Passerines (ord. Passeriformes)
It is a very large order to which they belong mostly small birds, except for the Corvidae family that includes larger birds.
In the examined area, 91 species have been reported, many of which are migratory; among the 44 species that reproduce in the area, some are located and present with few couplesonly.
The passerines observation in nature is not always easy and many birds, even if present, may go completely unnoticed. So become fundamental the censuses carried out during the breeding season, when all the nesting species can be identified, as well as direct observation, including song listening that is often the best way to locate them.
Outside the breeding season, especially during migration, many species can only be identified using the capture. In this case it is very effective of so-called "Japanese networks" or "mist nets" that allow the bloodless capture of small birds and their subsequent release after being fitted with special metal ring that, in the case of a subsequent recapture, can provide important data for the study of migrations.
Here are described some of the most characteristic species, specially chosen from among those nests in the resurgences area.
MOTACILLIDI (fam. Motacillidae)
The grey wagtail (Motacilla cinerea) is primarily a sedentary and breeding species, but probably also a regular migrant and winterer. It is very common across the plains and can be observed particularly along the main rivers; locally it is also present in the fish ponds. It attends cool, shady and sheltered places. The nest is usually built near running water and on slopes with rich vegetation ravines. Occasionally it can exploit the presence of artefacts such as stone embankments, retaining walls and old bridges. The first depositions occur in the month of April; first young can be observed in mid-May. Usually two depositions are carried out annually. Outside the breeding season the species may take more or less pronounced erratic. It can attends the villages, especially during the winter months.
The white wagtail (Motacilla alba) is sedentary and nester, but also regular migrant and winterer.
More frequently of the previous species, it is widely distributed over most of the region and extremely adaptable to different environments.
It can be found on the banks of rivers and canals, in the cultivated areas with scattered buildings and artefacts, within the quarries, in open wooded areas.
It is more common in areas with the presence of water, but it is less tied to humid environments than the grey wagtail. The earliest play are observed during April and may continue until August. Generally it makes two broods a year. Winter wandering interests at least a part of the local population and is also likely the transit of difficult to quantify migratory birds.
During the winter period it can build common dormitories, often consisting of several hundred individuals in urban and suburban areas, often located on evergreens.
THRUSHES (fam. Turdidae)
The robin (Erithacus rubecula) is a small thrush, known to all for the unmistakable plumage and the confidant behavior with man, in particular during the winter when it is present even within the towns. It is a regular winterer and migrant species.
During the winter period it is widespread across the plain. Its spring migration begin in March and reach the peak between the end of the month and the first week of April. The post-reproductive migration beginsin mid-September. In the region transit especially migrant contingents from Central and North America.
It nests mainly in wooded mountainous areas, but locally, even in the plains. In the resurgences area it is located during the breeding season.
Few couples nest using strips of woods and thickets, especially the more humid, shady and cool with thick undergrowth. It begins to reproduce at the end of April, probably with two broods per year.
Among other species of nesting turdies can be reported the blackbird (Turdus merula) and the rufous nightingale (Luscinia megarhynchos) which are the most common and widespread; much more localized is the stonechat (Saxicola torquatus) and the common redstart (Phoenicurus Phoenicurus).
At one time it also reproduces the mistle thrush (Turdus viscivorus), which in recent years has not been surveyed during the breeding season.
TRUE WARBLERS (fam. Sylviidae)
The Cetti’s warbler (Cettia cetti) is a predominantly sedentary species or at best erratic, all year round, but perhaps even partially migrant, over short distances.
It is not easy to observate, usually the unmistakable strong sound help to mark its presence. It has a fairly uniform distribution in the affected area but with considerable annual fluctuations because the very cold winters may strictly select the resident population.
This warbler prefers build its nest on banks of streams and ditches with intricate riparian vegetation characterized by dense herbaceous cover (reed, sedge, etc..) mixed with shrubs. It can sometimes nests in areas of reduced extension, also close to urbanized areas or in degraded areas.
