The SASOL guide to the establishment and operation of

THE SASOL GUIDE
TO THE ESTABLISHMENT AND OPERATION
OF SUPPLEMENTARY FEEDING
SITES FOR VULTURES
Contents
1. Introduction..............................................................................................1
2. Why are vultures important and why are they in trouble?......................1
3. What is a supplementary feeding site ?...................................................2
4. How to establish and operate a supplementary feeding site...................4
4.1. Building a hide................................................................................5
4.2. Managing a supplementary feeding site...............................................6
5. Monitoring at supplementary feeding sites.............................................8
6. Colour-marking of vultures......................... ............................................8
7. Further reading.......................................................................................11
8. Contact details........................................................................................12
9 . Acknowledgements...............................................................................12
1. Introduction
The use of supplementary feeding sites for vultures (also known as “vulture restuarants”) is widely
acknowledged as an important tool to assist with the provision of a sufficient, safe and reliable source
of food for these aerial scavengers. This booklet aims to inform land-owners, land-managers and
visitors to these sites of their importance, and key aspects to consider in their establishment and
operation. It also provides guidelines on how to set up and run a monitoring programme at these
sites.
Above: Vultures that died from feeding on a poisoned carcass
2. Why are vultures important and why are they in trouble?
Vultures are an important element of the environment because they recycle the flesh and bones of
dead animals into living tissue, thereby completing the cycle-of-life. Vultures are important to traditional society since they are part of African folklore and traditions - without vultures African societies
would be poorer.
Vultures are important for livestock farmers since they attract attention to stock deaths in
rugged and inaccessible areas, thereby enabling the farmer to establish the cause of death,
provide a free carcass disposal service, and rapidly clean the veld of carcasses, thereby
preventing or limiting the spread of fly-borne stock diseases1 .
Vultures have a very acidic stomach (pH 1-2) which kills bacteria; the body temperature of all birds is 4°C
higher than mammals and this helps kill most mammal-specific bacteria 1
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Vultures are an important component of ecotourism since increasing numbers of eco-tourists come
to see African vultures, and are making an increasing contribution to rural and local economies
through their use of local supplies, accommodation facilities and guides (job creation).
Vultures worldwide are under threat from a range of factors, mostly related to man’s
activities. This has led to large-scale declines in populations of several species, particularly in
Asia where certain species are faced with extinction due to the impact of a single non-steroidal
anti-inflammatory drug (NSAID), Diclofenac. In Africa, the populations of several species have
declined significantly. Some have been exterminated in parts of their historical range over the last
30 years, and may now only be found in protected areas. In addition to large scale transformation
of natural habitat, resulting in reduced availability of food and breeding sites, factors such as direct
persecution, poisoning, collisions with, and electrocution by, electricity infrastructure, and the trade
in vultures, either as live birds or for their body parts, have been responsible for this situation. Wind
turbines pose a growing threat to vultures.
Interesting facts about vultures
• Vultures are scavengers and only feed on dead animals.
• Vultures often cover large areas each a day in their search for food and can fly
at speeds close to100km/h.
• They rely on their keen eyesight to locate food by looking for carcasses on the
ground and by watching the activities of large predators and scavengers,
such as hyaenas, jackals and crows, as well as the movements and behaviour
of other vultures.
• The Cape Vulture Gyps coprotheres and African White-backed Vulture Gyps
africanus are ‘bulk’ or inside feeders and take muscle and internal organs
from large carcasses.
• The Bearded Vulture Gypaetus barbatus eats flesh, but mainly bones – if these
are too large it flies up with them and drops them on a hard rocky surface to
break them into smaller pieces, to make them easier to swallow.
• The Lappet -faced Vulture Aegypius tracheliotus and the White-headed Vulture
Aegypius occipitalis eat flesh, sinew and skin and also feed on small mammal
carcasses (e.g. mongooses).
• The Hooded Vulture Necrosyrtes monachus feeds on small scraps of meat
and bone marrow, which it scavenges at carcasses.
3. What is a supplementary feeding site ?
It is a place where carcasses of domestic stock, game and excess meat are put out, specifically to
provide an additional food source for vultures. These feeding sites can be in protected areas or on
privately or communally owned land.
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Supplementary feeding sites are important for vultures since they:
• supplement the ever-decreasing natural food base (carrion),
•
provide a source of food for the vultures that is free of poisons, agro-chemicals and,
harmfulveterinary drugs; provide safe places for vultures to feed,
•
improve the breeding success of vultures by providing additional food items, such as fat and
bone fragments (for calcium),
•
increase the survival rate of vultures, especially within their first year of leaving the nest,
•
can be used to attract vultures back to areas where they used to occur, and
•
assist with the provision of a safe source of food during the re-introduction of vultures to certain
areas.
