Bird ringing...Out dated.

[John]

I agree about the info we have got from the Cuckoos is far more than we have ever got. My point is that it doesn't answer the questions they wanted answers on and that was what is the migratory routes they use and where do they go to.

Five birds separated by 70kms in Britain all using completely different migration routes from each other with 3600km being the spread of their arrivals.

John

Originally Posted by FUDGEY

I have no problem with catching a bird once John, I do get your point. The sketchy info we have back on the Cuckoos isnt really sketchy it is crystal clear. We would never have got this info through ringing (the different routes and times) if we continued to do it for the next million years. We will have to agree to disagree on this one I guess

[fairplay]

I originally and wrongly placed this on the sticky: "If you find a baby bird" thread, but this spot is more appropriate methinks.

Anyways, having disturbed a Nightjar on July 28 during a Silver Studded Blue (Butterfly) survey, and realising 2 eggs were present, we went back last Monday Aug 15 to attempt to ring the now hatched chicks, but the ringer determined that they were still too young and the ring would have been too loose and may have interfered with the talons in time.

So we went back today only to discover that when the female flew off (on our approach) it was from a few metres from the 'nest' and when I looked at where the nest was, I could see no chicks. Assuming she had moved the 2 chicks, I told the people present to be careful where they step as the chicks have been moved.

Only one was found - the other was at the original site a few metres away, but had been eaten with only the wings and blood remaining.

First question: What had eaten it ? Plenty of Adders about, but it would have swallowed the lot - wings an' all. A Corvid would have taken it away to eat I expect, as would a Stoat ?? If a Fox, surely it would have had both chicks ?

Anyway the ringing was done as quickly as poss' but weighing and measurements had to be done too whilst lots of photos were taken.

After we left, I was wondering if I did the right thing by informing a registered ringer ?
Second question: Did our first visit alert any possible predators ? (Suffolk has a lot of open pig rearing units so we checked the sky for overhead corvids)

In my opinion, being such a late clutch, it would have provided a lot of information if any rings had been recovered, and this opportunity was too important to miss.

Third question: Was there ever any realistic possibility of a ring ever being recovered and therefore did we do more harm than good ?

Neil.

[FUDGEY]

A very good and thought provoking post Neil. IMO this can do more harm than good. I have in the past felt that I have been responsible for a nest failing because I found it. I can of course never prove this, but its a possibility. Take your Nightjar for example, 3 times this bird was disturbed and what are the odds on the ringed bird being recovered? Pretty slim Im sure you will agree. Ringing requires a lot of time for little return, I can not wait until technology moves to a point when it becomes unnecessary.

[FUDGEY]

Originally Posted by John

I agree about the info we have got from the Cuckoos is far more than we have ever got. My point is that it doesn't answer the questions they wanted answers on and that was what is the migratory routes they use and where do they go to.

Five birds separated by 70kms in Britain all using completely different migration routes from each other with 3600km being the spread of their arrivals.

John

John, Im sure I remember reading on here when this discussion came up before (before we knew that they were sat tagging Cuckoos) that the ones in favour of ringing said that we need to know where these Cuckoos go so we can find out if the numbers are declining in this area and if they are if there is any way we can improve the habitat or stop what ever it is that is causing the decline. These 5 birds have pin pointed exact areas where they go in no time. Another good thing about these tags is eventually we will be able to find out where they are dying. We will build up a pattern if its on migration in the UK or Africa. All valuable info.

[Dogghound]

Originally Posted by fairplay

First question: What had eaten it ? Plenty of Adders about, but it would have swallowed the lot - wings an' all. A Corvid would have taken it away to eat I expect, as would a Stoat ?? If a Fox, surely it would have had both chicks ?

Hard to say without seeing the body, young birds particularly ground nesters have a lot of predators. As you have mentioned Nightjar are prone to Adder predation (when young nestlings). A whole range of bird species will attack them, in particular tawny owls which is the most likely explanation in respect to what you have seen. Foxes, stoats are likely to take them to a sheltered site to feed (although I have not seen the site so hard to say), a badger would predate a nightjar and would eat it where it was killed. Like you say a mammalian predator would most likely have killed them both. Although you can still flush and get out of the way or they can adopt several postures which make them almost invisible.

Originally Posted by fairplay

Anyway the ringing was done as quickly as poss' but weighing and measurements had to be done too whilst lots of photos were taken.

