IBM Protocols:

Nest climbing and marking of nestlings in the wild

1)Introduction:

When the first wild-born Bearded vulture hatched in 1997 in the Alps after 100 years of absence, leading experts in the ecology of the species met in Goldau (Switzerland) to deliberate on some necessary rules together and decide the best action plan regarding the management of the breeding in the wild to avert any risk for the species. Among other solutions regarding the public awareness, the most important decision was to avoid any kind of disturbance of the natural development of nestlings born in the wild. Thus, everybody agreed not to take blood samples for DNA analysis and DNA data bank, not to put rings or any other marking pattern at the juvenile birds and not to approach the nest sites before fledging.

In the meantime, after a period of 15 years, the new established Alpine subpopulation has developed exceptionally: 14 offspring (at least!) fledged successfully in 2011. Some of these nestlings come from pairs of second generation already.

The monitoring activities (bleaching of feathers, coloured rings, network of observers, radio tracking and DNA analysis) ofvultures in the breeding stock and the birds released since 1996 increased our possibilities to follow the birds in the wild remarkably. Therefore within the Alpine in situ project we have the unique possibility to study the development of a whole new established subpopulation of Bearded vulture, its eventual connection to autochthonous European subpopulations and to recognize possible threats as soon as possible.

Until now it was only possible to conduct DNA analyses from a very small part of the offspring fledged in the wild by collecting feathers in the nests (after fledging) or found by chance, but in the overall knowledge this was not such a big problem as most of the birds came from the captive-breeding network. However, since 2007 the number of birds born in the wild has exceeded the number of released birds per year, and the estimation in 2011 is that ~38% of the total population is wild-born.There is therefore a lack of information regarding this largepart of the population. Furthermore Barbara Gautschi-Hefti and Franziska Lörcher demonstrated in their genetic studies the potential loss of variability of the Bearded vultures in the recent Alpine subpopulation, which makes it even more important to follow up how the situation is in the wild.

2)New strategy

During the meeting of the IBM Steering Committee and the International Bearded vulture Information meetingin Mallnitz (Austria, November 2011), and the meeting of the VCF (Vulture Conservation Foundation) in Madrid (Spain, December 2011), it was decided to modify the general trend and include the birds born in the wild in some of the marking/sampling techniques when possible. There are a few reasons why it became necessary now to do so; the overall intention is to find a balance between the necessity to disturb as less as ever possible at the nest site and the goal to collect data and increase our knowledgewith respect to this important fraction of the Alpine population.

Keeping in mind this prediction, the following questions should be answered in the protocol:

a)Which marking patterns/samples are absolutely necessary?

b)At what age should the process be done?

c)Procedure of the nest-climbing

d)Should the climbing be avoided in some case?

e)Behaviour of the adults

a) Which marking patterns/samples are absolutely necessary?

-Fixation ofcolour rings: Yes. It shall be made according to the marking pattern provided by the IBM Administration, different from the one used for the released birds.The ringing of birds in the wild is subjected to the Euring scheme, so this marking pattern shall be produced under the international guidelines. The material of the ring has been traditionally aluminium. A combination of a metal ring (officially from the EURING scheme) on one leg and a PVC ring (Darvic) on the other leg should give most advantages as possible. On one hand the metal ring doesn´t get lost (most probably) and gives the chance for a clear identification of the bird if it is found dead or recaptured. On the other hand the Darvic ring gives the possibility to identify the bird in nature when the ring can be observed under optimal circumstances or on a picture. The colour should be visible for a long time (up to now experiences on Bearded Vultures are missing). Additional a clear identification of the bird should be possible through the letters and/or numbers given on the ring (like they are used for Griffon Vultures for years already).

-Fixation of a radio transmitter: In principal no, but in special cases it might be discussed (for example to compare the behaviour between naturally- fledged offspring and released ones).

-DNA sampling: Yes, extremely important. For the chick this can be done either by taking blood samples (only in case the collector is experienced since there might be some complications) or plucking some feathers (trying to take them whole with the rootif possible). Besides, it is also very important to collect any other feather from the nest that might belong to the adult birds.In case there are rests, it might be of use to collect egg-shells.

-Wing tags: No, they are not used within the Alpine project because of several reasons: disturbance of the bird, especially in flight, confusion when wing tags get lost, etc.

-Bleaching of feathers: No. Although this might be very positive, it takes too long to be done properly

The average time invested should not exceed 15 minutes (“safe time”). The ringing of bothlegs and collection of samples for DNA analysis takes 5-10 minutes.

b) At what age should the process be done?

