Re: [CT Birds] Fires to blame?
Avian migration is a very complex phenomenon. I personally have not heard
any factual evidence about the impact (or lack thereof) of southern fires on
avian mortality. There are so many risk factors in migration that I would be
very hesitant to assume the fires played a significant role in this year's
migration. If there are significant and substantiated numbers of dead birds
that are known (that is an important word here) to have been killed through
respiratory impact then one can estimate the real impact. As for the smoke
obstructing the bird's view of the sky, migratory birds are believed to use
stars to navigate but it isn't the only guidance mechanism used. Magnetic
fields are also believed to play a role as well as leading edge migration,
and landmark recognition. By leading edge I mean following a coastline or
mountain ridge or some other visible topographic feature. Greg Hanisek has
recently contributed valuable info to this forum concerning how birder's
perception of a migratory season can be a little misleading about the big
picture (I have learned never to dismiss what Greg says lightly). Certainly
one species that would be impacted by the fires (if any) would be Cape May
Warbler. Nearly the entire population of that species migrates through the
fire impacted area and there seemed to me to be at least the usual number of
reports of them from the field this year. In past years I know I have heard
many theories about why a particular migration was disappointing. So if
anyone does have real evidence concerning the southern fires' impact on
avian migration I would be very interested to hear it. Until then I would
express the opinion that the real issue impacting the numbers of migrants
from year to year remains habitat degradation and habitat loss.
Dave
As a small addition to Dave's strong points, wouldn't the impact of fire,
since it is a natural occurrence, be one that birds are engineered to deal
with? It's my understanding that humans have drastically decreased the
number of natural wildfires because of our ability to extinguish/control
them before they spread. If this did not happen, fires would be both more
numerous and more widespread. The various species of birds have to be able
to cope with wildfires that have occurred over thousands of years of
evolution. If they couldn't, wouldn't they have gone extinct long ago?
And simply - can't they just fly above/around them? I've never seen a
situation where a bird is near a fire, but I would imagine they would know
to avoid it. It's not even as if the birds in question had nests or young
that could not avoid the flames. I would think birds that nest in areas
where wildfires occur would sustain a localized population hit (or a larger
one in special situations), but not those passing through/around the area.
But I'm no expert - just my thoughts and guesses.
--
Scott Kruitbosch
Stratford, CT
kbosch@gmail.com
Glad Dave chimed in on this. This is the kind of thing that really takes on
a life of its own on the Internet without any real facts to back it up. As
Dave said, the key here is complexity. Drawing big conclusions from events
hundreds of miles away just isn't likely to be possible over the short term.
I would also point out as a life-long professional journalist that my
profession doesn't always shine doing these kind of stories, especially
smaller papers that don't have reporters who specialize in environmental
issues. Even environmental reporters may be better versed in things like
water pollution or toxic waste than wildlife. They'll be at the mercy of
their sources, and if someone they're speaking to goes off on a speulative
tangent it may well end up in print. For a reporter used to covering zoning
boards and court hearings, anyone who knows a grosbeak from a garden hose is
an expert.
I have no expertise in the area on which I'm now going to make a brief
comment and would be glad to hear from anyone who knows more. But in general
fire in natural settings, especially pine scrub of the sort widespread in
parts of Georgia and Florida, can have a salutary effect by preventing open
habitats from being overgrown (to the benefit of things such as Bachman's
Sparrow). In many cases the negative public reaction to wild fires has much
more to do with threats to human life and property than threats to wildlife.
The situation in a dried out wetland such as Okefenokee may be different. I
don't really know.
I've seen one story from South Florida that mentioned some small birds (the
number 100 was mentioned) had been killed or injured when they became
disoriented by smoke and flew into windows etc. The overall effect of
something like this, and what it might mean on a continental basis, would be
speculative at best. To suggest it had anything to do with an individual
birder's perception of this spring's migration or local breeding populations
this month would be wildly speculative. It certainly would create a big
impression on anyone that observed it, but beyond that it quickly gets
swallowed up by the vastness of the continent.