After we left, I was wondering if I did the right thing by informing a registered ringer ?

Of course it was, the more knowledge we have about these birds the more we can do to help conserve them. Ringing information is absolutely vital to understanding birds. We have learnt a great deal through doing this, not only migration patterns (which is very complete for a lot of species), but weight, measurements, moult, bird condition, disease, breeding biology, survival etc. I visit a lot of nests through the season (not nightjars, although I do ring adults) and if you do it in a careful way (i.e. move vegetation carefully, dont leave tracks to and from the nest, be careful as you approach the nest) then it has no detrimental affect on the birds. A lot of studies have also indicated this. It is not in the ringers/nest recorders interest to cause a detrimental effect as not only are you causing unnessecary pressure on a species you also dont get any data from them.

The only issue is I would not have taken a group of people to the nest (but if possible) taken the bird to them. To avoid mammalian predators following the large amount of human scent.

Originally Posted by fairplay

Second question: Did our first visit alert any possible predators ? (Suffolk has a lot of open pig rearing units so we checked the sky for overhead corvids)

In my opinion, being such a late clutch, it would have provided a lot of information if any rings had been recovered, and this opportunity was too important to miss.

See my above points.

Originally Posted by fairplay

Third question: Was there ever any realistic possibility of a ring ever being recovered and therefore did we do more harm than good ?

Yes a very realistic one, nightjars are recovered in Africa, although ringing effort is not huge there at the moment. More birds are recaptured through Europe as they migrate south, this gives an important picture into migration route ways. This could form important data in the future to determine key areas to conserve, or areas not to build on, or put up wind farms etc.

Regarding ringing, using radio-tracking is useful in some species but unrealistic for most. Ringing birds is not just a means of tracking trans-African migration but getting a detailed account of local population structures, ecology and survival. It would be pointless to satellite track a wood full of willow tits, some species are quite sedentary but are still in decline. If the issue is capturing birds then you need to do it in the first place to put a tag on as John correctly points out. Cuckoo are notoriously difficult to catch in Mist nets, they are also hard to ring as pulli as small numbers are distributed in a wide area due to their parasitic nature (unlike if you found a nest full of another species). Just look at willow warbler for example birds like these which are easier to catch have decent amounts of data on migration. We also have additional information on wing length of willow warbler with longer wings found further north, we then have additional data on how long birds breed, how long moult occurs and where, how long it takes nestlings to fledge, how many birds survive, habitat preferences and the list goes on. Realistically your not going to get this info but strapping tags onto them unless you repeatedly recapture them.

[KentYeti]

Originally Posted by captaincarot

we could already measure every physical dimension of a flying bird were we so minded using nothing more complicated than a few IR laser diodes a couple of posts to stick them on and a fast pc to gather the data. the only thing you would be missing then is the weight

Originally Posted by John

And do you think that every ringing group is going to do that. I doubt it, plus the weight is an important factor in data collection.

You are all still missing the point I have raised twice regarding tracking devices and that is you still have to catch the bird to attach the device. If you have to do that what is the difference between that and a catch and record system.

John

Not all of us are missing the point John. Of course the bird will still need to be caught.

But the point I have made is that technology will bring down the size and shape of such a device that captaincarrot outlines to little more than that of a current ring. Cost will go up, but the inceased benefits of being able to constantly track nearly every bird caught and so dealt with will surely vastly outweigh the reduced number of birds handled this way.

How long before such a device is available?

No idea. Ten, twenty years, thirty years?

But I remember the BR Computer Center at Nottingham in the mid 1980s. Held the second biggest database in the world, only behind the Pentagon. Multi-Million pound center packed with mainframe computers. Enormous sized series of buildings. I would guess we are close to being able to have packed all that data in a £750 laptop nowadays.

And what will drive the development of such a device for birds?

Well, certainly not birds! It will be as a spin of from human medical research. Maybe as man/womankind builds up to an attempt at a Mars landing. Where monitoring of very detailed human biometrics over a long period of time with absolutely minimal weight equipment will become vital.

All IMHO of course.

Cheers,

Bryan

[FUDGEY]

Dogghound, I am no expert and acknowledge you are much more of an expert than me on these things, but can you explain some things to me. You said "We also have additional information on wing length of willow warbler with longer wings found further north, we then have additional data on how long birds breed, how long moult occurs and where, how long it takes nestlings to fledge, how many birds survive, habitat preferences and the list goes on" I can not see how knowing this helps us help birds? These to me are just facts that we have found out and they will stay pretty much the same for the future. I am probably missing something here and Im sure you will point out what. Thanks.

