Willow Warbler is a bird which is known scientifically by the name of Phylloscopus trochilus. These birds were known earlier by the name of Willow Wren. These birds are very common as well as wide spread leaf warblers. These can be seen breeding in the entire regions of northern as well as temperate parts of Europe as well as Asia. These birds were described in 1758 in a book called Systema Naturae by a scientist called Linnaeus. He had mentioned these birds under the genus by name of Motacilla.
The scientific classification of these birds is as given below:
Kingdom – Animalia
Phylum – Chordata
Class – Aves
Family – Phylloscopidae
Genus – Phylloscopus
Species: P. trochilus
Binomial name – Phylloscopus trochilus
These willow warblers are birds which have the habit of migration in a very strong fashion. One can see a major proportion of population of the willow warbler birds in the Sub-Saharan regions present in Africa. These are one among the first of the leaf warblers which return as soon as spring sets in, but these return only after the Chiffchaff returns.
Chiffchaff is a leaf warbler which is known scientifically by the name of Phylloscopus collybita. The Chiffchaff birds and the Willow Warbler are very difficult to be distinguished from each other.
The upper parts of the body of the Willow Warbler birds possess a greenish brown colour. The lower parts of the body of these Willow Warbler birds are bluff. These birds possess a stripe which is present on the upper part of the eyes. These stripes are pale.
The Willow Warbler looks more yellow in colour when compared to Chiffchaff. The supercilium of the Willow Warblers is longer. These birds also possess legs which are paler when compare to the legs of the Chiffchaff. The bill of this species of birds has a pale brown colour. The legs of the Willow Warbler have a colour which falls into the range of dark brown and flesh colour.
If the Willow Warbler birds are subjected to close examinations we will be able to find out that, these birds possess wings which are longer than Chiffchaff. The other major distinction is the absence of eye rings in the Willow Warblers.
During the autumn season, the young ones of the Willow Warbler birds possess a fresh plumage which gives the appearance that it is deep yellow in colour.
The Chiffchaff as well as Willow Warbler can be distinguished by the way they sing. The songs of Willow Warblers possess a melodic and rippling phrase which rises very fast before they die away slowly, Even though the calls are similar, the Willow warbler rarely sings during autumn.
The major foods of the Willow Warblers are insects. They can be seen searching for aphids on the lower parts of leaves.
The nests of these birds look like domes are made using rotten wood, moss, grass as well as roots. These nests can be seen mostly among grass or shrubs. The eggs are smooth, glossy and are white in colour. The female birds incubate the eggs. Once they hatch, both the parents feed the young ones.