Friday, January 20, 2023

William Brewster: Birder of Concord

By Richard B. Primack 


One early spring morning in 1858, upon hearing a Purple Finch singing, Thoreau noted in his journal: “How their note rings over the roofs of the village! You wonder that even the sleepers are not awakened by it to inquire who is there, and yet probably not another than myself observes their coming.” 


Thoreau carried out detailed observations of spring bird arrival times in Concord from 1851-1854 These observations were continued by later ornithologists, including William Brewster for 1886 and 1900-1919, on up to current years. These combined records allow researchers to use Concord as a living laboratory to investigate how climate change is altering bird populations in one place.  


A portrait of Brewster.

Brewster (1851-1919) was a pioneer in birding methods, research and conservation, and was a leader of an active birding group in the Boston area and a founder of the American Ornithological Union.   


A copy of Brewster’s journal in which he recorded his daily observations of birds.

During his lifetime, Brewster changed from shooting birds to observing them with field glasses.

A special exhibit about Brewster was recently presented by the Concord Museum.  

Monday, December 26, 2022

Northern species declining in New England

 By Richard B. Primack  


What a fine & measureless joy the gods grant us thus, letting us know nothing about the day that is to dawn.

-Henry David Thoreau in his Journal. 


In a recent paper in Northeastern Naturalist, Robert Bertin and Caitlin Spind demonstrate the effects of climate change on the flora of New England. Using a combination of historical data from herbarium specimens and current survey records, they found that rare northern species are most likely to persist in cooler towns, whereas rare southern species showed no such pattern.  


For rare northern species, towns where populations persist are cooler than towns where species have been lost. For example, current populations of Vaccinium vitis-idaea (mountain cranberry) are found in towns that are 2 degrees C cooler than towns where populations have been lost.

Rare species also showed a tendency to be lost from towns with a higher human population density, indicating that direct human influence was an additional factor in population decline.  

Mountain cranberry has tended to decline in warmer sites.

Further studies are needed to determine the mechanisms behind these changes in distribution of rare species. Is it due to drying out of habitats and heat stress during the summer? Lack of snow cover in winter? Mismatches with tree leaf out and pollinators in the spring? Or something else? 


Here is the reference: 

Bertin, RI, and CG Spind. 2022. Are rare northern plant species retreating from the southern edge of their ranges in southern New England?  Northeastern Naturalist 29: 393-414.  

Friday, December 23, 2022

Threats to Food Security

 By Richard B. Primack 


“All questions rely on the present for their solution. Time measures nothing but itself.” 

-Henry David Thoreau in A Week on the Concord and Merrimack Rivers 


A recent issue of Boston University’s Arts & Sciences magazine asks the Big Question: What is the greatest threat to human health from climate change? 


The greatest threat from climate change will likely be the danger it poses to plants and our food security. Throughout the world, stable crops such as wheat, corn, rice, and wheat will be harmed by the combination of heat waves and drought associated with climate change. This decline and loss of harvests will lead to sharply rising food prices or no food, hunger, starvation, and emigration.  


Corn crops will be harmed by droughts.

 The solution is to transition to an economy in which fossil fuels are greatly reduced, and alternative energy sources, such as wind, solar, hydroelectric, geothermal, and perhaps nuclear power are greatly expanded.  


Solar power is part of the solution.

 The main barrier to implementing these solutions is political. Individual people need to become involved in the political process, and to urge leaders to takes stands, to pass legislation, and to form alliances locally, nationally, and international to address climate change. Most importantly, the world needs an agreement between the US government and the Chinese government to reduce the production of greenhouse gases. 


President Biden and President Xi meet to discuss climate change.

 Here is a link to the issue: