Chapter 3 - Results Part 1

During the three years of the study, 1996-1998, our volunteer observers exhibited a extremely high level of dedication in surveying their assigned transects (Figure 1). A total of 8,640 point count circles could been surveyed during the three years: 8,467 were actually surveyed, or 98 percent.

Figure 1: 1996, 1997, and 1998 Count Circle Coverage
Possible 720 circles/state 4 state total
(1996) = 2794/2880; (1997) = 2824/2880; (1998) = 2849/2880

The total of all individual birds counted (in count circles, flyovers, and outside) during the 3 years, within the four sub-watersheds, totaled 102,259. Based on the south-north patterns the count numbers demonstrate, spring migrants using the Eastern Flyway reach the mouth of the CRV in larger numbers, then disperse throughout the valley and beyond as they continue north (Figure 2).

Figure 2: Individual Birds, State Totals 1996, 1997, and 1998
Total Birds (I + O + F) 1996-98 = 102,259

For the 60,000 individual birds observed within the point count circles or flyovers, a similar pattern emerged. For this group, 36 percent (21,600) were found in Connecticut’s Farmington River watershed, followed by 26 percent (15,600) in Massachusetts’ Deerfield River watershed. Moving north into New Hampshire and Vermont, 19 percent (11,400) of the birds were observed in each of these states.

A similar south-north pattern was observed in the number of bird species migrating within the Connecticut River Watershed (Figure 3).

Figure 3: Total Number of Species (I + F) by State: 1996, 1997, and 1998

The number of species varied from a high of 113 (Connecticut) to a low of 84 (Vermont). The highest number of species in any given year always occurred at the southern end of the system, in Connecticut. The fewest number of species always ocured in the most northern study area, the White River watershed of Vermont. A complete 3-year species list is provided at the end of this section, as Appendix A.

Inter-year species turnover rate (modified after Diamond 1969, Diamond and May 1977) was calculated to examine the relative stability of the group of species that migrate through the Connecticut River Watershed in spring (Figures 4 and 5, for method of calculating turnover rate, see Appendix B, below).

Figure 4: Species Turnover: 1996-97
Change in Number of Species: 0%
Percent Turnover: 5.8%

Figure 5: Species Turnover, 1997-98
Change in Number of Species: -5.07%
Percent Turnover: 5.58%

For the two turnover calculations (1996-1997 and 1997-1998) only 5.58 percent and 5.80 percent, respectively, of the species turned over. In regard to total number of species, 1996 and 1997 has the same number of species (n=138). Between 1997(n=138) and 1998 (n=131), 1998 had 7 (5 percent) fewers species. These statistic indicate a relatively stable species composition of spring migrants during this 3- year period. A number of the species that appeared in one year and disappeared in the next were typically the rarer species like Merlin, Orange-crowned Warbler, and Bicknell’s Thrush. These species are in contrast to the species that were consistently the most abundant, and present in all 3 survey years, and included the Veery, Red-eyed Vireo, Chestnut-sided Warbler, Black-throated Blue Warbler, Yellow-rumped Warbler, Black-and-white Warbler, American Redstart, and Ovenbird.

The efforts of the volunteer surveyors produced a most dramatic finding in regard to the central question of the study, "What areas of the Connecticut River watershed are migrants using during spring migration?" Of the 60,000 birds surveyed within the count circle or flying over the count circle, 47 percent used the “A” sites, or those along the main stem of the Connecticut River (Figure 6). This pattern of habitat use was seen on all sample dates. (Figure 7).

Figure 6: Habitat Use by Percent of Total Birds, 1996-98

Figure 7: All Species, Mean Birds per Hectare by Habitat and Period

The south to north pattern continued in regard to stopover habitat use, where Connecticut "A" sites experienced the highest density of migrant use (Figure 8).

