TRIPOLI (Reuters) - Dressed in rags and holding a cellphone, Muammar Gaddafi sits in the shade of an oasis palm in the southern Libyan desert. He gazes wistfully at signs that say "Niger 450 km", "Burkina Faso 2,700 km", "Algiers, 650 km".
The cartoon, displayed on an easel in the lobby of Tripoli's Mahari hotel, raises a smile from patrons checking their AK-47 assault rifles and machine pistols in the wooden gun rack behind the security desk.
Just about no one knows where the former leader is hiding, six weeks after Libya's revolution finally broke his hold on the capital in an operation coordinated with NATO and Arab powers.
His aides and some of his sons scattered to provincial strongholds, where at least two -- Mutassem and Saif al-Islam -- are now believed to be fighting for their survival, respectively in Gaddafi's coastal home town of Sirte and the inland town of Bani Walid.
Of their father, there is little trace.
But by coincidence rather than design, the mocking portrait of Gaddafi in the Mahari, temporary home to senior revolutionary fighters, illustrates neatly the working assumptions that lie behind the manhunt.
Such clues as exist seem to point south, placing the 69-year-old close to the country's southern borders with sub-Saharan Africa.
And, as the drawing suggests, those who are tracking him suspect he is seeking a refuge in a Sahelian or sub-Saharan country, the regions where the man who called himself Africa's "King of Kings" cultivated allies for decades.
A move abroad would place him at risk of arrest by African countries which are signed up to The Hague war crimes court. Many suggest he could outfox his pursuers by hiding in plain sight in an urban setting in Libyan's north -- a tactic employed successfully for years by al Qaeda leader Osama bin Laden until his killing by U.S. forces in Pakistan in May.
But in many respects the Sahara makes sense.
It may look near-empty from the map, but the world's biggest desert serves as a contraband superhighway, especially at night when fewer eyes -- including satellites -- are watching.
The 69-year-old may now calculate he can vanish among the smugglers, shepherds, bandits, illegal migrants and militants who roam this part of Africa without a trace.
As peace takes hold in Libya, the area may see a resumption in traffic from African migrants, creating the possibility of additional cover for an international fugitive.
Hisham Buhagiar, who leads the hunt for the interim National Transitional Council (NTC) that replaced Gaddafi, told Reuters he suspected his prey was near the ancient Saharan trading town of Ghadames, 550 km (350 miles) southwest of Tripoli on the Algerian border and home to a UNESCO World Heritage Site.
"One tribe, the Tuareg, is still supporting him and he is believed to be in the Ghadames area in the south," said Buhagiar, adding that Gaddafi had moved there from the southern town of Samnu.
Despite Buhagiar's lead, there appears to have been no attempt at capture, and security experts suspect the information that led to this belief was not sufficiently timely or precise to enable a raid to be mounted.
Therein lies the challenge for his pursuers. Actionable information is what they need, but most of what they receive from human informers is probably out of date.
Speaking on condition of anonymity, another NTC official said there was a presumption among his colleagues that the search could take months, if only because of the enormous size of Libya, Africa's third largest country.
"It could be a very long drawn process. It's a huge country. There's a lot to search," said the official, adding there was a feeling "he could be somewhere in the south, in villages around the southern town of Sabha", where he spent part of his youth.
"We've seen several convoys going across the borders -- more than have been publicly reported. The convoys are huge and very well armed. And the windows are all blacked out."
"But we don't think he has been among them."
Information about these convoys, which have crossed mainly into Algeria and Niger, comes from satellites or human informers, according to a person who is occasionally briefed on the campaign.
The few men who are believed to be with Gaddafi, the official said, will be trustworthy if only because they are relying on him as their means of survival. And Gaddafi may still have the means to recompense their loyalty.
One person familiar with part of the hunt said there had been a sighting of Gaddafi near Sabha in mid-September. The individual was flown to Benghazi for a detailed debriefing. But the result was inconclusive, the person said. "It was interesting," he said. "But he may have been lying."
A $1.5 million reward is on offer for information leading to Gaddafi's capture.
Many observers take seriously the notion that Gaddafi has received sanctuary among the Tuareg tribes, which are important to regional security because they have influence in the Sahara.
After all, Gaddafi's daughter Aisha, her brothers Hannibal and Mohammed, their mother Safia and several other family members fled to Algeria in August through a southern Saharan route and have lived there since.
Tuaregs have backed Gaddafi because he supported their revolt against the governments of Mali and Niger in the 1970s and later allowed many of them to settle in southern Libya. Libyan Tuareg tribes view with suspicion the NTC that is now in power in Tripoli.
George Joffe, a north Africa expert at Cambridge University, said he believed it was "quite possible that the Tuareg are protecting him and he has long had close contacts with them, but I do not know which branch of the Tuareg he deals with, almost certainly a Libyan-based group."
Whether that means Libyan Tuareg can easily escort Gaddafi to safe havens in Niger, Mali or elsewhere is not clear.
Niger's border with Libya is small for this part of the world -- 250 km (150 miles) long. However the lack of physical demarcation makes even that hard to patrol. "It's a big beach without the sea," one diplomat in Niamey put it.
