Kyleakin Lofts Posted January 13, 2018 Report Share Posted January 13, 2018 Which route do our pigeonsreally take from Barcelona?Part 2.In the first part we presented our project using geolocators. How we came tothese devices, why we use them and not GPS loggers and how the first testswent.The Barcelona weekend was of course D-day, now it had to happen. JelleJellema had three pigeons basketed with geolocators and had the necessaryconfidence in them not to let us down. We all know now that Barcelona 2013was a very tough race which only the valiant ones came through. The straightline distance from Barcelona to Nijverdal is 1260 km so under thesecircumstances it certainly was no piece of cake. Of the first four arrivingpigeons there were three with geolocators. These are the pigeon’s arrival timesand the provisional National results of the ZLU:18.58hrs 08-2027103 332nd National (113th hens)19.39hrs 09-1783744 423rd National (138th hens)07.01hrs 08-2027077 847th National (253rd hens)From this we can safely conclude that the geolocators do not impede thepigeons from being able to put up a top performance, a lot different to all theGPS loggers that we tried earlier. The same weekend Ultsje Jellema sent twopigeons to Cahors. Ideally both flights would overlap and we could establish theroute taken by the pigeons and we could use the data from Cahors as a Page2reference. Cahors, the cock that Ultsje sent had a number of leg feathers clippedso that maximum light could fall on the geolocator. Of the two pigeons he sentone was lost, the other was listed as the 3rd Steggerda pigeon and 18th in theFrisian Fondclub, 09-1653620 timed at 15.51 won a decent prize from 901birds. After returning home, the geolocators were read and the data analysed.The computer programme developed for this makes it a breeze. The data is thenpresented as in the picture below:Figure 1: Two beams with wave patterns.The top bar is a shrunken view over a longer time period. The area blocked inred is the part selected (11th and 12th July 2012 in this case), which is thenshown magnified below. The blue pattern shows the light intensity on the day.The light intensity is shown on the vertical axis, graded on the left starting at 1and rising to 100,000 lux. Horizontally, the times of the day are shown betweena green and red vertical line. The green and the red line shows that the lightincreases (sunrise) and decreases (sunset) from and to around 10 lux (twilight).The night between them is very clear; the light level is not far above the 1 lux.From anywhere in the Northern Hemisphere it is known for each day when the Page3sun rises and sets. This is used by fanciers to set the times for neutralization orhours of darkness.This data, and the amount of light that the geolocators have saved, makes itpossible to calculate where the pigeon was overnight. A very brief explanationis under Figure 2.Figure 2. Showing the earth with the sun to the right.The bold circle around the earth is the boundary between day and night. To theleft of the line is the night on earth and to the right, where the sun shines, it isday. The right globe shows the earth about 12 hours later. The sun is still on theright, but the earth has turned almost 180°. Circle B now gives the boundarybetween day and night. Now if we want to find the place where the sun rose onthe left and where 12 hours later it rose on the right, then it must be at a point onboth A and B. This position is where the two lines intersect, indicated by a redasterisk. If we know the times of sunrise and sunset and the date we cancalculate the exact location where these lines intersect and thus the positionaround midnight.Four pigeons, five nights.In the first part it was indicated that the geolocators have mainly been used inresearch on migratory birds such as waders, swallows and terns. These speciesmove over a greater period of time and therefore there are many observationsavailable over that long period containing many nights. So we used a device that Page4is not specifically designed for racing pigeons, which is a shortcoming. This didnot allow us to show anything with the data from Ruffec, because it was just aone day race and the pigeons did not have to stay out overnight. For Barcelonawe knew definitely that the pigeons would be out overnight and also Cahors theheavy flight conditions made for an overnight stay. This information we coulduse to make our calculations, based on the assumption that the pigeons wouldnot move between sunset and sunrise (although this is not necessarily a fact). Inaddition, there must be sufficient light received, otherwise it is only possible toestimate the latitude as it is a lot harder with longitude. For us this was the mostinteresting aspect as we wanted to know whether the pigeons went along thewest coast of France to fly home or along the eastern side, so we needed to takethe risk. Below we describe each pigeon and the results we now have:F956, trip with two nights.On Sunday morning at 7 am this pigeon was back home, so for the experimentthis was perfect because she was twice overnight and therefore can becalculated with more certainty. The luminosity which has been recorded isshown