Submitted by admin on Mon, 2011-05-23 08:11.
"Lioness waiting for rain" Tarangire NP - which is less than two hours from my home in Arusha
Nearly all the pictures in this post were taken in the period late September to early October.
The middle of October usually heralds the end of the long, cool, dry - a time when northern Tanzania gratefully receives its first rain showers after four months of drought.
Therefore this is the time of year when I wake and watch the migratory movements of birds with a bone dry focus.
The first real waves of my comrades, the Palearctic passerines, trickle through in October, to become a flood (we pray) during November and December.
These are my best and busiest birding months.
What's with Auspicious?
Well I now know that, in our time of cataclysmic environmental change, the actions of birds, their flights, are vital indicators.
They reveal what has happened, what is happening, and what is yet to come.
So don't you think, as I do, that our human so-called "leaders" (usually men!) should humbly take notice of Nature and do it now.
White Storks arriving beneath the active carbonite volcano of Ol-Doinyo Lengai. That's Maa for "the Home of God"
Let's just look at "Auspicious":
1590s, "of good omen,"
from Latin auspicium
"divination by observing the flight of birds,"
"one who takes signs from the flight of birds."
So the Romans were not all bad and, I suppose, neither are the Sino-Obamans -
the rulers who conspire to "keep things as they have been" at the end of the TCD
in C21 : TCD = Turbo-Capitalist Dynasty.
The Rift Valley in Maasailand, just 15 km north of the 'Ngorongoro highway', by Mto wa Mbu [the River of Mosquitoes]
(below) Striped Kingfisher by Steve Chalmers - 10/2007
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Submitted by admin on Mon, 2011-05-23 05:17.
Steve Chalmers October 2007 - Left alone birds take little notice of humans
More musings on Migration
There must be many instances of site fidelity observed among Palearctic-hatched passerines whilst they are in Africa.
I think there are quite a few examples in Roberts VII - if you can handle it!
Here in Arusha, we hosted a Spotted Flycatcher, for three consecutive years, that would come to roost each evening in exactly the same place, and in the same manner, right by our kitchen window.
It is sorely missed, as nowadays the SF is but a transient, lingering in the garden for just a few days (chiefly in October-December and February-April) despite my best efforts to create a much more welcoming fly-rich "home".
My qualitative and somewhat haphazard observations lead me to believe that many migrants adapt rapidly (or try to) to changing circumstances. Altering their routes across Africa to follow the storm tracks of the ITCZ. Surely this is the essence of the Afro-Palearctic migration system? We're benefiting from technology updating the ideas of Reginald Moreau and others. His "Sahel spring paradox" and all!
The world we birder-types have been seeing these past few decades is but a snapshot in the lifetime of these migrant species. And is it not very pleasing when one sees, as hopefully right now 'in the West', that despite our more recent massive depredations, migrant bird numbers in/from Africa can still seemingly bounce-back a bit, given zones with plenty of moisture over here and at least some kind of shamba-scrub-savanna mosaic in which they may forage. Aren't most of our familiar 'Palearctics' adapted to survive in such anthropogenic "savanna" habitats - even in Europe?
Over many thousands of years, they've had to become so! This seems especially compelling to me when one compares this Afro-Boreal system with that of most migrant species moving between tropical South America and North America, or between SE Asia and the northern Far East, which are/were covered in vast forests (and their birds) at both ends of the journey, and where there are, relatively, much smaller areas of savanna.
Further, that some species do not stay any longer than necessary in Europe is strongly indicated by e.g. that well-tracked female (Dutch) Black-tailed Godwit in June/July 2009!
But here of course, as an ecological refugee myself I am, of course, very biased.
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Submitted by admin on Sun, 2011-05-22 16:27.
St Mary's Isles of Scilly 2010
This April I travelled with a very keen Asian birder, Rob Tizard, on a "rapid transect across the entire shrike route".
Firstly from Arusha west to Lake Victoria back to Arusha and then from Arusha to Ushongo, Pangani and back - Pangani is on the East African coast just south of the Kenya/Tz border.
We went down to the coast on April 17 along the main NBI-Dar road passing Mount Meru, Kilimanjaro, Same, Segera and Muheza (East Usambaras).
We returned west on the same route during April 18/19/20 via a stop-over near Nyumba ya Mungu reservoir o/n on 19th.
There were no migrant shrikes visible on the way east to the coast even though [unusually] we had seen many, our first ones, at Ndutu (>30) way out in the steppes at the western Ngorongoro CAA/Serengeti NP boundary on April 15/16.
Their total absence along the main highway on April 17 was a remarkable and disturbing fact, as 'usually' there are scores and scores along this roadside by mid-April.
Early in the week, right on the Indian Ocean coastline, we had three significant rain storms, especially on 18/19, during which there were nice falls of both shrikes and also Spotted Flycatchers
On the slower return trip west and inland through good habitat (April 25-28) we saw a small number of female Red-backed Shrikes but, I thought, very few males 'and late for the time of year'.
Red-backed Shrikes, especially males who come through first, appeared to be in very small number and peaked well over a week late. They were much very concentrated in areas where there had been recent heavy yet isolated showers. Especially west of the Rift at Ndutu, and south of Pangani at the coast. There were very few birds in much of the central 200km wide part of their 'normal flyway route'. This northbound route is through the savannas of eastern Tz between Kilimanjaro and the coastal strip i.e. just south of Amboseli and the two Tsavo parks in Kenya. Thankfully a few males (day max. 15) reappeared at the coast with a flurry of females (day max.30) on April 18, 19 & 20.
