About Me

My photo
Canberra-based naturalist, conservationist, educator since 1980. I’m passionate about the natural world (especially the southern hemisphere), and trying to understand it and to share such understandings. To that aim I’ve written several books (most recently 'Birds in Their Habitats' and 'Australian Bird Names; origins and meanings'), run tours all over Australia, and for the last decade to South America, done a lot of ABC radio work, chaired a government environmental advisory committee and taught many adult education classes – and of course presented this blog, since 2012. I am the recipient of the Australian Natural History Medallion, the Australian Plants Award and most recently a Medal of the Order of Australia for ‘services to conservation and the environment’. I live happily in suburban Duffy with my partner Louise surrounded by a dense native garden and lots of birds.

Thursday, 15 July 2021

Shaba National Reserve; superb 'outback Kenya'

For the natural history aficionados among us (and surely that's anyone reading this blog), Kenya calls  loudly and clearly, even if we can't answer the call at the moment. Amboseli, Mount Kenya, the Maasai Mara and Tsavo are all eagerly sought destinations, but Shaba? Or Buffalo Springs? Perhaps not quite so much, but I'm hoping that in a small way I can do something about that. 

The green-fringed Ewaso Nyiro River flowing through a semi-arid volcanic landscape at Shaba.

Shaba is one of three adjacent reserves safely right in the centre of Kenya, though tours that do go there usually describe it as in the north; that's only relative to the bigger attractions though. 

The red arrow points to Shaba; note that Maasai Mara, Amboseli and Tsavo
are all down on the southern border with Tanzania (though you'll probably have
to click on the map to see that detail).

Shaba, along with adjacent Buffalo Springs and Samburu, was declared a reserve in 1974; Shaba is the largest of the three, at 23,900ha. Despite the designation of national reserve, it is actually managed by the local county council rather than the very experienced national parks service. I'm sure there's some political history there but I'm not aware of the details. 

The vertical red line is a major highway leading north from Nairobi to Ethiopia.
The Ewaso Nyiro River forms the northern boundary of Shaba and more or less
separates Samburu and Buffalo Springs.
I was going to write a single post about the whole unit, but there are obvious differences between the landscapes of Shaba and the western parks, and too much for a single post, so I'll leave Buffalo Springs for later (we didn't get into Samburu). I love the dry country of Australia, and so was very excited to be going into this different semi-arid landscape, which was the furthest north we went in East Africa, and with strong elements of the Horn of Africa among the animals, which caught my imagination when I first read about the trip. (I'd been a bit further north in Uganda, but I think of that as Central Africa, and it was very different again). 
 
Our lodge on the river was really more of a resort, and seemed a bit incongruous in the setting, with swimming pool and lush lawns; I think it was just outside the reserve. Our impression was that many of our fellow guests didn't venture far from the (excellent) buffet and the pool. It was a lovely setting on the river though.
Walking to breakfast pre-dawn (us that is, though the baboon was probably crossing
the river to try his chance around the restaurant). The Marabou was happy in the water.
At the lodge, big Nile Crocodiles come up on the bank at night, under lights, where doubtless they are fed. They are impressive animals.
 
They lie just below the path, with guards keeping an eye on them (and us, I imagine).

We did a couple of excellent drives, in late afternoon and early morning, and again as we left in early afternoon to cross the road to Buffalo Springs. The sandy plains are dominated by steep-sided volcanic plugs and ridges; the sand is comprised of eroded material from these outcrops.


These Umbrella Thorntrees are either Vachellia (formerly Acacia) elatior or V. tortilis;
both are present and look pretty similar from a distance.


The Doum Palms Hyphaene compressa (though some describe these as H. thebaica) are
characteristic of the park, and of many hot East African landscapes. Both species
are widespread and it could be that both are present.

The Doum Palms mostly grow along the river or near soaks. The branched form is
typical of the genus; most other palms are single-stemmed.

Succulents such as these big euphorbias are another feature of the plains and slopes.

Also characteristic are the huge and knobbly termite nest 'castles';
presumably, as in the Australian tropical savannas, the termites are reliant on the grasses.

As is often the case in Africa it's hard to say whether the birds or mammals are more exciting. I don't feel a need to take sides, but let's start with some birds, and in particular with one I was really looking forward to seeing. Until recently it was accepted that there is only one species of ostrich, but we now know there are two, with the Somali Ostrich Struthio molybdophanes replacing the widespread Common Ostrich S. camelus in the far north-east of Africa.