in Figure 3 but it is not of the intensity shown in the loops in Figure 1.The moments of liberation and homecoming are marked with a red arrow,which are clearly distinguishable. It is also striking that the light pattern on dayone is much more stable than the second day. Only in the afternoon of July 6there appear more lines which could mean that the pigeon on the first daytravelled a shorter distance.Figure 3: intensity of F956 during the period July 5 / July 7.Page5F957, Second to the loft.A smooth but hard trip for this hen that was home just after 7.30pm onSaturday, she was a little over 40 minutes later than her loft mate who camefirst. Even with her you can see the wave pattern and a clear peak athomecoming and at liberation. On July 7, she is already in the loft, which meansthe sunset is less well defined; we have manually marked this (solid red line at6th July evening instead of dotted line). The measurements in the afternoonclearly increased between three and seven hours, producing a clearer footprint.Figure 4: Intensity of F957, morning flight July 5th to evening July 6th.F958, first to the loft.This was the first hen to arrive with a geolocator at 18:58 and is the 3rd pigeonin NIC Borne. It has a much more stable light pattern than F957, both on thefirst and on the second day. Striking on her first flying day is the brightnessreduced at night, just before 2100 pm, she would then be roosting (almost 12hour flight). On the second day there is a dip in brightness around 1400 hours(1600 hours our time), perhaps a drink break? We cannot retrieve the intensitymeasurements or the temperature.Page6Figure 5: Intensity of F958, the first home on July 6.The F960 at Cahors, a different picture on the same day.With this cock of Ultsje we first trimmed the leg feathers so that they wouldkeep the geolocator free from the shade as much as possible. The fruit of this isshown by Figure 6. While the three hens at Barcelona show intensity valuesbetween 1,000 and 10,000 lux, this is very different for F960. The light levelsare truncated at 100,000 but during the afternoon of July 5 they were probablystill higher. It is also a much less erratic pattern, although of course we aredealing with a more constant airspeed and altitude. The liberation at 14:00 (12hUTC) is clearly visible, as well as the return the next day at 15:15 (13:15standard time).Figure 6: Light intensity measured during Cahors F960 on 5th and 6th July.Page7For F960 there is more data available because Ultsje Jellema has been in thehabit of weighing the pigeons. Regularly the weights of the pigeons arerecorded both at basketing and returning so the condition gradient becomesvisible. Pigeons being prepared for basketing put on some weight and pigeonsgenerally lose weight before they arrive at home. The amount of weight lossalso says something about the deviation of the flight line after all the moredistance a pigeon travels the more fat they will use to get home. Thesemeasurements have now been available for several years and have been alreadydeveloped in a graph which is shown in figure 7. As the pigeons have to travelmore miles, the percentage weight loss is greater equally if a pigeon is flying alittle it does not need to consume too much energy. In particular, the steepnessof the line can be used to say 1) whether a pigeon is economical in its energyuse or not, and 2) how far a pigeon has been flying if you know what the weightloss in % has been.Figure 7: weight loss versus distance,the result of three years of weight measurements U. JellemaWhen F960 was basketed this cock weighed 480 grams and on return a weightof 400 grams, which means that 17% of its weight at basketing has beenconsumed during the flight. Of course this is not an exact science, becausewhile staying in the basket one pigeon might eat and drink more than another,causing weight in the digestive tract. With this weight and the early prize (direct Page8flight) we can deduce from the figures that this pigeon must have flownbetween 900 and 1100 km, roughly. This seems to be fairly accurate.Probable overnight place.Previously this technique required all kinds of complicated calculations toadjust and determine the location nowadays this happens in the backgroundwithin the program. The key question is, where were the pigeons themselvesduring their stay? That is, given the low accuracy of this technique it cannot besaid with certainty. As indicated above, the latitude especially is pretty accurateand clearly 5° east was not the latitude for all three pigeons. 