camera trap

Thieves…

We have a few macadamia trees at home that have not yielded very much for luck of water. Last year we had very good rains so we were rewarded with a good harvest and we are busy drying them under the sun so that I can then proceed with the rather time-consuming exercise of opening them.

Macadamia’s shells are extremely hard and, after trying various methods, I have resorted to a vise in the workshop that so far is still working until its thread gives in!

Some time ago we have discovered hollowed out nuts in the garden and we could not believe that an animal could be so powerful as to gnaw such thick and hard shells! Eventually we found lots of empty nuts near a large hole and realized that we had a colony of Southern Giant Pouched Rats (Cricetomys ansorgei) [1].

After a while we stopped seeing them and they disappeared. Apparently they moved off our house one night in a group and entered under the gate of a neighbouring house but I was not a witness to this Pied-piper of Hamelin-like migration!

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The empty shells after the rats ate the tasty inside.

More recently, we noted that the nuts we were drying were being peeled from their green outer cover and taken away whole from the sunning box. We “smelled a rat”!

A search up and down the garden was organized and, eventually, a large hole was discovered at the farther corner of the garden. Suspecting that the giant rats were there I set up a camera trap pointing towards the suspected burrow and this is what I got:

We confirmed our fears as the various videos taken showed one rat at a time either entering or leaving the burrow. As I was curious to see how many there were, I decided to put some food hoping that they would gather to feed. Although I got over 180 ten-second videos, I still failed to get a rat gathering! However, I got a few that prompted me to write this post!

I have selected a few that I find interesting and/or funny. Please note that one is eating a few carrot pieces on the ground while the others are chewing a chunk of (delicious for humans at least) butternut hanging from a bush, the idea being that they would not drag it into their nest!

This giant rats are widely distributed in mainly tropical regions of southern Africa, notably Zimbabwe, Kenya, Tanzania, Zambia, and the Democratic Republic of Congo. I first saw them in Monze, Zambia while driving on the main road and I had difficulties stopping my Zambian workers from jumping from the moving vehicle to catch them as they consider them a delicacy!

Later, also in Zambia, Bruno, a colleague from Belgium, invited me with a surprise roast that happened to be delicious and it was a giant rat -as tasty as a piglet- with baked potatoes (tasting like potatoes!)! Giant rats were very abundant in that area at the time and I am sure contributed to food security of the village where the project was based.

Giant pouched rats are named after their large cheek pouches and they are only distantly related to the true rats. Recent studies place them in the family Nesomyidae and not in the Muridae as they used to be [2].

They are able to produce up to 10 litters of one to five young per annum and they are nocturnal and omnivorous with special taste for palm nuts and, as we have experienced, also for macadamia nuts. Interestingly, they are hind gut fermenters and coprophagous, producing pellets of semi-digested food that are consumed.

They are not only easily tamed as pets but useful for detecting land mines as they have an excellent sense of smell, particularly sniffing TNT while being too light to detonate the mines! But this is not all. They are also being trained to detect tuberculosis by smelling sputum samples. This procedure is faster than the normal diagnostic test and remarkably increases the sample processing. [3]

So a few disappeared nuts ended up producing an interesting story and  I am now positive that we  have a colony of rats (being fed on expensive macadamia nuts) that could potentially be bred to remove mines and improve human lives!

I regret now having eaten one (and liked it!) and I will not do it again!

 

[1] I am not a rat taxonomist so I base my identification more on distribution and abundance than on their morphology. The other possible species in Zimbabwe would be C. gambianus but the whole pouched rat taxonomy is under review. See: Olayemi, A. et. al. (2012). Taxonomy of the African giant pouched rats (Nesomyidae: Cricetomys): molecular and craniometric evidence support an unexpected high species diversity. Zoological Journal of the Linnean Society 165, 700–719.

[2] https://en.wikipedia.org/wiki/Giant_pouched_rat#cite_note-MetH-1. Seen on 6/12/18.

[3] https://www.apopo.org/en. Seen on 6/12/18.

