h2g2 The Hitchhiker's Guide to the Galaxy: Earth Edition

Hi Waz, nice to see you back, and thanks for the additional info and for putting together this entry-in-progress! It will need a lot of polishing, for sure ...
You've added a lot of stuff! Right now I'm looking at that Spanish site ... looks good!

It's interesting to me that we have, apparently, as many birds here in South Africa as are found in the whole of Europe!

The Spanish birds do seem to be OK ... I'm really happy to hear about the conservation measures being taken in the EU.

I want to add some more bits about the behaviour ... will do so in a subsequent posting, here!

OK ... for starters: the 'preference' for lime substrates: this is not because the birds 'like' limestone rocks, per se ... it is because these kinds of rock formations are more likely to have caves, cracks, overhangs and so forth, because of the way limestone erodes. Limestone is calcium carbonate, which is insoluble in pure water. But carbon dioxide in the atmosphere, dissolved in rainwater, forms carbonic acid - H2CO3. This weak acid solution is capable of dissolving limestone, and this process causes some interesting erosion features in areas dominated by limestone formations.

More on the bird's adaptation to its habitat:

Its dense feathers provide excellent insulation against the cold and the winds of its montane environment. Like mentioned in the Description, the body contour feathers are long, stiff and fit together snugly and cover the soft, downy insulating feathers beneath, and keep the cold winds away from the body below. The face, head and neck are feathered, unlike other vultures, and this, too helps to conserve heat ... a naked head will too easily get cold. Underneath the belly the feathers are long and shaggy, with long feathers on the legs down to the feet, the 'baggy trousers'. When the bird flies, it tucks its feet into these shaggy feathers of its legs, belly and undertail, so they're kept warm. When it roosts in caves, it sleeps on its belly again with the feet tucked into the nice soft warm feathers.

In this one source I'm using, there seems to be a bit of a contradiction. Firstly, it is said that experiments in captivity have found that Lammergeiers do not lose any body heat during the cold night when they're sleeping. Therefore they do not need to spend any time re-warming themselves the next day before setting out to hunt. But in the very next paragraph it says that Lammergeiers often sunbathe, especially early in the mornings! In the sunbathing posture they spread out their wings to the sun - either facing into the sun, or away from it so the sun warms their backs. The dark feathers on their wings of course absorb a lot of heat from the sun. In the early morning they often sit outside, before the sun has risen, facing east and already spreading out their wings as if they're waiting for and anticipating the sunrise. Also many of their nest-caves face to the East to catch the morning sun. So, Lammergeiers *do* warm themselves in the morning ... one might surmise, their feathery insulation is *very* effective, but still, they make use of whatever little bit of warmth they can catch from the sun as well.

In captivity, Lammergeiers show a trend of seeking dark and shelter: if a large box with a hole in it, sufficient to admit a Lammergeier, is placed in a cage, the Lammergeier will climb inside it; otherwise it will creep into the shadiest corner of its cage to roost there.

The next comment is about the Lammergeier's bone-eating behaviour.

It is true that the Lammergeier is the only kind of bird that lives *mostly* off bones. But I'd like to tell you of another intersting kind of bird, the Thick-billed Raven, Corvus crassirostris:

http://www.markhorrell.com/travel/ethiopia/simiens/raven3.html

http://www.oiseaux.net/photos/yves.thonnerieux/corbeau.corbivau.1.html

http://www.darwin.museum.ru/expos/zoogeo/6_12.htm

This bird also occasionally eats pieces of bone. Its very thick bill is capable of crushing bones, but apparently only small ones. It is said to occasionally snatch up pieces of bone broken from larger bones dropped by Lammergeiers, before the Lammergeiers can get to them. The Thick-billed Raven is endemic to the Ethiopian highlands, which as noted here still hosts a substantial population of Lammergeiers as well.

