Re: [cayugabirds-l] [nysbirds-l] Dryden, NY - Hammond Hill State Forest Birding: Few Birds
Dave, Chris I believe one has to look further than two years and at efforts that use the same methodology and criteria over long time periods for an accurate estimate. The American Bird Conservancy and the Bird Banding Laboratory are perhaps the best sources as are some of the long term banding studies documented in journals such as North American Bird Bander. Regardless of cause it is to be expected that there will be some pockets of plenty. The causes I believe are multiple, cumulative and you mention some. Habitat loss and obstructions have increased dramatically and quickly in the last two decades. Locally a very large negative is the growing dairy agribusinesses that are converting pasture and hedgerows to large swaths of sterile, monocropped land. Beyond this area chickens and hogs are being raised with the same methods and habitat loss. South and Central America habitat loss has also been on the rise. Yes a few species have been documented to have cyclical ups and downs. A few may also be subject to WNV and I believe Anne would have better data on that than I. Any counts that are aperiodic could well be the result of the cyclic nature of weather, blocking fronts, timing during migrations, observer bias and more. Insect populations are indeed crashing and the 'Have you see any bugs on your windshield?" type articles have increased awareness, but the loss has not been adequately studied. The combination of all this has greatly decreased habitat and food sources at the lower end of the life web. In any event I do not believe we can rely on birder reports for meaningful data but should rather look to long term studies with timing and protocols that are standard year to year. Thanks for your input. John --- John and Sue Gregoire Field Ornithologists Kestrel Haven Migration Observatory 5373 Fitzgerald Rd Burdett, NY 14818 42.443508000, -76.758202000 "Create and Conserve Habitat" On 2019-06-23 20:13, David Nicosia wrote: > Chris, > > Fortunately, I have found the opposite for the most part > > I did two trips this past week one to Triangle State Forest and Hawkins Pond > State Forest in Broome County and neotropical migrants were quite common > especially Red-Eyed Vireos, Ovenbirds. > > see: Triangle State Forest: https://ebird.org/view/checklist/S57456491 > Most of the warblers were found in a small stretch of about 1 mile in the > spruce, hemlock, pine, northern hardwood forests. > > and Hawkins Pond State Forest: https://ebird.org/view/checklist/S57564971 > Most of the birds were in the stretch of spruce, hemlock, pine and maple, oak > about 1.5 miles. > > I lost count of ovenbirds at Hawkins! Red-eyed vireos were all over. > Blackburnian warblers too were the most I have had at this location. Now > this is just my observations in one county. > > In the western Adirondacks, at Star Lake, Red-Eyed Vireos seemed everywhere > along with ovenbirds. Blackburnian warblers were quite common too. > > see: https://ebird.org/view/checklist/S57189909 for my Star lake walk. > > In my yard, there also seems to be more bird activity this year. I have at > least 2 maybe 3 pairs of Gray Catbirds this year vs just one pair most years. > I also have 2 pairs of red-eyed vireos vs one pair or in some years none! > > Anyway, what is the cause of the drastic declines that you are observing? > That is the bigger question. Could it be disease? Does west nile virus kill > songbirds? Have insect populations crashed? Habitat loss, increase in > towers, wind farms etc are happening gradually so the declines should be > slow. Or maybe there is a natural cycle and some areas are seeing the minimum > in numbers which is lower than any other minimum in the past? > > Concerned too (but optimistic), > Dave > > On Sat, Jun 22, 2019 at 9:01 PM Christopher T. Tessaglia-Hymes > wrote: > >> Good evening, >> >> This morning I was joined by Bartels Science Illustrator, Jessica French, >> for a birding trip to Hammond Hill State Forest. It was disconcertingly >> quiet up there. I probably should not have had such high expectations, given >> how quiet this spring has been (a handful of very quiet trips to the >> Hawthorn Orchard) and how few night flight calls were