Birds are very important in agro-ecosystem as they are good indicator of agro-biodiversity. They are also
known to play various important ecological functions in agricultural landscapes. As the maximization of
crop yield is the major concern for all nowadays, birds in agricultural landscapes are generally viewed
as 'pests' to a variety of crops.
However, there are many birds which are destroyers of insect pests and rodents, and hence they are beneficial to the crops
and the farmers. Moreover, birds which damage crops (depredatory birds) may also play vital ecological
functions in the agricultural landscapes as well as in other surrounding landscapes such as wetlands, urban
or suburban and forested areas.
So, the need of the hour is to manage the depredatory birds and to conserve the beneficial birds in agricultural
landscapes. The systematic approach to the bird pest management involves correct identification of the
depredatory birds, knowing its exact economic status by drawing a balance sheet of its useful and harmful
activities, breeding ecology and population estimates which are necessary pre-requisites for evolving
effective and economical control measures.
All these studies are come under a relatively new branch of
biology called "Agricultural Ornithology".
What is Agricultural Ornithology?
The science of agricultural ornithology deals with
obtaining scientific information on birds in relation
to agriculture and using this information for the
management of birds in agricultural landscape.
The term 'birds' used in this definition can be of two
types; one is beneficial species which can act as a
potent check on pests (e.g. insects and rodents) and
the other is pest (species) which are granivorous
birds that damage agricultural crops, fruits, etc.
Management of such birds will involve conservation of
beneficial species and control of pests (species).
Agricultural ornithology in India:
India is an agrarian country with farmers making
nearly 70% of the billion-plus population. Though
agricultural bird problems in India are as old as
agriculture itself, studies in agricultural
ornithology and the other aspects of applied research
were largely ignored until early eighties.
Studies on Agricultural ornithology were started in India in 1973 on the recommendation of renowned ornithologist Salim
Ali. Since then, there has been a steady progress in the study on the role of birds in relation to crop
production.
A number of need based bird management practices for increasing crop production have been
developed for adoption by the farming community in the
country. A total of 63 species of birds belonging to
19 families have been identified to damaging several
crops.
Among the 46 species of beneficial birds, which
devoured insects and rodent pests, all fed on insects
while six of them also consumed rodents. 28 species of
birds that inflicted damages to crops and fifteen of
the beneficial species were omnivorous (see ICAR
bulletin II "Research Accomplishments of Agricultural
ornithology).
In spite of all these progress in the
study on agricultural ornithology in this country,
data on depredatory birds, beneficial birds, role of
birds in relation to crop yields, etc. from the
agricultural landscapes in the eastern India and
north-eastern region of the country are lacking.
Moreover, farmland biodiversity forms an important
part of the total biodiversity of the region. There is
tremendous lack of knowledge on the agrobiodiversity
of the region.
Bird management in India should involve controlling
the harmful species and encouraging the beneficial
ones. For these, a proper understanding of the
ecological requirements and economic status of the
birds is required.
In order to have an effective and
proper management of agricultural birds one has to
study their economic status, feeding ecology, breeding
biology and population dynamics in different areas in
relation to agriculture. Only then, one could think of
making generalizations about how to control bird
(pests).
In India, the science of agricultural ornithology is
still in its infancy. Though research in this field
has been started in various parts of the country,
there are huge gaps / lacunae in knowledge,
information and research on agricultural birds of the
northeast India.
Practically, there are very few
systematic records of birds of Manipur in particular
and north east India in general. Studies on bird
community structure in the agricultural landscapes of
Manipur are lacking.
Since biodiversity studies need
inventorying and monitoring of different taxa, in
different landscapes, studies of such kind is the need
of the hour, particularly in the virgin and
biodiversity rich area, such as the North eastern part
of India.
Moreover, in order to meet food demands of
the teeming population of the region, crop yield
should be miximised. To do so, we need to resort to
conservation, management and sustainable use of
bioresources of the region including agricultural
landscapes. Studies on proper management of
agricultural birds- which forms the core of
Agricultural Ornithology are imperative.
And evolution
of any management strategy requires knowledge on
depredatory birds' feeding guild structure, breeding
and roosting ecology.
Agricultural ornithology in the world:
Many pristine natural environments are constantly
being modified by human activities. Such modifications
of natural landscapes result in the formation of many
new landscapes such as cultivated agricultural
landscape which is basically a totally new landscape
and differs in many important respects from natural
ecosystems.
Agricultural ecosystems are young on an
evolutionary time scale even where agriculture has
been practiced continuously for more than 4000 years
as in the case of rice cultivation in India, Thailand
and Southern China.
Thus, agriculture represents an
enormous unplanned experiment on how biodiversity
responds to environmental change.
Indeed, agricultural
landscapes are excellent models for studying the
relationships between biodiversity and the habitat
templet and the importance of biodiversity for
ecosystem function.
Agroecosystem were initially regarded as degraded
environments where the impact of human inferences is
quite significant, resulting in a species poor
landscapes. Avifauna structures of such landscape were
hardly studied in many palaetropical countries.
However, recent studies in both temperate and
neotropical countries have shown that this ecosystem
can be treated as a new ecological system which has
its own distinctive biodiversity. Since agricultural
landscape has been created and managed by humans,
there is 'planned diversity'.
Thus, agricultural
landscape represent as a laboratory for studying a new
aspects of biodiversity: impact of human activities on
(avian) biodiversity and importance of habitat
heterogeneity in maintaining biodiversity. Studies in
Europe and North America show that habitat
heterogeneity is associated with higher biodiversity
in the farmed landscape.
Habitat heterogeneity has
been implicated as a key to improving and conserving
biodiversity. Recent study by the author shows the
importance of habitat heterogeneity in improving
certain landscapes such as wetlands, urban landscapes,
etc.
Role of habitat heterogeneity in improving
agrobiodiversity using birds as indicator species can
be an interesting area for research.
Birds are not a new problem as regards to agricultural
crop damage. References to damages caused by birds
have been made periodically during the last five
centuries. The havoc played by them has led to the
enactment of laws for their control in Britain since
fifteenth century.
A proper and effective management
of birds of agricultural landscapes is very much
required, given that the volume of crops losses and
damages to agricultural products caused by birds is
too enormous to neglect. Moreover, the world today is
facing an acute shortage of food.
Another important aspect of agricultural landscape is
the indiscrimate use of pesticides to increase food
yield to meet the demands of the teeming population.
The 'Silent Spring' drew the world's attention on the
health hazards of excessive use of pesticides and
suggested management solution. Before the advent of
chemical pesticides, birds did the job of scanning
large tracts of agricultural lands for pests such as
insects and rodents.
Moreover, birds are indicator of
the level of pesticides or toxicity in the
agricultural field. These make studies on agriculture
ornithology very imperative these days.
Dr. Laishangbam Sanjit, Ph.D., a lecturer in Mount Everest College, Senapati writes regularly to e-pao.net
He can be contacted at [email protected]
This article was webcasted on August 20, 2005.
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