Date: 4/4/18 5:53 am From: Jeff Wells <jwboreal...> Subject: Fwd: FW: [Maine-birds] Re: More Tree Swallows and an Osprey in Gardiner
Hi Cathie and others,
Breeding Bird Survey analyses show a major steep decline in Tree Swallow numbers in Maine over the last half century. And Maine has had one of the highest abundances of Tree Swallows in North America (also based on Breeding Bird Survey data) making such a decline of particular concern. I will try to attach a BBS map showing where Tree Swallows are decreasing and increasing (red is decreasing and blue decreasing).
As far as the mismatch in timing of insect hatch with arrival and feeding of young, there are more and more studies documenting impacts to the survival and reproduction of birds (and other animals) related to such phenological shifts and misalignments. I know that the earlier arrivals of Tree Swallows (on average) across North America has been documented over the last half century or so but I am not sure if studies have been able to determine the real or potential impacts from mistiming between insect hatch and Tree Swallow survival and reproduction but I will check and report back if no one else does here on the listserve in the meantime.
Last night when I again saw 30 or so Tree Swallows over the parking lots and rooftops along Water Street and Cobbossee Stream, I hoped that they were finding some insects even though I hadn't been noticing any myself. Today I haven't seen the swallows yet but I'm guessing that the pickings may be slim but if there are going to be any insects it will be over the streams and rivers where some insects are usually hatching. A couple of years ago, Allison and I wrote about the importance of what we called "Swallow Lifeboats" -- waterways and wetlands -- in our Boothbay Register column (http://www.boothbayregister.com/article/swallow-lifeboats/32532).
*From:* <maine-birds...> [mailto:<maine-birds...>] *On Behalf Of *<cathie.murray...> *Sent:* Tuesday, April 03, 2018 5:29 PM *To:* Maine birds *Subject:* [Maine-birds] Re: More Tree Swallows and an Osprey in Gardiner
Hi Jeff and all, How do you think swallows are faring in central Maine? I realize tree swallows can eat some fruit that has overwintered when they first arrive...good thing! in recent years it has seemed like our swallows have had their timing off, compared to the insects they'd like to eat. I remember years when hundreds of swallows, multiple species, would be hawking fresh hatched insects from the Kennebec River and Cobbossee stream just in time to feed their young, but I haven't seen that lately. Last spring I was birding along Cobbossee Stream in May when a mayfly-type hatch occurred and there wasn't a single swallow enjoying it. I know this lack of synchronicity is happening in some parts of the world/country due to climate change, and not in others. How do you think our part of the world is doing? Cathie
On Tuesday, April 3, 2018 at 12:33:47 PM UTC-4, Jeff Wells wrote:
Numbers of Tree Swallows coursing over the Cobbossee Stream and nearby in downtown Gardiner have continued to grow so that there are at least 50 here at mid-day. An Osprey was sitting on the favored perch near the bridge next to Dunkin Donuts in Gardiner this morning as well.