Rehabilitation Release Considerations

Before being released after injury or illness the affected raptor and the release site must be assessed for suitability. The following criteria must be considered:

Fitness

Any raptor which has no hunting experience, or which has suffered a major trauma or illness, requiring lengthy convalescence, will need some sort of fitness preparation prior to being released. Such birds may be capable of flying around an aviary perfectly well, but will not be in hunting condition and will be completely unfit for release. Any bird released in this state will starve to death before it has built up the necessary muscle to out-manoeuvre and fly-down its quarry. It is therefore essential that released casualties are either made fit before being released, or are subjected to a controlled release programme with the provision of food. 

Assessing eyesight

   Thirty to forty percent of all raptor trauma cases involve damage to the eyes, and in 70% of these cases the damage is at the back of the eye where it may only be seen by a veterinary surgeon using an ophthalmoscope. A raptor’s eyesight must be assessed by a vet prior to its release.

Habitat assessment

   For any rehabilitation process to be successful, the natural habitat into which the raptor is released must be appropriate for the species concerned. The vegetation and other physical features must be suitable for the hunting strategies of the species being rehabilitated. Account must also be taken of potential man-related threats in the immediate area. Busy roads are potentially dangerous for rodent hunting buzzards, small eagles or owls because they may be killed by passing vehicles.  A large number of unprotected electricity pylons in the release area could be dangerous for the reintroduction of large eagles or vultures. The close proximity of subsistence farmers with free range poultry could prove to be too easy for a large accipiter or falcon to resist if released from nearby, once again getting the released raptor into trouble. 

Time of year

  The availability of natural prey is also an important factor when assessing any release site. During winter it may be beneficial to prolong a treated raptor’s stay in captivity and wait for spring rains before releasing it.
It may not be suitable to release certain at a specific release site during breeding season. During their breeding seasons yellow-billed kites and black-shouldered kites will, for example, chase any bird from near their nests.
Migratory species should not be released at, or after, the time that the wild birds are departing as they will not be fit enough to make the journey.

Territorial competition

Raptors are highly territorial, so short-term cases should be released directly back into the area from whence they came. Raptors in adult plumage must not be released in territories already occupied by the same species because they will just be displaced. Corvids can also be very aggressive towards raptors and if present in an area in large numbers they will attack and chase released raptors out of the area.

Pre-release requirements

Birds must not be released before being banded with a SAFRING band. To find a licensed SAFRING bander in your area, contact your local bird club.
Remember that permission and co-operation must always be obtained from landowners before rehabilitating birds onto their land.

Release Methods

There are numerous release methods which can be employed to re-introduce raptors back into the wild, each having advantages and disadvantages. The majority of release techniques are variations on traditional falconry hack methods, or based on falconry itself. The term hack originates from a process used to get young birds flying-fit prior to being trained for falconry. Juvenile birds will instinctively return to food left out for them at their site of release (called a hack site). When their visits for food decline in frequency, it is an indication that they are now hunting for themselves. The advantage of birds being put through this process is that they learn to hunt and get fit while still having access to food, should their initial attempts be unsuccessful.

1 A Hard Release: This is when a bird is taken to a suitable location and simply released from a travel box into the surrounds. This applies in cases when a raptor has had a minor injury or  slight concussion and on recovery the bird is immediately returned to where it was found. Hard releases may also apply in some medium stay cases, where the raptor is of a species that does not require a high level of fitness to survive. It is sometimes useful to release some species near a food source or roost.  

2

The ‘traditional’ hack:   This method is suited for a complete brood or group of young raptors of about the same age.  The birds are placed in an artificial nest site which is similar to that which the species would normally use in the wild. Food is placed on the nest at the same time each day, but it is important that precautions are taken to prevent the birds associating the food directly with the human provider. Food should be provided at night for the nocturnal species and during the day for the diurnal species.
  If the birds are already starting to branch or fledge, then they are too old to be hacked in this way. Birds of less than four weeks of age will stay in the nest long enough to associate it with food and are likely to return to this place.  This facilitates continued feeding as they learn to fly and hunt for themselves. Although this hacking method is reasonably successful, birds do occasionally get lost or killed by predators, as in any wild fledgling process.

3 A hackboard:   This is simply a food platform, where food can be tied down. This hacking method involves training the bird to fly to the board for food (falconry knowledge is essential here). Initially the flying distance is only a few metres. The bird is allowed to feed on the food which is tied down to prevent the bird flying off with it. The distance to the board is increased every day and the bird is flown on a creance line to avoid early, accidental release. The bird is allowed to finish its meal on the board. After a few weeks the bird should be flying 50 meters to the board and can then be flown free. 
Food is left on a daily basis, but after a few weeks the ration can be decreased.

4 The aviary hack:    The method involves placing the birds into an aviary or building that has a good view over the surrounding, suitable habitat. Food is provided daily at the same time via a hatch or pipe to minimise any association of food with the feeder. After the birds have been in the enclosure for four to six weeks the door is quietly opened. As with some of the other hack methods, it is better if more then one bird is hacked from an aviary at the same time.
   Food rations should be reduced just prior to release (opening the door) to encourage the birds to stay in the area as they are feeling hungrier. Food is left at the aviary every day as before. Once the birds have been at hack for a few weeks the amount of food can be reduced to encourage the birds to hunt for themselves. 

5 Lure hack:    This method requires knowledge of falconry methods and involves training the bird to fly to a lure on a daily basis in the area were it is to be released. This introduces the territory to the bird before release. This method works well on mature birds (with hunting experience) which have suffered severe trauma or which require the building up of muscle. The bird is flown straight to a lure over increasing distances until it is considered fit and released in the area.
  

6 The kite hack:    Falconry experience is also required for this method. It involves training a bird to fly towards a kite, to which food is attached.  The bird is flown daily to the kite and every day the kite is made to go a little higher. Eventually the kite can be raised to 700 or 800 metres. The food is attached to the kite with a quick release device which is detached when the bird grabs the food. This method introduces a territory to the bird,  gets it very fit, and when the kite is up it can be seen from a long distance which helps in calling the bird back after release.

7 A full falconry hack:    This is the method of choice for the rehabilitation of most species which have suffered severe trauma. It is unfortunately not suitable for owls, vultures and is difficult with big eagles. The method involves training the bird to accept man as a hunting partner. By flying the bird at natural quarry it gains fitness. The success of the bird on wild quarry will be the deciding factor in determining when it is ready for release. The person undertaking the training must be an experienced falconer, registered with the provincial club, with the understanding that the bird is to be released once fit.