John C., I'm still trying to figure out how we "know" Goshawks to be adverse to human disturbance. Anecdotal evidence is nice, as is your research on Golden-winged Warblers, but actual cited research on Northern Goshawks reports the following:
*"Disturbances associated with research are usually of short duration, apparently having little impact on nesting birds. Viewing nests for short periods after young have hatched does not cause desertion. Trapping adults during nesting for banding or attaching transmitters apparently does not cause abandonment. The percentage of nesting pairs with radios that successfully raised young (83%, n = 8, 1988–1989) was similar to those without radios (82%, n = 10, 1987–1990; Austin 1993 <http://bna.birds.cornell.edu/bna/species/298/articles/species/298/biblio/bib018>). Timbering activities near nests can cause failure, especially during incubation (Anonymous 1989 <http://bna.birds.cornell.edu/bna/species/298/articles/species/298/biblio/bib013>, Boal and Mannan 1994 <http://bna.birds.cornell.edu/bna/species/298/articles/species/298/biblio/bib034>). Logging activities, such as loading and skidding, within 50–100 m of nest can cause abandonment, even with 20-d-old nestlings present (JRS). However, see Zirrer (1947 <http://bna.birds.cornell.edu/bna/species/298/articles/species/298/biblio/bib242>) for descriptions of repeated renesting attempts despite extreme disturbance.* My takeaway from that is that unless someone starts logging/timbering at Foster Pond, I think Josh's goshawk will be fine, even if a few folks decide to go take a look for it. This is not a situation comparable to something like a roosting owl's location being posted, since there's no evidence at all that the goshawk will even remain at this exact location any longer than the single day on which Josh observed it. According to more research cited in the BNA account, the earliest-ever recorded date of this species being paired up and on territory is late February, and mid-March to early April is much more common. Exercising caution for the sake of leaving rare or poorly-known birds undisturbed is one thing, but I think it's also worth not immediately rushing to chastise and scold new contributors for their sightings, without any legitimate evidence that their reports will have any negative impact on said birds. -Scott On Fri, Jan 16, 2015 at 2:54 PM, John Confer <con...@ithaca.edu> wrote: > I'm just suggesting that an overdoes of caution for the sake of a > species that is known to be adverse to human disturbance is worth > considering. The evidence for goshawk nest abandonment that I know about > is limited but real. I doubt that at this time of year that there would > be any impact on reproductive success, but a visit in ~April-May might > have an impact. > > 40 years ago Dorothy McIlroy described to me one goshawk nest that was > abandoned while the birds were on eggs and 30 years ago John Snelling, a > former grad student of Tom Cade, with a strong interest in raptors, also > described such an instance. John Gregoire, below, added another > instance(s). This doesn't approach the sample size for a publication. > There is data for golden-wings that the number fledged per nest is lower > for renests, but that comes from pooling nearly a dozen major studies of > GWWA reproductive success, including a half-dozen PhDs, and is > detectable only with a sample size of on the order of 500 nests. This > won't happen for goshawk. So what we have is anecdotal. > > Since my information on goshawk is old and very personal and not > generally known among the public, I wanted to make the gentle > suggestion that for birds swuch as ravens and goshawk or similar birds > with individual pairs that can be adversely affected by human presence > that the location of (potential) territories and/or nests is probably > not a good thing to share. It is interesting that within a species there > may be pairs that are acclimated to human presence and pairs that don';t > often contact humans and may "over-react' to human intrusion. This the > consequence of visiting a nest or entering a territory is unpredictable. > > Cheers, > > John > > On 1/16/2015 2:17 PM, Anne Clark wrote: > > Hopefully this is not taking this outside the interest of many on the > list but: > > > > I am curious to know the evidence on reduced nesting success in > goshawks, in part because it is really important to know what such evidence > would look like. John, can you direct those of us who might want to follow > up to publications, people, organizations? > > > > Thanks, > > > > Anne > > > > On Jan 16, 2015, at 2:07 PM, John and Sue Gregoire wrote: > > > >> Heartly concur John. Count me as a bander who has both noted this and > had research > >> muddled by such