Male Somali Ostriches have distinctive blue-grey necks and legs, in contrast to the white neck
and pink legs of the Common Ostrich. They also lack the white ring around the lower neck and
like scrubbier country than the generally grassland southern species.

Here are some other north-eastern Africa specials which I was especially happy to see.

Female Buff-crested Bustard Lophotis gindiana; a bird of the arid bushlands,
about which not a lot seems to be known. It is beautifully patterned.

Black-faced Sandgrouse Pterocles decoratus. I'm a big fan of sandgrouse, though
I've not had many opportunities to get to know them. We regularly saw these attractive
birds on and by the roads. Again it seems that not a lot of work has been done in
this part of the world, which is perhaps not surprising.

Vulturine Guineafowl Acryllium vulturinum, a truly spectacular big bird -
the largest of the guineafowl - also restricted to the Horn of Africa and
adjacent countries. Like other guineafowl it congregates in big flocks,
but strangely we only saw two birds, and both were among the much more
familiar Helmeted Guineafowl Numida meleagris.

Male Eastern Violet-backed Sunbird Anthreptes orientalis, a truly
lovely little north-eastern special. Click on the photo to see the delightful
violet highlight on his back.

Eastern Yellow-billed Hornbill Tockus flavirostris. Previously there was just
one widespread species of Yellow-billed Hornbill recognised, but now the
north-eastern birds are separated. One obvious difference is the skin around
the eye - black here, red in the southern species. And I do like hornbills!

Red-bellied Parrots Poicephalus rufiventris (which should by rights be called
Orange-breasted, but you can't see it in this photo anyway) are yet another
bird of the arid and semi-arid north-east. Acacia seeds, which these may have
been snacking on before we distracted them, are an important food item.
Other Shaba birds that we enjoyed are more widespread in Africa, but I never tire of them so I hope you don't either. 

Black-bellied Bustards Lissotis melanogaster are found in grasslands across much
of sub-Saharan Africa. This is the male (she lacks the snappy black waistcoat).
I love that slightly manic stare.

Cinnamon-breasted Buntings Emberiza tahapisi have a similarly widespread
distribution but, like this one, are generally found on rocky hillsides.
However it had hitherto eluded me, and I recall it fondly as being my hundredth new
bird for this glorious trip.

Purple Roller Coracias naevius, yet another widespread African bird which I'm always
glad to see again, though it's not as colourful as many other rollers. It typically sits high
in thorn bushes (or on wires) in order to pounce on insects, spiders and small reptiles on the ground.

Rosy-throated Longclaw Macronyx ameliae. To an Australian, from a continent
with just one pipit, very sombrely clad, pipits such as longclaws are an exciting
revelation. They also sit up in bushes and hold singing contests.

Tawny Eagle Aquila rapax. This magnificent predator is found across Africa and India,
and scattered in the Middle East. They hunt hares and small antelopes, large birds such as
hornbills, bustards and guineafowl, and lizards.

White-throated Bee-eater Merops albicollis. Bee-eaters are another favourite group
of mine, and this one is well up there. It has an interesting life history, breeding
(when it rains) right across the southern edge of the Sahara, then flying hundreds of
kilometres south to spend the rest of the year in the tropical forests of central Africa.
The mammals, as I've noted, are equally impressive, in numbers and diversity, and for the presence of species not found much further south. As we with the birds, let's start with the biggest.

African Bush Elephants Loxodonta africana are well known as the largest living land
mammals; a big male can weigh ten tonnes. Tragically they are now listed internationally
as Endangered, but the Shaba park system supports an apparently healthy population.
Elephants - eg in Namibia - can live in desert situations, but in this dry land they have the
invaluable resource of the Ewaso Nyiro River. More on that when I post on the
other part of the reserve system, where we watched a herd drinking and bathing.


Reticulated Giraffes; these strongly-patterned giraffes are a sub-species
of the Northern Giraffe Giraffa camelopardalis. Giraffe taxonomy is still vexed,
but the knots are unravelling with the help of ever more powerful tools.
The existence of three species is now widely (but not universally) accepted;
my go-to reference for mammal taxonomy is the mighty Illustrated Checklist
of the Mammals of the World
, published in 2020 by Lynx Editions..
However a very recent study (2021) using whole-genome analysis
suggests a fourth species - this Reticulated Giraffe, which would be Giraffa reticulata.
These things might seem of little practical interest, but in terms of conservation they are
critical. There has been a tendency to say 'well, it's just a subspecies, we can afford to
lose it if necessary'. I think that's fallacious anyway (a subspecies is evolution in action)
but it becomes catastrophic if the population is really a full species..