A related species, the White-necked Raven, Corvus albicollis, occurs here in South Africa. It also has a thick bill, but not as much as that of the Thick-billed Raven. I haven't come across any references of its eating bones. The Thick-billed Raven as well as the White-necked Raven are omnivores and eat lots of things besides bones.

OK my next comment concerns this bit:

"There was initially a separation between two lineages, one in the Mediterranean region, and another over a broad region covering parts of Africa, Eastern Europe and Asia. This is attributed to a period or to periods of glaciation during which the birds were limited to distinct montane areas that escaped being totally covered by glaciers. After the retreat of the glaciers, the populations of lammergeiers expanded again, and birds from the eastern group (Africa/East Europe/Asia) came in contact again with the western group (Mediterranean region) in two places namely Central Europe and Northern Africa, which 'joined' together these separate lineages again. As a result there's no real genetic basis for distinguishing the two races 'barbatus' and 'meridionalis'! But there may be smaller, more recent differences hiding inside the two large 'mitochondrial lineages'."

This is merely my own interpretation of what you told me of the research into the Lammegeier genetic lines. As far as I'm concerned, it is conjecture. It's not yet established as fact, at least to my satisfaction. At best, we can say, 'some research suggests that there was initially a separation...' etc. Personally I'd like to see a heck of a lot more research trying to piece together the evolutionary history of this bird species.

OK I'll post this now and continue later ...

Polishing - yes, certainly will. I have such a bad menory I need to keep notes like this. Then the actual entry can be written from them. Could then keep this for detail left out of it.

As many in SA as Europe, yeah... I know. Still, they're aiming to increase them. And it's good news SA has more.

The main numbers are in Central Asia but I can't find numbers. I seriously think they can't count them out there, particularly in China perhaps. There was a count of 55 pairs in Georgia, a note of nine sucessful nests in an area of Kazakhstan, and an implication that Russia wasn't monitoring them.

I found a report from a workshop on vultures from the 3rd Ornithological Conference, 2002, that gave figures for Africa of 1650-2650 pairs, 4000-7000 individuals.

The problem with these numbers is they change over time and probably with how the survey was done.

I also found a note of there being four sub-species; aureus - Europe, Middle East and Asia, barbatus -northern Asia and meridionalis - Arabian Peninsula, eastern and southern Africa and "Birds from eastern Asia have sometimes been separated as haemachalanus". What do they mean by 'sometimes separated'? Sometimes distinguished perhaps? It's the first time I've seen 'aureus' I think. Any opinion on 2, 3, or 4 sub-species?

Further on the reintroduction in the Alps - it began in '86, first young were in '97, one site claimed there were now 200 birds there. An increase of 64! That is successful - as they said, if it's right. Anyway, because of that success, another reintroduction by release of captive birds is planned for the Sierra de Cazorla in Spain. Andalucia! Brilliant - just looked it up. Way north of where we go there, but still, brilliant .



Limestone - yes that makes sense. I wondered.

Tucking there feet into the feathers as they fly . So would I. I love the details like that. EEC Action Plan data doesn't include that sort of thing.

Ravens - thanks, many sites out there make that claim. I'll look our UK Raven up too.

The genetics/separation bit - I'll amend that. I did find an enormous pdf file report on genetic analysis but it was way beyond me to understand. It was investigating for the purpose of the reintroduction in Spain. Presumably to reintroduce so as not to distort the species mix.

By the way, vagrant birds have been sighted in the Netherlands and Denmark - so don't give up looking even when you're not in the Drakensbergs.

I've added some iron oxide theories I found, at the end, which you might be interested in. I've summarised all the scientific stuff drastically! Haven't changed anything else yet.

