NATURALIST'S CORNER 
Amphibians 
By JACOB MUETI 
mngwava(a)ya hoo.com 
natural HI 
history 
Venus 
. Aug 25 
4 
4 Venus 
Saturn* ^9 31 
Venus at dawn 
EVENING SKY 
By Ian Mackay_ 
Moon 
8 Last quarter; 16 New moon; 
23 First quarter; 30 Full moon. 
Stars 
Scorpius is at its best viewing 
this month. This constellation 
really resembles a scorpion, 
with bright stars defining the 
head shape and more stars 
forming the curving body and 
tail, all the way to the bright 
star Shaula in the tip of the 
sting, the likeness is amazing! 
Have a look first thing in the 
evening before it has climbed 
so high as to require excessive 
neck craning to see it. (As our 
Earth rotates towards the 
east, the stars appear to move 
slowly westward across the 
night sky.) 
Look for an unusually bright 
object with a white or bluish 
colour rising in the east- 
northeast. This is the star 
Vega in the constellation of 
Lyra, the lyre. The 
constellation Centaurus, the 
Centaur, including two brilliant 
stars, is directly south. Draco 
the Dragon, a winding line of 
stars, is directly north, and the 
golden-orange star Arcturus is 
in the northwest. 
Planets 
Mercury is visible for the first 
half of August, low over the 
sunset, before it disappears 
into the glare of the sun. 
Bright Jupiter is also setting in 
the west, but at a slower rate. 
Venus is brilliant in the eastern 
sky before dawn. Saturn, much 
less bright, is also rising in the 
east, and appears very close to 
Venus at month's end. 
Other info 
13th Aug Saturn south of Moon 
16th Aug Mars south of Moon 
18th Aug Jupiter south of 
Moon 
24th Aug Antares south of 
Moon 
31st Aug Venus just south of 
Saturn in the early morning sky 
Amphibians were the earliest 
land vertebrates to evolve. 
Their presence in an area is an 
indication of a safe 
environment, conducive to 
other creatures. The world 
populations of amphibians have 
declined markedly, a situation 
that calls for urgent attention. 
Frogs and toads are good 
weather forecasters. Their 
calls and other behaviour can 
indicate an impending rain 
season Amphibians were used 
in the first pregnancy test. 
Today some of the most 
efficient painkillers are 
derived from toxins extracted 
from frogs. In some 
communities, such as the Okiek 
or Dorobos, the toxins from 
toads are mixed with certain 
herbs and applied to 
arrowheads as a poison. 
The amphibian slump will 
automatically disrupt the food 
chain at certain levels. For 
instance some snakes and birds, 
such as Hamerkops, feed on 
frogs and toads. Frogs in turn 
feed on algae and insects 
particularly mosquito larvae, 
helping in malaria control. 
Today fewer amphibians are in 
evidence, compared to what was 
observed a decade ago. Where 
rivers pass through urban 
areas, and soluble toxic 
chemical compounds get in the 
water, they deplete the oxygen 
consequently limiting organisms 
that need dissolved oxygen to 
survive. 
Amphibians are also dependent 
on water for reproduction. 
Amphibians deposit myriads of 
eggs (in chains for toads and in 
masses for frogs) on water 
where they are accorded little 
or no parental care. After 
hatching, the tadpoles fend for 
themselves. The young toads 
and frogs can be seen at the 
edges of ponds and streams. 
A recent evening frogging trip 
to a pond in the Runda estate 
in Nairobi by members of the 
Declining Amphibian Populations 
Task Force-Kenya (DAPTF), 
revealed a diversity of frogs. 
It is possible to identify frogs 
from their calls. Calls are 
species specific. Just like 
birds, frogs can be accurately 
identified from their calls, 
even to the species level. 
Three different frog species 
(Hyperotius acuticeps, H. 
vir/diflavus, ferniquei, and 
Ptychadena mascareniensis) 
were identified at the pond in 
Runda. The intensity of calling 
points to a relatively high 
abundance of amphibians in the 
area. This is encouraging news, 
given that this is just a small 
pond in a suburban area. 
Bird Hotline 
3749957 
(July Sighting) 
Lesser Sandplovers L.Nakuru Fleur Ng'weno, Bridget 
Karanja, Rufus De Costa, Edith Wanjiru & John Kuria 
Scaly Chatterers Magadi Hoad Shailesh Patel, 
Bernard Chege & Itai Shanni 
Spotted Ground Thrush Arabuko Sokoke Forest Fleur 
Ng'weno d David Ngala 
3 