5° east is importantbecause almost the entire Rhone Valley is at that latitude. In the table below arethe probable coordinates displayed for the 4 pigeons. The latitude is a lot moresecure than the longitude, which may differ just one or two points, meaning thatthe pigeon may have been found 50 km to the north or south. Furthermore thedistance “as the crow flies†is shown in the last column. This shows that thepigeons fly more mileage than we account for, for all four pigeons deviate froma straight line, F960 is still the least on the first flying day. That is also theclosest to an average rate of speed of a pigeon with moderate headwind.Table 1: calculated on eight sites and perpendicular distance from liberation to nightlanding place.Of course, these coordinates can also be plotted on a map, and we have donethat in the final image.GEOLOCATOR NR. FLIGHT LATITUDE LONGITUDE DISTANCE TO NIGHT LANDINGPLACEF956 BARCELONA 51 3,7 1090 km (2nd Night)F957 BARCELONA 47 1,7 633 km in 11 hours (57 km/h)F958 BARCELONA 49 1,2 835 km in 13 hours (64 km/h)F960 CAHORS 48 3,7 480 km in 7 hours (70 km/h)Page9Figure 8: Markers of the Barcelona birds night spots (A, B, C), the blue marker showsthe night spot of the Cahors cock. At the top are the two lofts of Jellema Sr. and Jr. andunder the planes the liberation points Barcelona and CahorsIt is striking that the F960 from Cahors has picked the easternmost night spot.This pigeon is on the same latitude as the F956 and we know that she was athome on July 7th at 7 pm and may therefore have been sitting just two hoursfrom the loft. This means that they are already close to the Belgian border.Where this pigeon has been the first night is to less well known and we Page10therefore prefer to omit it until we have better information. The fact is that a lotof pigeons came home much later than Jelle’s three pigeons, since all three haveearned a neat position on the result. On Monday they were still timing inBelgium and also in (Northern) Netherlands with less than 25% home. Thesepigeons have spent the night further south than the pigeons in this experimentand it is obvious that they remain "stuck" in the Rhone Valley or that they havegone around the Pyrenees for their first night. The map above shows that allpigeons have taken the west coast of France route to go home, something thatno one had expected in advance. Depending on the location of the home loft, itcan be better for the pigeons to take the east side but with the Mistral present itmay not be the easiest route. "Detours" on the west side are perhaps moreinviting under harsh conditions, in addition to which many Dutch pigeons haveused this route for all other flights.So this first analysis of the data gathered with the geolocators has given us asmall glimpse of the potential route home of our Barcelona pigeons. Ourexperiment is not over yet, because we have two pigeons equipped with ageolocator at Orange and it is intended that F956, 957 and 958 go to Perpignan.We will tell all about that in the final Part 3.Jelle and Ultsje Jellema, Wiebren van Stralenwiebrenvanstralen@duivensites.nl Quote Link to comment Share on other sites More sharing options...
paddymac Posted January 13, 2018 Report Share Posted January 13, 2018 Which route do our pigeonsreally take from Barcelona?Part 2.In the first part we presented our project using geolocators. How we came tothese devices, why we use them and not GPS loggers and how the first testswent.The Barcelona weekend was of course D-day, now it had to happen. JelleJellema had three pigeons basketed with geolocators and had the necessaryconfidence in them not to let us down. We all know now that Barcelona 2013was a very tough race which only the valiant ones came through. The straightline distance from Barcelona to Nijverdal is 1260 km so under thesecircumstances it certainly was no piece of cake. Of the first four arrivingpigeons there were three with geolocators. These are the pigeon’s arrival timesand the provisional National results of the ZLU:18.58hrs 08-2027103 332nd National (113th hens)19.39hrs 09-1783744 423rd National (138th hens)07.01hrs 08-2027077 847th National (253rd hens)From this we can safely conclude that the geolocators do not impede thepigeons from being able to put up a top performance, a lot different to all theGPS loggers that we tried earlier. The same weekend Ultsje Jellema sent twopigeons to Cahors. Ideally both flights would overlap and we could establish theroute taken by the pigeons and we could use the data from Cahors as a Page2reference. Cahors, the cock that Ultsje sent had a number of leg feathers clippedso that maximum light could fall on the geolocator. Of the two pigeons he sentone was lost, the other was listed as the 3rd Steggerda pigeon and 18th in theFrisian Fondclub, 09-1653620 timed at 15.51 won a decent prize from 901birds. After returning home, the geolocators were read and the data analysed.The computer programme developed for this makes it a breeze. The data is thenpresented as in the picture below:Figure 1: Two beams with wave patterns.The top bar is a shrunken view over a longer time period. The area blocked inred is the part selected (11th and 12th July 2012 in this case), which is thenshown magnified below. The blue pattern shows the light intensity on the day.The light intensity is shown on the vertical axis, graded on the left starting at 1and rising to 100,000 lux. Horizontally, the times of the day are shown betweena green and red vertical line. The green and the red line shows that the lightincreases (sunrise) and decreases (sunset) from and to around 10 lux (twilight).The night between them is very clear; the light level is not far above the 1 lux.From anywhere in the Northern Hemisphere it is known for each day when the Page3sun rises and sets. This is used by fanciers to set