African Wildlife & Environment Issue 81

FAUNA, FLORA & WILDLIFE

Taking all of Leif ’s research into consideration, and add to this the fact that mammalian browsers enjoy eating Marula leaves and elephants also de-bark, break branches and thus can kill mature trees, it is

In the table below are the results for Marulas that clearly show no regeneration in 'Kruger', some regeneration on campus, and very healthy regeneration in the communal rangelands.

clear that Marulas are much threatened because they are targeted at all stages of their lives.

Sites

Juveniles

Sub-adults

Adults

Damaged Trees

Kempania (=KNP) SAWC

0

0

72

9

6

13

23

0

Welverdiend

95

32

46

1

But it was some of the other experiments Leif did that were particularly interesting. On campus we had a number of owl species and another volunteer was collecting pellets and analysing what species of rodents were being eaten locally. What Leif discovered was that on campus, because of the fairly dense grass-cover (no mammalian herbivory), there was a healthy and diverse rodent population. Outside in Kruger there were much fewer rodents and also fewer species as they were more easily hunted. And in the communal rangelands where there was minimal grass-cover there were few rodents and just three species. Leif then suggested that the rodents were perhaps the 'ecosystem engineers', and he set up a feeding experiment testing to see what rodents ate what seeds, AND whether the seeds or the seedlings were most preferred. These results were astonishing. The seeds tested were all locally common in and adjacent to Marulas and were Marula, Terminalia sericea , Dichrostachys cinerea , Acacia nilotica and A. exuvialis . All the seeds, except those of Terminalia were munched on, but it was the cotyledons of the germinating seeds that were much preferred (except for Terminalia that were generally left untouched, unless there was no other food available). When one considers that birds such as spurfowl also eat seeds (not Marula as they are too large), and also target seedlings, this adds to the predatory load. Bush squirrels also love Marula seeds, but they are absent from the communal lands! RIGHT: Usually elephants just remove a small piece of Marula bark, mostly on the northern side of the tree (is this possibly medicinal use?). TOP RIGHT: Where the tree has been ring-barked and is dying. BOTTOM RIGHT: Marulas can be tough to kill, here a tree that was almost pushed over is 'hedging' now that it is protected being on the Wildlife College campus.

Prof Eugene Moll Department of Biodiversity and Conservation Biology

University of the Western Cape eugenemoll74@gmail.com

25 | African Wildlife & Environment | Issue 81 (2022)