exact descriptions. > >> john > >> -- > >> John and Sue Gregoire > >> Field Ornithologists > >> Kestrel Haven Avian Migration Observatory > >> 5373 Fitzgerald Road > >> Burdett,NY 14818-9626 > >> N 42 26.611' W 76 45.492' > >> Website: http://www.empacc.net/~kestrelhaven/ > >> "Conserve and Create Habitat" > >> > >> On Thu, January 15, 2015 16:03, John Confer wrote: > >>> HI Folks, > >>> > >>> The barn door is open or the cat is out of the bag, BUT I HAVE A > >>> CONCERN ABOUT DESCRIBING LOCATIONS OF N GOSHAWK WHEN THEY ACT SOMEWHAT > >>> AS IF THEY HAD A TERRITORY. Northern Goshawk are known among banders > who > >>> climb to hawk nests to frequently abandon a nest, especially early in > >>> the nesting cycle, although not so much after the young have > >>> hatched.Individual birds can become accustomed to human disturbance at > a > >>> low level and provide an exception. Other birds that rarely see humans > >>> may well abandon a nest if disturbed. At this time of year, they > >>> probably haven't started laying and, even if the bird is considering > >>> nesting nearby, at this time of the year the bird might just move away. > >>> However, if they did start to nest and someone visited the well > >>> described site a couple months from now, the bird might abandon eggs. > >>> > >>> I know there is an excitement in seeing a good bird, and it is > very > >>> nice to share providing a very good motivation to share a siting with > >>> others, e.g., the Schofield Short-eared Owls, which do not seem to be > at > >>> all disturbed by humans watching them in a car. Other species of birds > >>> may have reduced nesting success if people visit them, and goshawk are > >>> known to be so affected. Discretion in individual circumstances is > advised. > >>> > >>> Cheers, > >>> > >>> John > >>> > >>> On 1/15/2015 11:14 AM, Donna Scott wrote: > >>>> Where is Foster Pond, please? > >>>> > >>>> Sent from my iPhone > >>>> Donna Scott > >>>> > >>>> On Jan 14, 2015, at 6:19 PM, Joshua Snodgrass <cedarsh...@gmail.com > >>>> <mailto:cedarsh...@gmail.com>> wrote: > >>>> > >>>>> I went birding at Foster Pond this afternoon, because high twenties > >>>>> feels like spring compared to the last few days. Past the frozen pond > >>>>> and down Backbone trail I ventured into the brushy field to get a > >>>>> better look at some waxwings when I flushed a Northern Goshawk from > >>>>> low cover. Life Bird! She (I'm guessing based on the size) perched in > >>>>> a small tree and posed for a long time. Excellent views. Adult with a > >>>>> bright eyestripe. I took pictures until my hands and toes went numb. > >>>>> She never flew away. As I was returning to the trail two Common > >>>>> Ravens flew over calling. Awesome Day! > >>>>> Photos: > >>>>> > https://www.flickr.com/photos/123875591@N03/16096262487/in/photostream/ > >>>>> > https://www.flickr.com/photos/123875591@N03/15662257883/in/photostream/ > >>>>> > >>>>> Sorry I didn't post earlier, but I have a dumb phone. > >>>>> Good birding! > >>>>> Josh > >>>>> -- > >>>>> *Cayugabirds-L List Info:* > >>>>> Welcome and Basics < > http://www.northeastbirding.com/CayugabirdsWELCOME> > >>>>> Rules and Information < > http://www.northeastbirding.com/CayugabirdsRULES> > >>>>> Subscribe, Configuration and Leave > >>>>> < > http://www.northeastbirding.com/CayugabirdsSubscribeConfigurationLeave.htm > > > >>>>> *Archives:* > >>>>> The Mail Archive > >>>>> <http://www.mail-archive.com/cayugabirds-l@cornell.edu/maillist.html > > > >>>>> Surfbirds <http://www.surfbirds.com/birdingmail/Group/Cayugabirds> > >>>>> BirdingOnThe.Net <http://birdingonthe.net/mailinglists/CAYU.html> > >>>>> *Please submit your observations to eBird > >>>>> <http://ebird.org/content/ebird/>!* > >>>>> -- > >>>> -- > >>>> *Cayugabirds-L List Info:* > >>>> Welcome and Basics < > http://www.northeastbirding.com/CayugabirdsWELCOME> > >>>> Rules and Information < > http://www.northeastbirding.com/CayugabirdsRULES> > >>>> Subscribe, Configuration and Leave > >>>> < > http://www.northeastbirding.com/CayugabirdsSubscribeConfigurationLeave.htm > > > >>>> *Archives:* > >>>> The Mail Archive > >>>> <http://www.mail-archive.com/cayugabirds-l@cornell.edu/maillist.html> > >>>> Surfbirds <http://www.surfbirds.com/birdingmail/Group/Cayugabirds> > >>>> BirdingOnThe.Net <http://birdingonthe.net/mailinglists/CAYU.html> > >>>> *Please submit your observations to eBird > >>>> <http://ebird.org/content/ebird/>!* > >>>> -- > >>> > >>> -- > >>> > >>> 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/ > >>> > >>> -- > >> > >> > >> -- > >> > >> 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/ > >> > >> -- > > > -- > > 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/ > > -- > -- 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/ --
