Category Archives: Rodents

New pitfalls created in Shimoni

It’s been a couple of months now since GVI expanded its research program by digging a two-bucket pitfall trap in Shimoni East forest – an experiment of sorts, and an attempt to start looking more closely at some species that have at times been overlooked in the past: frogs, lizards, and potentially some smaller snakes.

Two months on, it’s safe to say the experiment’s been a success. The Shimoni East pitfalls have been regularly catching frogs, toads, and one very special White-Toothed Shrew – a species not previously known to live in the area. So with that in mind, we decided to try it again. We picked Shimoni West forest (the larger forest patch to the west of Shimoni, where GVI is just starting to conduct research) as our next target, and went for a bit more of an ambitious approach…

The Shimoni West pitfalls didn’t come easily – it took two solid days of digging through pretty impossible-looking coral rag just to get the holes in place – but the result was definitely worthwhile. With 4 buckets (all of them deeper than those in Shimoni East) and a total of 30 metres of drift fence, it was hoped that we would start catching both a great quantity of creatures and a wider range of species (including, hopefully, some larger frog and reptile species that might be able to escape from the shallower Shimoni East traps).

It’s perhaps still too soon to tell how successful we will be, but we’re off to a promising start. We opened the traps up yesterday, just after we finished putting up the fence, and checked them out this morning. The result was 5 frogs in healthy condition – best of all, only two of them were the same species.

Frog species found in one of the pitfall traps

Frog species found in one of the pitfall traps

We’re now in the process of identifying them all from our photos – if we succeed in that, it’s pretty likely we’ll be adding to our species catalogue once again. Not bad for the first day’s haul – watch this space for more updates as the project continues!

A selection of tracks

A small selection of tracks from the mud

A small selection of tracks from the mud

Daily rains make spotting wildlife harder. Vegetation covers everything and with all the mud it is difficult to cover a lot of ground. One thing the mud does bring us though is very clear tracks! It is quite hard to  identify species reliably but they give us a very good indication of what might be out there.

I Smell A Rat

Has anyone heard of a giant pouched rat?  Ok, so imagine a normal rat, then triple it in size, and there you go!  We have been trapping these poor creatures for about a year and a half now, with the aim being to establish the population density (of relatively small areas, as we do not have enough traps to cover the whole forest) and potentially the average home range for one of these animals.
We started experimenting in a walled plot (approx. 200m x 200m), mainly because it was secure, and we were concerned about our traps being stolen.  The animals are able to get in and out thanks to small, regular holes that were left in the walls for exactly this purpose.  
We randomly moved the traps around the plot, and over time realized there were three resident giant pouched rats (fondly named Mr. Scarface, Mrs. Scarface and Bob).  Interestingly enough, just by looking at the locations where the three rats were caught, it appears their territories overlapped.  Wither this, or the smell of the bait encouraged them to wander out of their territory. 


 Giant pouched rat in the trap

Recently however, we have been daring enough to move the traps out of the plot and into the wider forest (making sure that they are hidden).  So far we have had the traps in three locations, and the preliminary results have been an interesting insight into the preferred habitats and density of rats between transect 1 and 2. 


 Aron and Kez preparing to get measurements

The first location was in an area of mature forest, where there was an area of low, dense shrubbery.  I assumed that this would be an ideal location for rat catching!  They were there for 14 trapping days, and there was not a single shred of evidence that any small mammal of any description came anywhere near the traps!  I was gutted to say the least…

We then moved them to a second location; in a man-made clearing with low shrubs and new growth.  Again, no evidence of small mammals, however we did catch another mammal trying to get at the bait – a yellow baboon!  The determined baboon manage to bend our trap out of shape trying to get at the bait after he’d sprung the trap!  Quite funny, but frustrating.



After a similar number of trapping days without success, we moved them a third time.  This time they were in a relatively small, isolated patch of mature forest with dense undergrowth, which is in the middle of the same man-made clearing.  Eureka!  We caught not one, but two giant pouched rats on the first day!  One of them was an enormous male, with various scars across his face and back.


 After measurments are taken, they are free to make their escape

This has raised our spirits once again, and we shall continue to move the traps around and record all the details of all the animals we catch.  I am confident it will reveal some really interesting results!  I hope you enjoyed the photos!

Rodents and Reptiles

Today’s blog has been written by Lorrayne Gaymer, an expedition member with GVI in Kenya.  She is 27, from England, and has written about today’s highlights! 

 Today our team was in Shimoni east forest, attempting to finish the canopy surveys on transect 3.  Firstly we checked the small mammal traps and found not to our surprise, Mrs Scarface (resident giant pouched rat), again!  Seeing as we already have her measurements, we simply took some photos and let her go on her way.


Mrs. Scarface  

We then managed to carry out over 30 minutes of primate behaviour on a troop of colobus, and finished all of the canopy cover surveys on transect 3 – a good feeling! After a nice lunch break looking out over the eastern peninsular, it was day over. The most exciting part of the day however, came on our way home when we were trudging back down the North-South spine, and our forest officer got the fright of his life as a very large forest cobra (over 1.5 metres) shot out of the bush right by his foot!  It headed into the shrubs to our left, before crossing the path about 4 metres in front of us, allowing for an excellent view.  It was SO long, really fat and lightning fast.  Unfortunately we didn’t get enough time to wip our cameras out, so no photos.  But to be honest, none of us really wanted to get that close for any length of time anyway!  Still, an awesome and extremely exciting sighting!


GVI conducting primate behaviour surveys 

More coming soon!



Power saws and Pouched rats in Shimoni forest

Today we ventured deep in to Shimoni East forest, to transect 5, to undertake bird point counts – we identified three red-capped robin chats foraging close together in the leaf litter, a silvery-cheeked hornbill flying overhead and a sun bird that was too quick through the vegetation to allow us to identify which species. Numerous other bird songs could be heard but the birds proved elusive through the dense vegetation.

However the peace of the forest morning was shattered during the bird surveys by the revving of a power saw overshadowing the birdsong, about 100m from us. Within 10 minutes the crashing sound of a tree falling through the undergrowth came, followed by chattering and laughter of people and distress calls from nearby Syke’s monkeys. And so once again Shimoni witnesses the loss of more critical coastal forest habitat to illegal and unregulated forest resource exploitation.

About 20 minutes later we recorded two adult Angolan black and white colobus travelling above us through the canopy of one of the tree species targetted by loggers. Their presence at the end of transect 5, close to the edge of the forest where the mangroves begin, is not often seen. It is sad to think that they are still vulnerable to habitat destruction so deep in the forest.




On a happier note, we did also manage to catch a gecko on our way through, which appears to be the flat-headed gecko Hemidactylus platycephalus. The real highlight however was the first capture in the small mammal traps we are trialling on transect 1. On day 2, we have been rewarded with first our rodent capture – the giant pouched rat. It looks to be a Cricetomys emini, a different species to the ones I am used to from Tanzania so particularly exciting for me. We clipped a small patch of her fur to see if we get her returning to the traps over this week…