the times for neutralization orhours of darkness.This data, and the amount of light that the geolocators have saved, makes itpossible to calculate where the pigeon was overnight. A very brief explanationis under Figure 2.Figure 2. Showing the earth with the sun to the right.The bold circle around the earth is the boundary between day and night. To theleft of the line is the night on earth and to the right, where the sun shines, it isday. The right globe shows the earth about 12 hours later. The sun is still on theright, but the earth has turned almost 180°. Circle B now gives the boundarybetween day and night. Now if we want to find the place where the sun rose onthe left and where 12 hours later it rose on the right, then it must be at a point onboth A and B. This position is where the two lines intersect, indicated by a redasterisk. If we know the times of sunrise and sunset and the date we cancalculate the exact location where these lines intersect and thus the positionaround midnight.Four pigeons, five nights.In the first part it was indicated that the geolocators have mainly been used inresearch on migratory birds such as waders, swallows and terns. These speciesmove over a greater period of time and therefore there are many observationsavailable over that long period containing many nights. So we used a device that Page4is not specifically designed for racing pigeons, which is a shortcoming. This didnot allow us to show anything with the data from Ruffec, because it was just aone day race and the pigeons did not have to stay out overnight. For Barcelonawe knew definitely that the pigeons would be out overnight and also Cahors theheavy flight conditions made for an overnight stay. This information we coulduse to make our calculations, based on the assumption that the pigeons wouldnot move between sunset and sunrise (although this is not necessarily a fact). Inaddition, there must be sufficient light received, otherwise it is only possible toestimate the latitude as it is a lot harder with longitude. For us this was the mostinteresting aspect as we wanted to know whether the pigeons went along thewest coast of France to fly home or along the eastern side, so we needed to takethe risk. Below we describe each pigeon and the results we now have:F956, trip with two nights.On Sunday morning at 7 am this pigeon was back home, so for the experimentthis was perfect because she was twice overnight and therefore can becalculated with more certainty. The luminosity which has been recorded isshown in Figure 3 but it is not of the intensity shown in the loops in Figure 1.The moments of liberation and homecoming are marked with a red arrow,which are clearly distinguishable. It is also striking that the light pattern on dayone is much more stable than the second day. Only in the afternoon of July 6there appear more lines which could mean that the pigeon on the first daytravelled a shorter distance.Figure 3: intensity of F956 during the period July 5 / July 7.Page5F957, Second to the loft.A smooth but hard trip for this hen that was home just after 7.30pm onSaturday, she was a little over 40 minutes later than her loft mate who camefirst. Even with her you can see the wave pattern and a clear peak athomecoming and at liberation. On July 7, she is already in the loft, which meansthe sunset is less well defined; we have manually marked this (solid red line at6th July evening instead of dotted line). The measurements in the afternoonclearly increased between three and seven hours, producing a clearer footprint.Figure 4: Intensity of F957, morning flight July 5th to evening July 6th.F958, first to the loft.This was the first hen to arrive with a geolocator at 18:58 and is the 3rd pigeonin NIC Borne. It has a much more stable light pattern than F957, both on thefirst and on the second day. Striking on her first flying day is the brightnessreduced at night, just before 2100 pm, she would then be roosting (almost 12hour flight). On the second day there is a dip in brightness around 1400 hours(1600 hours our time), perhaps a drink break? We cannot retrieve the intensitymeasurements or the temperature.Page6Figure 5: Intensity of F958, the first home on July 6.The F960 at Cahors, a different picture on the same day.With this cock of Ultsje we first trimmed the leg feathers so that they wouldkeep the geolocator free from the shade as much as possible. The fruit of this isshown by Figure 6. While the three hens at Barcelona show intensity valuesbetween 1,000 and 10,000 lux, this is very different for F960. The light levelsare truncated at 100,000 but during the afternoon of July 5 they were probablystill higher. It is also a much less erratic pattern, although of course we aredealing with a more constant airspeed and altitude. The liberation at 14:00 (12hUTC) is clearly visible, as well as the return the next day at 15:15 (13:15standard time).Figure 6: Light intensity measured during Cahors F960 on 5th and 6th July.Page7For F960 there is more data available because Ultsje Jellema has been in thehabit of weighing the pigeons. Regularly the weights of the pigeons arerecorded both at basketing and returning so the condition gradient