Water Closet for March 25, 2016

[pullquote]”This spring and summer, visit local rookeries especially where beavers have drowned pines and nests are clearly seen.”[/pullquote]What common skinny eight-pound, four-foot tall, croaky animals are now back at their reproductive sites here? Each March the answer is great blue heron, Ardea herodias.
Three heron rookeries in Middleton continue after 15 years to be places of great interest. Before beavers drowned the white pines and death took away their needles and twigs this millennium we knew of no nests here. Exposed bare branches sticking out at right angles from tall trunks are platforms upon which herons build nests of sticks. In the early years of beaver impoundments here few nests existed in this area. Now there are many. The oldest rookery above the Pond Meadow Pond beaver inundation now has forty two. Last year the “southwest Middleton Pond rookery” had twenty three. At last count several years ago the aerial village on a forested knoll surrounded by man flooded Emerson Bog had about forty nests. Maybe a canoe trip before the oak leaves come out will reveal this spring’s number. From Route 114 looking southwest across the bushy reservoir we can see but a few nests in the oaks and pines of the “Emerson Bog rookery”.

Ten of about twenty-one nests in dead pines of a great blue heron rookery near Middleton Pond. They and occupants are easily seen from the walking path encircling the pond. Herons started returning last week. – Judy Schneider photo

Let’s do some estimates of each year’s production of young in these three nurseries of about 100 nests active from mid-March to August. We don’t know the mortality rate of vulnerable chicks in such high open penthouses without guardrails. We guess the average nests in Middleton’s rookeries to be about fifty-five feet high; five building stories without fire escapes. Ornithologist Jim Berry says four eggs per nest per parent couple are usually laid. Let’s say two make it from hatching to fledging. We don’t know the rate of accidents or where larger better fed chicks, some hatched earlier, push out weaker brothers and sisters hatched later. The shallow waters below the nests are not easily visited by canoe or wading due to fallen trees and bushes. Victims of a push and fall are probably quickly eaten by scavengers. All isn’t pleasant in human terms below the sunlit villages above. Rich populations of countless organisms and scores of different species in the flooded beaver meadows interact in complicated food webs. The water at times is a soup of microorganisms and of those that graze on them and so on up food chains. Last week two girl scouts doing a project netted a dozen insect and crustacean species from the leaf-littered bottom water below the southwest Middleton Pond rookery where at least seven herons had returned. The first three returning this year from somewhere were reported on Monday, March 14th. Last year at this time thick ice and snow were below the rookeries when the herons returned.
Two days later roughly ten herons were seen through old cataracty eyes on nests above Pond Meadow Pond. Upon return the birds add sticks to the nests on which they raised a family the year before. The rookeries are quiet places early on. From now on we’ll visit each week to see the increase in returnees and wonder at their noisy antics in the air and on perches around the nests. Are they fighting, flirting, or just playing? Do they remember which nest is theirs? Did all survive the winter somewhere and make it back? Will newcomers claim unoccupied nests or build anew? Couples are thought not to winter together. Great blue herons are solitary birds except at rookeries. They are almost always spotted alone when hunting. As you can see there are more questions than answers, especially for us very amateur naturalists who neither radio-tag birds to follow their travels nor send peeping Tom drones above their nests. We just visit now and then to marvel at the huge birds’ comings and goings.
Drones, now so common at least on TV, remind us of a tragedy at the Pond Meadow Pond rookery several years ago. Fire fighters battling a late spring forest fire just south of the rookery, where all nests were occupied with chicks, called in helicopters to help. The huge manned “drones” scooped up water from Middleton Pond and flew low over the woods and dumped water on the front of the spreading fire. On returning for another load they turned around over the nests. On a check a few days later Stream Teamer Red Caulfield found the rookery strangely quiet, no herons were to be seen or heard. The parents had gone, no doubt spooked by the roar of the helicopters. We wondered how many corpses of abandoned young were in the silent nests. We were too old to climb and check. On later weekly checks that summer we saw no herons in the once very active rookery. One old Closeteer sadly remembered Viet Nam war documentaries where helicopters he helped pay for flew over abandoned paddies and scorched jungles.
Let’s hope that someday skies are free of the buzz of tiny drones and roars of choppers. Let the rookeries of the world including those of humans again be without frightening machines carrying bombs and cameras.
This spring and summer, visit local rookeries especially where beavers have drowned pines and nests are clearly seen. There are thousands of acres of impounded water behind beaver dams in the watershed. Watch the herons from a distance, send no drones, and if you are a fire chief have the helicopters avoid these aerial nurseries. Better still let the quickly moving spring fires run their courses where no houses are threatened. Forest fires like herons are natural things. Before the Old Worlders came from across the sea, lightning fires and those purposely set by Indians were valued for the habitats they made.
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WATER RESOURCE AND CONSERVATION INFORMATION FOR MIDDLETON, BOXFORD AND TOPSFIELD`

Ipswich R. Flow Rate (S. Middleton USGS Gage) in Cubic Feet/ Second (CFS):
For March 21, 2016  Normal . . . 131 CFS     Current Rate . . . 120 CFS
*Danvers Water Filtration Plant, Lake Street, Middleton is the source for actual precipitation data thru Feb.
**Middleton Stream Team is source of actual precipitation data for March.  Normals data is from the National Climatic Data Center.
THE WATER CLOSET is provided by the Middleton Stream Team: www.middletonstreamteam.org or         <MSTMiddletonMA@gmail.com> or (978) 777-4584