And on that general theme (though less controversially), while we often think of  'the Zebra' there are actually three zebras, two of which have limited ranges. One of them, Grevy's Zebra Equus grevyi, is found only in Kenya and Ethiopia. Fortunately for me its range includes Shaba, and this was another exciting moment for me.


Grevy's Zebra is an Endangered Species, but we later saw herds of them over the
Highway in Buffalo Springs. This was the first one for us though. Note the white
belly and narrow stripes on the rump, which distinguish it from the other two zebra species.
See here for more on this (but note that the discussion on giraffes there was written
before the recent publications).
Yet another Horn of Africa special that I'd looked forward to was the Desert Warthog Phacochoerus aethiopicus. The familiar Common Warthog P. africanus lives across most of the rest of the continent, but the story's not quite that simple. Until the 1860s another population of 'Desert' Warthog lived thousands of kilometres away in South Africa.

The key differences from Common Warthogs are in somewhat obscure features like
teeth, but one clue in this picture (at least if it is enlarged) is in the curled-back ear tips.
As you might expect, antelopes dominated the larger mammals in terms of species (and numbers). Many of these too are restricted to north-eastern Africa.

Galla Oryx Oryx gallarum. The oryxes comprise a group of big powerful antelopes, lovers
of arid lands. This one lives only in northern Kenya and adjacent Uganda.
Gerenuks were also high on my wish list for this trip. They are ridiculously slender and graceful antelopes, extended to browse shrubs out of the reach of other species (except giraffes). There are two species. The Northern Gerenuk Litocranius sclateri lives in a tiny area in Djibouti on the Gulf of Aden. The Southern Gerenuk L. walleri has a larger range, but still only from north-eastern Tanzania to Somalia. 

Southern Gerenuk females in the Shaba landscape.

Male Southern Gerenuk, a wonderful animal that made my heart sing.
Guenther's Dik-dik Madoqua guentheri, yet another Horn special!
There are 14 species of dik-dik, diminutive antelopes (this one weighs less than 5kg)
each occupying a small range, scattered across Africa, mostly in the east.
And finally of the north-east African antelope endemics, the Northern Kudu Strepsiceros chora is every bit as handsome and imposing as the other three kudus now recognised.
We intercepted a small group of Northern Kudus walking along the river bed while going
to drink in the heat of the day as we left.
Male above with the superb spiral horns, female below.
Compared with all these, the Ellipsen Waterbuck Kobus ellipsiprymnus is very widespread, extending through east Africa to South Africa. I'm always pleased to see them though.
Male Ellipsen Waterbuck taking a break in the limited shade available.
And with all these grazers there are bound to be predators. Lions and Leopards are both present (Joy Adamson's book Born Free was set here), though we didn't encounter any. Our one cat though was much rarer than these!
Cheetah Acinonyx jubatus, also seeking thorntree shade near the road.
We saw these lovely animals, a prize of any African trip, in no less than four parks
in the course of our three weeks. We were very fortunate indeed!
And we felt very fortunate to have had the opportunity to visit this wonderful off-the-track park with its wealth of restricted range species that would be hard to see safely elsewhere I imagine.

The Marabou in the predawn river isn't at all hard to find, but it's one of the images of Shaba that I'll treasure for the rest of my life. If you're able to get to Kenya in the future (and if you can you certainly should) be sure to incorporate Shaba-Buffalo Springs into your itinerary. It's special.


NEXT POSTING THURSDAY 5 AUGUST

I love to receive your comments and in future will be notifying you personally by email when a new posting appears, if you'd like me to. All current subscribers have been added to this mailing list and have already been contacted.
This will mean one email every three weeks at the current rate of posting. 
I promise never to use the list for any other purpose and will never share it.
Should you wish to be added to it, just send me an email at
calochilus51@internode.on.net.
You can ask to be removed from the list at any time,
or could simply mark an email as Spam, so you won't see future ones.
Thank you!


Thursday, 24 June 2021

Living on Fish

A while ago I offered a post on some of the huge number of bird species that live by eating insects; the numbers involved are staggering. At least equally so, and in terms of sheer mass probably more so, are the numbers of animals that live wholly or significantly on fish. Mostly I'll be talking about birds again, but not entirely. 

