gabar goshawk

Death at the water

Perhaps the most salient feature of the Kgalagadi are the humongous number of birds visiting the different water points throughout the area. At the various camps in the Mabuasehube area the situation repeated itself. Flocks of birds would come to drink constantly to the various water points.

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The scramble for water! Picture by Frank Rijnders.

The bird parade included from the largest of the vultures, the Lappet-faced (Nubian) to the small violet-eared waxbills, true living jewels .

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Lappet-faced vultures at a water hole.

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Violet-eared waxbills. Picture by Frank Rijnders.

Apart from photography, this situation offered a great opportunity for the various predators to get an easy meal. We saw several potential bird predators at the water holes, from snakes to jackals but the most interesting were the birds of prey.

These came in all sizes: various eagles (Tawny, Bateleur), Pale chanting and Gabar Goshawks, Red-necked Falcons and Greater Kestrels to name what we saw during this trip.

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A magnificent Bateleur eagle and picture by Frank Rijnders.

The methodology of the feathered hunters was similar at the various places. The raptors would perch nearby and every so often swoop down on their potential prey. It seemed a rather easy procedure in view of the numbers. That was also the impression I had when last year I watched the Tawny eagles dove-catching that I described in https://bushsnobinafrica.wordpress.com/2016/11/30/easy-pickings/. My belief was further strengthened by a lightening speed attack by a Red-necked falcon that caught one of the sparrow weavers from under our noses and took us completely by surprise!

At Monamodi we had time[1] to observe a Gabar Goshawk (slightly larger than a dove) attempting to catch its lunch. We noted the raptor after observing that every few minutes the drinking doves would get startled and the flock would literally “explode” in different directions only to return a couple of minutes later.

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The scared doves take off.

After a few of these scares, we noted that a Gabar goshawk was perched next to the water and that the scares coincided with its lunges at the drinking birds!

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We were somehow doubtful that the goshawk would be after the doves as they seemed too large for it However, it seemed that way until we realized that there were a few smaller birds drinking together with the doves. We observed several failed attacks and I even managed to register the “goshawk among the pigeons”! However, a painstakingly checking all pictures and video, I failed to register the bird actually catching anything. The pictures below show the goshawk during one of its swoops that, after going through the mass of flying birds, end up by it landing back at the starting point.

So, either catching lunch for the Gabar goshawk is is not as easy as it seemed or I was not good registering what was happening! The latter is probably nearer to the truth as I am sure the bird would not be there otherwise as I am sure that, unlike for me, time is important for it!

 

[1] In Africa it is said that  “When God made mankind, He gave the white people the watch, but he gave the black people the time!” Luckily, I have both now!

Cool birds

October is usually Harare’s hottest month with a maximum and minimum temperature averages of 29oC and 15oC respectively[1]. Surface water is very scarce so the garden birdbaths surprise you with their visitors.

Among the guests there are a few small birds of prey that are not “regulars” but that come sometimes: the Lizard Buzzard (Kaupifalco monogrammicus) and the Gabar goshawk (Miconisus gabar).

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The Lizard Buzzard standing in the water.

While at the water I noted that they both behaved in a similar fashion. Apart from drinking (the Gabar Goshawk also bathed), both species spent a long time (over thirty minutes two or three times a day on the days observed) standing on the water baths during the hot hours of the day, around midday.

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The Gabar Goshawk standing in the bird bath, having had a bath.

Was it a coincidence or did they find relief by the freshness of the water in their legs?

I subsequently learnt that birds lower their temperatures through a variety of different mechanisms[2]. The bare skin on their legs and feet helps them to dissipate heat. Water birds stand in the water, presumably to enhance the cooling[3]. Some birds such as vultures and storks also use urohidrosis, the habit of urinating/defecating on their bare legs to cool down by evaporative cooling.

It seems likely that both birds were using the water of the bird baths to cool down their legs and feet and in this way, as the water birds, increasing the cooling effect of their bare skin.

Interestingly, since I wrote these observations[4], two more birds of prey had come and both species had stood with their feet in the water: an African cuckoo hawk, (Aviceda cuculoides) and what I believe to be an African Marsh Owl (Asio capensis)[5].

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The more recent observation of the African Cuckoo Hawk (landing on the water) and the African March Owl below. These  4 pictures were taken with a Camera trap.

[1] World Weather Online 2016. Harare Monthly Climate Average, Zimbabwe. Accessed on 10/10/2016. http://www.worldweatheronline.com/harare-weatheraverages/mashonaland-east/zw.aspx

[2] Mayntz, M 2016. How Do Wild Birds Keep Cool in Summer? Accessed on 10/10/2016. http://birding.about.com/od/birdingbasics/a/howbirdskeepcool.htm

[3] Shriner, J 2012. 15 Unusual Ways Some Birds Beat the Heat. Accessed on 10/10/2016. http://www.birdinginformation.com/15-unusualways-some-birds-beat-the-heat/

[4] de Castro J. (2016). Feet bathing as a cooling down mechanism in two species of birds of prey. Biodiversity Observations 7.77: 1–2. URL: http://bo.adu.org.za/content.php?id=270. Published online: 22 October 2016

[5] Identification to be confirmed as the pictures of the owl have been taken with a camera trap late at night.