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Satellite tracking Lesser Flamingo movements in the Rift Valley, East Africa: pilot study report
Abstract
The Lesser Flamingo (Phoeniconaias
minor) is thought to be highly nomadic. In East Africa, the number of
individuals on a given lake has been shown to double or halve in a period of
just two weeks. In general, interlake movements are believed to take place
mostly at night. However, movement timing and patterns for individual birds are
unknown. Between 12 and 23 October 2002, we affixed two solar-powered and two
battery-powered satellite transmitters (PTTs) to four large (>2kg) adult
male Lesser Flamingos at Lake Bogoria, Kenya. During the first three months,
the four birds exhibited markedly different movement patterns. One moved 687km,
making seven visits to four different lakes (mean stay: 11.4d). Another made
five visits to only three different lakes (mean stay: 18.5 days), travelling
only 263km. On two occasions, it remained on one lake for long periods (34 days
and 70 days). A third moved among lakes in Kenya and Tanzania 44 times,
visiting nine different lakes, spending an average of only 2.3 days at each and
travelling a total of 4 792km in the process. The fourth is believed to have
been predated on Lake Bogoria at the end of the first month. During the last
six months of the study, the most active bird settled down and the behaviour of
the three remaining birds was much more similar. They each spent long periods
of time (e.g. 45–137d) at just one or two sites. During the study period, one
bird made several short (21–81km) interlake flights during daylight hours.
Flight speed was estimated to be approximately 68km h–1 during the
only flight when speed could be calculated. Both solar-powered PTTs functioned
well; light reaching the solar panels was not impaired by feathers or dried
mineral crystals, both initial concerns. The solar-powered PTT with a pre-set ‘on/off' duty cycle performed much better than the other with no pre-set duty
cycle, indicating that small solar-powered units need substantial ‘off' time
to recharge their batteries, even in areas with 12h of sunlight daily. The key
site network for Lesser Flamingos in East Africa consists of seven alkaline lakes
in Kenya and Tanzania (Logipi, Bogoria, Nakuru, Elmenteita, Natron, Manyara and
Eyasi) and an ephemeral fresh water wetland in central Tanzania (Bahi Swamp).
The conservation status of these eight sites varies from well-protected
(lakes Bogoria, Nakuru and Manyara) to completely unprotected (Logipi, Natron,
Eyasi and Bahi Swamp), with Elmenteita being partially protected.
Ostrich 2004, 75(1&2): 57–65
minor) is thought to be highly nomadic. In East Africa, the number of
individuals on a given lake has been shown to double or halve in a period of
just two weeks. In general, interlake movements are believed to take place
mostly at night. However, movement timing and patterns for individual birds are
unknown. Between 12 and 23 October 2002, we affixed two solar-powered and two
battery-powered satellite transmitters (PTTs) to four large (>2kg) adult
male Lesser Flamingos at Lake Bogoria, Kenya. During the first three months,
the four birds exhibited markedly different movement patterns. One moved 687km,
making seven visits to four different lakes (mean stay: 11.4d). Another made
five visits to only three different lakes (mean stay: 18.5 days), travelling
only 263km. On two occasions, it remained on one lake for long periods (34 days
and 70 days). A third moved among lakes in Kenya and Tanzania 44 times,
visiting nine different lakes, spending an average of only 2.3 days at each and
travelling a total of 4 792km in the process. The fourth is believed to have
been predated on Lake Bogoria at the end of the first month. During the last
six months of the study, the most active bird settled down and the behaviour of
the three remaining birds was much more similar. They each spent long periods
of time (e.g. 45–137d) at just one or two sites. During the study period, one
bird made several short (21–81km) interlake flights during daylight hours.
Flight speed was estimated to be approximately 68km h–1 during the
only flight when speed could be calculated. Both solar-powered PTTs functioned
well; light reaching the solar panels was not impaired by feathers or dried
mineral crystals, both initial concerns. The solar-powered PTT with a pre-set ‘on/off' duty cycle performed much better than the other with no pre-set duty
cycle, indicating that small solar-powered units need substantial ‘off' time
to recharge their batteries, even in areas with 12h of sunlight daily. The key
site network for Lesser Flamingos in East Africa consists of seven alkaline lakes
in Kenya and Tanzania (Logipi, Bogoria, Nakuru, Elmenteita, Natron, Manyara and
Eyasi) and an ephemeral fresh water wetland in central Tanzania (Bahi Swamp).
The conservation status of these eight sites varies from well-protected
(lakes Bogoria, Nakuru and Manyara) to completely unprotected (Logipi, Natron,
Eyasi and Bahi Swamp), with Elmenteita being partially protected.
Ostrich 2004, 75(1&2): 57–65
