The sight of a tree filled with vultures is an iconic and somewhat primeval African scene, instantly transporting the viewer to the essence of the continent. Vultures are an essential element in the natural functioning of the ecosystem as the clean-up crew that helps rid the landscape of rotting carcasses, limiting the spread of disease to animals and humans alike. Within the iSimangaliso Wetland Park, the uMkhuze section is the only part of the World Heritage Site that hosts vultures – and as endangered species, their wellbeing is a critical priority for conservation. With a recent surge in mass vulture poisoning incidents in Southern Africa, there has never been a more urgent need to educate and protect.
There are six species of vulture visiting uMkhuze. These are the White-backed, Cape, Lappet-faced, White-headed and the Hooded vulture, with a very occasional sighting of the Palmnut vulture.
The decline in vultures worldwide is well documented and sadly this is also the trend in KwaZulu-Natal. Threats include habitat destruction, food distribution and availability, and incidental or intentional poisoning. This last is frequently the result of misguided beliefs about vulture parts in traditional medicine, or they may be incidentally poisoned by a carcass laid out for jackals or other predators. The end result is the same – a drastic decline in populations.
As with all biodiversity, the goal for vultures is long term viability and resilience to change. Management objectives are therefore aimed at restoring population sizes. In order to do this each vulture species has set objectives that Ezemvelo KZN Wildlife is aiming to achieve over the relatively short term. These are outlined in the Provincial species monitoring documents (Howell and Goodman) and include:
- Restoring and maintaining breeding populations of vultures on state, private and communal land (e.g. in the case of Lappet-faced vultures 20 pairs);
- Achieving a reproductive success of 50%; and
- Restricting illegal mortalities.
In order to understand the status of vultures in KZN, annual surveys have been conducted in the province since 2005, but were not standardised until 2013 when Ezemvelo KZN Wildlife developed plans prescribing monitoring standards for the Lappet-faced vulture, White-backed, White-headed and the Bearded vulture (note that this last is not found within in iSimangaliso but rather in the Drakensberg mountain areas).
To determine the status of the vulture populations and whether the objectives for the conservation of vultures is being met, three population parameters are monitored:
- The number of active nests in the KZN population range;
- The reproductive success rate of the KZN population; and
- The number of vultures and their age class killed through illegal means.
Nest monitoring is done by aerial surveys conducted at certain times of the year (see textbox below extracted from the monitoring plan).
| Monitoring parameters include the following:
- The number of active nests occurring during a breeding season in the Province – by inference this is equivalent to a minimum estimate of half of the adult breeding population size. This is defined as the greater of: the sum of number of nests which are Incubating/brooding (A) + Active empty (C) from the August survey or, the sum of the Number of chicks seen (B) + Active empty (D) nests from the October survey.
- The reproductive success rate – this is defined as the number of surviving chicks seen at the end of the breeding season October survey, divided by the number of active nests. Since a maximum of a single chick is fledged per nests, a 100% reproductive success rate would mean that each active nest fledged a chick.
- The number of vultures killed illegally – defined as the number of vultures dying from unnatural causes (purposeful and accidental poisonings).
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