London’s Royal Courts of Justice had an unusual visitor last Thursday – a four-year-old African white-back vulture improbably named Nigel.

Nigel and his handler were hired by the charities Oxfam and the Jubilee Debt Campaign to highlight a judgment in the High Court. Zambia, the impoverished southern African state, was sued for $55m by an investment fund to force it to pay the full value of government debt bought at a huge discount.