Sixth in the Fuertes print series

Theoriginal painting was published as the color frontispiece of -Lore,Vol. XVII, NumberOne, January-February 1915. The text that accompaniedit was entitled "The Migrationof NorthAmerican Sparrows, 32rid paper" and was compiled by W.W. Cooke,chiefly from datafrom the Biological Survey. Unlike earlier texts that accompanied the Fuertes paintings for Bird-Lore,there were no plumage descrip- tions.The followingis an abridged version of theCooke text, with modern nomenclature added in brackets.The print facing was reproduced directlyfrom the originalpainting, which until recentlywas in the possessionof theNational Audubon Society.

The main range of the Rocky Mountains, from southern to The principal breedingjunco of New Mexico and Arizona is northern Mexico, is occupiedin summerby four forms of jun- the Red-backedJunco, [not shown]which occupies the higher co The Pink-sided [now considereda race of the Dark-eyed slopesof the mountainsof northern Arizona and most of the Junco, Juncohyemalis mearns•] is the mostnorthern, breeding mountainsof NewMexico, except the extremenorthern part from southernSaskatchewan through central Montana to nor- anda smallsection of thesouthwestern part of thestate. [This thern Wyoming and southern Idaho. juncois for the presentconsidered a race of theGray-headed Just to the south of its range comesthe Gray-headedJunco Junco,with the nameJ. canicepsdorsalis]. [still considereda full species,Junco caniceps],which is the TheArizona Junco is foundprincipally in northernMexico, commonest summer bird of the central Rocky Mountain but a few nest in the mountains of southern Arizona and region and is particularly abundant in the mountains of Col- southwesternNew Mexico. [This form is currently regarded as orado, where at 8-9000 feet, it nestsin dooryardsand about a raceof theYellow-eyed Junco, Junco phaeonotus palliatus] porches . . . It breeds from southern Wyoming to northern Baird'sJunco is a non-migratoryspecies, inhabiting the New Mexico and west in Utah and Nevada. [It is possiblethat mountainsof the southernend of Lower(Baja) California [It the J. caniceps group may be merged as two additional is now considereda race of Yellow-eyedJunco, J.p. bairdt]. subspeciesof the Dark-eyed Junco, for where rangesmeet, J. GuadalupeJunco. This speciesis known only from canicepsunquestionably interbreeds with J. hyemalisthurberi GuadalupeIsland, off the coastof Lower(Baja) California and J. hyemalis mearnsi; but a problem existsas to assortative [It is now considereda race of Dark-eyedJunco, J h mating]. insularis].

The assistanceof EugeneEisenmann in updatingthe taxomonyof this group is acknowledged.

Key to painting 1 Gray-headed Junco 2 (Arizona) Yellow-eyedJunco 3 (Pink-sided) Dark-eyed Junco 4 (Guadalupe) Dark-eyed Junco 5 (Baird's or Cape) Yellow-eyedJunco

726 American , September1980

Decline and disappearance of the Dusky from Merritt Island, Florida

One last chance to save a small, unobtrusive, critically endangered Florida endemic Paul W. Sykes, Jr.