recorded over our >> house in Etna. I'm still analyzing my night flight call data, but those data >> from May 3 through May 24 are concerning, to say the least. I have also read >> postings from VINS and notable Bicknell's Thrush researcher, Chris Rimmer, >> making similar observations about his Mount Mansfield, VT, field site this >> spring ("disquietingly low" vocal activity and mist net captures). >> >> Here are two checklists completed from our two, approximate four-mile, >> bushwhack walks this morning. Nice habitat. Few insects. Few birds. No ticks >> (but not complaining). >> >> Loop to SE of Star Stanton and Canaan Rd Intersection: >> >> https://ebird.org/view/checklist/S
Re: [cayugabirds-l] [nysbirds-l] Dryden, NY - Hammond Hill State Forest Birding: Few Birds
John/Chris, I totally agree that point counts from birding could misrepresent bird populations. I have been out on two different days and have seen big differences. I have a walk I take in the evening to listen to the thrushes. One evening I had 5 wood thrushes and 1 hermit thrush singing. The next night I had 3 hermit thrushes and 1 wood thrush. If you were doing a survey your numbers would depend on which night you chose. In Broome Co we don't have as much farming as John does and his comments on the large scale agriculture and the destruction of habitat on farms would make a big difference locally. Anyway, what do you make of this banding dataset from Canada? https://www.bsc-eoc.org/birdmon/default/popindices.jsp I look at Long Point Bird Observatory since it seems to have the longest record. It seems that most species are doing very well on this long term dataset. It is interesting to note an increase in the 1970s for most species. Is this artificial? or real? I know the climate of the 60s and 70s was very chilly and springs were often cold and wet then it warmed in the 80s and 90s especially. But I don't understand how they calculate their population index. I assume it is normalized to the man-hours of banding. But what happening in the 1970s? Why such increases? From 2006-2016 most birds seems fairly stable based on their population index. Anyway, what are your thoughts on this? I am curious. Also there was a study on breeding bird survey data and they found that some of the data is contaminated by observers who, through normal aging, lose hearing. This was especially true of certain species that have higher pitch songs. So BBS may not be totally reliable either. Is anyone doing a study on total radar returns during migration? Theoretically, spring and fall migration could be quantified by integrating all the radar returns at night. I know there was a study done many years ago which used the old NWS radar system and compared the 1960s to the 1990s and they found a significant decrease in birds coming across the Gulf. But, I caution that radar operators could adjust the gain on the radar from site to site which would in turn, affect the returns so there could be some human caused inconsistencies in this dataset. Plus the 1974C radars came out which were less sensitive than the 1957S band radars. I wonder if this caused the decrease or contaminated the data for this study. Our latest radar system from the 1990s to present, you can't adjust the gain and they are all the same wavelength - 10 cm, so it is consistent. The resolution has gotten much better in the last 15 years so that could be a source of error if one looked at the 1990s and compared it to today. But at least over the last 10-15 years I believe one could quantify all radar returns which would give a macroscale look at nocturnal migration and monitor trends. Boy would I love to have time to do this!! I have 6 years to go until retirement Maybe someday I can work on this... Anyway, just some thoughts. Thanks John and Chris for your insights! Best, Dave On Tue, Jun 25, 2019 at 8:43 AM wrote: > Dave, Chris > > I believe one has to look further than two years and at efforts that use > the same methodology and criteria over long time periods for an accurate > estimate. The American Bird Conservancy and the Bird Banding Laboratory are > perhaps the best sources as are some of the long term banding studies > documented in journals such as North American Bird Bander. > > Regardless of cause