Figure 8: All Species, Mean Birds per Hectare by State and Habitat

The same north to south pattern was seen annually, in regard to "A" site use (Figures 9 and 10). The highest percentage of “A” site usage was in Connecticut (3-year average, 56%), followed by Massachusetts (42%). Migrant use of riverside “A” sites in New Hampshire and Vermont was about equal, at 38 percent and 39 percent, respectively(3-year averages). In contrast to "A" site usage, the farther north migrants traveled, the greater use they made of "B" sites (3-year average "B" site usage: Connecticut (25%), Massachusetts (26%), New Hampshire (37%), Vermont (35%). The use of upland "C" sites was also higher in the north when Connecticut (3-year average, 19%) is compared to New Hampshire (3-year average, 27%) and Vermont (3-year average, 28%). Massachusetts (3-year average, 33%) does not follow this pattern and exceeds the "C" site usage found in the other three sub-watersheds.

Figure 9: Habitat Use by Percent of Total Birds, 1996-98
Connecticut and Massachusetts

Figure 10: Habitat Use by Percent of Total Birds, 1996-98
New Hampshire and Vermont


Diamond, J.M. 1969. Avifaunal Equilibrium and Species Turnover Rates on the Channel Islands of California. Proceedings of the National Academy of Sciences, 64: 57-63.

Diamond, J.M. and R.M. May. 1977. Species Turnover Rates on Islands: Dependence on Cenus Interval. Science 197: 266-270.



