Thankyou for your questions, concerns and curiosity about our Osprey ringing and tagging. We understand that there are some concerns so hope the answers to this detailed Q and A will help reassure you, and help you understand more of the rationale behind the project.
Why is the tagging and ringing done now?
Six weeks is the age judged by experts to be ideal for this task for several reasons: The chick is nearly full grown, having adult sized legs etc, so rings will fit; The chicks cannot yet fly, or try to prematurely, so are easier to handle and not in danger of injuring themselves during the process; the bond between parent and young is by now so strong and cemented that there is no risk of a parent abandoning the offpsring – Roy Dennis tells me he has never had a parent fail to return to a nest after a ringing in over 40 years.
Isn’t this whole thing stressful for the birds?
The whole process is kept as short, and stress free as possible, with the minimum of handling, and time away from normal routine for the birds.This is the first and only time in their lives these young Ospreys will be handled- and never having seen a human before , they do not know to fear us, but rather ‘play dead’ in response to the parents alarm call. The parents usually circle overhead shouting a lot but do not tend to attack or interfere, and quickly return to the nest soon after- though our female took her time today ( in fact she settled calmly in a nearby tree as soon as we left the nest) I have seen other Ospreys return to a nest within 5 minutes.
Why has the chick at Loch of the Lowes had both rings and a satellite tag fitted?
The satellite tag, though a marvelous tool, will only last 2-3 years on average, whereas the rings should last a lifetime and will enable us to follow the bird throughout what we hope will be a long and productive lifetime.
Is the single chick at a higher risk as a candidate for this technique?
No, we are assured by the experts that it is in fact an ideal candidate as it is large, strong and well fed, so has more advantages than many chicks in nests with siblings, and therefor a better than average chance of survival.
Will the tags and rings increase or decrease the chick’s chances of survival?
We believe neither, in that the results so far from this research (and similar research overseas) indicate a survival rate for juvenile ospreys is naturally low- perhaps as low as 30-40% over the first two years, and this is no different with birds carrying tags or transmitters. We are only now beginning to understand why, and the complexities of the challenges they face- and this project should give us more insight into this.
There are some excellent examples of young Ospreys still alive and well carrying transmitters and still teaching us new things every day: such as Rothiemurcas on Speyside.
Questions About Ringing:
Why is ringing done and how effective is it?
Ringing birds has been done in the UK for more than 100 years and is the research technique which has led to much of our current understanding about birds longevity, migration etc. The BTO administers ringing in the UK and it is done only by licensed practitioners with thorough training in each species special needs and techniques. Ringing with a metal band relies on the bird being sited again closely, caught, or found dead or injured, so that the ring can be read. Therefore only a small proportion of those birds ringed this way return information, however, those that do give us amazing insights. For more information, go to: www.bto.org
Why are there two rings?
One is the BTO metal band- the traditional ring, very durable, which the bird will wear all its life- this has a unique serial number and a contact address. The second ring is known as a Darvic ring, a super lightweight plastic ring that is designed to be highly visible from a distance. This has a unique colour, number and letter combination. These Darvic rings were developed to make studies of larger species possible, as they can be seen from a long distance and the birds don’t have to be re-caught to identify them, making behavioural studies etc possible.
Why are they that size?
In order to make them readable at a distance. Every species of bird, including all raptors, have a special size suited just to their needs, judged small enough not to interfere with the bird’s natural behaviour.
Don’t things get stuck under rings?
This seems to happen very rarely indeed- in many many years of bird watching, I have never seen this happen. If the bird were to get attached to something, the plastic ring would snap, and the metal ring also has a safety faultline that would allow it to break free. When birds with these rings are observed in the wild (from Whooper swans to songbirds) they shown completely normal behaviours and do not seem to experience any chaffing, ulceration or other discomfort, as long as the rings are correctly applied. .
Questions About Satellite Tracking
We are satellite tracking a young Osprey from Loch of the Lowes to answer the question: where inAfricado our Ospreys go in the winter and how do they get there? Unfortunately, we do not know exactly where our resident male and female spend their time as we have never had any reports of sightings of them from overseas, but we know most UK ospreys migrate to and fromWest Africa. A few birds seem to overwinter on route, in southern Spain etc so there is a wide range of possible routes and destinations. Since the current theory is that chicks inherit their route and/or destinations genetically from their parents, tagging this chick may give us insight into where our female ahs been going all these years- a mystery we’d love to solve.
Why Satellite Track Ospreys?