Lesser Grey Shrikes, however, seemed to be in more normal numbers and occurred throughout our route with e.g. >50 on the edge of the teeming short grass plains (bucket loads of dung beetles here!) at Ndutu on April 16 and >20 on April 27/28 at Lark Plains, Mount Meru. And in the northern Maasai steppe south of Arusha. Albeit I would guess that LGS's might have peaked about a week later than average - over the past five years.
May they arrive north very soon.
The U Ted Tizard ITY:
April 10: arrival at a rather dry Kilimanjaro International Airport
April 11: Arusha to Manyara NP in the Rift Valley first LGS in Toyota LC
April 12: Rift Valley to Ngorongoro Crater to Ndutu
April 13: west thru Serengeti NP via western corridor and Ndbaga gate to Speke Bay Lodge on Lake Victoria-Nyanza
April 14: to Mugumu [Mara region] via Ikorongo & Ikoma 'game controlled areas', o/n Mugumu
April 15: trans Serengeti east via Ikoma gate to Ndutu Safari Lodge
April 16: to Arusha o/n at home
April 17: to Ushongo south of Pangani [Tanga] henceforth in Land Rover
April 18: rest day [no vehicular travel] o/n Ushongo
April 19: to Mike Bryden's plots, near Pangani town o/n Ushongo
April 20: Ushongo flat lands o/n Ushongo
April 21: finding the forest, Amboni. o/n Ushongo
April 22: Amboni forest (excellent) o/n Ushongo
April 23: to Amani East Usambaras o/n IUCN
April 24: at Amani East Usambaras o/n IUCN - a wet but productive day
April 25: to TPC Golf Village south of Moshi, via reservoir of Nyumba ya Mungu
April 26: to Arusha o/n at home
April 27: Lark Plains day; o/n at home
April 28: attempted Taita twitch to kopjes of Naberera's Maasai steppe (we failed); o/n at home
St. Mary's Isles of Scilly
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Submitted by admin on Sat, 2011-05-21 15:15.
Ngorongoro Crater: Hippo pools - Steve Chalmers
First off, here's a request from Acrocephalus and Hippopotamus to Homo-termes:
Stop screwing-up ... just scroll-up!
Of Rains, Listserves, Great Snipe, Thrush Nightingales and Homo-Termes
- "It's time for Africa"!
Yahoo! Twitter and Tweet?
Vismig can go global?
Now we have technological ability I've long dreamed of in order to create:
"Afro-boreal migration watch"
Great Snipe and Thrush Nightingale and their wintering adaptations in Africa during 2010-2011
Are we simply observing the contrasting fortunes of two species in two different parts of Africa, or are we appreciating the, ever-present, adaptation to climatic changes by migrant birds, which we don't yet appreciate?
Two examples: the Great Snipe and Thrush Nightingale 'wintering' across Africa 2010-2011?
This is Vismig intercontinental via the internet!
This is a very interesting observation indeed.
In Israel this year there is a very big drop in the numbers of birds passing during Spring comparing to last years.
Nevertheless many of the species seem to have had a lag of 2-3 weeks from their regular appearance dates.
Thrush Nightingales which are regularly seen from mid April and onwards around Eilat, were arriving this year only around the second week of May, and last week they were one of the most abundant species after Blackcaps.
I will be happy to hear more about the weather conditions you described regarding the 'greater horn' as this may very well be one of the key issues (except for the
'homo-termes' human pressures).
I'd rather go birding...
Itai Shanni Negev & Arave Region Coordinator,
Israel Ornithological Centre (BirdLife partner in Israel)
Society for the Protection of Nature in Israel (SPNI)
First of all, I have no idea what the breeding season was like in Sweden last year, nor do I know what may have happened to Swedish passerines on their way between Sweden and Africa, or between Africa and Sweden,
That being said, from James's and Abdi's responses one could hypothesise that migratory passerines, like migratory waterbirds, may show not only site fidelity but also opportunism: don't migrate further south than you have to to survive and to fuel up for the return trip. Sweden's Thrush Nightingales and Red-backed Shrikes may be low in numbers this year, and/or late, as mentioned by Abdi, because of drought conditions in northern East Africa during the past six months, as described by James. The Great Snipe discussed yesterday may be in Western Europe in greater number this year because of high rainfall in the West African Sahel last year (June-Sep/Oct). Perhaps Sweden's Whitethroats and Redstarts winter in West Africa rather than East Africa, hence their high numbers this year. Recoveries in Niger in West Africa, of birds ringed in Sweden, do include 2 Sedge Warblers and 2 Willow Warblers, in addition to 5 Ospreys, 2 Wood Sandpiper and 2 Caspian Terns. When are the Swedes coming to Niger to study and ring migratory passerines :-) ?
Related to poor conditions in the Sahel, the attached contribution by David Kusserow and myself may be of interest. In brief, in September, just at the end of the rainy season, when the passerines arrive from Europe, the Sahel is a green shore to the Sahara. In April, when they move back north, at the end of the dry season, the Sahel is an extension of the Sahara, EVERY year. In April, David, who lives in Niger not far from Lake Chad, picks up Redstarts, White-throats etc. that are heat struck before they even start to cross the Sahara. Some pictures of heat struck birds have just been put on the blingual (English and French) Niger Bird DataBase site, www.bromus.net/nibdab
(click on Photos and sort on order of entry).
May 21: are these birds not late in their passage through Somaliland?
What about Marsh Warbler which, so far as I am aware, has been very scarce this April-May in eastern Tanzania, or 'in the Horn' are they usually very much concentrated/channeled and farther east?
