Populations and species

This thematic program consists of the following topics:

1. Birds:

1.1. Waterbirds: Doñana is a site of great importance for waterbirds, and they were probably the main factor behind its initial conservaton status in the mid-60s and its selection as one of the two first Spanish wetlands to join the Ramsar List in 1982. Indeed, Doñana meets Ramsar’s 6th criterion (‘supporting 1% of its population’) for at least 18 species; it hosts more than one third of the Spain’s wintering population of greylag goose, Eurasian teal and northern shoveler; and it is the main wintering site in Spain for at least 15 species. Doñana also hosts large breeding populations of more than 10 species, including conservation icons such as the marbled teal and red-knobbed coot. Waterbirds were the first group to be regularly monitored in Doñana and still represent one of its main monitoring efforts.

1.1.1. Aerial censuses: Aerial censusses were the first standardized monitoring program introduced in Doñaña, with the early support of Tour de Valat. Initiated in the early 1970s, it has been carried out at monthly intervals since then. Aerial censuses are made from a small plane and cover all large wetlands (lakes, marsland, river branches and rice fields) over an area of 84.628 ha, which includes the Eastern margin of the Guadalquivir marshes and part of the Western margins included in the Doñana National and Natural Park.  Besides rare and occasional observation, 49 species of waterbirds are regularlyregistered in the census. See protocol and summary data. Request raw data.

1.1.2. Ground censuses: Aerial censuses are complemented since the 1980s by ground-based surveys of waterbirds and other non-passerine birds across the Guadalquivir marshes and other wetlands included in the Doñana Protected Areas. These surveys provide estimates of habitat use (particularly, in small wetlands such as sandy lakes), allow for the monitoring of bird species that cannot be surveyed reliably from the air (e.g. grebes, herons, purple swamphen, gulls and terns) and for the detection of rare or threatened species or rallids and ducks (such as the red-knobbed coot, marbled teal, ferruginous duck and white-headed duck). Surveys are coordinated at national level and take place five times a year, in january, april,  june, september and november.  In january, the survey forms part of the International Waterbird Census. In these surveys, all white-headed ducks are carefully observed in order to detect individuals of or potential hybrids with ruddy duck, whose presence is communicated to the Park’s authorities since they are subjected to a control program. For threatened and/or protected species, all reproductive pairs detected in the surveys are subsequently monitored fortnightly to evaluate their reproductive success. See protocol and summary data. Request raw data.

1.1.3. Colonial breeders: The main aggregations of colonial breeders are monitored regularly during the whole breeding period. This monitoting program focuses in the heronry present in the Doñana Biological reserve (pajarera de Fuente del Duque), which is monitored monthly, from february to august, using telescope observations from a predetermined set of vantage points. The surveys provide information on the number of breedind pairs, as well as their productivity (number of eggs, chicks and fledged chicks per nest). See protocol.

1.1.4. Non-colonial breeders: Non-colonial breeders aremonitored by means of horseback transect across the Doñana marsh. Transects follow a pre-defined itinerary, and the observers register the presence of nests of the different species, the number of eggs or chicks per nest, and the occurence of nest predation. Surveys take place at monthly intervals during the complete breeding season, at 5 different transects of 9.5 to 16.8 km. This protocol focused initally oncommon coot and purple swamphen, but it provides regular observations of several species. See protocol and summary data. Request raw data.

1.2. Beach and litoral birds: Doñana Protected Areas include one of the largest natural beaches in the Iberian Peninsula. Its beach represent an strategic point to survey the coastal movements of seabrids from the Atlantic and Mediterranean seas. It is also a key point in the Eastern Atlantic flyway for many Charadriiformes (waders, gulls and auks), and provides a vantage point from which to record the abundances of other migrants using the Doñana marshes as resting and feeding areas. Since 1990, the ICTS-RBD ‘beach censuses’ provide standardized estimates of the population trens of all these groups of birds. Surveys consist of observations made from a 4×4 vehicule along two predefined transects of 29 km (national park) and 23.5 km (natural park), and take place at monthly intervals. See protocol and summary data. Request raw data.