This new modern technique can tell us so much more than previous methods about our birds- it is the cutting edge of scientific research. It is an enormously useful tool in collecting detailed information such as exact routes, timings and behaviours of migrating birds- it is amazing that for such a high profile species, there is still an awful lot we don’t know. This work is crucial to more detailed scientific study of the species and a better understanding of the ‘other half’ of the Ospreys’ lives. If we know more about their migratory routes for example, we can work more closely with organisations and governments in those countries to ensure the areas that Osprey’s use are protected. It may also help answer such questions as: Are there countries where osprey, and indeed other migrating birds have a higher mortality rate? If so, can we find out why? Do birds from UK stock migrate to the same locations as their cousins inScandinavia? Are the birds from the UK more prone to flying off course and ditching in the Atlantic?
Indeed, the data provided by tagging will contribute to the research theory that reintroduced and recolonised birds such as the UK population, produce chicks which tend to set off on migrations in a direction which relates to their ancestral origins (we think the information is part of their biological programming and therefore their course of travel might be predictable). Unfortunately, in the case of reintroductions, this is not necessarily the best route from the country of birth. Proving or disproving this theory has repercussions for future re-introductions.
Lastly, it will hopefully enable us to forge links with communities on the osprey’s migration routes and inAfrica, which will help promote their conservation more widely.
What is Satellite Tracking?
Modern technology allows us to attach small satellite transmitter packs to lightweight harness on birds. These are designed to send regular signals via a satellite link enabling the bird’s position to be tracked hourly, anywhere in the world. The new generation GPS satellite transmitters made by Microwave Telemetry: tiny satellite radios, called PTTs, have been designed and manufactured in recent decades for carrying out research on wildlife. We use radios, made by Microwave Telemetry in Columbia,USA( www.microwavetelemetry.com ). Each PTT has a unique identification number supplied under our conservation agreement with Argos CLS, the French Satellite Tracking company based inToulouse,France( www.cls.fr/welcome_en.html). The newest radios have GPS technology so that the positions of the bird are extremely accurate (within 18 metres), and they also record speed, altitude and course. A solar panel keeps the battery charged.
Has it been done with Ospreys before?
This technology has been around for many years but is getting smaller and cheaper all the time. It has been used very successfully on mammals and many birds such as raptors, geese, swans, cuckoos, and now even songbirds!
Our Loch of the Lowes birds have never been radio satellite tracked but Ospreys from Speyside and birds from Rutland have been, as well as Ospreys from Scandinavia and America. A famous example is ‘Logie’ a female Osprey tracked by Roy Dennis from the Highland Wildlife Foundation, and more recently chicks from the Lake District Osprey Project, RSPB Loch Garten, and Cors Dyfi Osprey Project in Wales. There are several websites where the migration of radio tagged ospreys can be followed.
This will be the first time this has been done with birds from this part ofScotland(Perthshire) and may show up some crucial local differences and variations.
How does it work?
The radio is attached to the birds’ back by a lightweight harness, like a tiny rucksack, and is programmed to take GPS readings at hourly intervals and then at intervals of between 1 and 10 days to transmit the data. CLS Argos have satellites which circle the earth, mainly collecting information from ocean weather buoys, and they pick up the signals. We can connect to the website and database, and extract our data then process it and put in on a map for you to see.
How are the tags attached?
The tiny transmitter packs are sewn to a lightweight harness which goes around the birds back and wings, like a small rucksack, The chicks are sewn into the harness with a few threads at the front – leaving enough room for the chicks to put on weight and allowing the harness to drop off at the end of its useful life. This ensures the harness puts no strain on the bird. There is a small flexible aerial on the top of the pack which receives the satellite signal. Crucially the pack doesn’t interfere with flight or the Ospreys hunting behavior, leaving their legs free.
Are the tags heavy for the birds to carry?
The tag weigh approximately 5% of the birds body weight, approximately 30grams. This is not thought to significantly impede the birds in their usual movement, or increase chick mortality.
How long will the tags last for?
Tags will run on their solar charging units for three to five years. The life of the tags can vary depending on battery life and the amount of data that is to be collected, as well as the conditions that it has to survive in. The bird may also lose its tag before the tag itself gives up, in which case the tag can be retrieved and reused. In most cases Osprey tags last 1-3 years.
What happens if the tag stops showing movement during migration?
If the tracking device suggests the osprey has stopped moving this could be for several reasons, including the following possibilities:
• the bird could be resting– this is common during migration / bad weather
• the battery could be flat due to lack of solar power
• the satellite might not be able detect a signal, e.g. if the bird is in forest
• the bird might be dead
It is possible to tell from the data received whether the battery was failing or if, in fact, the bird has stopped moving. In cases where transmission indicates no further movement, we will check the recent data and wait to see if more data is collected.
If we finally believe the bird is dead our actions will depend on where it was last located. We may try to recover the body if possible to find out what happened. This can obviously only be done in certain locations.