At about the same time Chat the Salvinia crisis was at its height, crayfish 
were introduced to the lake. These are voracious natural predators of many 
leech species, and are probably the most important factor in the leech decline. 
The final factor waS the introduction of Coypu. Although their importance 
compared to that of SaXvinia and crayfish is probably slight, the Coypu 
certainly helped to deplete the already retreating lily-beds still further. 
The Ewaso Narok River downstream of Thompson's Falls, Nyahururu, proved 
a leech hunter's paradise. Many different species were found in close assoc- 
iation on Che stones of the river bottom, and I spent a blissful hour squatting 
in the river anaesthetising my leeches with alcohol, picking them off with 
blunt-ended forceps and dropping them into lO;: formalin - the time-honoured 
method . 
Ecologists working on Mount Kenya have maintained a sinister silence in the 
literature with regard to Hirudinae there. My permit did not extend to the 
National Parks, and so systematic collecting on Che mountain was impossible. 
Leeches are certainly present in the Naro Moru River, however. Leech ecology 
at various altitudes on Mount Kenya would be trivially easy to study, and 
enormously interesting. 
The Methodist Hospital at Maua, near Meru, had reported several human 
casualties and fatalities caused by leeches. I went to investigate these. 
In the dry season when water is scarce, bad water is often drunk. This 
may contain minute leeches which, when swallowed, lodge in the oropharynx and 
may crawl up into the nasopharynx. 
Patients tjrpically present with anaemia, difficulty in breathing, coughing 
or sneezing blood, and understandable discomfort. Fatality, which is rare, 
and usually occurs with young children, may be a result of the anaemia, or of 
asphyxiation caused by the bloated leech blocking the trachea. Treatment is 
sometimes difficult. Occasionally the leech can be seen fastened to the back 
of the throat. It can then be anaesthetised with sprayed cocaine and removed 
forceps. In areas where this is a common problem, residents become quite 
adept at anaesthetising leeches with nicotine from chewed tobacco or inhaled 
tobacco smoke. Starvation of the patient and abstention from water is a 
ploy often used. If a dish of water is then placed in front of the mouth, 
the poor dehydrated leech will crawl forward towards the water, and can be 
seized before it can return to the safety of the oropharynx. The problem is 
not reported often from East Africa, but it is probably fairly widespread. 
Most of the Maua cases originated from the Mutuati region of the Nyambeni range, 
and involved a single species, presently being identified, which is ubiquitous 
in rivers and water-holes in the area. 
Eventually my time in Kenya ran out and I headed to England again. 
Everwhere in Kenya I encountered great ignorance of, and ironic interest 
in, leeches. Most people were unaware that there was more than one species 
of leech I 
The Hirudinae are a fascinating group and, I would suggest, are of far 
more economic importance than is generally thought. Careful farmers spend 
thousands of shillings eliminating leeches from their land, leeches kill 
thousands of fish in commercial Tilapia fisheries in Migori, human lives are 
lost in Maua, and still knowledge of East African leeches is practically 
non-existent. 
The author hopes to return to continue studies on leeches in Kenya and 
would welcome any leech records, specimens or stories, however anecdotal. 
These should be sent to the address below. 
ACKNOWLEDGEMENTS 
Hy thanks are due to St. John's College, Cambridge and to the Trustees of 
the Sir Battle Frere Travel Scholarship Fund for financial assistance. 
Also to Messrs Easton and Sims of the Annelida section, British Museum (Natural 
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