Farming Until the Early 1900-S. Dense Thickets of Brush and Trees, And

PROPOS電D MAmGEM田脚 P轟ÅN FOR WÅD|NG B工RDS 工相聞蜘ORWÅ轟K 工室重なⅣDS - 1994

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曹。。nhan。。 th。 P。Pulati。nS 。f her。n! and 。gr。tS in th。 N。rWalk Islands by increasing the quantitY and quality of nesting habitat.

BÅCKGROUND AND HISroRY OF CH|MON |S轟AND AND 甲H電 HERON CO重ONY

Chimon 工Sland is Iocated approximately l.5 miles off the coast of Norwalk, Connecticut in Long Island Sound. 曹his 70 acre tract represents the largest in a chain of 16 islands that were formed about ll,000 YearS agO during the final retreat of the Wisconsinian Stage of glacial melting. 曹his retreat of ice left glacial deposits that formed Long エSland and the Norwalk 工Slands. As the ice sheet continued to melt and the sea level rose, the water inundated the depressions between the higher areas of glacial drift, Creating 轟Ong Island Sound.

冒he island was named for the Mohegan 工ndian Chief Mamachimon who WaS living there when the first settlers landed at the island in 1640. 冒he island was probably cleared and burned bY native Americans many times before the arrival of European settlers. 冒he earliest records of European discoverY Of the island is from the Onrustls ships ledger. 工n 1614, Dutch ExpIorer Adriaen BIock WrOte, l-Off the port bow appeared some islands with trees.'一 He drew 15 or 20 small dots on his chart and named them the Archipelagoes. 轟ater, aS∴∴COIonists∴Settled the Connecticut Shoreline, the Norwalk エSlands were cleared and used for agricultural purposes. 冒he primary use of Chimon Island remained farming until the early 1900-s.

In 1901, a luxury resort called Chimon on the Sound, WaS built on the north shore of the island with daily ferry∴SerVice to the main⊥and. Several small cottages and a large bath house were COnStruCted on the island and for several years the proJeCt WaS SuCCeSSful. By 1937 however, hard times had forced the is⊥and resort to cIose down and the abandoned structures were s0On Vandalized, burned or leveled. Soon, Without the constant attention of the grounds-keepers, the island became overgrown with dense thickets of brush and trees, and bY the late 1960-s, the is|and was totally abandoned by humans with the exception of the OCCaSional, Curious boater.

Presently, the Norwalk 工Slands∴Chain consists of four maJOr islands, Chimon, Sheffield, Shea and Cockenoe, nine smaller islands, and 20 ''rocks一一(Ellis, 1962〉. 工n response to chang|ng habitat and land use, the Norwalk Islands became attractive breeding∴grOunds for wading birds. At some point in time, the three largest islands in the chain? Chimon′ Shea (also knom as Ram) and Sheffield, have been the maJOr neSting site for the wading bird coIony. 冒he first record of wading bird nesting was∴∴at 玖

Sheffie|d 工Sland in 1961 (Bu|1 1964), COnSisting of 8 pairs of SnowY Egre七s and 20 pairs of Grea七Egrets・ According to Bul|, in 1962 the maJOritY Of the co|onY had relocated to Shea エS|and, apparen七|Y due to some human dis七urbance; the coIony consisted of 14 Great Egrets′ 10 SnowY Egrets′ 2 Yellow喜CrOWned Night Herons′ and l Louisianna Heron・工t wasn「t unti1 1968 that wading birds Were reCOrded nesting on chimon.工S|and (Dater 1978)・咄at Year′ 25 pa|rS Of SnowY Egrets′ 10 paユrS Of B|ack-CrOmed Night Herons, Six pairs of Great Egrets and one pair of IJittle B|ue Herons were recorded・ BY 1971′ the c0lonY On Chimon had increased dramatica||Y t0 350 Snowy Egrets′ 300 B|ack-CrOWned Night Herons′ 38 Great Egre七s′ 15 Green-backed Herons′ 10 Cat七le Egre七s, three Ye||ow- CrOWned Night Herons, three GIossY エbises (first connecticut nesting) and one Little B|ue Heron (Burg 1971).

