & Nature Tours is a registered tourism company (RNAAT nº 25/2008 - Turismo de Portugal I.P.)