Helen and I travelled to Chobe River with CNP Safaris in March this year. That time of the year is fondly called ”the Jacana season” because African Jacanas were normally in the midst of their breeding season. This was the time when wildlife photographers would be able to see and photograph Jacana chicks with their fathers and all the fascinating behaviour that entailed.

“The river has great wisdom and whispers its secrets to the hearts of men.” ~ Mark Twain

During this trip, the Chobe River levels were considerably lower than average. Measurements of the water level of the Zambezi River at Katima Mulilo (which usually pushes water into the Chobe) were approximately four metres lower than last year. While of concern, there was some relief for the Chobe Riverfront from late rains in the latter part of May.

The level of water in the Chobe river has a distinct effect on the breeding behaviour of the African Jacanas. We saw very few adult Jacanas and even fewer chicks. A favourite place to see and photograph Jacanas, and many other species of water birds, is “Jacana alley”, a small inlet west of the Jackalberry trio (three large Jackalberry trees growing on the sandbank at the very northern edge of Sedudu Island).

We did not find any chicks in the usual places in “Jacana alley”. It looked as if the breeding had not begun in earnest delayed by the low water levels. African jacanas are not migratory, but are nomadic, driven along the river by the changing water levels.

Interestingly, there was not the usual plethora of water lilies in the inlets where we usually found the Jacanas. Water lily plant growth is known to be distinctly seasonal with plants at all water levels producing more and larger leaves and more flowers in the warmer months. Plants in deeper water have significantly greater biomass allocated to leaves and roots, while plants in shallow water around 30 cm deep have significantly greater biomass allocated to their rhizomes.

“Rivers flow not past, but through us; tingling, vibrating, exciting every cell and fiber in our bodies, making them sing and glide.“ ~ John Muir

This water lily was surrounded by what I think were water chestnut plants but I cannot find any definitive descriptive articles on it. This trip revealed a relative dearth of water lilies and a plethora of water chestnut plants with their serrated triangular leaves green above and red below.

Finding African jacana nests is difficult because they are usually, along the Chobe River, made of loosely knitted water lily stems to form a platform for the eggs and the platform is well camouflaged. One of the unusual places we found African jacanas was in the western channel past Sedudu Island close to the Chobe Water Villas on the Namibian side of the Chobe river. This was unexpected because of the high density of boat traffic along this channel. There were more lily pads probably because level of the water was much deeper in the western channel than in the “Jacana alley” inlet.

We did not get to see the polyandrous behaviour of African Jacanas. In behavioural ecology, polyandry is a mating system where one female mates with several males in a breeding season. The male must compete for the female’s attentions which he does mainly with his nest-building skills. The male mates with only one female and then takes on sole responsibility for raising the chicks. He builds the nest and incubates the eggs with no help from the female. The male is also responsible for the parental care of the chicks for around three weeks after hatching.

Well-known ornithologist, Warwick Tarboton wrote in the Ostrich, Journal of African Ornithology Volume 66, 1995 – Issue 2-3 that in the flood year, the African jacana’s breeding season was 30% longer than in the drought year, more birds bred (27–29 vs 8), more clutches were laid (39 vs 16) and hatching success was much greater (36% vs 0%). In the flood year all breeding females (n = 7) had polyandrous matings (with between 2–7 males) whereas in the drought year only two of five breeding females were polyandrous. In a drought year, opportunities for females to mate polyandrously were minimal because of the rapid rate of clutch loss and the aggressive behaviour of dominant males which prevented access of lower ranked males to breeding females.

Although we found fewer African Jacanas, we saw large flocks of Collared pratincoles. These summer migrants feed mainly in flight, catching prey aerially like swallows sweeping back and forth. The Collared pratincoles do most of its foraging in the evening or on moonlight nights. During the day they catch invertebrates on the ground such as grasshoppers, dragonflies, spiders and small molluscs. Collared pratincoles put wonderful murmuration displays which are mesmerising.

Although we saw very few African jacanas in “Jacana alley” we saw many other birds in the reeds around the inlet. We always see Malachite kingfishers hunting from the overhanging reeds. These minute fishermen look like colourful gems gleaming in the sunlight.

A Tawny flanked prinia building its nest on reeds overhanging “Jacana alley” waters. It was building a typical prinia-type pear shaped ball nest with its entrance on the one side near the top. The nest was finely knitted from lengths of grass and reed leaf strips.

“Rivers have what man most respects and longs for in his own life and thought-a capacity for renewal and replenishment, continual energy, creativity, cleansing.” ~ John M. Kauffmann

We saw many Squacco herons which were very busy in the reeds along the river’s channels. They feed in one section for a period and move frequently so as to not over work a particular area.

Squacco herons feed mainly on fish, frogs and insects which are in abundance among the reeds and grasses growing in the water.

Although, we saw many Squacco herons, we never saw any fighting like you could see when Great White egrets and other herons when they get too close to each other. Squaccos appeared to hunt in well spaced sections of the reed and grass beds.

Purple herons are secretive, spending less time out in the open than the Grey heron and tend to skulk in reed beds. Their long toes enable them to walk on floating vegetation and bushes, while not making any attempt to grip the branches. Purple herons always nest over water usually deep inside reed beds. The nest is a platform of reeds or rushes in the reedbed or papyrus, and sometimes in a tree lined with reed leaves and small water plants. Differences in habitat preference reduce competition with the reed-bed dwelling Purple heron, the dryland feeding Black-headed heron and the water’s-edge feeding Grey heron.

The Chobe River in northeast Botswana is part of the vast and interconnected Okavango-Kwando-Zambezi catchment system covering approximately 693,000 square kilometres, with its headwaters in the highlands of Angola. This region has highly variable seasonal rainfall with nearly all the annual rainfall, averaging 604 mm, occurring during the summer wet season (December–April), and minimal precipitation during the dry season (May–November).

“Life is like a river, it is always flowing, it can flow slowly or it can flow quickly, it can change course but nothing can stop the river from flowing. The same happens with life, there are no external circumstances that can stop it from flowing. One thing is sure: Life always goes on.” ~ Vasanth Pai

The Chobe River flows into the Zambezi river at the Kazungula quadripoint (where the borders of four countries meet: Botswana, Namibia, Zambia, and Zimbabwe). The combined flow cascades over the Victoria Falls about 80 kilometres down river from the Chobe-Zambezi confluence. To underline the seasonality, the peak flow over the iconic Victoria Falls is experienced between March and May. Thereafter its flow progressively drops until November when the cycle starts again. Interestingly, daily flow hydrographs, where measurements were taken at Victoria Falls, show peak flow over the Falls has been getting progressively earlier shifting from late April in 1990s to early and mid-March in recent years and the flow rate peaks have declined from over 6000 m3/sec in 1978 to just above 4000 m3/sec recently and 3600 m3/sec in 2021. The highest ever recorded flow rate over Victoria Falls was in March 1958 at 10 000 m3/sec which must have been spectacular, and somewhat frightening. Compare this to the Congo river which has an average discharge or flow rate of around 41 000 m³/sec with a peak of 73 000 m³/sec during the exceptional flood in 1962.

Explore, seek to understand, marvel at its interconnectedness and let it be.

Have fun, Mike