it is to be expected that there will be some pockets > of plenty. > > The causes I believe are multiple, cumulative and you mention some. > Habitat loss and obstructions have increased dramatically and quickly in > the last two decades. Locally a very large negative is the growing dairy > agribusinesses that are converting pasture and hedgerows to large swaths of > sterile, monocropped land. Beyond this area chickens and hogs are being > raised with the same methods and habitat loss. South and Central America > habitat loss has also been on the rise. > > Yes a few species have been documented to have cyclical ups and downs. A > few may also be subject to WNV and I believe Anne would have better data on > that than I. > > Any counts that are aperiodic could well be the result of the cyclic > nature of weather, blocking fronts, timing during migrations, observer bias > and more. > > Insect populations are indeed crashing and the 'Have you see any bugs on > your windshield?" type articles have increased awareness, but the loss has > not been adequately studied. The combination of all this has greatly > decreased habitat and food sources at the lower end of the life web. > > In any event I do not believe we can rely on birder reports for meaningful > data but should rather look to long term studies with timing and protocols > that are standard year to year. > > Thanks for your input. > John > --- > John and Sue Gregoire > Field Ornitholo
Re: [cayugabirds-l] [nysbirds-l] Dryden, NY - Hammond Hill State Forest Birding: Few Birds
Dave, et al, By the 1970s, there could have been a noticeable change in bird populations due to the banning of DDT in the 1960s. Interesting conversation... Steve Taylor Pittsford NY Sent from my iPhone > On Jun 26, 2019, at 8:02 AM, David Nicosia wrote: > > John/Chris, > > I totally agree that point counts from birding could misrepresent bird > populations. I have been out on two different days and have seen big > differences. I have a walk I take in the evening to listen to the thrushes. > One evening I had 5 wood thrushes and 1 hermit thrush singing. The next night > I had 3 hermit thrushes and 1 wood thrush. If you were doing a survey your > numbers would depend on which night you chose. In Broome Co we don't have as > much farming as John does and his comments on the large scale agriculture and > the destruction of habitat on farms would make a big difference locally. > Anyway, what do you make of this banding dataset from Canada? > https://www.bsc-eoc.org/birdmon/default/popindices.jsp > > I look at Long Point Bird Observatory since it seems to have the longest > record. It seems that most species are doing very well on this long term > dataset. It is interesting to note an increase in the 1970s for most species. > Is this artificial? or real? I know the climate of the 60s and 70s was very > chilly and springs were often cold and wet then it warmed in the 80s and 90s > especially. But I don't understand how they calculate their population index. > I assume it is normalized to the man-hours of banding. But what happening in > the 1970s? Why such increases? From 2006-2016 most birds seems fairly stable > based on their population index. > > Anyway, what are your thoughts on this? I am curious. > > Also there was a study on breeding bird survey data and they found that some > of the data is contaminated by observers who, through normal aging, lose > hearing. This was especially true of certain species that have higher pitch > songs. So BBS may not be totally reliable either. > > Is anyone doing a study on total radar returns during migration? > Theoretically, spring and fall migration could be quantified by integrating > all the radar returns at night. I know there was a study done many years ago > which used the old NWS radar system and compared the 1960s to the 1990s and > they found a significant decrease in birds coming across the Gulf. But, I > caution that radar operators could adjust the gain on the radar from site to > site which would in turn, affect the returns so there could be some human > caused inconsistencies in this dataset. Plus the 1974C radars came out which > were less sensitive than the 1957S band radars. I wonder if this caused the > decrease or contaminated the data