I say this far too frequently for it to warrant much merit but this is definitely a #favebird. Not only is it a highly skilled snake assassin but it has some rather fanciful “hair” to boot.
This one was solved pretty quickly on #BeakoftheWeek by our resident expert but it was mistaken for quite a few other accipitriformes first.
Check out the video below for a quick run through about this species before diving into a bit more detail.
What does it look like?
This rather large bird is over a metre tall (125-150cm), that is almost as tall as Kylie Minogue! I would love to say I have seen one of these birds in the wild, but I Should Be So Lucky. I will have to make do with wonderful pictures like the one below for the time being.
This species weighs between 2 and 4.5kg and has a large wingspan of up to 215cm (as wide as Shaquille O’Neal is tall- wow). It is an unmistakable bird with it’s long pink legs, bare orange face and black crest feathers. Males are similar to females, although females are slightly less blue in appearance and juveniles have a shorter tail and crest.
Moving swiftly away from celebrity heights…
Xeno canto has let us down on this occasion so the best I can do is relate a description of their calls from the fantastic Handbook of the Birds of the World. Their most frequent call, which they make whilst perched/in flight is described as a high-pitched “ko-ko-ko-ko-ka”. They can also be heard making a more audible “kowaaaaa” and a “cockerel-like broken “kurrk-urr””. I don’t know about you but I feel like I could do quite a good impression of a secretary bird now, thanks again HBW.
Where can you find this bird?
Endemic to Africa the secretarybird is typically found in open grassland and savannah in the sub-Sahara and tends to nest and roost in Acacia trees. As you can see from the range map below they are found extensively across Africa.
This species isn’t fussy, as long as there is a good level of food availability they will nest at any time of the year. Secretarybirds hold territories of 25-45km² in which they build their nests. Nests are formed 3-7.5m from the ground (although they have been seen much higher at 36m) on top of low trees such as an Acacia. The base of the nests is formed with sticks which are then lined with grass, wool and dung. They sometimes re-use nests but more often than not a new one is built.
One-three eggs are laid, which are then incubated by both sexes (42-46 days). The chicks remain in the nest for typically 75-90 days, and can remain dependent for 62-105 days.
You would be mistaken to think the secretarybird restricts its diet to our serpentine friends, it mostly feeds on arthropods. Particular faves are beetles and grasshoppers, but it isn’t a finicky eater. They have been known to eat a wide range of small animals, ranging from lizards and frogs to tortoises, squirrels, hedgehogs, hares and birds eggs and young.
In order to kill its prey is usually kicks them to death with its long legs and strong toes, before swallowing smaller prey whole and tearing larger prey apart whilst holding it down.
This species is known to hunt around grass fires, eating prey as it tries to escape/if it has been killed by the inferno. What a way to go.
Unfortunately this species is listed as “Vulnerable” on the IUCN Redlist, with some surveys estimating that total numbers are only in five figures. Rapid declines have been seen across much of its range, with no sightings occurring in Western African making it perhaps the most threatened raptor in the region.
There are number of factors which could be causing the decline in this species, such as cultivation, urbanisation, burning of grasslands reducing prey numbers and severe drought. It is hoped that by educating locals on the threats facing this species it will help to lessen this decline.
I have gone for a mix of further reading today, a bit of science mixed in with a bit of art.
Let’s start with art. The illustration below is by Louis Agassiz Fuertes (b1874, d1927), a man synonymous with ornithological art. He produced thousands of drawings and paintings in various mediums throughout his lifetime before tragically dying in a car accident.
Fuertes made his artwork from animals in their natural setting, as well as from fresh study specimens and in order to create these masterpieces Fuertes went on many expeditions, travelling thoughout much of the Americas and Africa.
By design this further reading is intended to whet the appetite and encourage you to go off and learn more. I recommend doing a simple search to see more of his illustrations to start with (here is his fantastic white-cheeked hornbill). John James Audubon, whom we have spoken about previously (click link and scroll down to further reading) was perhaps the most famous ornithological artist and Frank Chapman, curator of the American Natural History Museum who collaborated with Fuertes many times, wrote a comparison of Audubon’s and Fuertes’s work and personalities that can be read here. Frank Chapman also wrote an obituary of Fuertes in Auk where you can see in what high esteem he was held and read more about his achievements.
Now for a quick bit of science! Imagine the importance of accuracy when targeting a venomous snake, the consequences of missing could be deadly. This journal article (S.Portugal et al. 2016) looks into the locomotion and mechanisms behind the secretarybird’s kick and gives you a great insight into just how powerful this bird’s kick really is.
BirdLife International. 2013. Sagittarius serpentarius. The IUCN Red List of Threatened Species 2013: e.T22696221A49946506.Downloaded on 23 August 2016.
Kemp, A.C., Kirwan, G.M., Christie, D.A. & Marks, J.S. (2016). Secretarybird (Sagittarius serpentarius). In: del Hoyo, J., Elliott, A., Sargatal, J., Christie, D.A. & de Juana, E. (eds.).Handbook of the Birds of the World Alive. Lynx Edicions, Barcelona. (retrieved fromhttp://www.hbw.com/node/53186 on 23 August 2016).
Images and Videos
BirdLife International and NatureServe (2014) Bird Species Distribution Maps of the World. 2013. Sagittarius serpentarius. The IUCN Red List of Threatened Species. Version 2016-1.
Planet Doc Full Documentaries. 2015. Secretary Birds of Africa | Nature. [Online]. [23/08/2016]. Available from: https://www.youtube.com/watch?v=t1UEneEPZO8.