Preliminary Results of the Experimental Release of Griffon Vultures in Kotel Mountain by FWFF - How to Make a Release Cheaper and more Feasible in the Balkans Current Funding Climate

15/10/07

This article is the written form of a presentation given by FWFF at the international conservation conference in Melnik, Bulgaria. You may find it useful to read the summary of the viability study in PDF format before reading the following article.

To see a quick summary of results, please see the bottom of the page

Before discussing the results of the experimental release it is important to understand how Western European re-introductions of Griffon Vultures have been done as this is what the western funding bodies and experts want replicated in the Balkans:

• They build a very large aviary with several separately enclosed compartments for the different age groups. The aviary is located in the release area and the birds will be released straight from the aviaries.
  
  
• Each year roughly 12 birds of the same age are put in each compartment and the age groups are kept separate from one another. Only rehabilitated birds are used as captive bred birds are seen as unsuitable.
  
  
• The vultures are then kept in the aviaries until they mature which can be as long as 4 years if the birds were acquired at a young age. The birds must be mature when released as it decreases the chance of them wandering off to find new colonies as juvenile birds instinctively wander during there first years to find a home range suitable for themselves. It is believed they must also mature in the aviaries and not at another location so they become acclimatized to the area and not wander off elsewhere after release.
  
  
• Every year the age group that reaches maturity is released. A minimum of 12 birds MUST be released the first time so 7 or 8 will survive to form an initial nucleus which will keep the rest of the birds in the area as they are a highly social species and will fly away to another colony if not enough birds are present.
  
  
• A very successful method with just one downside, its huge expense.

It is also important to examine the current funding situation in the Balkans:

• The funding that is usually available is often only small grants which are designed to contribute to a larger funding goal to create a Western Europe type of release This funding takes a lot of effort to get with no guarantee that enough small donations will be received to reach the larger total.
  
  
• lLong term funding for the life of a project, which for a Western European style project is a minimum of 10 years, is extremely rare and almost impossible to get.
  
  
• Even if such long term funding is available donors are often reluctant to give money for the Griffon Vulture as they want the credit for saving a species from extinction and the Griffon Vulture is listed by IUCN as Least Concern (ie. not endangered) as its population is reasonably stable and not in a massive decline. This is despite 90% of the European population being concentrated in just 10% of its distribution area - Spain, a totally unhealthy scenario especially as even here it is not safe as is its just starting to experience a decline because of the closure of feeding sites and the increase of wind farms. Attempts to get funding for the more endangered vulture species which are also nearly extinct on the Balkans is difficult because an organisation is expected to have experience of re-introducing other less endangered species such as the Griffon Vulture which of course they can't because of the funding difficulties.
  
  
• Even if large scale funding does become available there is often a lot of arguments between conservationists within the recipient country(s) because it is argued the limited funds should be used for species with a more urgent threat of extinction such as the Imperial Eagle Aquilla Heliaca or Red-breasted Goose Branta ruficollis.

These funding issues combine to make it unrealistic to expect the Griffon Vulture to be re-introduced on the Balkans using the Western European method A NEW METHOD MUST BE FOUND

And we at FWFF believe that from our experimental release we may have found a method of doing a successful release but at a fraction of the cost. The biggest costs of the Western European releases are as follows:

• The cost of building the extremely large aviaries which may hold up to 50 birds in 4 or more compartments at any one time. 
  
  
• The cost of food to feed the birds in the aviary.
  
  
• The cost of fuel to get to the aviary as its often located in a very remote and inaccessible area.
  
  

Firstly we believe we can massively reduce the capital costs by building a far smaller aviary than the ones used in Western Europe like the one we built in Kotel which is just 12x6x3m. The Kotel aviary can hold a maximum of 8 birds instead of 50+. 

But it is argued that if we have just 8 birds we will be unable to release enough birds at the first release to have enough survive to create the essential initial nucleus. But we believe we can overcome this problem by releasing captive bred birds. 