for this study. Our latest radar system > from the 1990s to present, you can't adjust the gain and they are all the > same wavelength - 10 cm, so it is consistent. The resolution has gotten much > better in the last 15 years so that could be a source of error if one looked > at the 1990s and compared it to today. But at least over the last 10-15 years > I believe one could quantify all radar returns which would give a macroscale > look at nocturnal migration and monitor trends. Boy would I love to have time > to do this!! I have 6 years to go until retirement Maybe someday I can > work on this... > > Anyway, just some thoughts. Thanks John and Chris for your insights! > > Best, > Dave > > > > > > > > > >> On Tue, Jun 25, 2019 at 8:43 AM wrote: >> Dave, Chris >> >> I believe one has to look further than two years and at efforts that use the >> same methodology and criteria over long time periods for an accurate >> estimate. The American Bird Conservancy and the Bird Banding Laboratory are >> perhaps the best sources as are some of the long term banding studies >> documented in journals such as North American Bird Bander. >> >> Regardless of cause it is to be expected that there will be some pockets of >> plenty. >> >> The causes I believe are multiple, cumulative and you mention some. Habitat >> loss and obstructions have increased dramatically and quickly in the last >> two decades. Locally a very large negative is the growing dairy >> agribusinesses that are converting pasture and hedgerows to large swaths of >> sterile, monocropped land. Beyond this area chickens and hogs are being >> raised with the same methods and habitat loss. South and Central America >> habitat loss has also been on the rise. >> >> Yes a few species have been documented to have cyclical ups and downs. A few >> may also be subject to WNV and I believe Anne would have better data on that >> than I. >> >> Any counts that are aperiodic could well be the result of the cyclic nature >> of weather, blocking fronts, timing during migrations, observer bias and >> more. >> >> Insect populations are indeed crashing and the 'Have you see any bugs on >> you
Re: [cayugabirds-l] [nysbirds-l] Dryden, NY - Hammond Hill State Forest Birding: Few Birds
Comments in caps. Appreciate your input. John --- John and Sue Gregoire Field Ornithologists Kestrel Haven Migration Observatory 5373 Fitzgerald Rd Burdett, NY 14818 42.443508000, -76.758202000 "Create and Conserve Habitat" On 2019-06-26 12:02, David Nicosia wrote: > John/Chris, > > I totally agree that point counts from birding could misrepresent bird > populations. I have been out on two different days and have seen big > differences. I have a walk I take in the evening to listen to the thrushes. > One evening I had 5 wood thrushes and 1 hermit thrush singing. The next night > I had 3 hermit thrushes and 1 wood thrush. If you were doing a survey your > numbers would depend on which night you chose. In Broome Co we don't have as > much farming as John does and his comments on the large scale agriculture and > the destruction of habitat on farms would make a big difference locally. > Anyway, what do you make of this banding dataset from Canada? > https://www.bsc-eoc.org/birdmon/default/popindices.jsp > > CANADA IS MILES AHEAD OF US IN SUCH STUDIES. I DO BELIEVE THAT FOR OUR > EFFORT, THE CONVERSION OF DAIRY FROM SMALL FAMILY TO VERY LARGE AGRIBUSINESS > HAS BEEN THE PRIMARY DECLINE CAUSE. THAT HAS BEEN REFLECTED THROUGHOUT THE > NORTHEAST WHERE FARMING HAS CHANGED AND HABITAT/PREY BASE HAS BEEN DENUDED. > > LONG POINT AND A FEW OTHER HUGE STATIONS IN THE CENTRAL FLYWAY ARE DATA > BUSTERS FOR MANY REASONS. I TOOK A LOOK AT SAVANNAH SPARROW FROM THE MCGILL > DATA, A STATION I KNOW IS PROPERLY RUN AND SEE A LONG TERM DECLINE SIMILAR TO > THE ABA REPORTED DATA. I WANT TO GO BACK AND CHECK OTHER SPECIES. > > WE TEND TO SEE A DIFFERENT TREND LINE FROM THE CENTRAL FLYWAY AND I THINK > THIS IS LARGELY DUE TO WEATHER. WHENEVER THE ATLANTIC FLYWAY IS BOTTLED UP BY > FRONTAL SYSTEMS DURING SPRING MIGRATION WE SEE A LARGE CONCOMITANT SHIFT TO > THE CENTRAL AS SHOWN BY RADAR. PAUL H'S SITE IS TERRIFIC FOR SEEING THIS. FOR > SOME REASON THE PACIFIC FLYWAY SHARES LESS DATA AS MOST BANDERS ARE > ACADEMECIANS PROTECTING THEIR