As I noted in a post that Dave referred to, there are plenty of threats,
problems etc facing birds throughout the world, but they're measured over
time and distance through careful record-keeping. A given season's migration
is just too complex an event to yield really meaningful short-term
information in a limited geographic area. But keeping records from limited
areas can be an important part of this meaningful long-term accumulation of
knowledge.
Greg Hanisek
Waterbury
----- Original Message -----
From: "David Provencher" davidprovencher@sbcglobal.net
To: ctbirds@lists.ctbirding.org
Sent: Tuesday, June 05, 2007 8:15 PM
Subject: Re: [CT Birds] Fires to blame?
Avian migration is a very complex phenomenon. I personally have not heard
any factual evidence about the impact (or lack thereof) of southern fires
on
avian mortality. There are so many risk factors in migration that I would
be
very hesitant to assume the fires played a significant role in this year's
migration. If there are significant and substantiated numbers of dead
birds
that are known (that is an important word here) to have been killed
through
respiratory impact then one can estimate the real impact. As for the smoke
obstructing the bird's view of the sky, migratory birds are believed to
use
stars to navigate but it isn't the only guidance mechanism used. Magnetic
fields are also believed to play a role as well as leading edge migration,
and landmark recognition. By leading edge I mean following a coastline or
mountain ridge or some other visible topographic feature. Greg Hanisek has
recently contributed valuable info to this forum concerning how birder's
perception of a migratory season can be a little misleading about the big
picture (I have learned never to dismiss what Greg says lightly).
Certainly
one species that would be impacted by the fires (if any) would be Cape May
Warbler. Nearly the entire population of that species migrates through the
fire impacted area and there seemed to me to be at least the usual number
of
reports of them from the field this year. In past years I know I have
heard
many theories about why a particular migration was disappointing. So if
anyone does have real evidence concerning the southern fires' impact on
avian migration I would be very interested to hear it. Until then I would
express the opinion that the real issue impacting the numbers of migrants
from year to year remains habitat degradation and habitat loss.
Dave
This list is provided by the Connecticut Ornithological Association (COA)
for the discussion of birds and birding in Connecticut.
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Hi All:
I was among those who talked to Michael Dinan as he was developing the story. He wanted to know what some of the potential reasons behind this slow migration might have been. Essentially, I had said that it could be any number of issues causing the poor showing, coastal storms, stalled fronts and the extensive fires in the southeast and that these sorts of periodic events are a normal part of migration. Fires stand out in the article since they are mentioned first (although I don't think he ever said that large numbers died). The main point I wanted to get across was that there is a certain level of attrition assoicated with such long migratory travels and that there are occasional bad years, and this wouldn't normally be a cause for alarm, but when combined with the long-term large-scale population declines of some species, these sort of events can be one more strain on an already stressed system. Also, from a birding perspective, with reduced populations to begin with these events can have a more pronounced impact and we really notice a down year.
Patrick Comins, Meriden
-----Original Message-----
From: ctbirds-bounces@lists.ctbirding.org on behalf of David Provencher
Sent: Tue 6/5/2007 8:15 PM
To: ctbirds@lists.ctbirding.org
Cc:
Subject: Re: [CT Birds] Fires to blame?
Avian migration is a very complex phenomenon. I personally have not heard
any factual evidence about the impact (or lack thereof) of southern fires on
avian mortality. There are so many risk factors in migration that I would be
very hesitant to assume the fires played a significant role in this year's
migration. If there are significant and substantiated numbers of dead birds
that are known (that is an important word here) to have been killed through
respiratory impact then one can estimate the real impact. As for the smoke
obstructing the bird's view of the sky, migratory birds are believed to use
stars to navigate but it isn't the only guidance mechanism used. Magnetic
fields are also believed to play a role as well as leading edge migration,
and landmark recognition. By leading edge I mean following a coastline or
mountain ridge or some other visible topographic feature. Greg Hanisek has
recently contributed valuable info to this forum concerning how birder's
perception of a migratory season can be a little misleading about the big
picture (I have learned never to dismiss what Greg says lightly). Certainly
one species that would be impacted by the fires (if any) would be Cape May
Warbler. Nearly the entire population of that species migrates through the
fire impacted area and there seemed to me to be at least the usual number of
reports of them from the field this year. In past years I know I have heard
many theories about why a particular migration was disappointing. So if
anyone does have real evidence concerning the southern fires' impact on
avian migration I would be very interested to hear it. Until then I would
express the opinion that the real issue impacting the numbers of migrants
from year to year remains habitat degradation and habitat loss.