Pied Kingfisher Ceryle rudis, Queen Elizabeth NP, Uganda.
The fish resource, though severely depleted by human overfishing, is extraordinary. One authoritative source puts the annual human wild fish catch at 90-95 million tonnes. It's hard to imagine that in terms of numbers of fish, and of course many animals take fish smaller than those generally consumed by people.

Moreover fish is a food high in energy and protein, so energy-consuming hunting strategies can be profitably applied. The Pied Kingfisher above could well have caught his lunch (and it is a he, with that broad breast band) by hovering, which burns lots of energy. 

Pied Kingfisher hovering, Amboseli NP, Kenya.
Many birds plunge into the water from above, or swim on the surface then dive, and pursue the fish underwater, a high energy game indeed. Many of these birds hunt in flocks, which are sometimes vast, converging on schools of fish which can number millions of potential prey items. To encounter such a hunt is among the most dramatic spectacles nature can afford us.

Cormorants (several species) converging on a huge fish school, Humboldt Current, northern Chile.
This is only a small part of the vast loose flock that streamed out to sea in response to other
birds already there.
Kelp Gulls Larus dominicanus and Black-browed Albatross Thalassarche melanophris in the
Strait of Magellan; upwelling cold waters provide the richest fisheries.
Blue-footed Boobies Sula nebouxii (again a tiny part of a flock of hundreds) smashing into the water
from tens of metres up, Galápagos. Note how they close their wings just before they hit the
water. They have no nostrils, which would be a serious disadvantage here.

Peruvian Pelicans Pelecanus thagus diving, Isla de Chiloé, southern Chile.
To an Australian, seeing the two big brown American pelicans diving from on high is a real surprise. Australian pelicans (which are bigger), hunt by swimming, then dipping their huge bills with elastic pouch into the water. They too often hunt in flocks however, chasing the fish schools, often accompanied by cormorants.
Australian Pelicans Pelecanus conspicillatus and Pied Cormorants Phalacrocorax varius,
Longreach Waterhole near Elliott, Northern Territory.

Australian Pelicans fishing, Canberra. The water here is shallow so they had to turn their
heads side on to submerge them. They scoop up water in the bill pouch and squeeze it out, retaining
fish and other prey items.     

 
Pelicans waiting for fish - sometimes stunned by the turbulence - to come through the lock
at Blanchetown on the River Murray, South Australia. The resting cormorants are
presumably sated; you can catch enough fish to fill your energy needs in
a relatively short time.

The cormorants benefit from the fish stirred up by the bigger birds, and will even snatch fish from the corners of a pelican's beak. They of course do pursue the fish underwater.

Little Black Cormorants Phalacrocorax sulcirostris, fishing in Kinchega NP,
western New South Wales.
Fish are slippery - they have an antibiotic surface slime and very smooth scales for sliding efficiently through the water - so a specialised bill is required. Cormorant bills are strongly hooked.
Little Black Cormorant, Coffs Harbour, NSW.
You'll see the hook better if you click on the picture to enlarge it.
Penguins and petrels and shearwaters have similar hooks.
Flesh-footed Shearwaters Ardenna carneipes, Lord Howe Island.
However many effective fish-eaters do not. Darters - a group of four diving fishers superficially resembling cormorants - tend to stalk along the bottom and ambush their prey rather than actively pursuing it like a cormorant. They have sharp-tipped bills and tend to stab upwards, surfacing and swallowing the stricken fish head-first.
Female Australian Darter Anhinga novaehollandiae with fish.
The weird kink in the neck is due to a hinge between the eighth and ninth
cervical vertebrae which enables the bird to thrust its neck forward like a spear.
The bill actually has little serrations on the inner edges to assist in swallowing.
This can be seen better in other species, including these Royal Spoonbills Platalea regia.
Royal Spoonbills at Jerrabomberra Wetlands, Canberra. The one on the left is swallowing a small fish.
Below you can see the bill serrations if you click on the photo.

These spoonbills are hunting primarily by touch by means of a 'bill tip organ' comprising many thousands of tightly packed sensors both in the tip of the bill and in the upper and lower jaws. These combine touch and taste and cause the bill to snap shut if it encounters something edible. Many birds which hunt food in mud and muddy water have such sensors.

Wood Storks Mycteria americana, Pantanal, south-eastern Brazil.
The really big storks have such organs too, but often their fish prey is so big that they can rely on their vision.
Jabiru Jabiru mycteria with big fish, Pantanal.
Despite the bird's huge size, it struggled for a long time to subdue and swallow this mighty meal.
However I doubt that it needed another one that day!