NEXT PAPER AND THE AREA HAS MANY FEWER > VOLUNTEER BANDERS. > > I look at Long Point Bird Observatory since it seems to have the longest > record. It seems that most species are doing very well on this long term > dataset. It is interesting to note an increase in the 1970s for most species. > Is this artificial? or real? I know the climate of the 60s and 70s was very > chilly and springs were often cold and wet then it warmed in the 80s and 90s > especially. But I don't understand how they calculate their population index. > I assume it is normalized to the man-hours of banding. But what happening in > the 1970s? Why such increases? From 2006-2016 most birds seems fairly stable > based on their population index. > > REQUIRES SOME RESEARCH INTO HOW THEY DERIVE THEIR INDEX, I HAVEN'T A CLUE. > OVERALL THEY AGREE IN SOME AREAS AND DISAGREE IN OTHERS WITH THE ABA > PRESENTATIONS. > > WE HEARD SO MANY MORE IN THE 60S AND 70S THAN NOW. JUST A GENERAL IMPRESSION > ON MY PART BUT DAWN CHORUS AIN'T WHAT IT USED TO BE. > > Anyway, what are your thoughts on this? I am curious. > > Also there was a study on breeding bird survey data and they found that some > of the data is contaminated by observers who, through normal aging, lose > hearing. This was especially true of certain species that have higher pitch > songs. So BBS may not be totally reliable either. > > NEAR AND DEAR AS MY FRIENDS AND COLLEAGUES AT PATUXENT, CHAN ROBBINS AND > DANNY BYSTRAK, STARTED THIS (AND NORTH AMERICAN ATALSSING). OBSERVER BIAS > WAS A TOPIC I TOOK ON AND FOUND THAT BBS HAD VERY FEW NEW VOLUTEERS AND THE > MAJORITY WERE AGEING. AS ONE WHO HAS LOST ALL HIGHER FEQUENCY HEARING I FULLY > BELIEVE THAT SOME DECLINES (ALWAYS THE HIGH REGISTER BIRDS) ARE STRICTLY DUE > TO HEARING DEGRADATION. (IT'S DARN HARD TO ENJOY GENERAL BIRDING THESE DAYS > FOR ME AS I WAS SO USED TO AUDIO KEYING). > > Is anyone doing a study on total radar returns during migration? > Theoretically, spring and fall migration could be quantified by integrating > all the radar returns at night. I know there was a study done many years ago > which used the old NWS radar system and compared the 1960s to the 1990s and > they found a significant decrease in birds coming across the Gulf. But, I > caution that radar operators could adjust the gain on the radar from site to > site which would in turn, affect the returns so there could be some human > caused inconsistencies in this dataset. Plus the 1974C radars came out which > were less sensitive than the 1957S band radars. I wonder if this caused the > decrease or contaminated the data for this study. Our latest radar system > from the 1990s to present, you can't adjust the gain and they are all the > same wavelength - 10 cm, so it is consistent. The resolution has gotten much > better in the last 15 years so that could be a source of error if
Re: [cayugabirds-l] [nysbirds-l] Dryden, NY - Hammond Hill State Forest Birding: Few Birds
Good thought although DDT was still very prevalent in countries where "our' birds winter...and still is in some. We have also added so many new chemicals that are known to cause problems or highly suspected. There are so many variables in this problem. The joy is in seeing the tremendous upsurge of eagles, peregrines and osprey as a result of that ban. We had so few viable nests in the 70s that we could survey the entire Chesapeake Bay area in less than a week and banded very few young. At that time Barn Owls were in precipitous decline thanks to agricultural poisons (rodenticides chiefly) and I believe still are. Thanks for joining the conversation. John --- John and Sue Gregoire Field Ornithologists Kestrel Haven Migration Observatory 5373 Fitzgerald Rd Burdett, NY 14818 42.443508000, -76.758202000 "Create and Conserve Habitat" On 2019-06-26 12:18, Stephen Taylor wrote: > Dave, et al, > By the 1970s, there could have been a noticeable change in bird populations > due to the banning of DDT in the 1960s. > Interesting conversation... > Steve Taylor > Pittsford NY > > Sent from my iPhone > > On Jun 26, 2019, at 8:02 AM, David Nicosia wrote: > > John/Chris, > > I totally agree that point counts from birding could misrepresent bird > populations. I have been out on two different days and have seen big > differences. I