Incidentally the two shrikes appear to have passed in good numbers through here, many somewhat farther west than usual even though the Tanzanian shores of the Lake Victoria basin e.g including the western corridor of the Serengeti NP/Speke Bay were exceptionally dry up until ca March 20 when they received 65 mm in one night at SB Lodge.
It was not until Easter (i.e. mid-April) that the first real wave of shrikes came through the coastal strip at Tanga area (just south of Kenya border) coincident with some plentiful rainfall there.
These long-heavy rains seem to have arrived, and be lingering later, this season and so maybe many Palearctic migrants have likewise been forced, fat-wise, to delay their departure.
Very best wishes,
Abdi Jama here in Hargeisa, Somaliland!
We're seeing well-fed 'boat loads' of thrush nightingales as well as the common headed your way as I write this. There are excellent numbers of these nightingales as well as migrant shrikes (red-backed, lesser grey, and southern grey) and even common starts on a move your way in a long front all the way to 45E.
Hope and pray all reach your region safely.
Abdi A. Jama
I have posted this on the simplybirding.com forum for you.
Does Anders have contact details where folk can get hold of him?
October 31, 2010 on the "flood-plain" south of Mount Kilimanjaro
I suspect that the highly erratic, both spatially (they were especially localised and capricious last season) and also in terms of volume, vuli-rains which caused punishing droughts in many areas across the 'Greater Horn' [i.e. from Red Sea coastline in NE Africa down to southern Tanzania at least] during October- December may be at least partly responsible for this.
Furthermore light-aircraft pilots here in Arusha remarked that the the ITCZ rolled way south very quickly!
Certainly I felt that I was encountering/enjoying fewer than previously 'coming down' into Tanzania during the 'autumn' passage and boreal winter.
In wetter years before there have been several passing through the Arusha area, and off-passage for many days, e.g. up to four daily in our 'garden' during late November-December. And I clearly remember on many migrant mornings, in late November/early December 2010 that there appeared to be much more tension than usual between the 'dark ones' (Luscinia luscinia) - much chacking, churring and weeting, often ending in chases and scuffles in the leaf-litter!
So this year I think they moved through much more quickly, and interestingly were soon replaced by the 'pale ones' i.e. hafizi [Rufous] Nightingales, which in marked contrast, remained in good numbers until late in March. And of course L.l. likes to forage and 'winter' in markedly damper situations than does L. (m.) hafizi.
So what might have happened farther south I wonder?
Very pleased to see corroboration that the Sahel, despite the 'homo-termes' human pressures, is indeed bouncing back with [your] birds as wished!
Hope to see you here again sometime!
On 20 May 2011, at 23:08, Anders Waldenström wrote:
In Sweden we are urgently waiting for the Thrush Nightingales to arrive. In southern Sweden, so far, only few have arrived. At my local patch on the island of Oland, SE Sweden, where I normally at this time of year hear at least 4-5 singing males constantly, I have not heard one single singing male yet.
In Sweden we have a national database of birds and during the first three weeks of May only 72 Thrush Nightingales were reported, compared with 788 last year. You don´t have to have studied mathematics to realize that there is a reduction in 90% since 2010
I have contacted many other birders throughout Sweden and they all confirm this pattern. Red-backed Shrikes are also lacking in numbers, but they usually start arriving these days anyway.
At the other end of the scale Common Whitethroats are more common than usual, as well as Redstarts. As a matter of fact Common Snipes are also more common.
This all leads up to quite a few questions.
Has something occurred in the wintering grounds in eastern Africa? Has there been a serious drought?
It could be that they are delayed by inclement weather, strong headwinds or whatever? But it is usually very important for migrant songbirds to arrive at their breeding sites as early as possible in order to breed successfully, so being almost three weeks late must be a very serious matter.
Thus far we are very surprised and frustrated and we wonder a lot. That bird populations vary is normal, but a reduction in 90% in one year is ridiculous.
Does anyone of you living in Africa or elsewhere have any idea why our beloved summer guests haven´t arrived this year in their usual numbers?
Anders Waldenstrom, Oland SE Sweden
Thanks a lot for this, I'm alwasy interested in information pertinent to West Africa, particularly Niger, and birds. The two pictures of the Kennedy BRidge in Niamey didn't come across, could you send them to me separately? They look impressive on your website. Photo credits noted, of course.
There are very few records of Great Snipe in the Niger Bird DataBase,
: two singles and one group of 170, all by myself. Plus a single in Giraoudoux et al. (Avifaune du Niger, Malimbus 10). I have grave doubts about a record of about 400 from Kokoro wetland in NW Niger in August, that circulates in the literature: the same observers also report a lot of Black Storks and no Abdim's, very early for Black and at the time of year that Abdim's are still breeding locally.
From what I remember of the Great Snipe SSAP (single species action plan) some years ago, that a Norwegian contacted me about, the greatest number of observations of Great Snipe in West Africa was during autumn, the start of the dry season in that part of the world. When wetlands there dry out the birds may move on, and skip the then mostly dry West African wetlands on the way back in spring, at the end of the dry. This is similar to what Berthold and colleagues found for Eastern population White Storks: the move from the Nile Valley west into the Sahel in October (start of dry, still lots of green vegetation and grasshoppers (not locusts!)), then back to the Nile and on south in December-January, to the wet season and grasshoppers etc. in southern Africa. Western population storks don't do that, probably because the way back, west along the Sahel before going north to North Africa and Gibraltar, would be too difficult. See our comment on Berthold's paper, Ibis 145:499-501, which explains the ecology behind those movements in the Sahel (pdf available to those interested, 770 Kb).
So you may well be right about the cause for the surge of Great Snipe in West Africa: conditions were so good that they either did not need to move out of West Africa at all, or they could refuel there on the way back up.