Saddle-billed Stork Ephippiorhynchus senegalensis, with big catfish (I think),
Amboseli NP, Kenya.
A slightly different use of the bill-tip organ is applied by the fascinating skimmers, three distinctive species in the gull and tern family. Their bottom mandible is much longer than the upper. They fly along the water surface trailing the tip of the bottom one in the water and when it encounters a fish or other food item the bill snaps shut on it.
Black Skimmers Rynchops niger;
Pantanal above, and Isla de Chiloé, southern Chile, below.


Fish-eating birds of prey - fishing eagles, ospreys and even fishing owls - certainly have an appropriate hooked bill, but in fact they inherited that, ready evolved, from non-fishing ancestors. They catch their fish using powerful clawed feet.
Eastern Osprey Pandion cristatus, Hervey Bay, Queensland.
The two closely-related osprey species are found all over the world; they are the only
day-time birds of prey to be exclusively fish eaters. Their large back-hooked claws
differ from those of most fishing eagles, and are adapted to slippery fish.

White-bellied Sea Eagle Haliaeetus leucogaster carrying fish dinner,
Port Macquarie, NSW.
African Fish Eagle Haliaeetus vocifer, Queen Elizabeth NP, Uganda.
The ten species of fishing eagle, found across the globe, are now
regarded as all being in the one genus. Though the claws aren't hooked,
the power of the feet is evident in this photo.
Grey-headed Fish Eagle Haliaeetus ichthyaetu, Sabah, Malaysian Borneo.
Until recently this and another species were regarded as separate from the other
fish eagles; they are even more fish-reliant than the others and it is no coincidence
that they have oprey-like recurved claws.

Fishing owls are found both in Africa and Asia, with three species each; the two groups are quite separate and the African ones differ in being almost exclusively fish-reliant.

Buffy Fish Owl Ketupa ketupu, Kinabatangan River, Sabah.
The African fishing owls plunge their legs into the water like fishing eagles,
but the Asian ones are more fastidious, not liking to get their feathers wet.
The many species of abundant gulls, all over the world, do catch fish, but they also scavenge many fish carcases; these days of course many of these are due to discards from human fishing.
Pacific Gull Larus pacificus, Esperance, Western Australia.

Silver Gull Chroicocephalus novaehollandiae, Cairns, north Queensland.
Many marine mammals (especially seals, sea lions and toothed whales) and some freshwater ones are fish eaters. Of these some of the best-known and most specialised are the otters, a group of highly specialised aquatic weasels, some of them quite large. 
The magnificent Giant Otter Pteronura brasiliensis, here in the Pantanal of Brazil,
showing its beautifully adapted paddle-shaped tail.

Giant Otters sharing - and squabbling over - fish in the Manu section
of Peruvian Amazonia. These two areas are relative strongholds of this superb animal,
which can grow up to 2.5 metres long and weigh over 30kg. Populations though are
tragically depleted by illegal hunting for its fur. They are strongly gregarious.


Neotropical Otter Lontra longicaudis, Pantanal, in a roadside lagoon.
About half the size of the Giant Otter and solitary, it is not well known.

The Marine Otter Lontra felina, here off the Isla de Chiloé, southern Chile,
is rare and is also poorly understood. It is quite different from the
Sea Otter of North America.

There are fish-eating reptiles, most notably crocodilians, all of which eat a lot of fish; some eat little or nothing else.

Yacaré Caiman Caiman yacare with substantial fish lunch, Pantanal.
And there are even some fish-eating invertebrates, from sea anemones to insects such as giant water bugs and dragonfly larvae, to spiders. The genus of big fishing spiders, Dolomedes, is found across the world. The long-legged spiders run across the water surface where they seize and deliver a venomous bite to fish and invertebrates.
Fishing spiders in Yasuní NP, Ecuadorian Amazonia above,
and southern Sarawak, Malaysian Borneo, below.

If you like fish, you're not alone. Hopefully this post might have offered you a broader perspective on the fish dinner.

Ringed Kingfisher Megaceryle torquata with fish, Pantanal.

NEXT POSTING THURSDAY 15 JULY

I love to receive your comments and in future will be notifying you personally by email when a new posting appears, if you'd like me to. All current subscribers have been added to this mailing list and have already been contacted.
This will mean one email every three weeks at the current rate of posting. 
I promise never to use the list for any other purpose and will never share it.
Should you wish to be added to it, just send me an email at
calochilus51@internode.on.net.
You can ask to be removed from the list at any time,
or could simply mark an email as Spam, so you won't see future ones.
Thank you!