The Luangwa Valley stretches like a giant arm along the Eastern part of Zambia. This vast and unforgiving wilderness, partially protected within the confines of the North and South Luangwa National Parks, does not enjoy a brutality-free history but having survived most of the ravages of man’s exploits (all except the rhino!) remains today as one of Africa’s last. A side branch to the renowned Great Rift Valley, the flat-bottomed Luangwa Valley harvests the fertility washed down from her mother feature and with the provision of copious annual summer floods, consequently supports an inordinate abundance and diversity of life. Water gushes down a 200m wide snaking channel, over spilling its meandering banks to replenish numerous oxbow lagoons and watering the adjacent pastures. With so much surface water and the fertility of the Rift’s clay soils, the valley erupts in a summer harvest of incredibly high plant biomass which in turn supports a high biomass of herbivores including 3 endemic species - Crawshay’s zebra, Thornicroft’s giraffe and Cookson’s wildebeest. The valley consequently is alive with predators – lions, leopards, crocodiles.
Uncommon of most African rivers, the Luangwa River respects her political boundaries, rising in the highlands of Zambia’s northern frontier and terminating at the junction with the Zambezi on Zambia’s southern boundary. This spectacular river is home to the largest population of hippos in the world, and the entire ecosystem is dependant on her, the only river in the valley. And this is a vital characteristic of the Luangwa for although it is a fat and snaking river during the summer rains, Luangwa is a place of extreme seasonal contrasts and when the rain ceases, the river shrinks progressively into the dry months, eventually becoming a mere trickle interlinking deeper channels as temperatures soar into October. With the oxbows dried up and all other ephemeral water in the valley gone, creatures journey huge distances to the river for relief from a dementia-inducing time of dust and hardship – now certainly dependent of the only river in the valley. Interestingly, most creatures here exist in a smaller physical form than in the rest of Africa due to the isolated nature of the Valley, hemmed in by escapements formed by ancient tectonic movements and comparatively less fertile tracts of Miombo Woodland that extend beyond the Valley’s limits creating a relative biodiversity vacuum.
For the mega-population of hippos, ancient pig-relatives Hippopotamus amphibious, the Luangwa is patch of real estate extraordinaire! Luangwa houses an estimated 30000 hippos along its 1100km course - the biggest population anywhere in the world and so in the dry months, a shrinking river is not good news! The wide sandy beaches exposed by the retreating water, become a battleground for the hippo. For the top predators – lions and crocodiles - it’s a feast guaranteed!
So spectacular is the size of the Luangwa hippo population that any visitor to the valley can expect to count at least 80-100 individuals at any random point that one should choose to stop and tally. This in itself is remarkable but more so if one considers that the population was almost annihilated before the area was protected. In 1918 a hippo sighting was considered a significant one! But that really is a thing of the past and the numbers are staggeringly obvious when the river is at its lowest in late October into November.
Hippos seem to favour the quiet oxbow refuges and lagoon-flanked stretches of river as it is here that they can easily access the lush grass from the alluvial areas surrounding the floodplains. But after May, these choice habitats are no longer available, shrivelled to chunks of caked-mud in the heat, and with no where else to go, hippos migrate en masse to the deeper pools in the wide river channel. Survival through these times is a severe ordeal. Here they are vulnerable to the scorching sun and to the wrath of the resident bulls, irritated that their turf is being invaded by the competition. The deeper pools amongst exposed sandbanks are prized territories and conflict is the order of the day!
Enormous in size and decked with formidable canine-like tusks and muscular jaws, the hippopotamus is at the best of times a formidable beast, able to snap a 3m crocodile in half given good provocation! Survival instinct sets in among the swollen pods and it’s each to their own - sometimes with brutal consequences like the death of an infant trampled in the crowd! As the water level drops lower and lower, fights erupt in a flurry of water and honking and then fizzle out almost as quickly once dominance is established or space acquired.
But for the bulls, a deep pool in the river is gold to retain females and they have more important work than mediating commotion. For a bull, the fight is for territory and for the females and mating rights that come with that. During the height of the drought, fights spark swiftly between a proprietor of a sought after stretch of river, and any unwary immigrant male, displaced from the dried up lagoons. So fierce are the bull defenders that it’s all or nothing. Most fights are likely to end in the death of one of the combatants or at least the expulsion of the loser. The bizarre and somewhat unnerving honk-roars of hippos in combat ring out through the dry air throughout August, September and October, night and day. Most of the noisy charade seems to be an intimidation tactic – when matters get serious, the noise disappears, the only sounds being the clash and slash of mighty canines locked in confrontation accompanied by spectacular sprays of water and blood streaming from the afflicted combatants’ mouths. Powerful robust jaws supported by abnormally large head and forequarters and sword-like teeth are the fighting weapons of these massive opponents –the rest just tons of stubborn blubber. Characterised by violent head shakes and swift rushes, these scenes are spectacular, the noisy chorus’ indeed intimidating and the results all too often devastating!