1.3. Raptors: Doñana is also well-known for the diversity and abundance of its raptors.

1.3.1. Colonial raptors: Doñana host roosting sites of three raptors, the red kite, western marsh harrier and Egyptian vulture. These sites are surveyed once a year, coinciding the International Waterbird Census, using telescope observations from vantage points. See protocol and summary data. Request raw data.

1.3.2. Breeding raptors:  Breeding raptors are intensively surveyed by the ICTS-RBD monitoring program – particularly for endangered (red kite, hen harrier) or localy rare species (peregrine falcon, black-winged kite, short-toed snake eagle, western marsh harrier, northern goshawk and Eurasian hobby). Reproductive pairs are identified and active nests monitored to asses their reproductive success (number of eggs, chicks and/or number of fledged chicks per nest). Surveys take place from march to september. See protocol and summary data. Request raw data.

1.4. Perching birds (passerines):

1.4.1. Breeding passerines: Surveys of starting passerines were initiated in 2005, but the methodology was adjusted in 2012 to the national program SACRE. In both cases, surveys took place twice a year (april-may and may-june). (i) From 2005 to 2012, distance-sampling surveys were based in visual observations over 100-m transects. They included 10 different transects situated in 5 habitat types (gallery forest, shrubland, marsh-sand grass ecotone, pine forest and marshland). See protocol and summary data. Request raw data. (ii) Since 2012, surveys are based on distance-sampling at point stations, in which the observer recordes all birds singing over a period of 5 minutes. They were reduced to 4 localities (at 4 habitat types) and based on 20 points per locality. See protocol and summary data. Request raw data.

1.4.2. Wintering passerines: These surveys are integrated in the national program of bird censuses SACIN. They take place rwice a year (november-december and january-february) and consist of transects of 4,0-5,6 km in which the observer walks for 120 minutes and registers all birds observed. See SACIN protocol and summary data. Request raw data.

1.4.3. Ringing of postnuptial migrants with constant effort: Every autumn, ICTS-RBD runs this program at the Ringing Station of Manecorro (Doñana National Park). The campaign runs for 11 weeks, from September 1 to November 15, using 21 mist nets opened from dawn to dusk. Captured birds are identified, measured, ringed and immediately released. From 1994 to date, more than 65,000 birds belonging to 106 different species have been captured (3,700 birds per campaign, on average). The most abundant species trapped are: blackcap, common chiffchaff, pied flycatcher, garden warbler, European robin, willow warbler and reed warbler. See protocol and summary data. Request raw data.

2. Mammals: Doñana is well-known for its high diversity of mammals, with 38 species that include 4 insectivores, 12 bats, 9 carnivores, 8 rodents, 2 lagomorphs and 3 ungulates – plus 2 species of seals and 14 cetaceans present in its marine part. The monitoring focuses on a number of species considered of key importance for its ecosystems (carnivores, rodents, and herbivores) – and combines a suite of different technologies, based on direct observations, tracks and signals, photographic traps and remote sensing.

2.1. Herbivores (ungulates, rabbit and hare): Monitoring of herbivore abundance combines two different approaches: (i) Annual censuses of red deer and falow deer by direct counts during the mating season (rutting), in september-october. See protocol. (ii) Vehicle-based, distance sampling of wild boar, red deer, fallow deer, rabbit and hare using 8 different line transects of approx. 15 km, surveyeds three times a year (in march, june and september). See protocol and summary data. Request raw data.

2.2. Carnivores: Doñana’s diverse community of carnivores if monitored by means of track surveys along transect on sandy substrate. Traks left on moist sand over a 24 h period are tracked in transects of 1.5 m witdh and 2 km length, from dawn to midday. The surveys include 12 different transects distributed across the National Park (see map). Only 4 of the 9 species of mammalian carnivores present in Doñana appear reguarly in these surveys: red fox, Egyptian mongoose, European badger and Iberian linx. See protocol and summary data. Request raw data.

