Gray heron (Ardea cinerea)

Bird of great size and unmistakable appearance, the gray heron is not very numerous as nesting in the Iberian Peninsula, although it is expanding. It is, on the other hand, much more abundant during wintering and migration, when many European specimens come to our territory on their way to the African continent. During the winter, it is easy to observe these herons, both in flight and perched on the banks of rivers and reservoirs waiting for the passage of some prey, which they will capture with the help of its powerful peak

Classification: Order Ciconiiformes; Ardeidae family

Length: 84-102 cm

Wingspan: 155-175 cm

ID:
The gray heron is a large bird, the largest of the ardeidae that frequent our country, with a stylized figure, a long neck and general gray coloring, with a design that varies according to age and time of year. During the reproductive period, the head of the adults looks a white coloration and appears adorned by a black line and a pair of long feathers of this same color, while the neck, white also, is furrowed longitudinally by two parallel blackish bands (drawing 1). The long and sharp peak has a reddish hue, and the dorsal regions are mostly ashen, with a striking black spot on the shoulders. Outside the breeding season, the design is less contrasted, without the ornamental feathers of the head and with the yellowish bill. In flight adopts the characteristic position of the herons, with the neck shrunk in the shape of "S" and the legs stretched out from behind the tail, although the heron is easily differentiable from the rest of its relatives due to its large size ( drawing 2).

Singing:
Besides producing other vocalizations, fundamentally when it is in the company of other herons within the breeding colonies, it emits a very characteristic sound, like a aarj, rough and very sonorous.

Where do you live:

In the world:
The species is widely distributed throughout the Palearctic, where the subspecies cinerea breeds in most of Europe, Asia and Africa, including Madagascar. It also lives in many European regions, Africa and South Asia.

In Spain:
The gray heron is not a bird too common as a breeding in our country, where it is concentrated especially in the basins of large rivers (Douro, Tajo, Guadiana and Guadalquivir). It is also present in the Ebro delta and the lagoon of Valencia, as well as -in small nuclei- in other Catalan and Levantine localities and in the southeast of the peninsula. It is very scarce in the Cantabrian regions, which has recently colonized, while in the Canary Islands there have been some breeding attempts. During winter, the presence of this heron in Spanish territory increases notably -especially in the southwestern quadrant of the Peninsula and along the main coastal wetlands- and in the Canary Islands 3 it can be considered regular.

Displacements:
The most northern populations of the species are the only ones that carry out long-range migrations towards warmer latitudes, while the rest of the European breeding stock are considered sedentary or, at most, make movements of little amplitude. In their displacements, they choose the Iberian Peninsula as the main destination or forced passage to Africa. Consequently, in the Strait of Gibraltar every year between the months of October and November a very important migratory flow of these birds is detected. With regard to Iberian individuals, they can make dispersive movements to address other European countries as well as the African continent.

Populationon:
The European population is estimated at 210,000-290,000 couples. In Spain, which has 5,000-6,000 couples, the population trend is positive and in a clear process of expansion; In certain Spanish regions -such as, for example, the Duero basin, the lagoon of Valencia or Doñana-, the number of troops has increased considerably in recent years. It is estimated that about 86,000 individuals winter in Europe.

Habitat:
In the breeding season, this heron frequents lagoons, marshes or freshwater banks, provided they have emergent vegetation and nearby trees in which to install their nests. During the winter and in the migratory passages it is very undemanding and it is usual to occupy all kinds of wetlands, natural or artificial (rice fields, salt marshes, irrigation channels or rafts of fish farms), as well as pastures, meadows or beaches.

Feeding:
Although its basic food is the fish -in general, of good size-, the opportunistic nature of this heron leads it to include in its diet a great variety of vertebrates (amphibians, reptiles, chickens of other birds or small mammals), crustaceans , molluscs, earthworms, large insects and even plant matter. The most common hunting technique used is to remain motionless, on the prowl, next to the water, until some of its possible prey passes; Once localized, after a sudden movement of the neck, the clamp with the beak to swallow it.

Displacements:
The most northern populations of the species are the only ones that carry out long-range migrations towards warmer latitudes, while the rest of the European breeding stock are considered sedentary or, at most, make movements of little amplitude. In their displacements, they choose the Iberian Peninsula as the main destination or forced passage to Africa. Consequently, in the Strait of Gibraltar every year between the months of October and November a very important migratory flow of these birds is detected. With regard to Iberian individuals, they can make dispersive movements to address other European countries as well as the African continent.

Reproduction:

1475/5000
During the breeding season, the gray heron shows a very gregarious character and nests in colonies that are joined by other species of herons or even storks. The most common sites for these groups -in which there is a total hubbub- are the small riverside groves, as well as the forests close to a wetland. In mid-February, when the nuptial plumage looks, male and female go to the colony and begin the reconstruction of the nest they used in past seasons with the necessary contribution of sticks and branches. After a ritualized courtship-in which contractions of the neck dominate and vocalizations are frequent-the couple concludes the platform, which
upholstered with herbs and leaves; in it deposits the female of three to five eggs of green or pale blue color, which are incubated by both adults
for 25-28 days, usually since the first one. 4 Chickens are able to move around the nest within a few days of birth, although they will continue to depend for a while on the food provided by their parents. After 45-55 days, with the
plumage fully developed, the young herons are already able to fly.
Months in which the species can be seen in Spain
JanuaryFebruaryMarchAbrilMayJuneJuliusAugustSeptemberOctoberNovemberDecember
This section is an adaptation of part of the Encyclopedia of the Birds of Spain, edited by SEO / BirdLife and the BBVA Foundation in 2008

Threats and Conservation:
The main problems for the species are related to the fluctuations of the water levels of the wetlands, the scarcity of places
of nesting and the potential direct persecution by fishermen. The gray heron is included in the category "Of special interest" in the Catalog
National Endangered Species
Months in which the species can be seen in Spain
JanuaryFebruaryMarchAbrilMayJuneJuliusAugustSeptemberOctoberNovemberDecember
This section is an adaptation of part of the Encyclopedia of the Birds of Spain, edited by SEO / BirdLife and the BBVA Foundation in 2008.