Supplementary feeding sites are important for landowners since they:
• are the most economical and practical way of disposing of dead stock,
•
prevent the spread of fly-borne diseases, through the rapid consumption of carcasses,
•
when managed properly, offer landowners an excellent opportunity to contribute to the
conservation of vultures, and
•
provide an additional source of income, from tourism and photography. However the
generation of income should however never be the main motivation for the establishment
of a feeding site.
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Above: A well-constructed bird observation hide
The feeding sites are also important for other reasons. They:
• provide an opportunity for eco-tourists and photographers to see and photograph these
majestic birds,
•
provide an ideal location for scientists to study the biology and ecology of these
threatened species, and
•
provide the public with an opportunity to participate in the conservation of vultures by
recording and reporting observations of marked vultures.
4. How to establish and operate a supplementary feeding site
If there are vultures in your area and you have a source of food that vultures could potentially use,
and if there is no other site nearby, then consider establishing a new feeding site on your property.
It is essential that the area chosen for the feeding site is open, affording the vultures good
visibility so that they can observe other scavengers and locate the food from a distance. The site should
preferably be elevated (e.g. on a plateau or gently sloping hill) with access to the prevailing winds so
that the birds can take-off after feeding; valley bottoms are generally not suitable. The feeding site
will be more attractive to vultures if there are large rocks or trees nearby for perching on, before and
after feeding. Vultures are sensitive to disturbance and a feeding site should be located in a quiet
area and not close to infrastructure or areas frequented by people, road traffic and dogs.
Never establish a vulture feeding site within 2 km of an existing or planned power-line; all
power-lines in the surrounding area should be of a raptor-safe design and lines should be marked
with flappers or other devices to make them more visible. Consult with the Endangered Wildlife
Trust’s Wildlife & Energy Programme or your local conservation officer for advice on the choice of
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a safe site (See Contact details). If it is impossible to find a suitable site further than 2 km from a
power-line it is wiser to rather establish or contribute to a feeding site on another farm or abandon
the idea completely, rather than run the risk of condemning vultures and other large birds to injury
or death from electrocution by or collision, with power-line infrastructure.
Vulture feeding sites should not be established in an area where there is an active airstrip in close
proximity to the site. Not only does aviation pose a potential threat to vultures, but an aircraft
colliding with a vulture could be seriously damaged or crash, causing injury and possible death to its
occupants.
Fences are also dangerous to vultures taking off after a meal or when disturbed. No farm or game
fences should be within 100 m of a vulture site. If a fence is required to keep feral dogs or nocturnal
predators from visiting the feeding site, it should be erected to create an area greater than 150m
x 150m. Any fenced area smaller than this will influence the ability of vultures to land and take off
at the feeding site, this especially after a large meal when the birds are heavier and require a long
“runway”. The fence should extend to at least 50cm below the surface of the ground to prevent
jackal, etc. from digging under it.
In commercial farming areas, fencing the site will stop mammalian scavengers from spreading the
bones of the carcasses, which may cause botulism in domestic livestock. Cattle should be kept away
from a vulture feeding site in order to prevent them from eating large bones (known as osteophagy)
which may stick in their throat. It should not be necessary to fence a vulture feeding site on a game
farm or nature reserve where there is no domestic livestock. Seek professional advice if you intend
fencing the site.
It is essential that the feeding site is accessible by vehicle to facilitate carcass offloading and regular
management check-ups, and for visitors to gain access to the site. If you do not have a feeding site,
then take suitable carcasses or meat to one nearby. Encourage your neighbours to do likewise.
SUGGESTION
Although supplementary feeding sites play an important role, carcasses located in mountainous
and inaccessible areas should be left when they are - this helps the vultures to retain their natural
foraging ability.
Suggestio
4.1. Building a hide
Follow the guidelines below if you would like to observe and photograph vultures and other birds at
the feeding site.
• A hide should only be built after the vultures have been given at least six months to become
accustomed to feeding at the site.
•
The hide should not to be too close to the carcasses, in order to avoid disturbing the
vultures.
•
The placing of the hide must take account of the prevailing winds (to minimise offensive odours)
and it must face south (for photographic purposes, in the southern hemisphere
•
If it is known that the feeding site is to be used for ecotourism purposes then, in certain regions,
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Above: Fresh carcasses being placed at a supplementary feeding site
planting trees to the south of the hide will encourage vultures to perch where they are
illuminated by the sun, for best viewing and photography.
•
Seating must be carefully designed to allow easy and comfortable photography, and
openings for camera lenses must be covered with cloth to prevent vultures seeing
movement in the hide.