have a walk I take in the evening to listen to the thrushes. > One evening I had 5 wood thrushes and 1 hermit thrush singing. The next night > I had 3 hermit thrushes and 1 wood thrush. If you were doing a survey your > numbers would depend on which night you chose. In Broome Co we don't have as > much farming as John does and his comments on the large scale agriculture and > the destruction of habitat on farms would make a big difference locally. > Anyway, what do you make of this banding dataset from Canada? > https://www.bsc-eoc.org/birdmon/default/popindices.jsp > > I look at Long Point Bird Observatory since it seems to have the longest > record. It seems that most species are doing very well on this long term > dataset. It is interesting to note an increase in the 1970s for most species. > Is this artificial? or real? I know the climate of the 60s and 70s was very > chilly and springs were often cold and wet then it warmed in the 80s and 90s > especially. But I don't understand how they calculate their population index. > I assume it is normalized to the man-hours of banding. But what happening in > the 1970s? Why such increases? From 2006-2016 most birds seems fairly stable > based on their population index. > > Anyway, what are your thoughts on this? I am curious. > > Also there was a study on breeding bird survey data and they found that some > of the data is contaminated by observers who, through normal aging, lose > hearing. This was especially true of certain species that have higher pitch > songs. So BBS may not be totally reliable either. > > Is anyone doing a study on total radar returns during migration? > Theoretically, spring and fall migration could be quantified by integrating > all the radar returns at night. I know there was a study done many years ago > which used the old NWS radar system and compared the 1960s to the 1990s and > they found a significant decrease in birds coming across the Gulf. But, I > caution that radar operators could adjust the gain on the radar from site to > site which would in turn, affect the returns so there could be some human > caused inconsistencies in this dataset. Plus the 1974C radars came out which > were less sensitive than the 1957S band radars. I wonder if this caused the > decrease or contaminated the data for this study. Our latest radar system > from the 1990s to present, you can't adjust the gain and they are all the > same wavelength - 10 cm, so it is consistent. The resolution has gotten much > better in the last 15 years so that could be a source of error if one looked > at the 1990s and compared it to today. But at least over the last 10-15 years I believe one could quantify all radar returns which would give a macroscale look at nocturnal migration and monitor trends. Boy would I love to have time to do this!! I have 6 years to go until retirement Maybe someday I can work on this... > > Anyway, just some thoughts. Thanks John and Chris for your insights! > > Best, > Dave > > On Tue, Jun 25, 2019 at 8:43 AM wrote: > > Dave, Chris > > I believe one has to look further than two years and at efforts that use the > same methodology and criteria over long time periods for an accurate > estimate. The American Bird Conservancy and the Bird Banding Laboratory are > perhaps the best sources as are some of the long term banding studies > documented in journals such as North American Bird Bander. > > Regardless of cause it is to be expected that there will be some pockets of > plenty. > > The causes I believe are multiple, cumulative and y
Re: [cayugabirds-l] [nysbirds-l] Dryden, NY - Hammond Hill State Forest Birding: Few Birds