Best wishes to all, Joost
Joost Brouwer PhD
coordinator Niger Bird DataBase NiBDaB (in English and French)
The Great Snipe spring surge of 2011
Apologies for cross-posting and yet, especially in these disturbing days, no apologies for the 'federal plagiarism'.
Abundant fresh water in the Sahel and Guinea zones during 2010/2011 might well have reduced 'winter' mortality in Great Snipe populations, and enhanced their survival, along more westerly migration routes?
If true, are there any observations which might suggest that some other "summer visitors", from winter quarters across the 'upper west' of Africa, may have benefited in a similar way?
After all it's only Birding/Bird watching, which as we all know:
"Is not really Rocket Science, yet it is greatly assisted by, Satellite Science."
All thanks must go to the 'surveillance technologies' of the NOAA and the Niger River Authority.
Is this not ob-fusca-tion?
"Now what do you, sharp-headed 'fellas', think of me and my fabulous flying folk?"
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It's not Rocket Science yet it is Satellite Science
Greatly enhanced wintering conditions across much of western Africa 2010/2011 !
Submitted by admin on Fri, 2011-05-20 02:30.
The Kennedy Bridge over the Niger River shown in May 2003 after the area's driest year since 1987.
Submitted by admin on Thu, 2011-04-07 09:19.
On August 14 2010 Keith Betton produced an alphabetical list of the 288 bird species on the African list currently with names in the English language that commemorate a person. He rightly thought this might be of interest to at least some members of the African Bird Club.
The ABC is of course currently based within the "Emerald Triangle" of conservation-business interests in south-eastern England; as are both the Oriental Bird Club and the Neotropical Bird Club. Keith added: "Clearly there are many others that have a person's surname [only] in their scientic name".
Sadly Levaillant's putative Hottentot servant girl-with-a-difference, Narina (as in Narina['s] Trogon), if she ever existed, seems to have been entirely forgotten.
I suppose that there's a 'Lesson' in this for all of us [check: René Primavère Lesson - for he's the beau who suggested her existence in the first place]!
Anyway the winners of this close-run contest are (or rather were) either:
Wilhelm Rüppell with at least eight birds named after him or ... er ... Sir somebody or Captain somebody Shelley with six.
However, unfortunately for the British (or rather English) they fielded at least two Shelley's in Africa, so the winner is, without any doubt, that long-lived German:
Wilhelm Peter Eduard Simon Rüppell (1794 - 1884)
A fabled zoologist, explorer, collector and author for whose family name the English seemingly prefer to write: Rueppell.
Now fittingly, at this very blog-typing moment, a Rüppell's [ or Black-tailed] Robin-chat Cossypha semirufa intercedens (Cabanis) is singing its-heart-out. Just here in the lush tangle right beside my window. This particular individual, a virtuoso and a half, one individual in a very handsome species (in both a fabulous genus and family) which must be one of the most greatest mimics in the [bird] world, sounds as if he is incorporating an imitation of a Green Hylia's twin call note "peee-peee" - it's like an old-fashioned [pre-World War II] mafioso automobile horn. However this is a West African forest species and doesn't occur anywhere near Arusha. So very suddenly I realise it must be an imitation of one of those standard Nokia message alerts.
What would Wilhelm have made of that?
Meanwhile my little own iApp's [Singing] Cisticola Cisticola (cantans) pictipennis (soon to-be-split at least by MacBook-users) remains skulking (in a wood-pile in the foreground) still waiting for that perfect african moment.
Keith's List of Names:
Hall's Giant Petrel
Maxwell's Black Weaver
Mrs. Moreau's Warbler
Prince Ruspoli's Turaco
Von der Decken's Hornbill
Thank you very much gentlemen - all of you, and especially Keith Betton, for going to the trouble of compiling this "list of honour". Yet I do wonder:
Will it be all the same in a hundred years?
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Can anyone out there identify this hawkmoth - my 2nd record of this species - which seemingly accompanies the rains into Arusha - at 1,400m (26/3/11)
Submitted by admin on Thu, 2011-03-31 10:20.
Submitted by admin on Wed, 2011-03-30 09:36.
Forever pulsing life "Lush-Dub" it's Africa's ecological heart beat and by now the whole world should be listening-in!
Lub-Dub .. >> .. Lush-Dub ..
A forest heart, the Congo basin, pumps-out the rains-of-life. Rains cascading outward across the Tropics of both Capricorn and Cancer, and by extension even toward the pole, providing summers of life, out there, up there, be it south-or-north.
Lush->: East Africa's Long Rains, the major moisture months. Myriad insects and abundant insectivorous birds spread northwards to the Sahel and beyond from March to June. Like April showers bringing forth May flowers they settle anywhere from the northern fringes of the Congo basin, across the Guinea savannas, the Sahel fringe and Sahara desert, catching insects as far away as Farewell (Greenland Wheatear), in Siberia's Yakutia tundra (Eastern Willow Warbler) and even beyond that across the Bering Strait into the Mackenzie delta of Canada (Red-throated Pipit and Northern Wheatear).
Dub->: Vuli rains. East Africa's Short Rains - from October to December. Coursing southwards these rains boost the birdlife of an austral spring and create a summer of life as far away as the Cape of Good Hope. They 'deliver' manna: as quail, cuckoo, bee-eater, roller, swift or swallow, and many other passerines besides, all the way down into Africa's temperate toe.
It seems obvious that this phenomenon is vital to the maintenace of a healthy life not only across Africa but also far beyond her shores. So why does Equatorial Africa's crucially important biannual ecological service to her neighbours, to Europe and to much of the rest of Asia (largely north of the Himalaya) and to southern Africa, remain unknown, ignored or, at best, unacknowledged?
