What drying up of Lake Ol'Bolossat means

A dried-up section of Lake Ol' Bolossat in Nyandarua county on May 12, 2022. [Kipsang Joseph, Standard]

Except for small pools of muddy water interjecting the extensive mud cracks on the dry bed of Lake Ol’ Bolossat, it is near impossible to tell that the spot hosted hundreds of nests of grey crowned cranes.

Every year, there is less water and fewer nests, with extended mudflats.

Ol’ Bolossat boasts as the only lake in Nyandarua County whose waters flow downstream to support the livelihoods of communities in the dry Laikipia, Samburu, Isiolo and Garissa counties.

But despite its being one of the smallest lakes, covering 43.3km2, it is a critical site for hundreds of hippos and more than 300 bird species, a reason for its designation as an Important Bird Area.

The lake also acts as maternity for hundreds of the endangered grey crowned cranes, being one of the strongholds of the populations of the birds in East Africa. But the dwindling water volumes of Lake Ol’ Bolossat threaten the survival of the birds.

“The expansive dry area over there has been one of their historical breeding grounds. During the nesting season, hundreds of nests are often spread around here, but the trend has been declining during nesting seasons because the wetlands are dry,” Mr George Muigai, the founder of Crane Conservation Volunteers said.

Of the 15 species of cranes globally, Grey-crowned cranes are only found in Africa, with Kenya and Uganda being among the strongholds.

The bird species is listed as Endangered by the International Union for Conservation and Nature, meaning they are at risk of extinction within their ranges.

Despite being a once-common bird in wetlands and grasslands due to its high dependence on the habitats for breeding, foraging, resting and roosting, its population has been declining over the years across its range.

By 1988, the population of the birds in Africa was estimated at over 100,000, figures that dropped to between 26,500 and 33,500 in 2015.  

The population of the birds has also been declining in Kenya. By 1988, the Kenyan population was estimated at 35,000 but went down to between 8,000 and 10,000 by 2020, numbers which researchers say translate to a loss of over 700 cranes per year.

“It is sad because these are the birds we used to see in abundance some years ago, and now they are disappearing. Lake Ol’ Bolossat is one of the major breeding grounds, but the destruction is all clear now, from the destruction of catchment, encroachment and effects of climate change,” Mr Muigai said.

Data from monitoring of the species by bird experts at Lake Ol’ Bolossat reveals that breeding has been going down in tandem with shrinking water levels. The birds often breed every year from June through to April the following year. In the 2015/2016 breeding season, no chicks were recorded, yet there were several nests, a situation that prompted massive awareness of the dangers of poaching eggs.

During the 2016/2017 season, only one chick was recorded. In the following 2017/2018 season, 56 chicks were recorded. In the 2018/2019 breeding season, 94 chicks were recorded and in the last breeding season, no chicks were recorded.

From the batch of extensive dry lake bed, which Mr Muigai said hosted hundreds of nests years ago, farming activities can be seen in the once forested Satima escarpment overlooking the lake.

Livestock, too, are a common sight here, although Mr Muigai said the incidences of grazing within the breeding sites had reduced over the past few years since awareness campaigns to save the cranes kicked off in Ol’ Bolossat. But in the mid-morning hours, it is clear that the struggles within the lake are being felt by lone fishermen as well, each trying his luck for the day.

“You see, as local fishermen, we had sections where each of us could fish. But then the lake has been drying and we keep moving along with it. If the levels continue receding, I will have to look for something else to do because it is no longer profitable,” Mr Joshua Maina told Planet Action.

Besides the dwindling fish stock is another challenge; fear of being attacked by hippos within the lake. The vegetation around the lake comprised of grass and reeds has dried up, forcing the animals to stray into people’s farms.

This has seen cases of human-wildlife conflicts intensify around the lake. A number of hippo carcasses also dot the shores of the lake. “The drying lake does not only affect the cranes, it also affects the hippos that have been dying as a result of lack of food,” Mr Muigai said.

Part of the area that has been gazetted as a lake reserve hosts unique highland grassland that mainly comprises of the tussock grass.

The grass hosts some of the world’s rarest species, including the endangered Sharpe’s Longclaw and the widow bird.

Both species require the tussock grass to survive and being the only known protected area that hosts the species, if conserved, it may be the future home to the dwindling populations.

“But how do we conserve these grasslands that are crucial to endangered species if the lake suffers massive encroachment,” Mr Muigai posed.

A countrywide survey conducted in 2019 to establish the Kenyan population showed that not more than 5 per cent of Kenya’s grey crowned crane population was found in government land, purely dedicated to wildlife conservation, while the rest were within unprotected areas.

 In 2021, researchers highlighted another emerging threat facing the birds-power lines. “Although the cranes’ decline has been largely attributed to habitat loss and deterioration, loss of eggs and chicks and trapping of adults, in Kenya, deaths arising from power lines is emerging as a serious threat too.

This is as a result of increased power infrastructure for transmission and distribution types of power lines across the country,” researchers noted.

Between 2016 and 2021 when the report was finally released, a total of 13 cranes casualties resulting from collision and electrocution by power lines were reported.

Majority of the cases were recorded in areas around Lake Ol Bolossat, while others were in Kinangop.

Electrocution and the shrinking habitat aside, Kenya’s grey crowned cranes face another challenge. Demand in recreational parks, hotels and homes has now been found to be fast contributing to the disappearance of the birds in their wild habitats.

The demand has seen a rise in the theft of chicks and eggs in their breeding grounds.

“These birds have experienced about 70 per cent decline in 34 years. The demand for grey crowned cranes is a big threat to their survival in the wild. It is an issue that urgently needs to be controlled. People hunt their eggs and take their chicks, which is against the laws. Raising them in captivity does not help either,” Mr Wanyoike Wamiti, a researcher at the National Museums of Kenya, said.

While the birds are poor breeders in captivity, grazing of livestock in their key breeding grounds has also posed a major challenge.

“Tens of eggs are trampled on by herds that flock these wetlands in search of pasture. We are losing them rapidly to these challenges,” he added.

The challenges facing crane conservation in Kenya have been recorded across their critical ranges, including Lake Ol Bolossat and wetlands in Uasin Gishu, Nandi, Trans Nzoia  and in the Western region.

And now researchers have embarked on a ringing programme that will help unravel the lives of little known graceful crowned birds.

The ringing programme is expected to inform on their distribution, study their movements, determine regional populations, mortality and other aspects of their natural history such as age at first pairing and breeding.

Known life span

“We want to know even the life span of these birds. Previous researches conducted many years ago noted that the bird lived for up to 25 years in the wild, but our recent studies has shown they can even live up to 35 years in the wild. There is much we will collect from this programme,” Mr Wamiti added.

The initiative is a joint effort between local and international organisations, including National Museums of Kenya, Kenya Wildlife Service, Nature Kenya, Nature and Biodiversity, Bird Life International, Cranes Conservation Germany among other local ones.

“Research has helped a lot in understanding the current pressures these birds are facing. Previously, there were serious knowledge gaps on where the birds breed, feed and rest, but recent researches have helped us understand all these,” he said.

“The current ringing programme will help us generate more information on their movement patterns at different seasons of the year for purposes of conservation,” he added.

 The ringing programme, according to Mr Wamiti, will also enable the researchers to identify key grasslands and croplands where the birds rear their chicks and feed.  

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