Military sources say at least 2,000 soldiers - about a tenth of the army - have been deployed to the northern Agadez region of Niger up to the border since the Libyan conflict. They are performing spot and identity checks and patrols in both desert and mountain zones.
Typically they patrol in convoys of four to 10 four-wheel-drives with assault rifles, mortars, machine-guns and rocket-launchers. There is some aerial surveillance, with two DA-42 reconnaissance planes and two combat helicopters.
However Niger has acknowledged it doesn't have the means to fully monitor its border and diplomats say it has asked Western countries for help with additional aerial surveillance and night vision systems.
Niger has ratified the Rome Statute of The Hague war crimes court and has promised to respect its commitments if Gaddafi turns up -- widely interpreted as meaning they will arrest him if he is picked up in Niger.
But there is also the question of whether Gaddafi could pass into Niger incognito, perhaps en route to another exile destination in Africa. While that is seen unlikely, Niger is a route for drugs smugglers, so if narcotics can pass through the country in secret, then maybe he could be too.
Niger Tuaregs dismiss the notion they would give haven to Gaddafi and point the finger at their Libyan fellows.
Agali Bagou, a Tuareg former fighter, said: "If they are Tuareg, they are not from Niger. I know the Nigerien former fighters from our rebellions and they have returned, they are at home."
Ahmed Mohamed, a Tuareg artisan, said: "I don't know why we focus on the Tuareg, since Gaddafi's supporters have recruited from all of Libya's communities including the Tuareg, Arabs, Toubous. If the Tuareg are with Gaddafi, I think they are the Libyan Tuareg.
"In Niger it is said that it was Aghali Alambo, the former leader from the 2007 rebellion, who recruited Tuareg mercenaries from Niger. Aghali returned after the fall of Tripoli and I don't think a single Nigerien has remained (in Libya)."
The Tibesti mountain range in northern Chad just inside the border with Libya would make a potential hideout for Gaddafi -- an African Tora-Bora.
However as of last month that would have been blocked to Gaddafi because -- according to Aghali Alambo, the Nigerien Touareg who acted as guide for the escape of Gaddafi's security chief -- the route down to the Chad border was crawling with ethnic Toubou fighters loyal to the NTC.
Chad military sources also said that France, with which Chad has a defence cooperation pact, had also deployed drones to monitor the border.
Geography will be challenging for pursuers and the pursued. Conditions in the south can be desolate. Bandits, and extreme weather, are not the only dangers.
Alex Warren, a Libya expert at Frontier MEA consultancy, says that in the extreme central-south, which has no paved roads or mobile phone network, "are remnants of Libya's border war with Chad in the 1970s and 1980s which has left many areas heavily land-mined. "
In the deep south-east, the town of Al Kufra has a history of rejecting control from Tripoli. A tribal rebellion in 2009 was only quelled after the security forces sent in helicopter gunships, he wrote in a commentary in September.
"Around the town are the skeletal remains of World War II tanks and aircraft, a reminder of previous battles that have been waged over this patch of North African desert."
NATO countries are expected to provide intelligence help to the manhunt, in the form of electronic eavesdropping. Special forces teams, either working for private contractors or for member states' armies, are probably involved.
"Unless Gaddafi's operational security is impeccable, he will eventually be found," said Shashank Joshi, an associate fellow at Britain's Royal United Services Institution.
Noman Benotman, a former leader of a failed guerrilla uprising against Gaddafi in the 1990s, told Reuters cooperation from countries with powerful intelligence capabilities was going to be important.
According to Benotman, a friend of former Gaddafi spy chief Moussa Koussa, Gaddafi has always taken personal responsibility for his own security and there is every reason to think he continues to do so.
But a methodical and painstaking approach to gathering clues would eventually bear fruit, he said.
"This kind of hunt demands patience, he said. "You need to connect a lot of dots on the intelligence and the satellite imagery. You start to build a spider's web of contacts, everything from A to Z -- names, places and very high resolution imagery -- to get to him."
But high technology may only get the pursuers so far.
The political climate may shrink the potential flow of information from informers, especially Tuaregs and black Africans who may look askance at the NTC and remember Gaddafi as a benefactor.
As Gaddafi's regime crumbled, Tuaregs and other African migrants working in Libya faced violent attacks which appear to have been motivated either by racism or the belief among many Libyans that they are pro-Gaddafi mercenaries.
But Mukhtar al-Akhdar, a revolutionary officer from the western town of Zintan who knows Ghadames well, told Reuters he did not believe Gaddafi would be able to buy protection from the Tuareg.
"As for Gaddafi and paying any money, well I can confirm that Gaddafi, his money and his gold are over," he said.
Additional reporting by Samia Nakhoul in London, Abdoulaye Massalaatchi in Niamey and Madjiasra Nako in N'Djamena, Mark John and Richard Valdmanis in Dakar, Joe Logan and Ali Shuaib in Tripoli, Mark Hosenball and Phil Stewart in Washington; Editing by Giles Elgood