Tuesday, January 26, 2010

A Pair of White-Bellied Sea-Eagles Haliaeetus leucogaster Eat A Poisonous Toadfish at Ella Bay

Recently I have been communicating with Queensland Parks and Wildlife regarding the methods used and behaviour of their personnel at Ella Bay. This is something I will blog about in the near future. It has caused me to re examine the low impact methods I use to conduct field observations at Ella Bay as I am always seeking ways to do things better!

Whilst looking through my notes and photographs I was reminded of the following interesting observation I made on 12 December 2009. Incidentally this was the same day I first observed Snub fin dolphins at Ella Bay but that’s another story.
During this Ella Bay beach walk I was surprised when I accidentally disturbed a pair of White-bellied Sea-eagles that were on the ground near the high tide mark.

I snapped a photo of each bird as they flew away.

This photo was taken at 0834 hrs + 12 seconds
And I photographed the other bird seconds later
The pair had probably been feeding on something so I looked for the prey item.

The first thing I noticed was the prominent scratch marks left in the sand by the birds massive talons.
For those of you that have never seen a White-bellied Sea-eagle’s talons here is a close up!
Just the thing for snatching slippery aquatic creatures from the water!

I found some entrails left on the ground but no carcass.
I could not help but be distracted by the beauty of the tracks that these majestic birds had left in the sand and the drag marks made by those huge talons were awesome.
Of course the size of these tracks was nothing to be sneezed at either!
I was distracted by a crab that had boldly stood his ground after I caught it eating some scraps.
The eagle footprint in the background will give you some idea of scale!
Ok enough distractions it was back to the serious job of locating what the birds had been eating and I found their rather smelly breakfast next to some leaf litter.
To my surprise it was a toxic toadfish that the White-bellies Sea-eagles had been feasting on.

Before I continue I want to give a bit of a warning so listen up! Toadfish are VERY poisonous and eating ANY part of them can and most probably will kill you. Our seas are full of wonderful fish to eat and these toxic critters are definitely not one of them!

The toxins in a toadfish are concentrated in the skin and the internal organs (liver I seem to recall) so it was interesting to note the skin had been cut to expose the flesh underneath.

It was certainly unusual feeding behaviour as this toxic toadfish was scavenged (I found it by scent eventually) and it was far from fresh.

I was curious to find out if the consumption of toadfish by White- bellied Sea eagles had been observed by others and I was happy to discover that it had!

A report by James A Fitzsimons from Deakin University describes a very similar event. I recommend checking out the linked PDF report as it is a very interesting short story: "The Taking of a Dead Prickly Toadfish Contusus brevicaudas by a White-Bellied Sea Eagle Haliaeetus leucogaster".

Respect to Mr Fitzsimons for his thought provoking report and I must agree that the ability to utilise toxic toadfish as a food source which other scavengers would bypass could give White-breasted sea eagles an advantage over other coastal scavengers.

Toadfish are commonly washed up at Ella Bay and this is the first time I have seen them scavenged by anything!

Cheers Russ

4 comments:

  1. Good follow-through on the story, Russell.
    Not just a couple of shots, but a full story.
    Like it.
    Cheers
    Denis

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  2. Thank you Denis.
    It makes for a lot more work to tell a whole story but I always try to write something I would like to read myself. I must admit i am never short of subject matter at an amazing place like Ella Bay, it's more a matter of what I feel has priority at the time. Some observations are too interesting to ignore!

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  3. Nice observation Russell! Thanks for sharing, your stories are always interesting. I have never encountered a White-bellied sea eagle before (though there are some in Singapore) so this was truly a delightful read. :)

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  4. Thank you for your compliment Phong and I'm sure you will meet the eagle if you keep up your coastal visits as you have been. I really enjoyed your sand bubbler crab story and video at http://star-charmed.blogspot.com/2009/12/tanah-merah-beach-18-dec-2009.html as I didn't know much about these little critters which I often see in this area.
    Your own blog is looking great too!

    ReplyDelete

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