Date: 6/23/20 9:32 pm
From: Robert O'Brien <baro...>
Subject: [obol] Re: swallows?
Larry mentions Bats. I could have thrown them in also. In the early,
abundant, swallow days bats were fairly common. Nowadays I see about 1 bpy.
One bat per year. They're gone also.
Bob OBrien

On Tue, Jun 23, 2020 at 8:10 PM Larry McQueen <larmcqueen...>
wrote:

> Further: Maybe there is enough research to ascertain bird specialization/
> insect prey. I haven’t done a search. Stomach contents used to be top
> drawer with preparing specimens. I do know that ground Caprimulgids
> (Poor-wills,etc.) specialize in large moths, witch are also not so
> populous. I would guess that most of insect prey tends to be not so
> selective (if in fact that should be the case), but does anyone know if
> there are more specialists, that is, avian dependents on certain species of
> insects? This information I would expect, would be fundamental to
> conservation attempts.
>
> I was just raising the question. And what about bats? Each species of
> flying insect has its own circadian clock and season.
>
> Complexity is what we are given to unravel.
>
> Larry
>
>
>
> On Jun 23, 2020, at 3:31 PM, Robert O'Brien <baro...> wrote:
>
> I agree completely with Larry. This is serious, and has been recognized.
> A recent article in National Geographic details what has happened to insect
> populations over recent decades. As usual it mostly uses human interest
> aspects, rather than 'the big picture'.
> The major organization trying to combat this, in this case with respect to
> pollinators, is Xerces. http://xerces.org/
> An uphill battle. And, as Larry states, pollination is just the tip of
> the iceberg. A great many birds depend upon insects, whether they
> pollinate commercially important crops or not. And I suspect Xerces has
> just focused on pollinators because it is currently a matter of widespread
> discussion. Environmental work over decades has brought back the Wolf.
> More or less. Insects will be much more difficult. But infinitely more
> important.
> Bob OBrien Carver OR
>
>
> On Tue, Jun 23, 2020 at 12:08 PM Larry McQueen <larmcqueen...>
> wrote:
>
>> It is the same situation in my neighborhood. Swallows and swifts are no
>> longer seen and heard in the sky, when in the recent past they were
>> seasonally omnipresent. There is no more enjoyable spring-time chattering
>> of Violet-greens at 3 a.m.
>> Kill off the insects and guess what happens! This trully, is serious.
>> Larry
>>
>> On Jun 22, 2020, at 11:02 PM, Robert O'Brien <baro...> wrote:
>>
>> I've been watching swallows nesting at my place for 40+ years. Their
>> numbers have greatly declined over this period. At one point there were
>> barn, tree, VG.
>> The tree dropped out first, then the barn, leaving VGs in decline. Here
>> is the pattern I see for VGs (and perhaps the others but there are none to
>> observe).
>> They show up with 'good weather days' i.e. no rain, and start
>> investigating our many birdhouses. if good weather persists they commence
>> nest building, etc.
>> In good years young are produced. In most years a multiday rainy period
>> occurs, and after some days they simply abandon the nest and don't nest
>> that year.
>> That happened again this year, but, as Darrel says, with the good weather
>> of recent days they are flying around the nests again, which had been
>> partially built.
>> It's still early in the nesting period, so likely enough time to be
>> successful. We live about 1/4 mile from the Clackamas River and the
>> riverine area undoubtedly provides lots of insects, maybe even during rainy
>> periods. Our swallows could and probably do feed there, but nevertheless
>> prolonged rainy periods terminate nesting. I'm not suggesting this
>> phenomenon occurs elsewhere but it certainly happens here. Perhaps
>> swallows nesting in other areas are successful every year weather
>> notwithstanding?. ,
>>
>>
>> On Mon, Jun 22, 2020 at 12:22 PM <t4c1x...> wrote:
>>
>>> Has anyone else noticed a recent reduction in swallows? A few weeks ago
>>> there were about six or eight pairs apparently preparing to nest here at
>>> Thornton Creek, (Lincoln), but now there are only a couple pair each of
>>> Barn Swallows and Violet-greens. It could be that the females are sitting
>>> on eggs, but it looks more like some birds simply left the area. It stayed
>>> cold and wet here right up to the end of last week, and I wonder if some of
>>> the birds just departed to more suitable places.
>>>
>>> Darrel
>>>
>>
>>
>

 
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