The breeding season begins around early April and may have also two depositions.
The marsh warbler (Acrocephalus palustris) is regular migrant, breeding in summer and quite common, once more common. Outwardly it is very similar to the European reed warbler (A. scirpaceus) and it is recognized in nature especially through its sing.
During the breeding season the marsh warbler is closely linked to the presence of cane thickets in water-rich areas.
The marsh warbler rather frequents dry environments with dense coverage of tall grasses mixed with shrubs and bushes and is less dependent by the presence of water. During the spring, the first individuals arrive in the first half of May. Post reproductive migration begins inlate July and continues until early October.
The common chiffchaff (Phylloscopus collybita), within the reseurgences area is a regular migrant and present during the winter, but not evenly distributed; it is localized as summering and nesting.
The fall migration begins in mid-September and reach the maximum intensity in late September and October. The first migration in the pre-reproductive period are reported in February-March.
The nest sites are found in bushy areas at the edge of woods, meadows and woodlands with clearings with abundant herbaceous vegetation.
The depositions can begin in late April and continue until June. Maybe even two broods. It was verified the wintering of individuals belonging to the Siberian subspecies tristis in recuded number but regularly present.
TITS AND CHICKADEES (fam. Paridae)
The blue tit (Cyanistes caeruleus) is fairly common during migration (late September to November and March/April) and wintering, when it can be observed in various types of environment; it plays mainly in the mountainous region.
Once a highly localized as nesting across the plains, in the last decade has reported an increase of the population that breeds in lowland environments. Even in the Stella resurgences was noted an increased presence of this tit during the breeding season, when the couples present are located in wooded areas not too dense and full of old trees with cavities suitable to accommodate the nest.
It can also nest in old parks in residential areas. The deposition began in April with probably even two broods a year.
It also recalls the great tit (Parus major) that among titis is the most common and widespread species. It is mainly sedentary, but also regular migrant and winterer.
PENDULINE TITS (fam. Remizidae)
The penduline tit (Remiz pendulinus) can be considered regular migrant and winterer, very localized as nester in few stations within the region; it is in marked decrease in recent years.
Until the 80s it was quite popular as breeding in all areas of resurgences, which was not unusual to find the characteristic nest-shaped bag hanging from the branches of willows and poplars along the waterways. From recent surveys conducted in different environments suitable for reproduction in which the species was once present, it is emerged that one of the most characteristic birds of the wetlands of the plains has almost disappeared from our region as a breeding species.
It is still observed during the migration, especially in coastal environments with the presence of large reeds. The post-reproductive migration (a time particularly evident with substantial flocks that were standing in the reeds at the river mouths, but also in inland wetlands of small extension) start in late September or early October and can continue until mid-December.
The return to the spawning areas (north-eastern and central Europe) begins at the end of February and continues until mid-April.
ORIOLES (fam. Oriolidae)
The European golden oriole (Oriolus oriolus) is a regular migrant, widespread in all wooded environments of the lowlands of the region.
The first arrivals are recorded at the end of April and the migration continues throughout the month of May. The post-reproductive migration begins in August and continues until mid-September.
It nests in all suitable environments, with the presence of tree cover, although modest extension. It is not always easy to observate because it lives among the tall treetops; it is typically located through its characteristic song.
It is unmistakable even for the plumage that, particularly in the adult male, is bright yellow with wings and tail black; females and young plumage is less showy. The nest, shaped like a hammock, is secured to the bifurcation of the lateral branches of the trees.
It is fairly evenly distributed in the resurgences area where it can also colonize older poplars planting. The first depositions are observed at the end of May. The first fledged young can be observed at the end of June; usually only one brood.
SHRIKES (fam. Laniidae)
The red-backed shrike (Lanius collurio) is a regular migrant, nester and summer species. The first arrivals are recorded at the beginning of May and the transit of migration continues until the end of the month. The post-reproductive migration begins in late July and continues until mid-September.
