Rare gerbil thrives at Coega
WITCHING hour for the pygmy hairy-footed gerbils is 10pm.
Emerging after dark their activity level peaks at this time as they hop along the high water mark foraging for crustaceans and through the dunes digging busily for beach pumpkins (the grey-leafed succulent with pumpkin-like yellow flowers), pausing only for a sand bath or a foot drum (a rear foot is thumped rapidly on the sand to communicate).
In the morning they’ll be gone, leaving only their delicate “feather duster spoor” (from those furry little paws) looping through the dew.
The wonderful world of the pygmy hairy-footed gerbil (PHFG) has been probed in the past by the University of San Diego and NMMU, but now exciting new work is being done by the Urban Raptor Project at the Port of Ngqura. Prior to the construction of the port in the mid-2000s the environmental impact assessment (EIA) noted the unconfirmed presence of this rare endemic rodent and called for it to be protected if a population was found.
In line with this recommendation Transnet commissioned the Urban Raptor Project – that was already applying its zero-poisons pest control system at Ngqura – to establish whether or not the PHFG was resident in the 1 000ha port zone. For months, project directors Arnold Slabbert and Allison Cawood found no sign.
Tracks in the dunes turned out to be other little indigenous denizens – Karoo bush rats, Namaqua rock rats and striped field mice.
Meanwhile, however, nighttime monitoring cameras had been posted at the eastern breakwater. This was the key infrastructure from where, the concern had been raised in the EIA, alien Norwegian rats could swim the 1km to Jahleel Island and decimate the penguins nesting there. No rats were spotted but, one night, the camera picked up something different.
Guided by these images, Slabbert and Cawood scoured the area on foot and spotted some interesting-looking spoor. They erected traps, baited them with seed and not long afterwards caught the first of what turned out to be a colony of 20 to 30 PHFGs.
Having found the PHFGs, the project could now focus on studying them. The little animals feed on the leaves of the beach pumpkin and stash the seeds for lean times in pockets in the sand in the zone around their burrows.
They don’t eat the leaves so for a while it was a mystery where they were getting moisture from.
Then Slabbert realised the clue was in the rocks which had been dumped on the site by Transnet. The seawater table lies only just beneath the sand and condensation occurs as the sun causes this water to evaporate.
A crust of salt is left behind on the sand and rivulets of fresh water on the underside of the rocks. This is the moisture sustaining the PHFGs.
The rocks also helped protect the PHFGs from being dug out by stray dogs, feral cats, otters and black-backed jackal, he realised. Jackals especially are proliferating, possibly because of the hotter, drier conditions caused by climate change and the opening up of habitat by agriculture and development.
The rocks on the PHFG eastern breakwater site were dumped there by Transnet when it was building the port. It seems that before Ngqura displaced this colony of PHFGs they lived at the Coega River mouth where there was natural rock structure.
Now, with the eastern breakwater site having been earmarked for development, the project team was given the task of finding another suitable site for the colony. The perfect spot was found about 1km east and after gaining permission from the provincial environment department, phased trapping and translocation began.
At the same time a corridor of rocks was created to encourage the migration of animals which could not be trapped and to provide an escape route for them when development started. Breeding has now begun at the new site, indicating the success of the move.
A PHFG colony is resident around the bay at Woody Cape but this population would have been historically separated from the Ngqura population by the Sundays River, as they still are, Slabbert argues. Further searches have turned up no more PHFGs at Ngqura or east as far as Hougham Park.
It is possible there are one or two more colonies closer to the Sundays River, but the population that occurred to the west at St George’s Strand has almost certainly been wiped out by predators. So there are probably a maximum 200 of this genetically distinct PHFG left in the world today, he says.
There is no official protection of the PHFG, and Slabbert is calling for this legislation to be tabled and enacted. The Port of Ngqura is meanwhile looking to ensure the long-term protection of its colony.
It is safe to say this population would no longer be around if poisons had been used at the port, Slabbert notes.
Should we care either way? If we campaign at all for wildlife, it seems, we do so too often only for the animals which have financial value to us. But if the PHFG is lost, the world would be a poorer place.
Surviving against all odds in such a small inhospitable corner – it’s a living miracle.
Moreover, like so many other little species, the PHFG lives in a specific niche with specific relationships about which we still know little. The PHFG could be the nail, Slabbert warns, in that proverb of long ago: For want of a nail the shoe was lost For want of a shoe the horse was lost For want of a horse the rider was lost For want of a rider the message was lost For want of a message the battle was lost For want of a battle the kingdom was lost And all for the want of a horseshoe nail.
