Robin or “Erithacus rubecula” is
a redbreast 14cm from beak to tip of tail 5 to 9cm high bird. The robin enjoys popularity
with man unrivalled by any other species. A familiar visitor at the bird table
in winter and constant gardening companion, even nesting in the tool shed, it
is a year round bird. This is close to association with man is a special
feature of the robin’s relationship with the British. Robins of exactly the
same species nest over most of Europe,
but a tendency on the continent to shoot and eat small birds has made robins
there generally shy and retiring woodland birds. The robin is a particular favorite
among bird lovers; everyone enjoys the attentions of this familiar redbreast in
the garden during winter. But despite all the efforts made to feed this bird in
the harsh weather, thousands perish each year.
The bird’s popularity in Britain
has built up over the years and legends about the bad luck incurred by anyone
harming a robin go back to 16th century. A Christian link has been
attached to the legends because the robin’s red breast was supposedly stained
by blood after the bird had been pricked in old books. The adult bird get
together as pairs in early January. As they look exactly alike, the sexes can
only recognize each other by display and posture. An unmated male singing
loudly in his territory will, at first behaves aggressively to any intruding
robin.
If the intruder is a male it
either retreats or tries to oust the occupier. If the new bird is a female seeking
a mate she persists in approaching the resident male, apparently unimpressed by
his threats. Over a period of some hours, sometimes as much as two days, the
bond between the two is built up so that they accept each other. In several
species this pair bounding is directly followed by nest building and egg lying.
With the robin, pairing is accomplished weeks or even months before any nesting
attempt is made. During this time the birds occupy the same territory and recognize
each other as mates but do not pay much attention to each other.
As the weather improves the hen
bird starts to build her nest, using moss and dead leaves and lining it with
hair. In the natural state she may
choose a rocky crevice or hollow of a tree, most often, a bank or an ivy-covered
tree usually well concealed and difficult to find. However some robins select
the most likely sites. One nest was found in a chest of drawers in a tool-shed.
The drawer was held closed and the nest at the back was only discovered when
the drawer was opened.
Moreover, when she starts to
build the nest the female also starts to receive food from the male. This
so-called courtship feeding was initially thought to be a ritual designed to
reinforce the pair bond between male and female. In fact it is an important
source of food for the female one that she almost completely relies upon during
incubation. The clutch of white eggs with pale reddish freckling is laid, one
egg each day, and the complete clutch is generally 5 to 6 eggs, although up to
nine have been recorded. Robins are well famous for making their nests in such
unlikely places as kettles, old buckets even the pockets of jackets left in
garden sheds. The incubating female loses the feather from her breast and belly
and the blood vessels just under the skin enlarge greatly. The bare skin and
increased blood supply allow her to transfer heart more efficiently to the
eggs.
After two weeks the eggs hatch
out and the blind chicks, covered in thin dark down, increasingly dominate the parent’s
lives with their enormous appetites. Both adult and young robins feed on
insects, spiders and worms. They do not generally eat seeds or berries. About
15 days after hatching these young robins now weighing more than their parents,
leave the nest. Two particularly attentive parents were reported by naturalist
David Lack. They built their nest in a cart which had to go on a 200 mile round
trip just after the young hatched. Undaunted, the adult birds accompanied their
off spring, feeding them on the way.
Therefore, when the young birds
leave the nest they face two or three days of great danger since they cannot
yet fly well. At this stage they have a soft speckled brown plumage with no
trace of their parents, red breast. By the beginning of June they start to lose
their body feathers and to develop their red breasts growing from the bottom
upwards. The wings do not moult but continue to develop until July of the next
year when they reach their full size. In its first year, the robin has a one in
six chance of survival. Once reach the maturity they proudly displaying its red
breast and singing its rich spring song, lays claim to its territory and warns
off other birds.
Moreover, once the young are
fledged the adult build new nest within the same territory and, unless they are
prevented for any reason disturbance by a cat, flooding of the nest in bad
weather or thoughtless hedge-cutting, will raise another brood in May. During
the summer season for a period of five weeks the adult robins replace their old
feathers with new ones they stay in the same area, but make themselves less
obvious and less active, concealed in shrubberies and thickets. During this
moult the adult robins also fall silent the only time of the year when the
robin song is not a feature of countryside.
As the second brood of young
birds acquires its red plumage and the adult birds their replacement plumage,
the autumn song starts up. The rich and fruity spring song of the males gives
way to the thinner, more piping song of young and old, cock and hen, as each
claims its own territory; this is kept with a few local alterations, through
the winter until pairing takes place. In times of real food shortage,
territoriality breaks down as all the birds concentrate on feedings. Robin migrate
each autumn, most stay within a mile or two of their birthplace. So what happened
to all these robins? If each pair of adults raises two broods with 5 to 6 young
in each, there are six times as many robins at the end of the breeding season
as at the start.
A single pair would become almost
ten million pairs at the end of 10 years about twice the total of British
population of Robins. In fact the majority of them die. As many as a million
robins may be killed by cats; while owls, cars, plate glass windows and harsh
winters also take their toll. Sadly but naturally of the original pair and
their off spring on average only one adult and one youngster survive to breed
the following year. Harsh winter weather often provides the greatest danger so
millions of people who feed birds leave out all sorts of tidbits even mine meat
and grated cheese to ensure that their robins are the ones to survive. This feeding
also encourages the robins to stay in backyards and gardens.
Almost all birds are territorial.
It is generally during the breeding season that teaches bird defends a home
area, and will not tolerate any bird of the same species apart from its male
within its territory. Robins are no exception, and like other song birds such
as blackbirds and song thrushes they stake but quite large claims by their
presence at strategic song posts. Other birds restrict themselves to much
smaller areas gannets, for instance, only defend the immediate nest area.
Moreover, the blackbird singing full of joys in
spring seasons, but much more important to itself and other blackbirds. It is saying,
this part of my territory keep off, if the message is not understood it may
still have to chase off the encroaching birds a sight often seen when disputing
birds dart at each other along a lawn or hedgerow without actually making
contact. It is both these aggressive fluttering and song patterns that prevent actual
fighting unless large numbers of birds are competing for a very small
territory.
