garden

Rain bird

A few days back we have started hearing the by now familiar ‘wip-wip-weeu’ that the rain bird or red-chested cuckoo (Cuculus solitarius) make endlessly at the time the rains should start in Zimbabwe. But, where have they been since their appearance last year?

 

Before I knew much about bird movement and migration, I often asked myself this question. I recall watching in awe widowbirds displaying in Northern Kenya and asking my friend Paul about their whereabouts during the rest of the year. His reply, was that they would go to the Sudd[1], a huge swampy area located in Sudan.

Sudd_swamp Credit NASA (Public domain)

Sudd Swamp -a Flooded grasslands and savannas ecoregion in South Sudan. To the left the river/wetland Bahr al-Ghazal connecting to Lake No (top). This photograph was taken during the driest time of year—summer rains generally extend from July through September. Taken from space, May 1993. Credit: NASA (Public domain).

So, every time that someone asks me now where a particular bird is when it is not seen, I say that it is in the Sudd, a very convenient reply!

The truth about the rain bird is that they are intra-African migrants that breed in southern Africa between September and March, although most arrive in mid-October and the majority are gone by the end of April.

The rest of the year they reside in Sub-Saharan Africa, in countries of Central, East and West Africa, including the Sudd wetlands in South Sudan!

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Rainbird distribution map. Attribution: BirdLife International (2019) Species factsheet: Cuculus solitarius. Downloaded from http://www.birdlife.org on 02/11/2019.

Their preferred habitats are woodlands where they perch high up in the trees. The red-chested cuckoo is usually solitary and it takes on more than a single mate so it is polygamous. Every year they visit our garden where they are occasionally seen while they feed on caterpillars and other insects in the tall msasa trees.

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While in Southern Africa -including Zimbabwe- the rain birds practice brood parasitism by breeding through egg-laying in other bird species nests, some twenty-seven of them! The most common hosts are thrushes and robin-chats and the Cape robin-chat (Cossypha caffra), the Cape wagtail (Motacilla capensis) and the white-throated robin-chat (Cossypha humeralis) are the most popular hosts.

The cuckoo’s resemblance with a small bird of prey (like a sparrow hawk for example) scares the future parents from their nests and the cuckoo female lays the egg that, not always, resembles their hosts’. It is estimated that they lay about twenty eggs scattered in various nests every season. Then it is up to the surrogate family to raise the chick.

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A cape robin feeding an almost fully-grown rain bird. Attribution: Alandmanson [CC BY-SA 4.0 (https://creativecommons.org/licenses/by-sa/4.0)%5D. https://upload.wikimedia.org/wikipedia/commons/f/f4/Piet-my-vrou_%26_cape_robin.jpg. Downloaded from Creative Commons on 2/11/19

A very interesting biological phenomenon helps the cuckoo chick to have a head start from the other chicks in the nest: the female cuckoo literally incubates the egg inside her for 24 hours before laying it! [1] This ensures that the chick will hatch first and eliminate the competition at the nest.

Cuckoos are great travellers, capable of flying enormous distances during their migration and, although the red-chested cuckoo covers less distances than others, it uses the same mechanisms to do so. These navigation skills are genetically passed on to their young. The latter stay behind to complete their development while their parents depart but the new generation are able to fly back north on their own to join their parents!

Now we only need good rains while we watch the cuckoos until they depart and then we wait for them to announce the rains in 2020.

 

[1] See: https://www.bbc.com/news/science-environment-11401254

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.

 

Spot the beast 47

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Today, while walking in the garden, we spotted this beast. It is not easy to see as it was already late when I took the pictures…

If you do not see it, follow the telephone wire…

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In any case, here it is. What I believe to be one of our rat control team: a Spotted Eagle-Owl (Bubo africanus). We did have years back a lady tenant that used to rehabilitate injured owls so perhaps this is one of their offspring? Whatever, it is amazing to have them in the garden!

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Regret that the image is a bit blurred but these are crepuscular birds and pictures are  challenge!

Spot the beast 45

After a few weeks of silence, I return to blogging for one day to let you have this beast for you to search for.

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I am sure it was not that hard. It is the first chameleon we find this year in our Harare garden. I think it came out a bit early as it is still quite cold and it was in good condition but moving slowly like the bushsnob in cold weather!

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From the rather prolific garden in Harare for you to find:

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A young praying mantis doing its job in insect control.

Closely related to cockroaches and termites, there are over 2,400 species of mantises -both flying and flightless- worldwide. They feed on other insects but not necessarily all of them damaging to agriculture!. Larger species can even hunt small reptiles and birds and about 30% of wild males get cannibalized by their sexual partners.

They have flexible necks that enables them to turn their heads 180 degrees, a feat that no other insect can do and, although they have two large and bulging eyes, they only have one “ear” located in their abdomen so their hearing is limited.