2.3. Water vole: Surveys of water voles (Arvicola sapidus) were based on search of indirect evidence of presence (galleries and faeces)  in 48 localities comprehending the varios aquatic habitats occupated by this species in Doñana (lakes, streams, channels and marsh-dune ecotone). This monitoring program was ceased in 2014. See protocol and summary data. Request raw data.

3. Reptiles: Doñana host 21 native species of reptiles, making it one of the most important areas for Spanish reptile fauna. The ICTS-RBD monitoring includes protocols for the following groups:

3.1. Lizards and geckos: Doñana hosts 8 species of lizards , including two of conservation interest: the Iberian endemism Podarcis carbonelli and a species in accelerated local decline, Lacerta lepida. Every year, these species are surveyed year in may-june and september-october. Surveys consist of direct counts taken in 7 transects of 1015-2845 m length, located in different habitats: 3 of them in dunes, 1 in shrubland, 1 in open pine forest, and 1 in gallery forest. See protocol and summary data. Request raw data.

3.2. Greek tortoises: Doñana host one of the two only populations of this species in peninsular Spain, where they are considered critically endangered.  The ICTS-RBD monitoring program estimates tortoise abundance every second year. Surveys are made twice a year, in february-april and october, by registering the number of tracks left on sandy substrate along  10 different transects of 2.1 to 10 km length. See protocol and summary data. Request raw data.

3.3. Pond turtles: Two species of pond turtles occur in Doñana, the Mediterraena turtle Mauremys leprosa y and the Auropean turtle Emys orbicularis. Since 2008, their distribution and local abundance has been surveyed in june-july every second year since 2008. Each survey consists of 23 localities, where turtles are trapped using 3-5 collapsible nylon traps, counted, measured and released. See protocol and summary data. Request raw data.

4. Invertebrates: The biodiversity monitoring program targets also several groups of invertebrates, selected because of their ecological importance or as indicators of global change. These include:

4.1. Butterflies: Since 2014, Doñana’s ICTS-RBD contributes with 8 transects to the Butterfly Monitoring Scheme and hosts its data repository. Six of these transects were monitored since 2007 with the same methodology, thus providing longer data series. Transects, 475-710 m long and 5 m wide, are surveyed 10 times a year in march-june and september-october. See protocol and summary data. Request raw data.

4.2. Ants: Doñana’s ant community is being severy impacted by the arrival and spread of an aggresive invader, the Argentine ant Linepithema humile. In Doñana, Argentine ants are strongly associated to buildings and/ or oak trees, where they displace all other ant species. The ant monitorng program measures the spread on Argentine ant populations and its effect on native ants. For this purpose, it surveys once a year:

4.2.2. The buildings of the Doñana Biological Reserve, including the one where the first invasive population was recorded and all neighboring buildings. See protocol and summary data. Request raw data.

4.2.3. The oak trees of the heronry and grassland ecotone (“vera”). See protocol and summary data. Request raw data.

4.3. Dung beetles: Dung beetles play a key ecological role, facilitating the incorporation of nutrients to the (nutrient-poor) soils. They are also particularly abundant and diverse at the Doñana Protected Areas, owing to the abundance of ungulates and to the moderate impact of anthropogenic impacts (notably, the use of anti-parasitary drugs in free-ranging cattle) on this area. Dung beetle monitoring focuses on the two largest species, Scarabeus sacer and S. cicatricosus. From 1994 to 2012, surveys took place once a year, in spring, in 4 to 11 localities. Beetles were captured for 24 h in pit-fall traps baited with dung, counted and released. See protocol and summary data. Request raw data.

5. Flora: Together with Doñana’s National Park conservation office and Dunas del Odiel’s Botanic Garden, the ICTS-RBD team monitors since 2005 the distribution and population dynamics of threatened plant species present in the Doñana Protected Areas. These include 118 taxa  – most of them endemic species asociated to coastal oligotrophic habitats, with others associated instead to wetland habitats. The information is incorporated to the FAME database and geovisualizer. See protocols for distribution and population dynamics. Request raw data.