[Dogghound]

Originally Posted by FUDGEY

You said
"We also have additional information on wing length of willow warbler with longer wings found further north,

Wing length is correlated with migration length (as well as sex, body mass etc) in willow warbler and similar small passerine species. So once you determine the races (with longer winged forms occuring into Scandinavea acredula) you can see what kinds of changes are occuring overtime. Are willow warbler migrating further due to changes in habitat type. Wing lengths appear to be getting larger could this be linked to the increasing size of the Sahara?. Do wing lengths change over time in an individual as it ages etc. You get a more complete picture than with tagging.

Originally Posted by FUDGEY

we then have additional data on how long birds breed,

Important for conservation, woodland management for example needs to work around breeding length. Could increased time in the nest result in more predation? could decreased time in the nest result in more 2nd broods? the list goes on, they are all aids in conservation of a given species. Knowledge is power.

Originally Posted by FUDGEY

how long moult occurs and where,

They may use an important area, this is often seen with wildfowl and waders where large portions of a population visit a given site. You could build a windfarm on it or drain it for farming without knowing the importance. Tagging would show they are using the site but not why and not the stage or part of moult which is occuring. Is moult liked to earlier breeding?

Originally Posted by FUDGEY

how long it takes nestlings to fledge,

see above point,this one is quite important in my opinion.

Originally Posted by FUDGEY

how many birds survive,

Very important, most of the data we have on birds comes from ringing. You could tell the proportion of marsh tits in a woodland which make it to breeding age, or you may find that no firecrests survived a given winter, or that dry summers are bad for song thrush numbers, or that oil seed rape is important for linnet survival.



For the record I think satellite tagging is great for species like cuckoo, nightjar and raptors etc, species which are less likely to be recaptured in Africa/Asia. But it is still second to ringing by a long way in my opinion, in the context of general species.

[John]

I totally agree with you regarding this info that is being gathered. Far better than anything we had before and it has to be hoped that more info will be forthcoming.

I think we already new some info regarding Cuckoo's but although this info is good it doesn't answer too many questions. For instance, they wanted to know the migration route the Cuckoo took. This hasn't answered it as two birds routes are widely different to the other three. Of those three, two took fairly similar routes, one a different route that eventually crossed both the other Cuckoos before re-crossing one of the other Cuckoo's paths. The other two took an easterly path, completely different from the other three.

They wanted to know where they went. This has been answered to a degree but they are still about 2000 miles apart.

Technology is brilliant but not the be all just yet but I also totally agree that if technology became that advanced that a bird needn't be caught then that would be the icing on the cake but being realistic I doubt if that will ever happen.

Regarding the disturbed nest. This is an area I am not comfortable with. I can understand one nest disturbance but if you can't get what you want from one visit in my opinion you should not revisit that nest again.

John

Originally Posted by FUDGEY

John, Im sure I remember reading on here when this discussion came up before (before we knew that they were sat tagging Cuckoos) that the ones in favour of ringing said that we need to know where these Cuckoos go so we can find out if the numbers are declining in this area and if they are if there is any way we can improve the habitat or stop what ever it is that is causing the decline. These 5 birds have pin pointed exact areas where they go in no time. Another good thing about these tags is eventually we will be able to find out where they are dying. We will build up a pattern if its on migration in the UK or Africa. All valuable info.

[KentYeti]

Originally Posted by John

.............Technology is brilliant but not the be all just yet but I also totally agree that if technology became that advanced that a bird needn't be caught then that would be the icing on the cake but being realistic I doubt if that will ever happen................


John

I doubt the "wwbw" will happen in our lifetimes John.

But if human "progress" continues apace without any major setbacks I am convinced it will happen.

A World Wide Biometric Web, (possibly satellite driven), that can pinpoint any chosen individual, human or otherwise and monitor a full set of biometrics. Without any pervious physical contact with the individual. Maybe based on a health care system for humans, but subequently adapted for any species.

That could be a very long way off. But I would be very surprised if somewhere, maybe inside NASA or a "secretly funded" part of NASA or equivalent, scientists etc are not already working on something that will eventually evolve into the wwbw.

Very little stays the same for ever.

Bryan