Date: 6/26/26 5:07 pm From: David Facey <dcf2005...> Subject: Re: Third Breeding Bird Atlas update: continued low numbers of cuckoos
Here is the latest drought information for Pennsylvania:
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In May 2008 I saw both a yellow-billed and black-billed cuckoo one day apart during an outbreak of spongy (Gypsy) moth caterpillars. That was the last time I can remember an outbreak and it coincided with a particularly dry spell of weather. I have seen a yellow-billed once more and have not seen a black-billed since. Spongy moth outbreaks coincide with substantial dry weather.
It would be interesting to know if there are any spongy moth outbreaks currently in southeastern PA.
David Facey
From: State College (PA) Bird Club <SCBIRDCL...> On Behalf Of Debra Rittelmann
Sent: Friday, June 26, 2026 4:21 PM
To: <SCBIRDCL...>
Subject: Re: Third Breeding Bird Atlas update: continued low numbers of cuckoos
Ironically, my neighbor and I were just talking about this this past week; we both noticed the lack of Cuckoo calls and we've had them in the yard in the past. Also on my neighbor's farm. Hope it's not a forever thing.
Deb Rittelmann
On Fri, Jun 26, 2026 at 1:54 PM Gyekis, Joseph Peter <jpg186...><mailto:<jpg186...>> wrote:
Statewide breeding bird survey analyses over the past 30 years show significant declines for both cuckoo species.
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From: State College (PA) Bird Club <SCBIRDCL...><mailto:<SCBIRDCL...>> on behalf of Nick Bolgiano <nickbolgiano...><mailto:<nickbolgiano...>> Sent: Friday, 26 June 2026 07:53:46
To: <SCBIRDCL...><mailto:<SCBIRDCL...> <SCBIRDCL...><mailto:<SCBIRDCL...>> Subject: Third Breeding Bird Atlas update: continued low numbers of cuckoos
After year one of this breeding bird atlas, I sent out an email on this topic, but now we are into the third season and not much has changed. Both Yellow-billed Cuckoo and Black-billed Cuckoo continue to be reported in low numbers.
During the second Breeding Bird Atlas, in 2004-2009, Yellow-billed Cuckoo was reported in 66% of blocks while Black-billed Cuckoo was reported in 34% of blocks. In my two Breeding Bird Surveys, regular cycles have occurred, with periodic higher numbers coinciding with caterpillar outbreaks, such as spongy (formerly gypsy) moths and webworms. But, no cuckoos in my two routes during the three years of this atlas, which is unprecedented. During the atlas, I have recorded 9 Yellow-billeds and 1 Black-billeds, where I would normally have expected to record many more. (Around here, Yellow-billeds usually outnumber Black-billeds by roughly 10:1.)
Not having many cuckoos means that PA has not experienced widespread caterpillar outbreaks, which is probably a good thing for the trees. However, the low cuckoo numbers are very atypical of what we usually find.
