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CHARACTERISTICS OF URBAN ECOSYSTEM OF BARCELONA |
EFFECT
ON Peregrine Falcon |
WHY? |
| Geographical location |
Flat
relief in the north enclosed by a hill range, with hills
within the city and a coastal cliff
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The
Montjuïc cliff provides sufficient natural breeding habitat
for a pair to live.
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Sea
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The
sea as an open space is an ideal habitat for Peregrines and
more so if it coincides with migratory bird routes, such as
the case of
Barcelona
.
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Located
between two deltas
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The
natural lagoons of the Delta del Llobregat attract a great
number of birds which potential quarry for falcons.
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Climate and weather conditions |
Mild
winters and sweltering summers
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The
mild winters encourage bird species which are the basic
diet of Peregrines to winter here.
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Heat
island
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*****
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Temperatures
are higher within the city than in the surrounding areas
and this means that many birds fly in for shelter.
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Atmospheric
pollution
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*
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Nothing
is known about the levels and effects of the
bioaccumulation of heavy metals (lead, mercury, cadmium,
etc) which can enter the tissues of Peregrines through
their prey.
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Noise
and light pollution
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Little
is known about the effect of noise pollution on birdlife in
general and Peregrines specifically. Light pollution may
favour the bird as it has been observed hunting after
sunset thanks to the artificial light
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| Urban structure |
Hegemony
of urbanised area over green areas
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Green
areas are not an essential requirement for the species
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Dominant
vertical structure
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The
highest and least disturbed buildings, in imitation of
natural cliffs, are ideal points to scan for their prey and
for breeding. However, the glass surfaces of high buildings
are risk factors because of possible collisions.
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Presence
of vertical elements in the buildings
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Antennas,
cables, ventilation ducts, electric appliances and air
conditioning units on top of buildings are risk factors for
Peregrines
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Only
artificial ponds are present
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**
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The
absence of natural ponds, with their considerable
associated birdlife, limits the availability of food within
the city. The artificial ponds of
Barcelona
are not rich in diversity.
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Practical
absence of farmland within the city
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**
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Farmland,
as an open space, is an ideal habitat for hunting by
Peregrines.
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High
horizontal mobility of vehicles and people
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The
high level of horizontal mobility of vehicles and people
has no effect on the nesting of Peregrines but could have a
negative effect on their search for food by making it
difficult to capture prey close to the ground.
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Open
food cycle
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The
remains and rubbish produced by humans provides food for
many commensal species
(pigeons,
starlings, monk parakeets, etc.) which are, in turn, basic
food of Peregrines.
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| Biotic factors: fauna
and flora |
Very
low plant production
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Ecosystems
without the additional input of nutrients, and where plant
production is low, also have low animal production.
However, in an urban ecosystem this deficit in plant
production is compensated by the abundance of food remains
of a human origin, enabling a presence of greater numbers
of wildlife in the city than there would otherwise be
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A
city full of wildlife
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*****
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The
huge number of urban birds (pigeons, starlings, monk
parakeets, etc.) provides Peregrines with a large quantity
of food.
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Presence
of non-native fauna and vegetation
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Peregrines
do not distinguish when hunting between native and
non-native bird species, and so for example, the Monk
Parakeet, originally from South America and with a large
colony in the city represents a significant percentage of
the diet of
Barcelona
's Peregrines
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