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 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... > > THAT'S THE LAST STUDY I HAVE SEEN DAVE ALTHOUGH I DON'T KEEP UP WITH THE > LITERATURE AS WELL AS I SHOULD THESE DAYS. TOO MANY JOURNALS WHEN IN THE OLD > DAYS ONE COULD KEEP UP BY READING THE BASIC 5 OR 6. WOULD BE A TERRIFIC STUDY > FOR YOU GIVEN YOUR INTEREST AND NWS BACKGROUND. > > I WILL TRY TO SEE IF ANYONE AT PATUXENT IS LOOKING AT THIS. THEY SHOULD BE. > THANKS FOR THAT INTRIGUING CANADIAN LINK. APPRECIATE THE DISCUSSION. BETTER > OBSERVATION AND THOUGHT IS SO MUCH MORE INTERESTING THAN THE TICK LISTS. > > Anyway, just some thoughts. Thanks John and Chris for your insights! > > Best, > Dave > > On Tue, Jun 25, 2019 at 8:43 AM <k...@empacc.net> 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 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 > <c...@cornell.edu> 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/S57605395 > > Notably absent or low numbers of birds -- > Barred Owl > Red-bellied Woodpecker > Pileated Woodpecker > Least Flycatcher > Great Crested Flycatcher > Red-eyed Vireo (very low numbers) > Winter Wren > Wood Thrush > Baltimore Oriole > Mourning Warbler > Hooded Warbler > American Redstart > Chestnut-sided Warbler > Black-throated Blue Warbler > Black-throated Green Warbler > Canada Warbler > Scarlet Tanager (very low numbers) > Rose-breasted Grosbeak > > Loop between Hammond Hill and Canaan Rd: > > https://ebird.org/view/checklist/S57605776 > > Notably absent or low numbers of birds -- > Barred Owl > Red-bellied Woodpecker > Pileated Woodpecker > Least Flycatcher > Great Crested Flycatcher > Red-eyed Vireo (very low numbers) > Winter Wren > Wood Thrush > Baltimore Oriole > Mourning Warbler > Hooded Warbler > American Redstart > Chestnut-sided Warbler > Black-throated Blue Warbler > Black-throated Green Warbler > Canada Warbler > Scarlet Tanager (very low numbers) > Rose-breasted Grosbeak > > Concerned, > Chris T-H > > -- > Chris Tessaglia-Hymes > PO Box 488 > 8 Etna Lane > Etna, NY 13062 > 607-351-5740 > -- > NYSBIRDS-L LIST INFO: > Welcome and Basics [1] > Rules and Information [2] > Subscribe, Configuration and Leave [3] > ARCHIVES: > The Mail Archive [4] > Surfbirds [5] > ABA [6] > PLEASE SUBMIT YOUR OBSERVATIONS TO EBIRD [7]! > -- > -- > CAYUGABIRDS-L LIST INFO: > Welcome and Basics [8] > Rules and Information [9] > Subscribe, Configuration and Leave [10] > ARCHIVES: > The Mail Archive [11] > Surfbirds [12] > BirdingOnThe.Net [13] > PLEASE SUBMIT YOUR OBSERVATIONS TO EBIRD [7]! > -- Links: ------ [1] http://www.northeastbirding.com/NYSbirdsWELCOME.htm [2] http://www.northeastbirding.com/NYSbirdsRULES.htm [3] http://www.northeastbirding.com/NYSbirdsSubscribeConfigurationLeave.htm [4] http://www.mail-archive.com/nysbirds-l@cornell.edu/maillist.html [5] http://www.surfbirds.com/birdingmail/Group/NYSBirds-L [6] http://birding.aba.org/maillist/NY01 [7] http://ebird.org/content/ebird/ [8] http://www.northeastbirding.com/CayugabirdsWELCOME [9] http://www.northeastbirding.com/CayugabirdsRULES [10] http://www.northeastbirding.com/CayugabirdsSubscribeConfigurationLeave.htm [11] http://www.mail-archive.com/cayugabirds-l@cornell.edu/maillist.html [12] http://www.surfbirds.com/birdingmail/Group/Cayugabirds [13] http://birdingonthe.net/mailinglists/CAYU.html -- Cayugabirds-L List Info: http://www.NortheastBirding.com/CayugabirdsWELCOME http://www.NortheastBirding.com/CayugabirdsRULES http://www.NortheastBirding.com/CayugabirdsSubscribeConfigurationLeave.htm ARCHIVES: 1) http://www.mail-archive.com/cayugabirds-l@cornell.edu/maillist.html 2) http://www.surfbirds.com/birdingmail/Group/Cayugabirds 3) http://birdingonthe.net/mailinglists/CAYU.html Please submit your observations to eBird: http://ebird.org/content/ebird/ --