becomesvisible. Pigeons being prepared for basketing put on some weight and pigeonsgenerally lose weight before they arrive at home. The amount of weight lossalso says something about the deviation of the flight line after all the moredistance a pigeon travels the more fat they will use to get home. Thesemeasurements have now been available for several years and have been alreadydeveloped in a graph which is shown in figure 7. As the pigeons have to travelmore miles, the percentage weight loss is greater equally if a pigeon is flying alittle it does not need to consume too much energy. In particular, the steepnessof the line can be used to say 1) whether a pigeon is economical in its energyuse or not, and 2) how far a pigeon has been flying if you know what the weightloss in % has been.Figure 7: weight loss versus distance,the result of three years of weight measurements U. JellemaWhen F960 was basketed this cock weighed 480 grams and on return a weightof 400 grams, which means that 17% of its weight at basketing has beenconsumed during the flight. Of course this is not an exact science, becausewhile staying in the basket one pigeon might eat and drink more than another,causing weight in the digestive tract. With this weight and the early prize (direct Page8flight) we can deduce from the figures that this pigeon must have flownbetween 900 and 1100 km, roughly. This seems to be fairly accurate.Probable overnight place.Previously this technique required all kinds of complicated calculations toadjust and determine the location nowadays this happens in the backgroundwithin the program. The key question is, where were the pigeons themselvesduring their stay? That is, given the low accuracy of this technique it cannot besaid with certainty. As indicated above, the latitude especially is pretty accurateand clearly 5° east was not the latitude for all three pigeons. 5° east is importantbecause almost the entire Rhone Valley is at that latitude. In the table below arethe probable coordinates displayed for the 4 pigeons. The latitude is a lot moresecure than the longitude, which may differ just one or two points, meaning thatthe pigeon may have been found 50 km to the north or south. Furthermore thedistance “as the crow flies†is shown in the last column. This shows that thepigeons fly more mileage than we account for, for all four pigeons deviate froma straight line, F960 is still the least on the first flying day. That is also theclosest to an average rate of speed of a pigeon with moderate headwind.Table 1: calculated on eight sites and perpendicular distance from liberation to nightlanding place.Of course, these coordinates can also be plotted on a map, and we have donethat in the final image.GEOLOCATOR NR. FLIGHT LATITUDE LONGITUDE DISTANCE TO NIGHT LANDINGPLACEF956 BARCELONA 51 3,7 1090 km (2nd Night)F957 BARCELONA 47 1,7 633 km in 11 hours (57 km/h)F958 BARCELONA 49 1,2 835 km in 13 hours (64 km/h)F960 CAHORS 48 3,7 480 km in 7 hours (70 km/h)Page9Figure 8: Markers of the Barcelona birds night spots (A, B, C), the blue marker showsthe night spot of the Cahors cock. At the top are the two lofts of Jellema Sr. and Jr. andunder the planes the liberation points Barcelona and CahorsIt is striking that the F960 from Cahors has picked the easternmost night spot.This pigeon is on the same latitude as the F956 and we know that she was athome on July 7th at 7 pm and may therefore have been sitting just two hoursfrom the loft. This means that they are already close to the Belgian border.Where this pigeon has been the first night is to less well known and we Page10therefore prefer to omit it until we have better information. The fact is that a lotof pigeons came home much later than Jelle’s three pigeons, since all three haveearned a neat position on the result. On Monday they were still timing inBelgium and also in (Northern) Netherlands with less than 25% home. Thesepigeons have spent the night further south than the pigeons in this experimentand it is obvious that they remain "stuck" in the Rhone Valley or that they havegone around the Pyrenees for their first night. The map above shows that allpigeons have taken the west coast of France route to go home, something thatno one had expected in advance. Depending on the location of the home loft, itcan be better for the pigeons to take the east side but with the Mistral present itmay not be the easiest route. "Detours" on the west side are perhaps moreinviting under harsh conditions, in addition to which many Dutch pigeons haveused this route for all other flights.So this first analysis of the data gathered with the geolocators has given us asmall glimpse of the potential route home of our Barcelona pigeons. Ourexperiment is not over yet, because we have two pigeons equipped with ageolocator at Orange and it is intended that F956, 957 and 958 go to Perpignan.We will tell all about that in the final Part 3.Jelle and Ultsje Jellema, Wiebren van Stralen,wiebrenvanstralen@duivensites.nlNot too worried about the route as long as its the first bird home I'd be happy Quote Link to comment Share on other sites More sharing options...
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