Is it not time that the Congo's forests, that giant hydro-meteorological generating system (via the courier of the Inter Tropical Convergence Zone), be recognised for the provision of such a essential ecological services? Not least of which are the summer migrant lives who stream out of Africa: in the form of both insects and insectivorous birds.
Since moving to Arusha, in June 2005, this Birdman has become fascinated, if not utterly obsessed, by the seasonal "rains migrations" of myriad insects and of the birds that, as if in anticipation, 'follow' them. Migratory movements pulsing outwards from the very centre of Africa, her ever-moist, and as yet still green and forested heart. This heart is formed by the wide expanses of the Congo drainage system whose relatively unscathed forest and woodland communities provide both oxygen and moisture. It's a seasonal movement that helps sustain much of our idea of summer itself. For it is in essence the great sponge of the Congo basin which inspires these waves of life that break-out across the tropic lines, stream into the reawakening temperate lands, and even filter onto the sunlit pole beyond.
When still a boy, in 1972, I read and was enthralled by Reginald Moreau's pioneering book The Palearctic-African Bird Migration Systems. However one senses now that Reg Moreau lost an opportunity back there and then, or he simply got it wrong. Surely he should have entitled his work the Africa-Palearctic Bird Migration System?
Understandably enough though, Europeans, even most of our globalised euro-birders alive today, tend to think of those migratory Palearctic-breeding birds which "winter in Africa", such as Common Cuckoo, Willow Warbler, Spotted Flycatcher, Northern Wheatear, Common Nightingale, Barn Swallow and Common Swift, as fundamentally their birds. After all these are migrant species whose breeding range lies mostly within Europe. Thus they are their birds because currently these species breed within Europe in "summer", and then they only spend the "winter" in Africa. However this is a very narrow spatio-temporal view of such migration phenomena, one unbecoming to any globalised ecologist, birder, or bird watcher, alive in this interconnected century.
As has been said elsewhere, numerous times, in this Birdman blog, this migration system revolves around a vitally important tropical meteorological phenomenon called the Inter Tropical Convergence Zone (or inevitably - the ITCZ).
"The atmosphere is a vast heat engine, transferring heat from the tropics toward the poles.
In the tropics convection continually lifts warm, moist air up into the atmosphere. A semi-permanent line of convective clouds [the ITCZ] is easily visible on satellite images.
This rising air sets up giant convection cells north and south of the equatorial zone. Most of the moisture falls as rain over the tropics, but the air flows north and south and descends in the subtropical high-pressure zones. The descending air warms and becomes extremely dry, so this is where the world's deserts are found.
The air flows out from the relatively stationary, subtropical highs at the surface. Some returns toward the Equator, but a significant amount of warm air moves toward the poles where it encounters the cold dense air flowing from the poles."
Storm Dunlop in 1996 pp.172 - Collins Gem Weather
This ever moving "rain band" is at its heart a billowing gun-metal grey mountain range of the loftiest clouds on Earth. These mighty clouds, which even technological man must fly around, unleash raging thunder storms which deluge life-giving rain onto, the often parched, lands below. The storms move polewards, and back again, with the ebb and flow of each hemisphere's summer, tracking the apparent austral or boreal trajectory of the sun. Thus 'in a year' they alternately thunder across the tropic zones of either the southern or northern hemisphere. Associated with this, this lush-dub or lub-dub, is an almost incomprehensibly vast southward, or northward, movement of winged life; primarily of insects and of birds.
To look at one example: Common Swifts Apus apus apus vacate their breeding sites in northern, western and central Europe any time between (depending upon which population you consider) the beginning of August and the end of September. However, like most of the insectivorous birds which breed in the West and Central Palearctic, these swifts do not appear in significant numbers in equatorial East Africa until November-December. They arrive accompanying the first wave of the ITCZ as it sheds, somewhat erratically, the first "Short Rains" across the region. Similarly most of these same northern-breeding swifts do not return to their european nest sites until some time in April, May or even early June, again depending upon the location of the colony.
Here in East Africa the shorter rains, of November-December, typically dispense sufficient water to top-up soil moisture all across the land. This enables many of the region's plant communities to spring-out of a dormancy enforced by a drought of up to six months. A 'dry sleep' that has gripped much of the land. This dormancy is brought about by the long cool-and-dry season of eastern Africa; it's our relatively insect-less or 'winter' season. And of course it coincides neatly with the ITCZ having gone away, having tracked the apparent movement of the sun 'up there' into the northern hemisphere between April and August. And that period, of course, is the insect-rich summer breeding (and cropping) season upon which all life in northern lands depends.
Here it's the rain, and in the absence of severe cold, only the rain, that really matters to preserving life. Tropical rains which often cascade in torrential downpours, lashing the bush, the desiccated thicket and wilted scrub. Overnight the rain brings forth savanna leaves and grasses, whose unfurling in turn transforms zillions of 'aestivating' eggs, into caterpillars and other larvae, or ruptures the pupal casings of a soon-to-be airborne invertebrate horde. The airborne horde upon which, for example, all of our, and all of your, cuckoos, nightjars, swifts, swallows and martins depend - no matter where they hatched from their egg.
Just now, as a rain storm abates over Arsuha, our garden is full of flying termites, hundreds of thousands, disinterred by the soaking of the storm. A yellow-throated trochilus Willow Warbler, a fuscus Reed Warbler, a Garden Warbler, and a neumanni Spotted Flycatcher have 'fallen' from the leaden sky into our private 'Heligoland' - a bird trap (or migrant decoy) as yet with neither wire walls nor roof. Most times, as now, I can only hear these migrants, in the tangled thicket, my spikey protective quilt of alien, as well as indigenous, bush clearly visible through each of several windows, and which almost fills our "red roof wedge" - 'my' rented acre of 'our' Planet Earth. Fabulous and essential (to me at least) many beautiful avian migrants (inter-continental travellers all) are appearing - or at least calling - out of the greyness of dawn.