Ring-necked Pheasant Phasianus colchicus
Ruffed Grouse Bonasa umbellus
Wild Turkey Meleagris gallopavo
Northern Bobwhite Colinus virginianus
Turkey Vulture Cathartes aura
Osprey Pandion haliaetus
Bald Eagle Haliaeetus leucocephalus
Northern Harrier Circus cyaneus
Sharp-shinned Hawk Accipiter striatus
Cooper's Hawk Accipiter cooperii
Northern Goshawk Accipiter gentilis
Red-shouldered Hawk Buteo lineatus
Broad-winged Hawk Buteo platypterus
Red-tailed Hawk Buteo jamaicensis
American Kestrel Falco sparverius
Merlin Falco columbarius
American Woodcock Scolopax minor
Rock Pigeon Columba livia
Mourning Dove Zenaida macroura
Black-billed Cuckoo Coccyzus erythropthalmus
Yellow-billed Cuckoo Coccyzus americanus
Great Horned Owl Bubo virginianus
Barred Owl Strix varia
Northern Saw-whet Owl Aegolius acadicus
Common Nighthawk Chordeiles minor
Chimney Swift Chaetura pelagica
Ruby-throated Hummingbird Archilochus colubris
Belted Kingfisher Ceryle alcyon
Red-bellied Woodpecker Melanerpes carolinus
Yellow-bellied Sapsucker Sphyrapicus varius
Downy Woodpecker Picoides pubescens
Hairy Woodpecker Picoides villosus
Northern Flicker Colaptes auratus
Pileated Woodpecker Dryocopus pileatus
Olive-sided Flycatcher Contopus borealis
Eastern Wood-Pewee Contopus virens
Yellow-bellied Flycatcher Empidonax flaviventris
Acadian Flycatcher Empidonax virescens
Alder Flycatcher Empidonax alnorum
Willow Flycatcher Empidonax traillii
Least Flycatcher Empidonax minimus
Eastern Phoebe Sayornis phoebe
Great Crested Flycatcher Myiarchus crinitus
Eastern Kingbird Tyrannus tyrannus
White-eyed Vireo Vireo griseus
Yellow-throated Vireo Vireo flavifrons
Blue-headed Vireo Vireo solitarius
Warbling Vireo Vireo gilvus
Philadelphia Vireo Vireo philadelphicus
Red-eyed Vireo Vireo olivaceus
Blue Jay Cyanocitta cristata
American Crow Corvus brachyrhynchos
Fish Crow Corvus ossifragus
Common Raven Corvus corax
Purple Martin Progne subis
Tree Swallow Tachycineta bicolor
Northern Rough-winged Swallow Stelgidopteryx serripennis
Bank Swallow Riparia riparia
Barn Swallow Hirundo rustica
Black-capped Chickadee Poecile atricapillus
Tufted Titmouse Baeolophus bicolor
Red-breasted Nuthatch Sitta canadensis
White-breasted Nuthatch Sitta carolinensis
Brown Creeper Certhia americana
Carolina Wren Thryothorus ludovicianus
House Wren Troglodytes aedon
Winter Wren Troglodytes troglodytes
Golden-crowned Kinglet Regulus satrapa
Ruby-crowned Kinglet Regulus calendula
Blue-gray Gnatcatcher Polioptila caerulea
Eastern Bluebird Sialia sialis
Veery Catharus fuscescens
Gray-cheeked Thrush Catharus minimus
Bicknell's Thrush Catharus bicknelli
Swainson's Thrush Catharus ustulatus
Hermit Thrush Catharus guttatus
Wood Thrush Hylocichla mustelina
American Robin Turdus migratorius
Gray Catbird Dumetella carolinensis
Northern Mockingbird Mimus polyglottos
Brown Thrasher Toxostoma rufum
European Starling Sturnus vulgaris
American Pipit Anthus rubescens
Cedar Waxwing Bombycilla cedrorum
Blue-winged Warbler Vermivora pinus
Golden-winged Warbler Vermivora chrysoptera
Tennessee Warbler Vermivora peregrina
Orange-crowned Warbler Vermivora celata
Nashville Warbler Vermivora ruficapilla
Northern Parula Parula americana
Yellow Warbler Dendroica petechia
Chestnut-sided Warbler Dendroica pensylvanica
Magnolia Warbler Dendroica magnolia
Cape May Warbler Dendroica tigrina
Black-throated Blue Warbler Dendroica caerulescens
Yellow-rumped Warbler Dendroica coronata
Black-throated Green Warbler Dendroica virens
Blackburnian Warbler Dendroica fusca
Pine Warbler Dendroica pinus
Prairie Warbler Dendroica discolor
Palm Warbler Dendroica palmarum
Bay-breasted Warbler Dendroica castanea
Blackpoll Warbler Dendroica striata
Cerulean Warbler Dendroica cerulea
Black-and-white Warbler Mniotilta varia
American Redstart Setophaga ruticilla
Worm-eating Warbler Helmitheros vermivorum
Ovenbird Seiurus aurocapilla
Northern Waterthrush Seiurus noveboracensis
Louisiana Waterthrush Seiurus motacilla
Kentucky Warbler Oporornis formosus
Mourning Warbler Oporornis philadelphia
Common Yellowthroat Geothlypis trichas
Hooded Warbler Wilsonia citrina
Wilson's Warbler Wilsonia pusilla
Canada Warbler Wilsonia canadensis
Scarlet Tanager Piranga olivacea
Eastern Towhee Pipilo erythrophthalmus
American Tree Sparrow Spizella arborea
Chipping Sparrow Spizella passerina
Field Sparrow Spizella pusilla
Savannah Sparrow Passerculus sandwichensis
Fox Sparrow Passerella iliaca
Song Sparrow Melospiza melodia
Lincoln's Sparrow Melospiza lincolnii
Swamp Sparrow Melospiza georgiana
White-throated Sparrow Zonotrichia albicollis
White-crowned Sparrow Zonotrichia leucophrys
Dark-eyed Junco Junco hyemalis
Northern Cardinal Cardinalis cardinalis
Rose-breasted Grosbeak Pheucticus ludovicianus
Indigo Bunting Passerina cyanea
Bobolink Dolichonyx oryzivorus
Red-winged Blackbird Agelaius phoeniceus
Eastern Meadowlark Sturnella magna
Rusty Blackbird Euphagus carolinus
Common Grackle Quiscalus quiscula
Brown-headed Cowbird Molothrus ater
Orchard Oriole Icterus spurius
Baltimore Oriole Icterus galbula
Purple Finch Carpodacus purpureus
House Finch Carpodacus mexicanus
Red Crossbill Loxia curvirostra
White-winged Crossbill Loxia leucoptera
Common Redpoll Carduelis flammea
Pine Siskin Carduelis pinus
American Goldfinch Carduelis tristis
Evening Grosbeak Coccothraustes vespertinus
House Sparrow Passer domesticus

APPENDIX B--- TURNOVER RATE: Percent turnover rate between the the survey years, 1996-1997 and 1997-1998) was calculated with the equation: 100 (E + H)/C + D, where E is the number of species that occured in the earlier season but not the next, H is the number of new species that were not present in the earlier season but were present in the next season, C is the total number of species in the first season, and D is the number of species in the following season.

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