On http://www.lairweb.org.nz/vulture/bearded.html I found the following miscellaneous bits of info to add, or not, as the case may be, given the last item. I haven't seen that referred to anywhere else at all.
Reintroduction programmes are helped by taking ‘younger eggs’, ie siblings that would almost certainly not survive, and hand rearing them. They are taken back to ledge in the Alps three weeks before they’re due to fly, where they learn to fend for themselves. (I wondered where they got them all from.)
Up to 30 drops may be taken to break bones. Captive reared birds have this skill.
The tongue is the same shape as the marrow scoops used last century when marrow was considered a delicacy.
There are reports of the bird trying to force people and animals over cliffs! But no data to support this. (Well, that's a relief.)

Oh, a note to remind me that although the Alps reintroduction is being called a success, that's because most birds survive and some have started breeding. It's also said that it's too early to say, it needs another 10 to 20 years, which I'd agree with. It needs to demonstrate a stable or increasing population.

Thanks for the additional stuff Waz! I have to go to bed now ... will comment on all of this next time I go online. All the best to you till then!

'night Willem

I should have incorporated what you've added in this thread by then.

I've updated, your comments and more bits I found. I might do some rearranging/polishing yet.

I haven't added the four species bit, as I don't understand the fourth one, nor why it's not mentioned anywhere else.

In an article in an SA paper there was a claim the there were 6 breeding pairs in Zimbabwe's Eastern Highlands. I'd love that to be so, but does it seem likely to you?

It would be one of your stepping stones from Tanzania to SA.

Don't worry about the subspecies and genetic intricacies Waz!

I'd be very happy if there are breeding Lammergeiers in Zimbabwe's Eastern Highland! It is certainly possible. In the Nyanga and Chimanimani Highlands there ought to be useable cliffs. I searched for it on the 'net ... didn't get any info. But it's possible and I would be delighted if it was true.

Thanks for your work on this! I will help with the 'polishing' sometime. I will take the whole thing, rework it where I think reworking is needed, and post it in its entirety in an entry here ... would that be OK?

The bit you added about the red coloration from iron oxides is very interesting! Here in South Africa iron oxides are very widespread in rocks and soils ... the red sands of the Kalahari for instance, which are spread over much of the interior of the country, as well as numerous red rock and cliff formations which are very characteristic of the landscape.

At any rate, I've a bit more to add today, coming under the heading of behaviour. But it shows how all the different aspects link together ... the physical description having to do with the bird's adaptations and the way its behaviour impact upon it.

LAMMERGEIER FLIGHT

Lammergeiers make very efficient use of air-currents around the mountains where they are mostly found. Other big birds of prey make use of thermal updrafts, especially on hot and sunny days, to help them soar high and far with minimal expenditure of energy. Lammergeiers use the updrafts from winds blowing up mountain slopes and can fly in cold weather or on overcast days(as they often do). They fly quite fast and are agile and graceful in flight, in many ways more resembling a huge kite than a vulture. It can glide at speeds in excess of 120 km/h (about 75 mph). It can also go into a very fast dive, similar to that of a falcon. A lammergeier has been observed dropping a bone from very high, and then diving down and catching it in its bill. That means it could actually exceed the rate of free-fall! A lammergeier has also been observed maneuvering very adroitly while chasing a White-necked Raven in a downward dive over about 250 m. (Note again the White-necked Raven! ... and my post about this species maybe being one of those that also eats bones and will try and snatch some from Lammergeiers.) Adaptations to its mode of flight include the huge wings ... it has one of the biggest wingspans of *any* bird of prey, bigger even than those of many vultures and eagles that are bigger and heavier in body ... and also the proportionately very large and long tail, wedge-shaped or diamond-shaped, which helps with maneuvring. Its wing beats are described as 'slow and buoyant' ... the large wings generate a lot of lift with every beat... and it flaps its wings very infrequently, only when it needs to gain height and there's not a handy updraft nearby.