It seems I feel it more than most. No rain hereabouts will mean no termite hatches, and no termite alates (the winged reproductive caste) will mean there will be no swifts, no swallows or martins circling in the heavens above our garden! And no rain means fewer butterflies, and hardly any other 'fly' species (whether Orthopterans, Odonatids, Coleopterans, Dipterids), few 'flies' means few warblers, few chats and even fewer flycatchers.
The aforementioned bird species are, naturally enough, what most birders would consider very european birds. They are european because, currently and only currently, the breeding range of these species is largely within Europe and the 'Near and Middle East'... yet often, as slightly different taxa, those erstwhile 'subspecies', their range extends as far as Central Asia and even into Western Siberia ... Thus wider consideration of this, the Afro-Palearctic migration phenomenon, particularly when viewed from where we few afro-birders sit, and try to think, i.e. within tropical Africa itself, should clearly reveal, to any unbiased mind, a very different picture.
A picture wherein this fantastic migration, of insects as well as birds, proves to be very largely an extension of the great inter-tropical African rains migrations. Itself, for me, an awe-inspiring movement pulsing outward, tending either southwards (September-December) or northwards (March-June), from the Equator. To reiterate, think of these countless forms of life as a series of waves surging polewards - twice-yearly - from the Congo basin. South, or north, alternately, from Africa's evergreen heart,. Surging through the season, in wave after wave, on the storms of the advancing ITCZ. These inter-African movements, are the heart beat then, the
of life, and it is they sustain the afro-palearctic ecological system through the vicissitudes of time.
Now these migration pulsations involve currently incalculable numbers of more strictly African birds of a great many species. Recognising the ecological centrality of this biannual pulsation becomes especially compelling, even for a european, when one imagines the changes to the amplitude of these Afro-Palearctic migrations during previous periods of maximum glaciation. In those 'barren' icy times, up there, most of the bird movement between e.g. the present day West Asian peninsula, (which for too long we've been calling Europe), and today's Africa remained almost entirely within Africa!
So it must be obvious, to my mind anyway, taht it is within this intra-african seasonal flow, back and forth, that we should look for most of the antecedents of the great "north-south" or "south-north" or better yet "inbound-outbound" migrational flights that so enthrall us northerners, by rekindling summer joys, after the bleak austerities of winter.
Anf these are some of the flights which so impressed 'europeans' even as they themselves first walked-out, out of Africa, and became in essence what they did. Becoming have-ers rather than be-ers. Unfulfilled 'havings' instead of natural beings. I'm thinking of menfolk in the main, men who persuaded others to amass their chattels, as capital, and not simply as cattle(s). Men intent on industrialising and radically transforming (read: simplifying and weakening) entire swathes of landscape and, in so doing, unleashing ever greater amounts of carbon dioxide. Subduing those temperate zones, beyond the already degraded mid-latitude deserts where the ITCZ declines, at storm-swept positions nearer to the pole.
Later it was we europeans who exploited the trade winds and conquered the whole world. And we wrote so many very biased histories of our achievements. Stories wherein we ignored, or at best skated-around, our early acts of cold-blooded genocide, ecocide and matricide. For such behaviours, at such a large scale, were once upon a time largely contained within the Holarctic zone. Very sadly (at least to me) we northerners have triumphed. Temporarily. Via turbo-capitalism, for something like a second, we think we've succeeded in exporting these, our crass ecological attitudes, all around the world. Daily now, I read in the news, delivered to my Inbox, evidence that we have become a species indeed intent upon a-knock, knock, knocking on heaven's door. For truth like lemmings streaming to the brink!
As it is in the north so it is in Africa. And as old-ways agriculture everywhere, even across ever larger parts of Africa, is 'modernized', it's the traditionalists, and of course nature, who appear to most economic analysts to be the initial and, for the time being, only serious losers. So it does not really matter then does it?
Yet, for many, many moons, in my bones (and perhaps in your's too) we've known that with every old-growth corner that Africa (for example) looses, life 'in Europe' falters further and that, no longer gradually but all too rapidly, this Mother Earth who nurtured all of ourhuman inventiveness and fecundity, herself succumbs.
So when, (well might one cry), when oh.. when .. will the hungry ghosts who think they run this Titanic horror show - the captains of our shiny corporations, their media moguls and all 'our' puppet-minded [democratic] politicians - get it? A Capital question.
One might imagine, by the time they do, there'll be many a pallid face leering from the parapets of bridges. Roughly skewered faces, the skulls of those, who seldom if ever in this life considered, any of the rivers flowing past, the lives of others, streaming out there, beyond their petty will.
Perhaps right now these decision makers could reflect on why?
A single Swallow does not a summer make.
And surely now is not too late for us all to appreciate, if not yet to worship, the Lush-Dub beat of an Africa that remains alive, rather than the Lub-o'-Dosh, the worship of a Mammon soon-to-be dead!
The illustrations above depict five migrant species with different needs and distributional strategies, all to varying degrees flexible, in view of the ever-changing environmental conditions they must face. Yet all five remain in essence fundamentally African species. Discussions regarding subspecific breeding ranges, within fluid paleoclimatological and ecological paradigms, are scheduled for some later appendix!
Steve Rooke Sunbird/Wings Tanzania Safari
btw: we 'netted' over 410 species (seen well by most) in the twelve days tour.