It breeds widespread but not evenly distributed in the lowlands. Usually it is fairly localized or absent in intensively cultivated areas. It nests in open places with low trees and shrubs.
The nest is often located at low altitudes on young plants. The first deposition is generally the end of May. Probably only one brood.
At one time more common, in recent decades it has been adversely affected, locally more marked, by the use of pesticides and by modern farming techniques that have reduced its suitable habitats.
CORVIDS (fam. Corvidae)
The Eurasian jay (Garrulus glandarius) is a sedentary and breeding species. It is widely distributed in much of the region, in areas with tree cover of various types. Among the corvids present in the resurgences area, it is the most arboreal species and related to the presence of wooded areas, although of limited size. It has secretive habits during the breeding season when are often observed as isolated pairs.
It is more easily observable in the autumn-winter period when it can also form small "noisy" groups that frequently emit lines and calls when they move in search of food. The depositions are generally in May, more later nests are probably due in replacement clutches.
Among other species of corvids is also the black-billed magpie (Pica pica) and carrion crow (Corvus corone). Both are permanent and particularly widespread and common across the plain. In the resurgences area are not evenly distributed, especially the magpie that is found only in the most open environments with little tree cover, at the edges of cultivated areas.
TRUE FINCHES (fam. Fringillidae)
The chaffinch (Fringilla coelebs) is considered a regular migrant and common winterer of the resurgence area. Locally it is even nester.
It is particularly related to the woodlands, but it is very suitable when it choose its reproduction habitat. In environments of plain it can be found in both deciduous and woods, in parks and gardens, orchards, roadside trees, etc.
it is present alsowithin large population centers.
In the resurgences area it nests even completing two annual broods in different sites, usually in the woods and glades with the presence of sparse woods, starting from the month of April.
The post-reproductive migration begins in mid-September and lasts until late November, in the winter can also be very large groups.
Often, for the search for food, it joins with other finches (bramblings, linnets, goldfinches), and with passeridi emberizidae passerines.
The migration takes place in February and March.
EMBERIZIDAE (fam. Emberizidae)
The yellowhammer (Emberiza citrinella) is relatively popular as breeder in the Apennines and the Alps up to 2100 m and it is present, even if locally, in different regions of the Po Valley. In Friuli region it is still quite common in mountain valley and in different environments such as alluvial forests, lowland forests and wetlands resurgences.
In the resurgence environments it is sedentary and breeder but even migrant and regular winterer, perhaps in slightly decrease in recent years. During migration and wintering it mostly attends open plains where it can form mixed groups with other emberizidae and finches.
In the breeding season it is localized in open areas with shrubs and often with hedges and isolated trees. The depositions begin in April; typically it have two broods.
Among other buntings reported in the resurgence area there is the corn bunting (Emberiza calandra) that records a decrease in most ofEurope; was once it reproduces in the wet meadows at the edge of the bog, now it is present as very localized nester in some surrounding areas with grass and cereal crops or uncultivated areas with low vegetation.
The environmental restoration work carried out by the Regional Administration could help the re-nesting of this species.
The reed bunting (Emberiza schoeniclus) is a species reported during the migration and one of the most widespread and abundant during the colder months.
The transiting and wintering populations belong mainly to the nominal subspecies (or "nose end") which reproduce itself in the northern and central regions of Europe.
In the resurgences area it attends a wide range of environments, not necessarily wetlands, such as arable fields, uncultivated areas, ditches, etc.
In the peat bogs they form night-crowds, sometimes composed by hundreds of individuals, who can share the environment with other species (such as the pipit).
Lastly the rock bunting (Emberiza cia), not very frequent in winter and during migration and the cirl bunting (Emberiza cirlus), a species reported in the past during winter migration only that from several years records a growth as breeder at regional level.