Captive bred birds have not been used before as they are thought to be unsuitable as when ever they have been released they have died because they have not learnt to fly before the 40 day starvation limit is up as they have no prior experience of flying and in a release situation there is no experienced individuals to teach them. 

But again we believe can overcome this problem by allowing the birds to have an initial training period. In our experimental release B53 and B59 both failed to learn to fly before reaching the starvation limit, we know this for certain for B53 as it was thankfully recovered collapsed on the ground just before it would have died and we can be confident that B59 is dead or dying. But B54 managed to learn to fly and is doing well, why the difference when the birds have very similar life histories? 

We believe the key is that B54 escaped in 2005 and was able to spend 30 days flying in the wild. Although during this escape it did not learn to successfully fly (it was recovered floating in a reservoir!) it was able to gain 30 days flight experience. This gave it the advantage when it was released as part of the experimental release because while we described it as having first soared 6 days after release we should have said 36 as this was the total flying experience this bird had. On the other hand both B53 and B59 started at 0 days flight experience when they left the aviary and we believe this explains why they have both failed to adapt to conditions outside the aviary. 

So we believe that you can use captive bred birds as long as they are allowed to fly for an initial 30 days (to gain essential flight experience) then recaptured, rehabilitated and released again. During a full release radio-tracking would be essential which unfortunately we did not do in this experimental release. This is not an added expense how ever as in a full release using radio-tracing devices is seen as standard. 

Now we have shown that captive bred birds can be released we can now explain why we think this is important for creating the initial nucleus. In the W Europe releases 12 birds are released in the hope that at about 7/8 birds will attach to the area to form the initial nucleus so it is argued that by releasing just 8 birds we will not be able to have this nucleus as not enough birds will survive or stay in the area to create the nucleus. 

But these captive birds once released still act very much like captive birds. They just stay in the area around the feeding area waiting for food to be placed, occasionally soaring to nearby areas but always staying within a few kilometers of the release site as B54 is showing a the moment. This means that the initial 8 birds have a higher chance of remaining in the area and forming the nucleus. Also there survival rates may be higher as they are not traveling to more dangerous areas and will always have access to food at the feeding site. Also we believe if just 5 birds survive this is still enough to start an initial nucleus. 

Once the initial nucleus has been set up it is less important whether you use captive bred birds or not. 

So we have shown that even with a small aviary you can create an initial nucleus. But now it is argued we will not be able to release any further birds for at least 3 years. Only after the initial birds have been released will space become available in the small aviary to place the next 8 birds. According to the W European model these 8 birds will then need to mature for about 3 years in the aviary to get attached to the area. 

But we believe this unnecessary, it is necessary to use mature birds for release but it's unnecessary to mature them in the acclimatization aviary. B54 spent a total of 11 months over a 17 month period in the acclimatization aviary including spending just one month in the aviary before release and he is showing satisfactory attachment to the area even though he has the ability to soar to several other large cliffs in the area. 

We believe birds can be matured in an aviary anywhere and then spend just a short amount of time actually in the acclimatization aviary before release. Obviously 11 months has been shown in this experiment but we think it is feasible that just 6 months (perhaps even less as B54 did only spend one month in the aviary directly before release) can be spent in the aviary although further experimentation is needed. 

This will dramatically reduce the biggest cost, feeding of the birds in the aviary during maturation. If the birds can be matured anywhere then they can be placed in Zoo's, rehabilitation centres and other appropriate centres where the cost of feeding will be effectively nothing for the organisation involved in releasing the birds. These centres have on site staff already so staff and transport costs for feeding the birds (which are some of the biggest costs in the Western European releases) are reduced to nothing during the maturation period, the only expense will be food which can be arranged for free from slaughter houses and perhaps a small fee to the hosting organisation for use of their facilities but as these organisations are usually conservation minded it is hoped the vultures will be allowed to stay for free. 

Also if it is found that birds can spend just 6 months or less in the acclimatization aviary then 2 or even 3 releases could happen a year with proper planning of the age of maturing birds. This will reduce the time of the overall re-introduction project again reducing costs.