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Submitted by admin on Mon, 2011-03-28 14:25.
Forever Pulsing Life: "Lub-Dub" Africa's ecological heart beat. The Rains-of-Life which cascade outward toward the pole each "summer"
Gallery forest along Grumeti river within Serengeti ecosystem; rains of November 2010
Lub: water, bugs and insectivorous birds - spread northward like April showers bringing forth May flowers, everywhere from the fringes of the Congo to Cape Farewell, Yakutia and beyond.
Dub: and again, spreading this time southward as the austral spring in November-December.
Yet why does Africa's crucially important annual ecological service to Europe and much of Asia remain unknown, ignored or, at best, unacknowledged?
Is it not time that the Congo hydro-meteorological generating system (via the ITCZ) be recognised for providing such an absolutely essential ecological service?
Since moving to Arusha, in East Africa, in June 2005 I for one have become fascinated, if not obsessed, by such seasonal "rains migrations" of both insects and the birds that follow them. Movements pulsing outwards from the very centre of Africa - our ever-moist green heart - that is of course the Congo basin. A seasonal movement - that sustains each summer - rivers of life that flow out across the tropic lines, to reawakening temperate lands and even to the sunlit pole beyond.
Understandably enough Europeans tend to think of migratory Palearctic-breeding birds that "winter in Africa", such as Common [or European] Cuckoo, Willow Warbler, Spotted Flycatcher, Common [or European] Swift and Barn Swallow, as
their birds. They are their's because currently these species breed within Europe.
Common Swifts Apus apus apus vacate their breeding sites in northern and central Europe any time between (depending upon which population you consider) the beginning of August and the end of September. However they, like many of the smaller insectivorous birds which breed in the West and Central Palearctic, do not appear in any numbers in equatorial East Africa until the rain-bearing waves of the ITCZ (Inter Tropical Convergence Zone) sheds their increasingly erratic "Short Rains" in November-December. Whilst these swifts do not return to their european nest sites until some time between March and June, again depending upon the location.
The Inter-Tropical Convergence Zone is a billowing recycling mountain of the mightiest, tallest clouds on Earth. The clouds nurture great storms of life-giving rain. Storms that move polewards, and back again with the ebb and flow of summer, tracking the apparent austral or boreal trajectory of the sun they thunder across the tropics of either the southern or northern hemisphere depending. Associated with this 'lub-dub' is an almost incomprehensibly vast poleward movement of winged life: of insects and birds.
An unidentified Hawk Moth (Sphingidae) brought by these rains to 'my study' on March 26, 2011
Here in East Africa the short rains of November-December typically dispense sufficient water to top-up soil moisture across the land. This enables many of the region's plant communities to spring-out of a dormancy enforced by drought. A 'dry sleep' that has gripped much of the land for up to six months. This dormancy is brought about by the long cool-and-dry season of eastern Africa; this is our relatively insect-less or 'winter' season. It coincides with the ITCZ having tracked the apparent movement of the sun 'up' into the northern hemisphere between April and August, which of course is the insect-rich summer breeding season of northern lands.
Rain, and only rain; rain which often cascades in torrential downpours, lashes the desiccated thicket and wilted scrub. Instantly the rain brings forth savanna leaves and grasses, whose unfurling in turn ruptures 'aestivating' eggs or pupal casings of an airborne invertebrate horde. This is the horde upon which all 'our' cuckoos, nightjars, swifts, seallows and martins - no matter where they were hatched - depend. Right now, as the rain abates, our garden is absolutely full of flying termites, hundreds of thousands, brought out by this storm. A yellow-throated trochilus Willow Warbler and a Spotted Flycatcher have fallen from the leaden sky into this private 'Heligoland', appearing in the bushes outside my window as if from nowhere. No rain hereabouts means no termites, and no termites naturally means no swifts, swallows or martins!
The aforementioned species are apparently very European birds. They are europeans because, currently, the breeding range of these species is largely within Europe and the 'Near and Middle East'... and Central Asia and Western Siberia ...
Thus wider consideration of the Afro-Palearctic migration phenomenon, particularly when viewed from where we few afro-birders sit and think, taht is within Africa itself, should clearly reveal to all a very different picture. One wherein this fantastic migration, of insects as well as birds, proves to be largely an extension of the great inter-tropical African rains migrations. An awe-inspiring movement pulsing outward, tending either southwards (October-December) or northwards (March-May), from the equator.
Countless forms of life surge polewards twice-yearly from the Congo basin - Africa's green heart - in wave after wave, on the back of the advancing ITCZ. These inter-African movements, are the heart beat, the lub-dub of life, and sustain the afro-palearctic ecological system. The pulsations involve incalculable numbers of strictly African birds of a great many species. Recognising the ecological centrality of this biannual pulsation becomes especially compelling when one imagines the changes to the amplitude of the Afro-Palearctic migrations during previous periods of maximum glaciation. In those times most of the bird movement between e.g. the present day West Asian peninsula, which we've been calling Europe, and today's Africa remained almost entirely within Africa!
So, to my mind anyway, it is within this intra-african seasonal flow, back and forth, that we should look for most of the antecedents of the great "north-south" or "south-north" or better yet "inbound-outbound" migrational flights. Those flights which so impressed Europeans even as they themselves first 'walked' out, out of Africa, and became in essence what they did. Have-ers rather than be-ers. Menfolk in the main who learned to amass their chattels, as capital and not simply as cattle(s). Men industrialising and radically transforming (read: over-simplifying and weakening) entire swathes of landscape, and unleashing ever greater amounts of carbon dioxide, in those temperate zones, nearer to the Pole.
