Why would a smart and adaptable bird that eats almost anything and can survive happily In even the most heavily degrade habitats, have a work range of less than 5,000km2? That question has baffled and confused scientists ever since the Ethiopian Bush Crow peculiarly restricted distribution was discovered back In the 1930s. But now,after researching the exact location of the birds and there nests In Southern Ethiopia,a team of problem-solving,sherlock Home style scientists have unravelled the mystery. And the answer Is elementary. A new study published In the "Journal of Ornithology shows the globally threatened bird's range exactly follows the edge a unique bubble of cool,dry climate. The mystery surrounding this bird and Its odd behavior has stumped scientists for decades,many have looked and failed to find an answer. But the reason they failed we now believe,Is that they were looking for a barrier Invisible to the human eye,like a glass wall. Inside the 'climate bubble',where the average temperature Is less than 20°c, the bush crow Is almost everywhere. Outside,where the average temperature hits 20° or more,there are no bush crows at all. A cool bird,that appears to like staying that way. The reason this species Is so completely trapped Inside Its little bubble Is as yet unknown,but It seems likely that It Is physically limited by temperature either the adults,or more likely Its chicks,simply cannot survive outside the bubble,even though there are thousands of square miles of identical habitat all around. Ethiopian Bush Crow Is a small,starling like crow with a pale grey head and body,black wings and tail,and bare,blue skin around the eye. The bird,listed by wold red list as endangered. Scientists are now planning to start a monitoring programme on the temperature of the birds nests to see If It can unlock the answer to the next question "why are they so sensitive to climate?"