When we left off, things were looking pretty grim for the cliff swallows on the BCC campus. For starters, we had record breaking rainfall for the month of May 2025. The Pittsfield airport reported 6.98” of rainfall. The KPSF AWIPS system was down for about a week at the Pittsfield airport. This outage may have influenced the rainfall measurements they received. The Cocorahs station at BCC (MA-BE-31), received 8.56” of rainfall for the month of May. Either way, the precipitation record for the month of May was broken.
Initially as of May 13 BCC had 13 cliff swallow nesting attempts. However no only did we have record breaking rainfall, it was also quite chilly. The last nesting pair had a clutch failure on or about June 6-7, before they too, abandoned the colony at BCC. Then around June 20 a single pair of cliff swallows returned to the college. A nest was constructed on an area of Hawthorne where no cliff swallows had nested in 8 years. I was alerted to another cliff swallow presence on June 24 by Ellie our resident bird goddess. Unfortunately, our hope was soon dashed here as well. This cliff swallow nest was taken over by House Sparrows within 2 days. Then on the third day, the structure of the nest failed. At this juncture, I need to point out that BCC did not have source mud available for the cliff swallows since construction work was ongoing at the time. Not that I didn’t try. The construction crew was cleaning up the mud almost as fast as I was laying it down. After the 3rd attempt, I attempted another mud spot elsewhere, but that attempt failed. It was investigated, but no takers. Needless to say, and since there was an abundance of mud everywhere, the cliff swallows accessed mud from elsewhere. However, the content of the mud was sandier, hence lacked the structural integrity. (BCC has a respectable amount of clay in the soils around the campus) This explains the structural failures of many of the nests in 2025.
The cliff swallows at all the other colonies we were monitoring were having a really tough time this year. The dominant atmospheric feature saw the persistent trough-ing pattern and associated damp and cold temperatures throughout late April and much of May. The cold and associated lack of insect prey, played a significant factor in the high incidences of abandonment and mortality of the local swallow colonies.
For example, Simon’s Rock DAC had a slow start. Cliff swallows showed up 2 weeks later than when we normally began seeing them, and instead of the 350 plus individual birds normally observed, there were 252 ( 126 nesting attempts). When the cold and wet month of May hit that number dropped to 104 individual birds (52 active nests). There was nest abandonment here and a few nest mortality events as well. . As June progressed, a few more mortality events occurred here as well, but a few cliff swallows streamed their way back and again attempted to nest. In all, the 2025 nesting season at Simon’s Rock saw 71 nests successfully fledged young. A success rate of around 56% A normal year at Simon’s Rock in previous years had a success rates of between 73%-81%.
To summarize, The 2025 Nesting Season looked like this:
BCC : 14 nesting attempts/ Colony Abandoned
Glendale Bridge: 3 Nesting Attempts /Colony Abandoned
NLRB 15 Nesting Attempts/ 13 Successfully fledged
Aryhill Farm (Estimated) 17-20 Attempts 12-15 successfully fledged (the reason I estimate here is most of the nests are in the bull pen with real bulls!)
Simon’s Rock DAC 126 attempts 71 Successfully fledged
Rowe MA Town Hall which usually fledges 30-40 nests successfully per year, only successfully fledged a handful of cliff swallow nests for the 2025 season. The town of Rowe has since pulled the plug on the cliff swallow conservation project that had ongoing for nearly 10 years. Since the Rowe cliff swallow colony was a significant one, their future hangs in the balance.
With the closure of Simon’s Rock, the fate of the largest cliff swallow colony in Massachusetts also remains uncertain.