The Introduction of Love Birds (Agapornis) to Lake Naivasha, Kenya, and Their Effect on the Lake's Agriculture and Indigenous Avifauna
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Date
1987Author
Thompson, Jeremy J
Type
ThesisLanguage
enMetadata
Show full item recordAbstract
Fieldwork was conducted between August 1985 and June ;_986 in the
forest surrounding Lake Naivasha. The number of lovebirds was
es t imat ed by both the fixed-width 1ine-transect and mar-k -r-eccp tur-e
methods. There was good agreement between the v?rious estimn:es and
the final population estimate for 95 per cent confidence was 5942 ± 612
lovebirds. The strengths and limitations of the methods are discussed
in relation to over-or-underestimation of population size a.nd in
relation to the results of previous workers. The present work
provided a comparison of some bird census methodologies over a
medium-sized area.
Lovehirds were observed to initiate most of the avia.~ damage to
.malze at Naivasha. Their strong bill and efficient technique of
exposing kernels not only make the~ an important Dalze pest but also
allows faster depredation by other species. At present, lovebirds
have a relatively minor impact on commercial maize production SInce
most ma i ze grown at Naivasha is intende d for consrnp t i on by cattle and
harvested before being vulnerable. \'iorstdamage to ma i ze grown for
human consumption was measured in small plots f'arried on a part-time
basis. Large commercial fields we re either ade quat ely protected or
too large for lovebirds to have a significant impact.
Lovebirds were aggressed upon by many other speCIes and their
behaviour is one of retreat rather than agg res si on . Love!:lirdsmay
out-crnnpete other hole-nesting spe~les by more indirect methods
xiii
however. For example their modification and permanent inhabitation of
nesting cavities.
Primary moult was examined and no regular annual moulting
periodicity could be detected. Since primary moult is linked with
breeding, this could indicate their ability to breed at any time of
the year at Naivasha.
All lovebirds captured had intermediate hybrid characters
although biased towards the fischeri phenotype. This bias is probably
the result of an unbalanced genetic expression in plumage colouration
rather than a difference in fitness of the fischeri genotype or the
result of assortative mating.
Publisher
University of Nairobi
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Attribution-NonCommercial-NoDerivs 3.0 United StatesUsage Rights
http://creativecommons.org/licenses/by-nc-nd/3.0/us/Collections
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