Uncommon of most African rivers, the Luangwa River respects her political boundaries, rising in the highlands of Zambia’s northern frontier and terminating at the junction with the Zambezi on Zambia’s southern boundary. This spectacular river is home to the largest population of hippos in the world, and the entire ecosystem is dependant on her, the only river in the valley. And this is a vital characteristic of the Luangwa for although it is a fat and snaking river during the summer rains, Luangwa is a place of extreme seasonal contrasts and when the rain ceases, the river shrinks progressively into the dry months, eventually becoming a mere trickle interlinking deeper channels as temperatures soar into October. With the oxbows dried up and all other ephemeral water in the valley gone, creatures journey huge distances to the river for relief from a dementia-inducing time of dust and hardship – now certainly dependent of the only river in the valley. Interestingly, most creatures here exist in a smaller physical form than in the rest of Africa due to the isolated nature of the Valley, hemmed in by escapements formed by ancient tectonic movements and comparatively less fertile tracts of Miombo Woodland that extend beyond the Valley’s limits creating a relative biodiversity vacuum.
For the mega-population of hippos, ancient pig-relatives Hippopotamus amphibious, the Luangwa is patch of real estate extraordinaire! Luangwa houses an estimated 30000 hippos along its 1100km course - the biggest population anywhere in the world and so in the dry months, a shrinking river is not good news! The wide sandy beaches exposed by the retreating water, become a battleground for the hippo. For the top predators – lions and crocodiles - it’s a feast guaranteed!
So spectacular is the size of the Luangwa hippo population that any visitor to the valley can expect to count at least 80-100 individuals at any random point that one should choose to stop and tally. This in itself is remarkable but more so if one considers that the population was almost annihilated before the area was protected. In 1918 a hippo sighting was considered a significant one! But that really is a thing of the past and the numbers are staggeringly obvious when the river is at its lowest in late October into November.
Hippos seem to favour the quiet oxbow refuges and lagoon-flanked stretches of river as it is here that they can easily access the lush grass from the alluvial areas surrounding the floodplains. But after May, these choice habitats are no longer available, shrivelled to chunks of caked-mud in the heat, and with no where else to go, hippos migrate en masse to the deeper pools in the wide river channel. Survival through these times is a severe ordeal. Here they are vulnerable to the scorching sun and to the wrath of the resident bulls, irritated that their turf is being invaded by the competition. The deeper pools amongst exposed sandbanks are prized territories and conflict is the order of the day!
Enormous in size and decked with formidable canine-like tusks and muscular jaws, the hippopotamus is at the best of times a formidable beast, able to snap a 3m crocodile in half given good provocation! Survival instinct sets in among the swollen pods and it’s each to their own - sometimes with brutal consequences like the death of an infant trampled in the crowd! As the water level drops lower and lower, fights erupt in a flurry of water and honking and then fizzle out almost as quickly once dominance is established or space acquired.
But for the bulls, a deep pool in the river is gold to retain females and they have more important work than mediating commotion. For a bull, the fight is for territory and for the females and mating rights that come with that. During the height of the drought, fights spark swiftly between a proprietor of a sought after stretch of river, and any unwary immigrant male, displaced from the dried up lagoons. So fierce are the bull defenders that it’s all or nothing. Most fights are likely to end in the death of one of the combatants or at least the expulsion of the loser. The bizarre and somewhat unnerving honk-roars of hippos in combat ring out through the dry air throughout August, September and October, night and day. Most of the noisy charade seems to be an intimidation tactic – when matters get serious, the noise disappears, the only sounds being the clash and slash of mighty canines locked in confrontation accompanied by spectacular sprays of water and blood streaming from the afflicted combatants’ mouths. Powerful robust jaws supported by abnormally large head and forequarters and sword-like teeth are the fighting weapons of these massive opponents –the rest just tons of stubborn blubber. Characterised by violent head shakes and swift rushes, these scenes are spectacular, the noisy chorus’ indeed intimidating and the results all too often devastating!
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