Hi Chris, I hope you agree this thread is within the rules of CayugaBirds, even though it ranges over things that go beyond the Basin. But it's the best conversation I've seen on the list in many months, so I hope it can continue! Best - Alicia On 6/26/2019 8:49 AM, k...@empacc.net wrote: > > Comments in caps. Appreciate your input. > John > > --- > John and Sue Gregoire > Field Ornithologists > Kestrel Haven Migration Observatory > 5373 Fitzgerald Rd > Burdett, NY 14818 > 42.443508000, -76.758202000 > "Create and Conserve Habitat" > > On 2019-06-26 12:02, David Nicosia wrote: > >> John/Chris, >> I totally agree that point counts from birding could misrepresent >> bird populations. I have been out on two different days and have seen >> big differences. I have a walk I take in the evening to listen to the >> thrushes. One evening I had 5 wood thrushes and 1 hermit thrush >> singing. The next night I had 3 hermit thrushes and 1 wood thrush. If >> you were doing a survey your numbers would depend on which night you >> chose. In Broome Co we don't have as much farming as John does and >> his comments on the large scale agriculture and the destruction of >> habitat on farms would make a big difference locally. Anyway, what >> do you make of this banding dataset from Canada? >> https://www.bsc-eoc.org/birdmon/default/popindices.jsp >> >> >> CANADA IS MILES AHEAD OF US IN SUCH STUDIES. I DO BELIEVE THAT FOR >> OUR EFFORT, THE CONVERSION OF DAIRY FROM SMALL FAMILY TO VERY LARGE >> AGRIBUSINESS HAS BEEN THE PRIMARY DECLINE CAUSE. THAT HAS BEEN >> REFLECTED THROUGHOUT THE NORTHEAST WHERE FARMING HAS CHANGED AND >> HABITAT/PREY BASE HAS BEEN DENUDED. >> >> LONG POINT AND A FEW OTHER HUGE STATIONS IN THE CENTRAL FLYWAY ARE >> DATA BUSTERS FOR MANY REASONS. I TOOK A LOOK AT SAVANNAH SPARROW FROM >> THE MCGILL DATA, A STATION I KNOW IS PROPERLY RUN AND SEE A LONG TERM >> DECLINE SIMILAR TO THE ABA REPORTED DATA. I WANT TO GO BACK AND CHECK >> OTHER SPECIES. >> >> WE TEND TO SEE A DIFFERENT TREND LINE FROM THE CENTRAL FLYWAY AND I >> THINK THIS IS LARGELY DUE TO WEATHER. WHENEVER THE ATLANTIC FLYWAY IS >> BOTTLED UP BY FRONTAL SYSTEMS DURING SPRING MIGRATION WE SEE A LARGE >> CONCOMITANT SHIFT TO THE CENTRAL AS SHOWN BY RADAR. PAUL H'S SITE IS >> TERRIFIC FOR SEEING THIS. FOR SOME REASON THE PACIFIC FLYWAY SHARES >> LESS DATA AS MOST BANDERS ARE ACADEMECIANS PROTECTING THEIR NEXT >> PAPER AND THE AREA HAS MANY FEWER VOLUNTEER BANDERS. >> I look at Long Point Bird Observatory since it seems to have the >> longest record. It seems that most species are doing very well on >> this long term dataset. It is interesting to note an increase in the >> 1970s for most species. Is this artificial? or real? I know the >> climate of the 60s and 70s was very chilly and springs were often >> cold and wet then it warmed in the 80s and 90s especially. But I >> don't understand how they calculate their population index. I assume >> it is normalized to the man-hours of banding. But what happening in >> the 1970s? Why such increases? From 2006-2016 most birds seems >> fairly stable based on their population index. >> >> REQUIRES SOME RESEARCH INTO HOW THEY DERIVE THEIR INDEX, I HAVEN'T A >> CLUE. OVERALL THEY AGREE IN SOME AREAS AND DISAGREE IN OTHERS WITH >> THE ABA PRESENTATIONS. >> >> WE HEARD SO MANY MORE IN THE 60S AND 70S THAN NOW. JUST A GENERAL >> IMPRESSION ON MY PART BUT DAWN CHORUS AIN'T WHAT IT USED TO BE. >> Anyway, what are your thoughts on this? I am curious. >> Also there was a study on breeding bird survey data and they found >> that some of the data is contaminated by observers who, through >> normal aging, lose hearing. This was especially true of certain >> species that have higher pitch songs. So BBS may not be totally >> reliable either. >> >> NEAR AND DEAR AS MY FRIENDS AND COLLEAGUES AT PATUXENT, CHAN ROBBINS >> AND DANNY BYSTRAK, STARTED THIS (AND NORTH AMERICAN ATALSSING). >> OBSERVER BIAS WAS A TOPIC I TOOK ON AND FOUND THAT BBS HAD VERY FEW >> NEW VOLUTEERS AND THE MAJORITY WERE AGEING. AS ONE WHO HAS LOST ALL >> HIGHER FEQUENCY HEARING I FULLY BELIEVE THAT SOME DECLINES (ALWAYS >> THE HIGH REGISTER BIRDS) ARE STRICTLY DUE TO HEARING DEGRADATION. >> (IT'S DARN HARD TO ENJOY GENERAL BIRDING THESE DAYS FOR ME AS I WAS >> SO USED TO AUDIO KEYING). >> Is anyone doing a study on total radar returns during migration? >> Theoretically, spring and fall migration could be quantified by >> integrating all the radar returns at night. I know there was a study >> done many years ago which used the old NWS radar system and compared >> the 1960s to the 1990s and they found a significant decrease in birds >> coming across the Gulf. But, I caution that radar operators could >> adjust the gain on the radar from site to site which would in turn, >> affect the returns so there could be some human caused >> inconsistencies in this dataset. Plus the 1974C radars came