Dave
_______________________________________________
This list is provided by the Connecticut Ornithological Association (COA) for the discussion of birds and birding in Connecticut.
For subscription information visit http://lists.ctbirding.org/mailman/listinfo/ctbirds_lists.ctbirding.org
Here is the link to the original story, which I think is much better than the shorter AP versions:
http://www.greenwichtime.com/news/local/scn-gt-a1birdssundayjun03,0,2063032.story
If that link doesn't work, just go to the Greenwich Time website and do a search for something like birds or migration.
Patrick
-----Original Message-----
From: ctbirds-bounces@lists.ctbirding.org on behalf of COMINS, Patrick
Sent: Tue 6/5/2007 9:25 PM
To: David Provencher; ctbirds@lists.ctbirding.org
Cc:
Subject: Re: [CT Birds] Fires to blame?
Hi All:
I was among those who talked to Michael Dinan as he was developing the story. He wanted to know what some of the potential reasons behind this slow migration might have been. Essentially, I had said that it could be any number of issues causing the poor showing, coastal storms, stalled fronts and the extensive fires in the southeast and that these sorts of periodic events are a normal part of migration. Fires stand out in the article since they are mentioned first (although I don't think he ever said that large numbers died). The main point I wanted to get across was that there is a certain level of attrition assoicated with such long migratory travels and that there are occasional bad years, and this wouldn't normally be a cause for alarm, but when combined with the long-term large-scale population declines of some species, these sort of events can be one more strain on an already stressed system. Also, from a birding perspective, with reduced populations to begin with these events can have a more pronounced impact and we really notice a down year.
Patrick Comins, Meriden
-----Original Message-----
From: ctbirds-bounces@lists.ctbirding.org on behalf of David Provencher
Sent: Tue 6/5/2007 8:15 PM
To: ctbirds@lists.ctbirding.org
Cc:
Subject: Re: [CT Birds] Fires to blame?
Avian migration is a very complex phenomenon. I personally have not heard
any factual evidence about the impact (or lack thereof) of southern fires on
avian mortality. There are so many risk factors in migration that I would be
very hesitant to assume the fires played a significant role in this year's
migration. If there are significant and substantiated numbers of dead birds
that are known (that is an important word here) to have been killed through
respiratory impact then one can estimate the real impact. As for the smoke
obstructing the bird's view of the sky, migratory birds are believed to use
stars to navigate but it isn't the only guidance mechanism used. Magnetic
fields are also believed to play a role as well as leading edge migration,
and landmark recognition. By leading edge I mean following a coastline or
mountain ridge or some other visible topographic feature. Greg Hanisek has
recently contributed valuable info to this forum concerning how birder's
perception of a migratory season can be a little misleading about the big
picture (I have learned never to dismiss what Greg says lightly). Certainly
one species that would be impacted by the fires (if any) would be Cape May
Warbler. Nearly the entire population of that species migrates through the
fire impacted area and there seemed to me to be at least the usual number of
reports of them from the field this year. In past years I know I have heard
many theories about why a particular migration was disappointing. So if
anyone does have real evidence concerning the southern fires' impact on
avian migration I would be very interested to hear it. Until then I would
express the opinion that the real issue impacting the numbers of migrants
from year to year remains habitat degradation and habitat loss.
Dave
_______________________________________________
This list is provided by the Connecticut Ornithological Association (COA) for the discussion of birds and birding in Connecticut.
For subscription information visit http://lists.ctbirding.org/mailman/listinfo/ctbirds_lists.ctbirding.org
_______________________________________________
This list is provided by the Connecticut Ornithological Association (COA) for the discussion of birds and birding in Connecticut.
For subscription information visit http://lists.ctbirding.org/mailman/listinfo/ctbirds_lists.ctbirding.org