The Sennheiser MKH 8040 pair was set in a Jecklin disk between two beech trunks at 04:42, twenty-eight minutes before official sunrise on the eleventh of May. Jasper Wynn sat thirty feet downslope with the recorder on his lap and waited.
The first voice was an Eastern wood-pewee, low and unhurried, from somewhere near the upper edge of the stand. It was not yet light enough to see the tree it was in. The second was a wood thrush, the song that begins with the throat-clearing introductory note, then the fluted phrase.
By 04:51, six species were singing. By 05:08, fourteen. The recordings show the assembly is not random.
The wood is called the Toftrees tract, a 32-acre fragment north of State College that was logged in 1948 and has been left alone since. It is mature now but not old-growth, with beeches at about sixty centimetres diameter and tulip poplars rather larger.
Wynn was there at the invitation of an ornithologist named Linda Vasiliev, who has been mapping breeding territories in the tract for nine years. She wanted recordings to pair with her territory maps, to test which males held which corners by song alone.
He used the same setup on the mornings of the eleventh, twelfth, fourteenth, and fifteenth. The fifteenth was rained out by 05:30 and is included only as a counterexample.
The pewee always sang first. On three of the four mornings it was the same individual, a male holding the upper-edge territory Vasiliev had marked as T-3. The recordings put him within a metre of the same perch tree each morning.
The wood thrushes were next, in a roughly fixed order. The male in T-7, near the lower spring, came in second on all four mornings. The male in T-1 always came third, regardless of weather.
This is the part that interests the literature. The order of entry to the dawn chorus appears to be conservative across mornings, within a wood, even when light levels differ. The two leading hypotheses are that dominant males sing first to advertise survival, and that song order is partly determined by territory position relative to the prevailing light angle.
Wynn does not adjudicate. He brought equipment, not theories.
What the recordings make clear is the architecture of the chorus. The pewee occupies the lower frequencies, around 2.5 kilohertz. The wood thrushes are higher, around 3 kilohertz, with the fluted upper notes reaching 4.
A black-throated green warbler came in at 05:12 from the canopy, much higher in frequency, around 4.5 to 6 kilohertz. A red-eyed vireo started around 05:15 in the mid-canopy and continued, more or less without pause, for the next two hours.
The vireo is the metronome of the eastern wood in late spring. He sings, in some published counts, more than twenty thousand phrases in a single day. The Toftrees individual in T-4 produced 1,247 phrases in the first hour, by Wynn's count from the spectrograph.
By 05:30 the chorus was full. Scarlet tanager, eastern towhee, ovenbird, hooded warbler, blue-headed vireo, blue jay. The blue jay was the only species whose calls were not song proper, but the jay was nonetheless part of the soundscape.
By 06:15 the wood was quieter. The pewee still sang, slower now, with longer gaps. The thrushes had largely stopped. The vireo continued.
Wynn packed the equipment at 06:40. Vasiliev arrived with coffee in a steel thermos and they went over the morning's notes on the tailgate of her truck.
The thing she wanted to know was whether the recordings could be used to identify individuals across mornings without banding. The answer, from a first pass, is partly yes. Wood thrushes have measurable variation in the upper terminal note of their fluted phrase, and three of the seven recorded individuals showed consistent signatures across the four mornings.
The pewee did not. Wynn suspects this is a limitation of his recording position rather than the species. The pewee was further away and the signal was thinner.
For the citizen birder, the Toftrees mornings are a reminder of something simple. A dawn chorus is not a wall of sound. It is a series of entrances, in a near-fixed order, by individuals who are mostly the same individuals as the morning before.
If you sit in a wood every morning for a week, you will start to recognize them. Not as species. As particular birds, with particular perches and particular phrasings.
The recordings will be archived at the Macaulay Library at Cornell with Vasiliev's territory data. The Toftrees tract is unposted and walkable; the road is closed to vehicles in spring. Anyone can sit in it at 04:42 on a May morning and hear roughly what was heard then.
