Under the searing sun of the Tsavo East National Park, a herd of elephants as red as the soil around them browse near the newly constructed standard gauge railway cutting across the 13,747 square kilometre park.

This section of the railway, near the park?s Manyani Gate, is on a steep embankment to attain a high gradient for the trains. A 70-metre-wide and five-metre-high underpass in the embankment allows elephants to move across from the adjoining 9,065 square kilometre Tsavo West National Park.

Until this steep embankment of the SGR was built a year ago, the elephants of Tsavo crossed the Nairobi-Mombasa Highway and the century-old railway line from anywhere along the 137-kilometre highway and rail that ran through the two parks.

Elephants also migrate from Tsavo East to the Coast into Arabuko Sokoke forest near Malindi or to the Shimba Hills near the famed South Coast, but these migrations are becoming increasingly difficult due to expanding human settlements blocking the migratory routes.

?In March 2016, Save the Elephants collared 10 elephant families — that is five matriarchs leading five groups and five big bulls — to monitor them so that we can see how the elephants are coping with the SGR and the designated underpasses, and also to understand how the SGR is affecting movement and distribution patterns of the elephants,? said Ben Okita of Save The Elephants — a veteran wildlife research scientist with more than 20 years specialising in Africa?s mega herbivores — the rhino and the elephant.

Since Save The Elephants began recording data in March, eight elephants have been killed due to the SGR embankment barriers. In recent years, the average annual kill from road carnage was two elephants. Unless new infrastructure is properly planned, casualties could increase dramatically.

Limo Elisha, a Kenya Wildlife Service ranger at the Manyani Gate, took a short video of an elephant moving towards the gate and then going through the underpass to cross the road and the old railway line into Tsavo West.

Save The Elephants has pictures of elephants stuck by the side of the high embankment after crossing the road from Tsavo West to enter Tsavo East. They now have to walk along the impenetrable barrier until they find one of the six underpasses to cross into Tsavo East.

Tsavo lies at the crossroads of elephant migrations between Tsavo East and Tsavo West. The elephants then migrate from Tsavo West into Mkomazi National Park in Tanzania, or from Tsavo West into the Chyulu Hills and beyond into Amboseli and Kilimanjaro in Tanzania.

Save The Elephants, founded by Dr Ian Douglas Hamilton, who pioneered elephant research in the 1950s, has been commissioned by the Kenya Wildlife Service to monitor the elephants.

Its aim is to generate information that can help with better management of underpasses and connectivity between landscapes for elephants during migration, and the sustainability of such structures through community-owned land bordering the park.