For security reasons any activity inside the nest with an offspring of unknown ageshould be avoided. The best age for handling the chicks is when they are between 2.5- and 3-months-old. During this life span there is noserious risk that the young vulture might jump from the nest because of the disturbance and that parents could abandon the nest since both leave their offspring alone for hours, having though a good chance to avoid any negative stress of the adults.

A special situationthatmight arise is the attachment of radio-transmitters, if it is decided to use this method under special circumstances as mentioned above. In this case thetransmitter cannot be fixed at this age (between 2.5- and 3-months-old), so the bestoption would be to try to catch the fledglings in the surrounding of the nest site (if ever possible when the parents are absent) after fledging when they are still not able to fly properly.Consequently it is necessary either to know the time of hatching of the offspring or,in case it is possible to have a clear look at the bird in the nest from a bigger distance, to estimate its age accurately.This requires thus an intensive monitoring of the nest to be as accurate as possible.

c)Procedure of the nest-climbing

Before undertaking any action, the IBM Administration should be informed.The manipulation should be done by or under the guidance of an experienced rock climber(to avoid any unnecessary risks and realize the climbing as fast as possible using professional equipment), together with a specialist accustomed and experienced with the behaviour of Bearded vultures. It is also advisable to count with a veterinary in the team that doesn’t have to climb to the nest but should remain at close hand to act in case of emergency (e.g. there’s a problem with the chick and this has to be removed from the nest). If possible the team should not be larger (2 climbers and a veterinary close by). Any accumulation of inquisitive people near the nest during this action should be avoided. In some countries (for example Austria and France), besides the required permits to climb the nest,it is necessary to ask for special permission (Ministry of Science) when collecting blood samples, so please bear it in mind beforehand to ask the appropriated authorizations.

Although it is specifically not advisable for the difficulties and risks for the chick it implies, in case it is decided that the marking procedure is done by the rock climber alone,he/she has to be trained carefully beforehand. It is especially important to explainin detail how and where to put the rings on the chick, how to take feathers and from which area and how to store them afterwards. It is not recommended to take blood samples in this situation.Likewise, this person should be preparedin advance for the possible reactions of the nestling, so it is necessary to explain how to lay it at its backside, how to fix its body or legs and how to react in the case of aggressions in order to save time in the nest.

The ideal would be to create an expert teamto do this job for a longer time and perhaps at several nest sites. Once you have the experience on how to approach a certain nest site and knowing the possible reactions of Bearded vulture nestlings, this work can be done more professionally and in a much shorter time.

d) Should the climbing be avoided in some case?

It’s common sense that the climb should be avoided under unsuitable weather conditions to avoid unnecessary risks both for humans and animals. Before starting the climbing, the team should assess the situation and decide whether the whole process of approaching the nest is too complicated to do it within a safe time(see point 2.a), since otherwise it is better not to start.

It is very important to avoid the marking of offspring of a new pair breeding for the first time. It is better not to disturb them in any way during the first breeding attempt. Therefore, the marking of chicks in the nest is limited to pairs that have reproduced successfully at least once in their history.

The process should not be started in case the age of the bird is unknown (see point 2.b)

e) Behaviour of the adults

So far, our experience regarding the behaviour of the adult returning to the nest site during our activity at the nest is quite limited. To our knowledge no aggressive behaviour has been observedin the Pyrenean population up to date during the hundreds of nest visits by our Spanish colleagues. But in many cases (such as captive-bred-and-released birds) the birds are more accustomed to humansand every since in a while it has been observed within the breeding network that some parents are defending their nestling violently. Nevertheless the climbers should be prepared if an adult decides to attack. This is by no means as dangerousas theviolenceshown by angry Golden eagles, but the surprise can cause an accident both for the climbers and the chick. It might be recommended to keep walkie-talkie connection with the third member of the team (the veterinary) that acts thus as lookout and could inform in case of parental approach.

The behaviour of an aggressive bird defending its nest is as follows: it tries to grasp the intruder with both legs and to fix him, andthen attacks with the beakaccompanied by powerful wing beats. This is not very painful or dangerous but impressive, and it is really difficult to get free if the bird succeedsin grasping an arm or leg. The talons are extremely strong and it is difficult to release the grip if you are alone avoiding hurting the bird.

3)Acknowledgements:

This protocol was created by Dr. Hans Frey and edited and adjusted by the IBM Administration in cooperation with some collaborators of the IBM and the VCF.

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