(Now for the bone-dropping flight pattern thing!) When dropping bones, Lammergeiers will start by flying downwind, holding the bone in their feet, with the tip of the bone facing forwards, to minimise drag from air resistance. It takes sometimes takes an approach of as long as several kilometres to line itself up to its target. Just before releasing the bone it will dip rapidly to give it a bit of momentum to start with. The bone must be released in just the right place: in general, the Lammergeier will target a flat slab of rock, in general with an area of about four square meters, and the bone will be released at a height of about 30 to 40 m above it. This requires quite a good aim! It is similar to reaching a target 20 cm in width from a distance of about four metres, complicated by the factor that the bone is irregular in shape, and having to take the winds into consideration as well. Furthermore, after having dropped the bone the Lammergeier needs to get to it as rapidly as possible for there is a danger of it being snatched by White-necked Ravens (and like I said earlier, in Ethiopia, by Thick-billed Ravens). To do this, it will go into a dive, turn around into the wind, spread out its tail and flap its wings to brake it quickly. If the bone isn't broken it has to repeat the whole process!

I'll post this bit now ...

Oh I should have added this ... Lammergeiers can be quite persistent, in some cases dropping a bone fifteen times to break it! And also, the ossuries ... the rocky places on which they break the bones ... are used for long periods ... here are interesting questions: do these ossuaries form important features of the territories claimed by Lammergeiers? Is there any sharing? Are they 'inherited' by a pair's offspring? May some ossuaries have been in use by succeeding generations of Lammergeiers and how old might the 'oldest' active ossuary be??

Further notes on diet:

Lammergeiers do not eat bones alone. They scavenge carcases along with other vultures, *but* they are usually last in line to get to the carcass. These vultures may either be larger and stronger than the Lammergeiers, or they may be present in greater numbers. Be that as it may, there are usually only bones left by the time the Lammergeier gets to eat. *But* if there are still bits of meat left, it will eat them.

It is able to swallow quite large pieces of bone, since it has a very wide gape - about 67 mm in width.

Aftet grass fires - which occur frequently in the Drakensberg mountains - they will go looking for the carcases of small (or large, if possible) victims of the fire. They will also scavenge scraps of food discarded around rural human settlements. They will even follow humans ploughing a field for the up-turned grubs!

As for active hunting ... Lammergeiers *have* been recorded as hunting and eating Rock Hyraxes, or Dassies. One bird has been seen grabbing a Dassie in its claws, lifting it up and dropping it from about a 100 m height. An average Dassie might weigh about 2.5 kg or 5-6 pounds. A Lammergeier has also been seen carrying a monitor lizard 45 cm (18 inches) long.

There has been at least one reliable sighting of a Lammergeier attempting to drive an Oribi (a small antelope) over a cliff. The attempt failed, but this shows that the stories of Lammergeiers driving animals over cliffs might be true.

To continue.

BREEDING

Lammergeiers court one another by means of displays of flying prowess: dives, swoops, rolls and twists. They utter their high, thin whistling calls while doing this. Here is an interesting bit: many species of EAGLE have the habit of locking their claws together and cart-wheeling during mating displays. The book about South African raptors that I'm using as a source mentions that Lammergeiers sometimes present their claws to each other, but have not actually been seen cart-wheeling; however, a juvenile and adult have been seen doing it (it is described as 'probably aggression' but I'm not so sure). The presence of this kind of behaviour certainly suggests a strong genetic link to eagles. As far as I know, no species of 'real vulture' has anything resembling a 'cartwheeling' courtship display.

Has cartwheeling ever been observed in Lammergeiers in Europe or Asia?

A couple in Lesotho has been observed preening each other and mating repeatedly, over a period of about a month prior to the laying of eggs.

In Southern Africa, they typically nest in sheer sandstone cliffs about 120-180 m in height, overlooking river valleys. Why river valleys? Well probably because the river happened to carve those sheer cliffs! Sandstone formations are usually found just below the 'capping' layer of basalt in the High Drakensberg. The sandstone erodes faster than the basalt. Thus one frequently finds 'overhangs' and caves in the sandstone just below the basalt layer. Rivers are the main agents of erosion seeing as this is a high-rainfall area.

