Welcome to Mr Aslanov’s Lessons QUESTION-TYPE BASED TESTS Aslanovs_Lessons
TEST 8 – Saving the British Bitterns The reading passage has seven paragraphs, A-H. Choose the correct heading for paragraphs A-H from the list below.
List of Headings
i research findings into habitats and decisions made
ii fluctuation in bittern number
iii protect the young bittern
iv international cooperation works
v Began in calculation of the number
vi importance of food
vii Research has been successful.
viii research into the reedbed
ix reserve established holding bittern in winter
A . Breeding bitterns became extinct in the UK by 1886 but, following recolonization early last century,
numbers rose to a peak of about 70 booming (singing) males in the 1950s, falling to fewer than 20 by the
1990s. In the late 1980s it was clear that the bittern was in trouble, but there was little information on which
to base recovery actions.
B. Bitterns have cryptic plumage and a shy nature, usually remaining hidden within the cover of reed bed
vegetation. Our first challenge was to develop standard methods to monitor their numbers. The boom of the
male bittern is its most distinctive feature during the breeding season, and we developed a method to count
them using the sound patterns unique to each individual. This not only allows us to be much more certain of
the number of booming males in the UK, but also enables us to estimate local survival of males from one
year to the next
C. Our first direct understanding of the habitat needs of breeding bitterns came from comparisons of reed
bed sites that had lost their booming birds with those that retained them. This research showed that bitterns
had been retained in reed beds where the natural process of succession, or drying out, had been slowed
through management. Based on this work, broad recommendations on how to manage and rehabilitate reed
beds for bitterns were made, and funding was provided through the EU LIFE Fund to manage 13 sites within
the core breeding range. This project, though led by the RSPB, involved many other organisations.
D. To refine these recommendations and provide fine-scale, quantitative habitat prescriptions on the bitterns
preferred feeding habitat, we radiotracked male bitterns on the RSPB’s Minsmere and Leighton Moss
reserves. This showed clear preferences for feeding in the wetter reed bed margins, particularly within the
reed bed next to larger open pools. The average home range sizes of the male bitterns we followed (about 20
hectares) provided a good indication of the area of reed bed needed when managing or creating habitat for
this species. Female bitterns undertake all the incubation and care of the young, so it was important to
understand their needs as well. Over the course of our research, we located 87 bittern nests and found that
female bitterns preferred to nest in areas of continuous vegetation, well into the reed bed, but where water
was still present during the driest part of the breeding season.
E. The success of the habitat prescriptions developed from this research has been spectacular. For instance,
at Minsmere, booming bittern numbers gradually increased from one to 10 following reed bed lowering, a
management technique designed to halt the drying out process. After a low point of 11 booming males in
1997, bittern numbers in Britain responded to all the habitat management work and started to increase for
the first time since the 1950s.