Certhia brachydactyla

Certhia brachydactyla

The short-toed treecreeper (Certhia brachydactyla C.L.Brehm, 1820) is a passerine bird belonging to the Certhiidae family.

Systematic –
From a systematic point of view it belongs to:
Eukaryota domain,
Kingdom Animalia,
Phylum Chordata,
Subphylum Vertebrata,
Aves class,
Subclass Neornithes,
Superorder Neognathae,
Order Passeriformes,
Suborder Oscines,
Passerida infraorder,
Superfamily Certhioidea,
Family Certhiidae,
Genus Certhia,
Species C. brachydactyla.
The terms are synonymous:
– Certhia brachydactyla subsp. bureaui Jouard, 1929;
– Certhia brachydactyla subsp. parisi Jouard, 1929.
The following subspecies are recognized within this species:
– Certhia brachydactyla megarhynchos Brehm, 1831 – widespread in an area that goes from northern Portugal to north-western Germany;
– Certhia brachydactyla brachydactyla Brehm, 1820 – nominal subspecies, present from the Iberian peninsula (except the northern coastal strip) to the south-west of Lithuania and Turkey, including Italy;
– Certhia brachydactyla mauritanica Witherby, 1905 – endemic to the Atlas Mountains, from central Morocco to north-west Tunisia;
– Certhia brachydactyla dorotheae Hartert, 1904 – endemic to Crete and Cyprus;
– Certhia brachydactyla rossocaucasica Stepanyan, 2000 – endemic to the north-western Caucasus;
– Certhia brachydactyla stresemanni Kummerlöwe & Niethammer, 1934.

Geographic Distribution and Habitat –
Certhia brachydactyla is a bird that inhabits Eurasia (except in the Scandinavian peninsula) and the Northern Islands; in the south it can reach as far as northern Africa.
This species is widespread in much of Europe (from the Iberian peninsula to western Ruthenia, as well as in Hungary, in the western and southern portion of the Balkan peninsula and on the coasts of Turkey, as well as in the Caucasus) and along the coasts of the Maghreb. In Italy the species is present in the foothill areas of all regions, excluding Sardinia.
Its habitat is represented by deciduous or mixed forests but with a prevalence of broad-leaved trees, possibly primary and well mature (but also parks and city gardens), with the presence of large trees with split bark, avoiding instead coniferous forests: while in central Europe it inhabits the plain areas, in the south of its range the treecreeper is a piedmont and high hill species, and can be observed up to 2000 m above sea level.
It is a sedentary species, whose populations, during the reproductive period, can rise to altitude from the warmer areas to find the environment favorable to nesting, represented by areas with an isotherm between 17 and 26 °C.

Description –
Certhia brachydactyla is a passerine with a length of approximately 12.5 cm, a wingspan of 19-20 cm, for an average weight between 7.5 and 11 grams.
This bird has a plumage that is dark brown on the upper part with whitish spots and streaks, while on the lower part it is white with brown sides. This coloration gives this bird an extremely camouflage appearance, so much so that if it stands still it cannot be distinguished against the background of a bark.
The livery tends to become more reddish-brown as you go from west to east.
The wings have a darker scapular area and golden-brown flight feathers with a darker base: the tail and undertail are also of the latter color, while the throat and chest are white and the eyebrow is beige, delimited at the bottom by a brown facial mask that starts from the sides of the beak and joins the brown of the nape.
It has a plump and rounded appearance, with a large pear-shaped head, which is rounded at the nape and elongated in the direction of the beak; this seems to be recessed directly into the torso.
The beak is rather long and thin, curved downwards; it also has a blackish upper mandible and a pinkish-orange lower mandible.
The eyes are dark brown.
The wings are pointed and the square tail is rather long and has stiff and strong feathers.
The paws have long clawed toes and are flesh-colored.
The eggs are subelliptic with an opaque surface and a creamy white color with reddish-brown specks more concentrated towards the less pointed end.
The call of these birds is high-pitched and composed of four short notes, reminiscent of the creaking of a metal wheel.

Biology –
Certhia brachydactyla is a bird whose reproduction begins at the end of March and lasts until June.
These are monogamous birds (although males may exhibit polygyny, with females sometimes nesting together).
It always nests sheltered from bad weather in tree trunks, in deep cracks or under strips of peeling bark, generally low above the ground. It normally builds its nest in holes and cracks in trunks, among ivy or behind large pieces of bark.
The cup-shaped nest is built by weaving twigs, blades of grass, pieces of bark, spider web and pine needles and lining the inside with down, fluff and lichens.
It very rarely uses typical nest boxes for young birds (<0.5% occupancy). Here it nests twice a year (between 3 and 6 eggs for each laying). The number of eggs does not vary between the first and second clutches and the eggs are hatched by both spouses. Egg incubation lasts, on average, 14 days. Hatching success is around 90% and the percentage of chicks leaving the nest is high, around 98% of eggs hatched. The female lays the eggs which she hatches on her own (with the male remaining near the nest and taking care of finding food for himself and his partner) for about two weeks: the chicks are blind and featherless when they hatch, and are fed by both parents (although only the female takes care of them, with the male solely responsible for bringing the food). The young are able to fledge between two and three weeks of age: however, after fledging they remain at the nest for a few more days, sleeping with their parents (who in the meantime are generally preparing to carry on another brood, building a new nest), following them in their movements and asking them (especially the females) more and more sporadically for their food, before moving away definitively just under a month after hatching.

Ecological Role –
Certhia brachydactyla is a sedentary bird that loves to frequent gardens and groves, where it climbs trunks and branches, and is very linked to the broad-leaved environment, especially along watercourses, although it is sometimes found in woods of conifers. Sometimes it also stays on cultivated land.
It has diurnal and generally solitary habits, although it can also be observed in pairs; they spend most of the day looking for food, flying to the base of a tree and traveling in a helical manner along the entire trunk and branches, before eventually moving on to the next one.
It is an insectivorous bird, which uses its long curved beak to inspect the cracks and cracks in the bark and holes in the trunks in search of small insects, larvae, spiders and other small invertebrates, which make up the majority of its diet. During the colder periods, these birds can also feed on seeds and grains.

Guido Bissanti

Sources
– Wikipedia, the free encyclopedia.
– GBIF, the Global Biodiversity Information Facility.
– C.Battisti, D. Taffon, F. Giucca, 2008. Atlas of nesting birds, Gangemi Editore, Rome.
– L. Svensson, K.Mullarney, D. Zetterstrom, 1999. Guide to the Birds of Europe, North Africa and the Near East, Harper Collins Publisher, United Kingdom.

Photo source:
– https://observation.org/photos/62207172.jpg