In this article we will discuss about a few other behaviours, including flocking, defence and survival, adaptation to climate change, and self-care.
In
this final article in a series of five, we will discuss about a few other
behaviours, including flocking, defence and survival, adaptation to climate
change, and self-care.
• Flocking
Some
birds prefer to stay alone, while some others prefer to stay in groups. This is
called flocking. The number of birds in the group vary according to the
species. Sometimes, especially in temperate countries, several species of birds
flock together, for protection as well as efficient feeding.
Birds are actually quite social beings. They often have many interesting interactions within their flocks. Some flocks have clearly dominant individuals, while others comprise of equal members.
Despite belonging to flocks, birds can become quite territorial, especially in breeding season. As we saw earlier, birds sing to establish their territory. If other birds (of the same species) do not heed this warning, then fights break out.
 |
| A congregation of black-headed ibises ©Bhavana |
• Defence and Survival
As
with any other organism, survival is important to birds as well. Although
larger flocks may draw the attention of predators, it does have its advantages.
- Sentry duty: Large flocks often have a bird on sentry duty. This bird is responsible for keeping an eye out for predators and other possible threats. When a threat is detected, it will sound the alarm.
 |
| Camouflage of a tailorbird nest ©Bhavana |
 |
| The plumage offering camouflage ©Bhavana |
While
discussing about survival, it is important to talk a little bit about bird
language.
Bird language is an important aspect in the communication of danger. Just like we, humans, have a verbal and nonverbal aspect in our communication, birds too, have vocalisation and body language. Together, these make the bird language.
Bird
language is important because it can help to not only track a bird, but to also
ensure our survival when we’re out in the wild. Bird language does not merely
say that there is a danger. It also conveys the nature of the predator, whether
it is just passing through or hunting, how fast it is moving, has it spotted
anyone close-by, etc. A good example of this that we can observe in our
surroundings is the behaviour of the babblers when there is a snake nearby.
Interpreting bird language is not easy. It requires patience and practice.
• Adaptation to climate
change
First,
we’ll look at the natural change in climate, during the different seasons.
In temperate countries, as winter approaches, some birds prepare by storing food, and changing their plumage. These birds will spend winter in those places. Some other birds, however, travel to warmer regions for that duration. This is migration.
The distance of migration varies for different species, with the artic tern having the longest distance travelled - from the artic to antarctic!
When to migrate - or the timing of migration, is decided by the ‘annual internal clocks’ that birds have. Where to migrate, however is a little different. For some species, it is clearly proven that where to migrate is actually determined genetically, while for other species, the birds learn during their first migration, from tutors (usually other birds of the same species).
Migratory birds fly a great distance, with very few rest stops. How is this possible? To make this easier, they fly in certain formations. These flight formations are known as ‘echelons’. The common formation we see are the V-shaped formation and the J-shaped formation. Although they are spectacular to look at, these formations are not for aesthetic purposes. These formations make flying long distances more efficient, as they reduce the energy utilised by the birds, by reducing the air resistance that the birds have to encounter. Some birds use air current to their advantage and glide along to their migration destination, without have to flap their wings too much.
Now,
a few words about how birds are adapting to global climate change. This is a
vast topic in itself, and what is given below are just two examples.
-
Birds
are now being forced to breed earlier due to the climate change. Although many
birds have adapted to this, some haven’t. If this persists, some of the birds
belonging to this latter group can eventually become extinct.
-
With
increasing temperature, some birds living in mountainous areas are found to be
moving further and further uphill. This is reducing the range of these birds,
and it is becoming difficult to spot them in lower altitudes.
It is clear that the climate change is having a huge impact on birds.
• Self-care
These
behaviours help maintain the health of the bird. The main self-care behaviour
is called ‘preening’. The major part of preening is taking care of the feathers
by removing the dirt, dust and parasites. The birds also align the feathers in
optimum position, not only for better aerodynamics, but also for better
protection against the forces of nature. Most birds have a gland near their
tail called the preen gland (uropygial gland). This gland secretes an oily
substance that the birds spread to all their feathers when preening. This
substance helps waterproof the feathers and keep them flexible. Some birds,
like the parrot, owl, and pigeon, do no have these glands. The feathers of these birds break down into a
powdery substance called ‘powder’ down, which has a similar function as that of
the preening oil.
Interestingly,
there is a behaviour known as allopreening, in which mates preen each other.
This is thought to improve their bond. Eurasian spoonbills, which can be seen
in Jaffna during the migration season, engage in allopreening.
- Bathing: There are two types of bathing - water bathing and dust bathing. Many song birds engage in water bathing, which helps them to get rid of parasites and dirt. Smaller birds, like the tailor bird, can be seen bathing in the water collected on large leaves after a rain. Birds like the sparrows engage in dust bathing - they roll around in the dust. This not only removes parasites, but also absorbs the excess preening oil.
 |
| Drying ©Bhavana |
 |
| Preening (painted stork) & Sunning (grey heron) ©Bhavana |
 |
| Dust bathing ©Bhavana |
In conclusion:
Each species of birds have their own unique behaviour profile. In the beginning, it was discussed how each behaviour serves a purpose. The birds gain something they need due to their behaviour. What they get from their behaviour is their reinforcement - the motivation for them to continue that behaviour.
But what happens when something they do, even something they regularly do, caused harm to them, or disturbed them? They are less likely to engage in that particular behaviour (in that place) again.
COMMENTS