•
A sheltered walkway into the hide will allow visitors to enter without disturbing the
vultures.
4.2. Managing a supplementary feeding site
A vulture feeding site requires careful management, and if you are not prepared to implement certain
minimum standards then you should not be making carcasses available to vultures.
• Do not provide animals that have been put down using drugs such as barbiturates, or that have
been treated with non-steroidal anti-inflammatory drug such as sodium diclofenac (also known
as Voltaren), ketaprofen, phenylbutozone, carprofen, flunixin etc. To date, Meloxicam is the only
safe NSAID registered for vulture consumption (see Text Box on page 7 for details). If you do
not know the treatment history of a dead animal do not make the carcass available to vultures
in any way.
•
•
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Do not put out carcasses that have been shot with lead bullets. If the animal has been killed
using a lead bullet to the head then first remove the entire head. Avoid putting carcasses out
where they have been killed using a body shot, or at least remove all the internal organs and all
tissue within 20 cm of the lead bullet path. Ideally, ammunition should be changed to non-lead
bullets. Where possible, kill domestic animals using a bolt gun.
Keep the vulture feeding site and its surrounds clear of all items such as plastic cattle
ear-tags, bullets, pieces of glass, china, porcelain, pottery, plastic, bailing twine, string etc.
Vultures often ingest these or, in the case of bailing twine and string, get tangled in them
with fatal results. Remove ear tags prior to putting the carcass out, and preferably remove
the stomach (which often contains bailing twine), liver and kidneys (this is where toxic
compounds accumulate).
•
Do not let the grass in and around the vulture feeding site grow more than 10cm high as this
makes it difficult to locate and remove the above-mentioned items from a site.
•
Any alien vegetation that may emerge at a site should also be removed.
•
Once a quarter, break up the bones from carcasses into pieces about 10 cm long and leave them
scattered at the restaurant for the vultures to ingest. Fragmenting the bones makes it easier for
the vultures to swallow them.
•
The skin of the carcasses must be slit open along the belly and chest, and along the inner sides
of the legs, to facilitate access by the vultures.
•
Remove old carcasses and hides as often as possible and at least once every two months.
•
A freezer room nearby will allow for stockpiling of carcasses (e.g. after a die-off during an
extreme weather event), thereby facilitating a more regular supply of carrion, or provisioning, to
the feeding site in important periods.
Carcasses containing any of the following products should NEVER be left where
they are available to vultures:
•
Barbiturates (used for euthanasing animals e.g. Phenobarbitone, Pentobarbital etc.).
•
Sodium Monofloroacetate – a natural toxin contained in some plants, e.g. Gifblaar
Dichapetalum cymosum that may be ingested by livestock or game causing death.
•
Non-steroidal anti-inflammatory drugs [NSAIDs] (used to treat a variety of ailments but
lethal to vultures; Sodium Diclofenac (active ingredient of Voltaren®) caused a 99.5% crash
in the vulture populations in Asia; there is only one registered NSAID in South Africa that is safe
for vultures - Meloxicam (also known as Metacam). This drug was previously unavailable for
large animals but is now in production and available).
•
Antibiotics (especially Tetracycline or Penicillin).
•
Lead (the main source of lead is from animals shot with lead-containing bullets which
fragment on impact into many small (often microscopic) pieces; vulture mortality has been
linked to lead ingestion).
•
Dips (any animal recently dipped in an organophosphate dip should not be accessible to
vultures; the skin should be removed from livestock recently dipped against ticks using externally
applied sprays or pour-on treatments).
•
Other agricultural products that that are deadly to vultures and should not be used in
vulture areas include Strychnine, Aldicarb, Monocrotophos, Methamidophos,
Diazinon and Ethylfenthion.
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5. Monitoring at supplementary feeding sites
It is good practice to keep records of:
•
the numbers, types of animals, causes of death and dates of carcass provision,
•
the sources and contact details of persons providing carcasses, and
•
the numbers of vultures of each species that are observed, together with the dates of the
observations and the names of the observers.
It may be interesting to note how long after death a carcass was put out and to keep a record of which
carcasses do, or do not, get fed on by the vultures. Likewise, where possible record the age classes
of vultures feeding at the site.
A Vulture Count Day is held on the first Saturday in September each year as part of International
Vulture Awareness Day. All vulture feeding site managers are encouraged to ensure that carcasses are
provided and to record all vultures arriving between sunrise and midday on this day.
Data forms and information about the International Vulture Awareness Day can be obtained from:
Endangered Wildlife Trust: website www.ewt.org.za, and the Birds of Prey Programme: contact
raptor@ewt.org.za.