 

Garden and gadgets

As I mentioned earlier (see: https://bushsnobinafrica.wordpress.com/2015/06/19/drones-in-the-bush/), we did get an improved drone as soon as prices dropped. Although my son immediately managed to fly it, I am still building my confidence after the earlier mishaps! However, as this contraption almost flies by itself, I believe that with a bit of practice I will soon manage. I will report on “droning” in a future post.

In addition to the drone, I have improved on my camera and bought a Nikon Coolpix P600 with a 60X optical zoom. I chose this (in fact my daughter did…) because it is powerful while being quite light. We are already loaded with binoculars to add more weight! Not being a pro, it is good enough to capture what I see although I have always believed that there is no substitute for your eyes! To this I added a tripod and downloaded an App that enables you to take pictures wirelessly using my smartphone.

Going almost beyond my mental capability I also got a camera trap! Its increasing use worldwide has made these affordable so I decided to get one as well to top up my gadget bag that already contains a number of goodies such as UV torch, normal torches, battery boosters for phones, video camera, night vision googles and binoculars.

They both have been a great success so far.

The very day I got the camera trap -brought from the USA by my son- I set it up in the garden and I have done so for a few nights over the last couple of weeks. Although It is not meant to take high resolution images, its pictures are good enough to identify animals, provided that you point it in the right direction!

Through the pictures and videos it took during the day I managed to confirm some of the birds visiting our bird bath and feeding table as well as to detect some new ones. So far we had mourning dove, forked-tailed drongo, dark-capped bulbul, kurrichane thrush, white-browed robin chat, yet unidentified weavers and fire finches, blue waxbill, variable sunbird and purple crested lourie. In addition, leaving the camera overnight confirmed the crepuscular habits of both robin chats and drongos.

A laughing dove.

A laughing dove.

A robin chat and bulbuls.

A robin chat and bulbul.

A pair of variable sunbirds.

A pair of variable sunbirds.

A close-up of a purple-crested lourie.

A close-up of a purple-crested lourie.

I also did some detective work in connection with the unravelling of a garden mystery: the nocturnal disappearance of the bird seed from the feeding table! I managed to expose the culprits that were no others than the suspected African Giant Pouched Rats (Cricetomys sp. Ansorgei). They were already high on the possible culprit list as we had evidence of their presence through large fresh burrows and macadamia nut shells found in the adjacent areas. If you have tried to crack one of these nuts, it will give you an idea of the gnawing power of these animals!

Macadamia nut husks (top) and whole nuts (bottom) to show the way the rats eat them.

Macadamia nut husks (top) and whole nuts (bottom) to show the way the rats eat them.

In addition to finding the somehow expected rats, we came across another animal that came as a surprise as Nature will not disappoint you if you look for new things! One of the nights we were after the bird seed-eating culprits an African civet (Civettictis civetta) came by for a drink! Consulting the Internet I learnt that they do move into urban environment and that they also climb on house roofs!

The African civet drinking.

The African civet drinking.

Having detected the birds and animals present in the garden, it was time to use the tripod and remote control on the Nikon camera and attempt to document some of the visitors with a better resolution. This I am doing at the moment and learning.

Better pictures of the lourie taken with the Nikon camera and remote control device.

Better pictures of the lourie bathing taken with the Nikon camera and remote control device.

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The louries have always been in the garden but always high on the trees. It is only recently that they have decided to come for a dip in the birdbath. The hamerkop comes often to decimate the toad population in our water storage tank (read swimming pool).

The hamerkop taking up position by the pool.

The hamerkop taking up position by the pool.

Stalking toads.

Stalking toads.

Gotcha!

Gotcha!

I need to take advantage of the present dry conditions prevalent in Harare so when the rains come later in the year the animals will disperse.

 

Note: this post has not been checked by my Editor.

 

Added on 5 September 2015: Although I identified the night cat-like visitor as an African civet, subsequent Internet search makes me think that it could in fact have been a genet. I am trying to get another picture to clarify the situation.