They seem to prefer cliffs at lower altitudes. The High Drakensberg rises to an altitude of over 3 000 m, from an undulating countryside at about 1 200 m, thus there are many different 'altitudes' at which cliffs 120-180 m in 'height' can be situated. At the greatest altitudes the weather is extreme - cold, windy and wet. Lammergeiers will rather nest at about 1800-2000 m. They will select a pothole cave beneath an overhang in the middle of a cliff face - so that the nest is almost inaccessible (very determined mountaineers can do it). The nest site is selected so as to be sheltered from wind and rain. Within the cave the pair build a huge nest ... a base of sticks, lined with a variety of insulating materials they pick up from the surroundings, like sheep's wool, rags, sacks, ropes, animal skins and furs, tufts of dry grass, or small bushes. Nests can frequently be two metres wide and 60 cm deep. A nest of 2 m in depth has been recorded.

Pairs may have more than one nest in the same general area. They will only use one at a time for breeding. They may use one nest for a few years, then move to another, and then maybe another, or move back to the first nest again. This may be due to a nest becoming unhygienic or infested by parasites.

It is not clear how big Lammergeier territories are, or need to be. In Ethiopia nests were found 3,5 km from each other, while in Lesotho nests were found within about 20 km from each other. What limits the size of territories: availability of food, or availability of suitable nesting sites?

Both members of the pair contribute to the nest-building. They start in late Summer or early Autumn. Nesting material is carried in the feet, though small bushes and tufts of grass are pulled out with the bill. Some nesting material may be collected from the 'alternative' nests. The eggs are laid in Winter - in South Africa, from May to August. The average clutch size is about one and a half ... two eggs being laid about as frequently as one. The eggs are oval, rough-surfaced, and white with a pale reddish wash and a few rusty speckles.

If two eggs are laid, they are laid a few days, up to a week, apart. The pair will start incubating the first egg as soon as it is laid; both sexes incubate. The male and female relieve each other, but apparently don't bring food to each other. While one bird sits, the other will fly around and scavenge for food, or go to drink and bathe. The incubating bird will sit for several hours at a stretch, only standing up for short periods to defecate or to tuck the eggs in beneath itself. Since this is in the Winter, outside temperatures can drop very low and the eggs need to be continually covered.

The pair will defend the eggs especially against White-necked Ravens (Thick-billed Ravens in Ethiopia) and also chase away eagles that approach too close. Humans, however, are apparently tolerated.

The incubation period seems to be in the order of about two months. If two chicks hatch, only one will survive. (This is why taking a second egg is a good strategy for captive breeding of this species ... it will not affect the numbers of wild chicks raised, but will add those raised in captivity.) It is not clear whether the first chick actually kills the second chick, as happens in many species of eagle, or whether the parents simply neglect the second chick, which inevitably lags behind the first in strength and development. It may even be that the parents themselves kill the second chick.

The chicks are downy and grey with darker heads. The parents brood, feed and shelter the nestling. At first the female broods, while the male brings it food, carried in the feet or bill. Sometimes the male will regurgitate food into the nest. The nestling is fed three to nine times per day. It is given pieces of meat or offal or pieces of bone, up to 20 cm long, to swallow whole. The parents start to leave the chick on its own at about its seventh to ninth week. By this time it is large enough to defend itself against ravens, but the parents will still fly around in the near vicinity so it is not totally left to itself. But the parents will gradually leave it for longer periods until at about thirteen weeks they only visit it to bring food. The chick starts to fly at about fifteen to sixteen weeks' age. It may stay in the same area for a while longer while its parents will still feed it. It's not entirely clear (well, from my books!) when it becomes completely independent, but probably it maneges to do this before the start of the next breeding season.

These birds appear to breed annually, so after raising the chick the parents will start preparing for the next one.

OK I'll post this now.

Oh my! 75mph., diving faster than free fall, a several km line up ... this is some bird isn't it! I love those descriptions of its flight.