The wading bird census was abandoned for the next six years.工n 1977′ When reinitiated′ the overall number of wading birds was Similar to the 1971 census a|though some species had increased and Others decreased during that tim? (Sibley 1983).工n 1981, the Connecticut Åudubon Society (CÅS) |nitiated a program of censusing, trapp|ng′ banding and co|or-dYing of JuVeni|e herons to monitor the, COIonY’s∴∴StatuS and its dispersal patterns (Erskine 1981). Dur|ng that Year′ 七he Chimon co|onY had increased dramatical|y and COntinued to increase through the 80Is (甲ab|e l).

TABL田l・ ADUIl題 POPU工Å甲工ONS (PA工RS) OF 胴S富工NG WADING BIRDS ON CH工MON 工S|]AND, NORWAエK - 1981-1987.

I81 -82 {83 ー84 185 -86 -87

BCNH 509 197 372 341 480 100 643

乎CNH 2 0 0 0 0 2 2

S田 217 105 213 231 200 80 194

G田 28 31 36 37 30 38 35

C日工7 0 15 21 8 10 9

G工 23 25 32 14 10 11 7

GBH 12 10 8 11 10 4 1

1BH 13 8 4 12 5 6 12

曹0甲A1 821 376 680 667 743 251 903

BCNH = B|ack-CrOWned night heron′ YCNH = YeユIow葛CrOWned night heron′ SE = SnowY egret′ G圏= Great egret′ CE = Cattle egret′ G工二GIossY ibis′ GBH = Green-backed heron′ LBH = Little b|ue heron エn addition to the wading birds, the eastern shore of the is|and has provided habitat for a maコOr neSting c0lony of herring and grea七 b|ack-backed gulls (Tab|e 2). A to七al of 125 species of birds have been recorded on the island, Of which approximate|y 40 breed there. Ma||ard and Canada g○○Se neS七ings have been documented on the island, and adjacent waters provide important Wintering habitat for a number of other wa七erfow| species inc|uding black duck and At|antic brant. Mammals include white-tai|ed deer, raccoon, S七riped skunk and norwaY rat, and two species of snakes have been observed. W○○dy trees and shrubs now comprise the maJOrity of the island-s |andscape′ but old fields, Salt marsh and Sand dunes∴Can also be found. Wi⊥dflowers are abundant in spring With as manY aS 65 species recorded.

曹ABLE 2. ADUL曹 POPULA冒工ONS (PA|RS) OF NESTING GU轟LS ON CH|MON 工SIAND, ⅣOR嶋AIK - 1981-1989.

i77 I80 183 i84 (86 189 192

GREA曹

BLACK-BACK田D 60 50 13 40 20 41 45

HERRエNG 1850 1500 1000 1000 1024 915 664

AU題HOR工冒Y ÅND MANAG田MENT

工n Sep七ember 1984,曹he Nature ConservancY (冒NC) purchased Chimon エS|and for $1.13 mi||ion and in March 1985,七ranSferred it to the U.S. Fish and Wi|dlife Service. Chimon エSland was the first |and unit secured as part of the Stewart B. McKinney National Wi|d|ife Refuge (NWR) with the purpose of preserving nes七ing habi七a七for the |argest co|onY Of wading birds in the State. A Special Use Permit is∴g|Ven tO the Ci七Y Of Norwalk each Year Which allows public use of the 3 acre beach located on the western shore of the is|and. In 1986, Stewart B. McKinneY∴NWR entered into a Cooperative Agreement with the CAS and the Connecticut Department of Environmen七al Protection (DEP) , Wi|dlife Division′ tO inventorY and monitor the gu||s, herons, egretS and ibises nesting on Chimon 工S|and. 甲hat agreement continued to permit the CÅS to conduct the wading bird inventorY they began in 1981. 甲his inventorY has provided the Refuge wi七h va|uable information about the species COmPOSition and estimated nesting pairs of the co|ony.

|n 1987′ the need for a p|anned, SYStematic approach to understanding the co|onY and the impact of na七ural and man induced stresses to the herons was recognized. So in October 1987, the Refuge emp|oYed the assistance of the Connecticut DEP, Rhode工S|and Depar七ment of Environmental Management,七he CÅS, Manomet Bird Observatory (Mass), and DesertエS|and Lab時aine) at a workshop and fie|d review to discuss management alternatives for the is|and and the heronrY. The resu|t was the deve|opment of a habitat management plan for the island which established the techniques and guide|ines to systematica||Y inventory the wading bird c0lonY, measure nesting habitat parame七ers and productivitY, and quan七ifiab|Y describe the vegetation on the island. The primarY goa| of the pro七ection p|an was to discourage and prevent disturbance of the nesting and wading birds during the nesting and br0Od rearing period (Apri| 1-August l).