Later we conquered the whole world, and wrote so many very biased histories of our achievements. Stories wherein we ignored, or at best skated-over, our early acts of genocide, ecocide and matricide. Such behaviours, at such a scale, once upon a time were largely contained within the Holarctic zone.
An economic backwater? Lilly pool in central Africa - during the dry season
Very sadly (at least to me) we northerners have triumphed. Temporarily we've succeeded in exporting these, our, ecological attitudes all around the world.
Daily now, I read in the news, delivered to my Inbox, evidence that we are indeed a-knock, knock, knocking on heaven's door.
And so as old-ways agriculture, across ever larger parts of Africa, are 'modernized' it's the traditionalists, and nature, who appear to most to be the initial and, for the time being, only serious losers.
Yet in my bones (and perhaps in your's) we probably know that with every old-growth corner that Africa looses, life 'in Europe' further falters and that, no longer gradually, the Mother Earth who nurtured all of our inventiveness, succumbs.
But when oh when will the hungry ghosts who run this show - the captains of our shiny corporations, their media moguls and 'our' puppet-minded democratic politicians - get it?
One might imagine, by the time they do, there'll be many a pallid face leering from the parapets. Roughly skewered faces of those, who seldom if ever in life considered, any rivers flowing past, out there beyond their will.
Perhaps they should reflect: a single Swallow does not a summer make!
Olduvai Gorge & Museum - "where it all began" - African exodus
Painted Lady butterfly, one of the most prolific rains-life migrants, dispersing poleward from the tropic zones
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Submitted by admin on Tue, 2011-03-22 12:57.
Mount Meru (in northern Tanzania) she's always more beautiful when under a cloud
Puffy (non-ITCZ) clouds over Ivory Coast/Liberia border December 2010 from KQ 510
For further explanatory graphic illustration see Greg Laden's excellent blog from which the following brief account has been largely composed:
The storms currently revolving [March 22, 2011] around mighty Mount Meru in Tanzania are part of a weather pattern that stays within the tropic lines and therefore holds relatively near to the equator. Result: a mass of truly awesome storms that move either north or south in accordance with our two hemispheres' bipolar summer seasons.
At this time of year (First Equinox) in Africa the storms seem to be gathered right over us. Over Lake Nyanza (aka Lake Victoria), and from there they're sloshing-out vast amounts of moisture, enough to sustain the rain-forests of Africa's Amazon - our mother - the Congo and, somewhat earlier in March, to have sparked fires which our Sunbird/Wings birding group just witnessed in the tinder dry savannas of the Serengeti.
The storms system through which Greg Laden flew across Lake Victoria on a day over twenty years ago are here again, and it is the same storm system that may (or may not) be blamed for downing Air France Flight 447 over the Atlantic. This is the storm system that is always there, and it is the most important storm system on the planet.
It is called the Intertropical Convergence Zone, or ITCZ. (Where I come from we would say "Eye Tee See Zed" but these days some younger folk are calling it the "Itch")
What is the ITCZ?
Greg was glad you asked, and was happy to explain in his blog.
The earth is a big ball, and spins on an axis that is perpendicular to the plane of the sun. That means that the middle (equator) of the ball is more or less always either facing the sun (at noon on a given spot) or has just finished facing the sun (p.m./evening) or is about to face the sun (a.m.). So, it gets hot around the middle of the planet. There is this map of heat [also at the website indicated above] where more red equals more heat; this helps to demonstrate that the equator is extra hot.
With that kind of heat, you can imagine that the heating air would rise dramatically at the equator.
And if that happens, you can imagine that air will be sucked into the void where the heated air is rising.
And the air that has risen, will move away and cool off and drop down, again being sucked into the rising air column, like this:
Which essentially causes a circle, when viewed in cross section, of air rotating in and out of the equatorial region. You are looking here at the cross section of a giant donut that encircles the earth, called a Hadley Cell. The rising part of this column is, essentially, a thunder storm generator.
But of course, there are two of them, one for the northern and one for the southern hemisphere.
At this point, the air is actually pushed up higher than anywhere else on the planet, and the storms are bigger. This is a continuous process happening all the time. The ITCZ is this juncture of the two Hadley cells. The ITCZ moves north in the northern summer, and south in the southern summer, but is always near the equator. You can think of the ITCZ as being the "tropical equator."
Because the air is higher and the storms thicker at this point, it is virtually impossible to fly over the ITCZ. Planes flying north or south across the equator always cross it, and normally there is turbulence at this point. The flight I describe above, over Lake Victoria, was notable because it was along the ITCZ, parallel to it's central axis, staying within this zone of turbulence the whole time.
Greg has flown over the equator many times, and usually (but not always) at night.
always makes sure he is awake when passing through the ITCZ because the sensation of flying through a 'Giant Turbulent Donut' that encircles the earth is the closest thing you can get to realizing that you are on a huge spinning ball with a very thin atmosphere.
The ITCZ is as persistent, and as important, as a major mountain range, but it is made mainly out of gaseous nitrogen and water vapor. It is a topographical feature of the landscape that is made out of energy. It is the engine that drives the formation of hurricanes. It is the place where the extra solar energy resides before it dissipates towards the poles, and it is this dissipation of energy that causes, ultimately, all of the weather on the planet Earth.
So when crossing the equator, he wants to know -- wants to feel -- that he's flying through the ITCZ.
And if he's travelling with anyone else, and they are woken by the turbulence, he tells them:
"Don't worry, this is routine. It's just the ITCZ"
Greg says there is a part of him that wants there do be some other explanation for the crash of Air France Flight 447
Current View: afternoon at GMT - March 22, 2011
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