The Oribi story, yeah, well, it is a bird of prey. I get the feeling from other www articles that bad PR is avoided. I think that's a bit daft really.

It was a busy week last week, in lots of ways, but I hope to have time to look at this again tomorrow or Monday. Helping with polishing - yes, please. Feel free.

About your question on the other thread - I don't know how many martins fledged but it was two nests. I saw maybe six, seven swooping up to the nests and back later on, but I don't think that's necessarily the youngsters. Or not just the youngsters. I've seen that before and it happens not long before they migrate. It's like they're memorising the place or something.

More feascinating stuff .

Cartwheeling - I saw that somewhere. I'll try and find it again to see if it was Europe or Asia related.

I also found a research paper full of statistics on mating timing (start and end of the day) and frequency. It was looking into whether it was related to ensuring the mate had the best chance of actually fathering the offspring. But it seemed to put forward a theory and then lots of stats and not draw anything very conclusive from them.

I've seen harriers doing the cartwheeling thing. Quite spectacular. Would be even more saw in these much bigger birds.

Hey there .

I hope your speech goes well *next* Thursday, then. That's (most) students for you!

I've updated for the last few posts.

To be a readable EG length piece I think it needs to be about lammergeiers in general, perhaps with anything specific to a particular area detailed separately at the end?

I'll do some googling to try and find what of your SA based info applies to other areas.

All these notes are interesting, I want to keep them so I think a new entry for pulling all this together... what about the structure...

Some kind of intro,
description, habitat and diet (they're all related aren't they - I like that adaptation to habitat info you found and it's much more interesting to relate description to why it is that way.
breeding habits,
other behaviour patterns,
miscellaneous bits,
detailed distribution and conservation issues,

Something like that?

Hi Waz! That sounds very good! I'll be giving the whole thing a look over today and see what I can contribute today.

Waz, I will look at the whole thing again over the coming week, and perhaps do a bit of re-writing of parts of it and try to organise it into the order you suggest there. I think your arrangement makes sense and will work well. I will come back next Sunday and see if you've added anything, and post my suggestions.

Oct 9th , where does time go?

I was tryng to find out if the SA info you have applies across the board. I did some general googling and from what I've seen it applies to the European branch of lammergeiers and there's very little detail on lammergeiers from the the middle/far east to tell one way or the other.

So...I think we should work on the basis that the info we have applies throughout as that's the best information available and seems likely. We could footnote that assumption.

How should we do the next bit, Willem? You still up for rewriting parts of it? And if so what parts?

My choice on that would be for you to include the description and behaviour bits because your enthusiasm comes through in your writing.

Perhaps I could take on the conservation part and perhaps the ancient history? Though we might need to drop that eventually, or make it pretty minimal. It's of interest but not wholly relevant.

But I'm easy, don't mind how we divide it up, so if you've ideas just say.

Waz, yes I'm up for rewriting parts of it... let me think about this a while ... the description and behaviour bits I could do! But I may have some general suggestions on some other parts as well! You can do the conservation and ancient history, sure ... no need to drop anything that at least *some* folks might find interesting!

I am really pressed for time right now ... I'm off to visit some friends in a few minutes and don't know when I'd be back later! I'm generally very busy in 'real life' right now which is why I've not been around much lately! But I think I'll have some time in the coming weeks so I'll see what I can do!

Busy real life is good, well as long as it's not all chores .

There's no rush, and I'll have a go at the conservation and history bits.

Real life is extremely busy and also extremely good, Waz! I'm exploring places, meeting people ... had a *very* successful art exhibition ... studied German this year and got extremely good marks ... I'm going to be extra busy even during this holiday season! I only get online every now and then ...

If you're interested, please check out my Webshots site again ... I've added lots of stuff recently:

http://community.webshots.com/user/pillowfighter

Anyways I hope I can get some really relaxed time to sit and work on the Lammergeier entry soon!