工n 1988 and 1989, tWO SeaSOnal research assistants emp|oYed by the CAS imp|emented the p|an. エn 1988, habitat and productivi七Y da七a Were CO||ected on the nesting herons and a vegetation survey was COnduc七ed. エn addi七ion, inventories were done on o七her nesting bird co|onies in the Norwa|k 工Slands, a gull banding program was Carried out and is|and visitors were educated about the sensi七ivi七Y of the heron co|onY tO human disturbance and prevented from accessing the co|onY. The Chimon Island Report 葛- 1988 and its recormendations guided the study in 1989. An additiona| study was a|so undertaken in 1989 to determine the |ocations of critica| heron feeding sites in the area surrounding Chimon 工Sland, and due to the expansion of the heronrY tO nearbY GrassY 工S|and, an inventorY Of that island-s resources also became a priority. On|Y the inventorY POr七ion of the studY WaS COntinued from 1990 through 1993、 Refuge Staff conducted most of the data c01lection with assistance and overview bY CAS researchers.

CURREN題∴S田A曹US OF H田RON COLONY

As indicated in 題ables 2 and 3, the number of nesting herons and egrets has varied greatly from year-tO-Year・ At an October 1987 workshop for Chimon 工S|and′ Wading bird bio|ogists McCrirmon and Parsons indicated that |arge variances in nesting pairs is not uncormon.冒his maY demonstrate the birds- mobi|itY be七ween nes七ing c0lonies or a large percent of non-breeding birds in certain YearS. However, from 1990 through 1992, the co|onY On Chimon exhibited a sharp dec|ine and in 1993, nO Wading birds occupied the is|and.

As mentioned previous, a POrtion of the co|onY aPPeared to have shifted over to GrassY 工Sland, |ocated just east of Chimon. This co|onY increased in size from 1988 to 1992 (甲able 4).

曹ABLE 3. ADUI.T POPURA甲|ONS (PA|RS) OF∴NES冒工NG WAD工NG B|RDS ON CHエMON 工SLAND, NORWALK - 1988-1992.

ー88 -89 - 90 - 91 〇二〇♀圭

BCNH lO40 875 200 100 61

ycN櫨 1 3 1 0 0

S田 169 52 14 0 0

GE 30 87 28 25 57 ● ∴∴∴ゝ

CE 1 2 0 0 0

G工 8 1 2 0 0

GBH 3 2 3 0 0

IBH 8 3 0 0 0

題0曹A工 1260 1025 248 125 179

TABLE 4. ADUI.T POPULA曹1ONS (PA|RS) OF∴NES着工NG WAD|NG B|RDS ON GRASS平工S工AⅣD, ⅣORWA工K.

喧♀ ⊥皇呈二〇♀旦

BCNH 80 250 256

S丑 25 125 11

GE 1 1 29

C田 2 1 0

G工 14 1 0

GBH 1 1 0

IBH 2 3 3

賞0題A工 125 382 299

JUS甲|F|CA甲工ON FOR PROPOS田D MANAGEMEN冒

Based on past research efforts and general observations′ Refuge and CAS staff speculate that the movement of the co|onY maY be a resu|t of changes in the is|and-s vegetative structure and/or predation.

FU曹URE MANAG田MEN冒 PROPOSAL

甲herefore′ the Refuge proposes to contract a nuisance wi|d|ife ナシ

章ノ

COntrO| officer (NWCO) to systematica|1Y traP these islands during the fall and earlY Winter months. 甲he number and species of each animal caught will be recorded and a|| p〇七ential predators wi|| be dispatched and disposed of by the NWCO. Non鵜target SPeCies CaPtured wi|l be re|eased on the is|and unharmed.