6. Colour-marking of vultures
Ringing and colour marking have been used in southern Africa for almost 60 years as a
cost-effective method to study many aspects of the biology and ecology of a wide range of bird species,
including raptors. The first birds to be ringed in South Africa were a group of Cape Vulture
(Gyps coprotheres) nestlings at the Kranzberg colony in Limpopo in 1948.
Colour-marking a bird enables researchers to individually identify birds in the field after release. The
colour-marking method that is currently in use for vultures is known as “patagial tagging”. Patagial
tagging refers to the fitting of a plastic tag to the “patagium”, (or frontal flap of skin on the wing of
a bird) and has been used worldwide with great success on a wide range of bird species, including
vultures and condors in Europe and America. A smaller number of vultures has been marked with
colour leg bands consisting of two types: coloured PVC bands with white or black alphanumeric codes
and colour combination rings.
Information on the following aspects of vulture biology can be obtained by the use of ringing and
colour-marking:
•
Local movements and dispersal patterns
•
Migratory patterns and seasonality
•
Survival rates and longevity
•
Causes of mortalities and potential threats
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A vulture marked with a tag on its wing
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What to do when you see a marked vulture
Because vultures regularly re-visit well managed supplementary feeding sites, these sites play a vital
role in contributing to our knowledge of bird movements, through people reporting marked birds
sighted there.
Should a marked bird be seen or found dead at the site or nearby, the observer should record the
following details:
•
Date
•
Time
•
Locality
•
GPS co-ordinates
•
Species of vulture
•
Habitat
•
Type of marking (ring, patagial tag, transmitter)
•
Tag/ring number
•
Tag/ring colour/combination
•
Condition of the bird
Information can be reported to the South African Bird Ringing Unit (SAFRING) in Cape Town at
telephone number +27 (0)21 650-2421/2 or safring@adu.uct.ac.za
Alternatively, you can contact the Birds of Prey Programme at raptor@ewt.org.za
or +27 (0)11 372 3600.
In KwaZulu-Natal sightings can also be reported to Ezemvelo KZN Wildlife at vulture@kznwildlife.com
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7. Further reading
Roberts’ Birds of southern Africa, edited by P.A.R. Hockey, P. Ryan & R. Dean, VIIth edition,
pulished by The John Voelcker Bird Book Fund, Cape Town. 2005. This is the most comprehensive work
ever published on birds in southern Africa and contains a brief but comprehensive review of every
vulture species found on the sub-continent.
Vultures of Africa, written by Peter Mundy, Duncan Butchart, John Ledger and Steven Piper, pulished
by Russel Friedman Books & Acorn Books: Mid-Rand & Halfway House. 1992. This book has a detailed
description of the biology and ecology of all African vulture species. The book is now out of print but
it may be found in certain libraries.
Vultures and Farmers, written by Duncan Butchart, published by the Vulture Study Group:
Johannesburg. This useful little booklet may be obtained from EWT-BoPP, see (address below).
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8. Contact details
Endangered Wildlife Trust - Birds of Prey Programme;
Private Bag X11, Modderfontein, 1609, Gauteng
Tel: (011) 372 3600, Mobile: 082 962 5725, Fax: (011) 608 4682,
Website: www.ewt.org.za
9. Acknowledgements
This booklet has been condensed from a document prepared by post-graduate students
Grant Rhodes, Angela Segal and Sally Hofmeyr and edited by Mark Anderson and Peter
Mundy. It was designed by André Boshoff, with considerable input from Steven Piper and
André Botha, and first published by the Birds of Prey Programme of the Endangered Wildlife Trust
in 2007.
A revision of the text incorporating new information was done in 2011 by André Boshoff,
André Botha, Sonja Krüger, Ian Rushworth and Kerri Wolter. All are thanked for their input.
Dr Vinny Naidoo of the Onderstepoort Veterinary Faculty at the University of Pretoria and
Kerri Wolter from VulPro NPO kindly provided specific input with regard to veterinary medicines and
other substances that could pose a threat to vultures.
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Bearded Vulture
Albert Froneman
White-headed Vulture
Hooded Vulture
Andrè Botha
Andrè Botha
Lappet-faced Vulture
Andrè Botha
Rüppel’s Griffon
Cape Vulture
Andrè Botha
Chris van Rooyen
African White-backed Vulture
Egyptian Vulture
Andrè Botha
Andrè Botha
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Private Bag X11, Modderfontein, 1645
Tel: +27 11 372 3600 Fax: +27 11 608 4682
www.ewt.org.za
The Endangered Wildlife Trust was established in 1973 and is registered as a Non-profit Organisation. Registration
number 015-502 NPO and PBO number 930 001 777. The EWT is 501 (c) (3) compliant, US IRS Reg. EMP98-0586801.
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