Tree Swallows at Broadmoor Wildlife Sanctuary

Posted by Lucy Zipf

“Swallows are more confident and fly nearer to man than most birds.  It may be because they are more protected by the sentiment and superstitions of men.”

Henry David Thoreau, May 20, 1858.

This summer I have been working with Mass Audubon’s Broadmoor Wildlife Sanctuary. With the help of sanctuary director Elissa Landre, I am investigating how climate change is affecting tree swallow nesting behavior, especially the timing of reproduction and clutch size.

Broadmoor’s Wildlife Pond fields dotted with nest boxes

A nest box at Broadmoor

Volunteers at Broadmoor have been monitoring the nest boxes on and off since 1987. There are 55 nest boxes on Broadmoor’s 624 acres, 44 of which were occupied this year by tree swallows.

A tree swallow looks out of a nest box at Broadmoor (Photo by Broadmoor Volunteer Chris Leuchtenburg)

Tree swallow nestlings in a nest box at Broadmoor (Photo by Broadmoor Volunteer Chris Leuchtenburg)

Preliminary analysis indicates that tree swallows are nesting earlier now than in the past, and are nesting earlier in warmer springs. While clutch size has not changed over time, clutch sizes are lower in very rainy years perhaps because there are fewer flying insects to eat.

Volunteer Richard Kent counting tree swallow eggs in a nest box

End of Field Season, A Look Back

Posted by Caitlin McDonough MacKenzie

In celebration of the end of the Acadia field season, here's a look back at the final phenology transects of the last two summers.

These summit photos capture the exciting development of the past year. While the field seasons have steadily continued — the same three transects across the same three mountains, monitoring the same phenophases on the same species for four seasons — there's been a dramatic, far-reaching, joyful change that is not reflected in the routine spreadsheets or analyses of our field season data. 

In 2016 Mara was a great field baby, and while we had some fun adventures in the baby backpack, she spent most of her days in town while I was hiking. But, to mark the last transect of the last dissertation field season, Mara needed to be there! It's been a wonderful treat to share the last two field seasons with my daughter. Now if only she could be so helpful at writing manuscripts...

Primack Lab in National Geographic magazine!

Posted by Richard B. Primack

“I am on the alert for the first signs of spring...” 

-Henry David Thoreau 

A recent article, published in the July 2016 issue of National Geographic magazine, summarizes our 16 years of research on the effects of climate change on the phenology of plants and birds in Concord, MA. We are delighted to share our research with such a broad audience; National Geographic circulates to 3.5 million readers in the U.S. and around 6.7 million readers internationally, in 40 languages.

The article highlights the possibility of ecological mismatches between the spring flowering and leafing out times of plants and the spring arrival times of birds. Plants are now flowering and leafing out two weeks earlier than in Thoreau’s time due to warmer temperatures, while birds have changed hardly at all. Could this be affecting the ecology of birds and the insects that they are feeding on? We don’t know yet.

The article also provides a figure showing that most wildflower species have a first flowering date that is earlier now than in the past. In contrast to this general pattern, three species are shown to be flowering later now than in the past, but no explanation is provided. This later date of current first flowering is probably due to the declining population sizes of these species, which is a complication of working with first flowering dates rather than average flowering dates.  

Find the full article HERE.