 

Live Cham 4

A short update of the situation with the gravid chameleon.

We saw the female again in the early hours of the 28 Jan and it was moving in the poinsettia bush. IMG_3156 copy

An hour later it had disappeared and despite our thorough search in the original poinsettia and surrounding bushes, we could not find it! We checked on the ground as we were convinced that it would not walk more than a few metres around the bush. Still nothing!

We got concerned about its fate as we know that pied crows are around and that they are capable of killing chameleons. However, there was not much else we could do. Stephen would have found it but it was his day off so there was no hope there.

There was lots of hope in other parts of the garden though. The female we saw digging the nest during the night of the 26 Jan (Live Cham 3) had finished its job as described and then it left quietly. The nest area is now fenced and protected.

In addition, a third female was spotted at a passion fruit plant and she was also gravid and very active.

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Yesterday (28 Jan) it changed position to a lemon tree, walking about 10m to get to it.

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The female moving through the grass.

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Searching for a suitable spot.

It climbed on the tree through a stick and remained on the tree for rest of the day.

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It eventually decided to climb up a lemon tree. The eggs bulging through the skin can be seen in its ventral part.

Luckily yesterday (28 Jan) Stephen returned home by mid afternoon and immediately located the missing female that we had lost earlier during the morning! It had moved 33m! to another area of soft earth and it was busy digging, despite its rather bulgy belly. By the time we left it last night, it could go in its totality inside the hole but it was already dark for pictures. We protected her again to avoid dog interference and left.

This morning, as with the previous female, it had finished and covered the hole, looking dark and rather quiet. I am sure it will soon recover and move away.

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So we are now left with the third female that has now climbed down from the lemon tree and it is -again- walking in the garden, looking for the right spot to lay her eggs.

As we are traveling to Uruguay before dawn tomorrow, this is the last post from Zimbabwe but I will resume once I touch down at the other end.

In any case, I am beginning to think that next year we will have a “chameleon population explosion”!

 

 

Live Cham 3

After the last post we have observed the gravid female until this morning (27 Jan) and she has hardly moved from the poinsettia bush. She is clearly waiting for her time to come. So, not a lot of news there, I am afraid. Only a few pictures of her.

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She spent most of the 26 Jan on top of this bush.

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Still there this morning (27 Jan)

However, lo and behold, three (yes, 3) more suspected females were found  in different places, looking in various degrees of gestation! The situation became almost out of control! But things got really bad when my post-siesta time was interrupted with calls of “it is digging, it is digging!” proffered by Stephen and my wife that were watching at the time.

After my first -sluggish- reaction I joined them to watch chameleon 2 effectively digging her egg nest project next to the bayleaf bush! I took a video (26/ Jan, late afternoon) of the action:

As the process was not done before dusk, we protected the site from our dogs and came back this morning.

The chameleon had finished laying, covered the hole and it is there, probably resting after such an effort!

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The female after the effort!

One done, three to go… More info coming soon…

Live Cham 2

As promised, I had followed the evolution of the gravid chameleon throughout the day. These are the observations so far from this morning:

09:00 Still in the same bush but its colour changed.

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12:00 Started to rain quite heavily. Cham still in the same bush when rain started.

12:30 Rain stopped. Found again. I had moved to another smaller flower bush about 1m apart:

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12:30 to 1515 Observer’s lunch and siesta. No data!

15:35 Moved another metre to a Poinsettia bush (Euphorbia pulcherrima) and climbed about 150cm high. Colour changed again. It appears that coloration is more a reflection of the animal condition than its surroundings!

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1600 to 16:20 hs Shower.

1627 The chameleon is still a the same spot but head down and green in colour.

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It is now 17:10 hs and I will have a last look before night fall.

Hope to find it tomorrow…

Live Cham

There was some excitement this morning when a chameleon was found in the garden. I thought it was a bit exaggerated for such event but I was not right (again).

Stephen had spotted a rather fat chameleon that on close inspection revealed that it was gravid! So, as this is happening right now as I write, I post a few pics to show this great creature on its bush.

I am watching her every hour with the binocs to avoid disturbing her but to follow her “progress”.

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“Spot the chameleon”. The Masau (Ziziphus mauritiana) bush where the female was found.

Here it is:

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There she is hanging on!

A few more pictures to show you her condition:

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From above to show her enlarged body. A true egg sac!!!

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The eggs can be seen protruding in the ventral area.

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A sideways picture that shows the mass of eggs better.

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Despite her condition, her eyes still keep track of you!

As I think it is quite close to laying time and I hope to see her digging her nest, I am checking on her hourly hoping that it will happen soon and before nightfall!

I will keep you posted on developments…