predation

Rescue!

While in Salta I got an invitation to join a group of friends on a fishing trip near a place called Goya, in the mighty Paraná River, the same river where we have spent some great days fishing in the eighties (See: https://bushsnob.com/2015/01/28/a-fishing-expedition/).

This time the fishing was not memorable as there seems that the river is suffering from too much fishing pressure and the large fish are disappearing.

At one stage during the fishing we were traversing a smaller tributary known as the Santa Lucía River when I spotted three large birds of prey circling a floating object. I kept watching their activity from about one hundred metres away and saw that one of them landed in the water and started to peck the object.

I realised that the birds were three Caranchos or Caracara (Caracara plancus) and I was surprised to see one landing in the water. Then, the bird lifted the object in its paws and started to fly away but dropped it. At that time, I saw that what they were mobbing was a smaller bird so we went to have a look.

While moving towards the spot, there was a second attempt at lifting the bird again and, again it was dropped.

Our approach scared the predators and we found the prey to be a Ringed Kingfisher (Megaceryle torquata), a rather unusual target for the Caracaras that, although known as opportunistic, I did not think capable of going for a rather large kingfisher!

When we approached the bird, it swam with the aid of its wings towards us.

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A “rushed” picture of the kingfisher “swimming” towards us seconds before I lifted it.

I lifted the bird, risking its rather strong beak. Soon I managed to close it with a sticking plaster to avoid becoming a victim myself! I checked the bird and, fortunately, it did not show any visible injuries.

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Bushsnob and soaked wet rescued bird with its beak closed by the plaster!

I kept the bird on the boat for about two hours, waiting for it to dry and to keep it from struggling I covered it with my hat, burning my bald head in the process!

Eventually, it got dry and became rather active so I judged that it was as ready for release. As soon as I removed the plaster and held it in my hand for a few seconds, it flew away strongly.

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Waiting for the now dry kingfisher to fly off.

Unfortunately I can only speculate as to how the kingfisher ended in such a tight spot that, surely, would have cost it its life if we would not have come to look. In my view, the most probable scenario is that it was a young and inexperienced bird that had recently left the nest and, being still insecure, made a mistake spotted by the caracaras that took advantage of the situation. However, I could well be wrong.

Killer banana

The incident I will narrate took place during our last year’s trip to the Mabuasehube area of the Kgalagadi Transfrontier Park in Botswana. As the observation was being published, I delayed its writing until this took place on 8 July 2018 [1]. For easy access I have also inserted the published document (Hornbill predation) as a PDF file under Pages in this blog.

Let me start by saying that if you find the Southern Yellow-billed Hornbills likeable, you may need to review your stand after you read this piece.

While at Camp No. 2 at Monamodi Pan in October 2017 we were startled by the dryness of the place. Birds from the surrounding area will immediately come to drink in any water that we had around the camp. Common visitors were Southern Grey-headed Sparrows (Passer diffusus) but Cape Sparrows (Passer melanurus), Violet-eared Waxbills (Uraeginthus granatinus) and Sociable Weavers (Philetairus socius) were present in large numbers.

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There was a constant stream of birds drinking at the waterholes.

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Birds looking for food and water around our camp.

In addition, a few Southern Yellow-billed Hornbills (Tockus leucomelas) were residents at the camp and were regularly seen on the ground.

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Southern Yellow-billed Hornbills scavenging around the camp.

At mid-morning during the second day of our stay some of the small birds suddenly flew off where they were foraging in a response usually observed when there detect danger such as an attack by a predator.

They all flew away but one! A Southern Yellow-billed Hornbill had caught one of the adult Southern Grey-headed Sparrow and it was in the process of killing it by violently shaking it and thrashing it against the ground. We were startled as we did not expect this to happen.

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Picture by Frank Rijnders.

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The sparrow died fast and the hornbill started removing its feathers and then it took its victim up a nearby tree where it continued defeathering it by vigorously hitting and rubbing the sparrow against the tree. Interestingly, there was no panic reaction or mobbing of the predator by the small birds that returned to the water only after a few minutes.

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Picture by Frank Rijnders.

After about 30 minutes the hornbill decided that the victim was naked enough for it to be swallowed!

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Picture by Frank Rijnders.

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Although it was known that the Southern Yellow-billed Hornbill’s diet included “a wide range of invertebrates and small vertebrates” such as nestlings of Red-billed Quelea (Quelea quelea) the list does not mention predation on adult birds [2].

It is possible that the observed behaviour was incidental. However it seems realistic to expect that the hornbill was prepared to take advantage of the chaos created when large numbers of birds gather at waterholes or are distracted when foraging together to catch their prey unaware.

So, like with the observed carnivory in hippos [3] the present observation may not be nice but, again, it goes to show how nature works.

 

[1] https://journals.uct.ac.za/index.php/BO/article/view/500

[2] Hockey PAR, Dean WRJ and Ryan PG 2005. Roberts – Birds of Southern Africa. The Trustees of the John Voelcker Bird Book Fund.

[3] https://bushsnobinafrica.wordpress.com/2015/02/22/hippos-from-hell/ and https://bushsnobinafrica.wordpress.com/2015/03/23/hippos-from-hell-the-videos/

 

My thanks go to Biodiversity Observations for publishing this observation.