HE USKY SEASIDESPARROW, (1928), and extensivecollecting of speci- dian River, Banana Creek, and Banana ,4mmospiza maritima nigrescens, mensand clutchesof eggs.Trost (1964, River. Except where otherwise noted, (Figs. 1 and 10) was first discoveredby 1968, pets. comm.) was the first to ac- reference to Merritt Island refers to Charles J. Maynard near Salt Lake on tually conducta study of this sparrow, North Merritt Island, which is separated the St. Johns River west of Titusville, concentrating his work mainly on the from Merritt Island to the south by Brevard County, Florida, on March 17, Canaveral Peninsula from 1961 to 1963. Banana Creek and contains the remain- 1872 (Maynard 1875, 1881). Later that The limited range, alternation and de- ing habitat for the Dusky SeasideSpar- spring, Maynard found the sparrow to struction of its habitat for row. be quite common in the salt marsh on control and other purposes,and its de- Between 1958 and 1962 the National the Canaveral Peninsula in what is now clining population led the U.S. Fish & Aeronautics and Space Administration the Merritt Island National Wildlife Ref- Wildlife Service to declare the Dusky (NASA) acquired all of North Merritt uge (hereafter, N.W.R.) on the John F. Seaside Sparrow endangered in 1966 Island as well as most of Merritt Island Kennedy Space Center. The first Dusky (Committee on Rare and Endangered north of Cocoa and established the John nestswere found 42 years later when Os- Wildlife Species1966). Following this, F. Kennedy Space Center. An agreement car E. Baynard and Henry Simpson lo- Sharp (1968, 1970) made an extensive between the U.S. Fish and Wildlife Ser- cated three on the peninsula along the study of the sparrow's status and distri- vice and NASA on August 28, 1963, edge of Indian River on May 21, 1914 bution on the Merritt Island N.W.R. established the Merritt Island National (Baynard 1914). The sparrow was abun- and on the St. Johns River from March Wildlife Refure on NASA-owned land dant in the marsh on the east of the In- to July 1968. From 1972 through 1978, The refuge is administered by the Fish dian River until the 1950s (Maynard Baker (1973, 1978) made surveyson the and Wildlife Service and includes all 1881, chapman 1899, Baynard 1914, St. Johns and experimentedwith fire as Kennedy SpaceCenter lands not directly Vars 1926, Howell 1932, Sprunt 1954). a management tool. All these studies used for spaceprogram purposes.These By the early 1960s, the sparrow had dis- were primarily surveys, some incorpo- lands encompass all of the sparrow's appeared from much of its former range rating vegetative analysis. Little is habitat on Merritt Island. and a decline occurred in an area under known of this subspecies'biology. In 1969 the Fish and Wildlife Service study on Merritt Island (Trost 1964, I monitored the population status of entered into a cooperative agreement 1968). the Dusky SeasideSparrow on the Mer- with the Brevard Mosquito Control Dis- The Dusky SeasideSparrow, relegated ritt Island N.W.R. on the North Merritt trict that allows the district to manage to subspecific rank in 1973 (A.O.U. Island from the spring of 1969 through water levels in the three impoundments Check-list Committee 1973), has, as far the spring of 1976. The present paper under my study. The District con- as we know, always been restricted to presentsthe general history and habitat structed the dike system and still con- northern Brevard Country. It was once of the sparrow on the Canaveral Penin- trols the water levels in the impound- present on the east side of the St. Johns sula, the resultsof this study, and man- ments on the refuge for mosquito con- River in the vicinity of Salt Lake south agement recommendations. trol purposes. A subdike was construct- to Persimmon Hammock, and on the ed along a NW-SE axis acrossthe center AREA AND MEIHODS Canaveral Peninsula (North Merritt of impoundmentT-10-K (see Fig. 2D) Island) from Haulover Canal south to HE ENLARGEDPORTION of the so that the east half could continue to be Banana Creek and east to the north end Canaveral Peninsula on the east flooded for mosquito control. The outer of the Banana River (Chapman 1899, shore of Indian River and opposite dike on the west half was breached at the Howell 1932, Trost 1968). Titusville, here referred to as North head of Black Point Creek to allow the Before 1961, little work had been Merritt Island (Fig. 2), consistsmostly drainage of rainfall into the creek and done on the sparrow other than some of upland habitats with bordering permit the inflow and outflow of tidal minor habitat studies by Nicholson marshes along Mosquito Lagoon, In- waters. Thus, T-10-K was to be flooded

728 AmericanBirds, Sepiember 1980 only by natural means and T-10-J re- tern of alternate flushing of the marsh follow-up researchthrough the springof mained flooded for mosquito control. wi•h fresh and salt waters. Heavy flood- 1979. The census method chosen was the Impoundment T-24-C was drained from ing with salt water occurredonly during singing-male count, but non-singing February through August and flooded storms, as a result of wind tides, and birds were also censused. This method from September through January. The during the high springand fall tides. On- and its limitations are discussedby subdike in T-10-K was completely ly the outer edgeof the marsh was flood- Sharp (1970). The study areas were the removed in December 1972, eliminating ed frequently.There was no floodingof southern third (77 ha) of T-10-J, west continuous flooding in the east and west the marsh on a daily basis as occurs in half (116 ha) of T-10-K, and the east half half of the outer dike along Black Point the low-type ( alterniflora) (41 ha) of T-24-C (see Fig. 3B for loca- Creek and Indian River was removed in marsh. The tidal fluctuation was rather tions of impoundments). I established 1978 to allow more natural movement of small; over a month, it normally ranged transectsto givecomplete coverage of all water in the marsh. about 0.3m (Trost 1964) but higher with sparrow habitat remaining in these The original high-type (relatively dry) wind and storm tides. areas.I plottedthe locationof eachsing- salt marsh on Merritt Island extended ing male during eachcensus and usually from the shore of Indian River eastward ROM1969 TO 1976I monitored censused between 6:50 a.m. and 9:45 to the upland habitats. The width of this the Dusky SeasideSparrow popula- a.m. to take advantageof the most ac- marsh ranged from 0.8 to 4 km and ex- tion in the three areas in which it remain- tive period of singing.Twenty-nine cen- tended unbroken except for numerous ed on Merritt Island N.W.R., with some susestotaling 80 hours ([ = 10/yr) were short tidal creeks and small ponds from Dummit Creek south to the west end of Banana Creek (Fig. 2A). This con- tiguous marsh community contained about 3076 ha. Much smaller and dis- continuous marsheswere scatteredalong Banana Creek and at the north end of Banana River. The main marsh con- t sisted of dense stands of glasswort (Salicornia bigelovii, S. virginica), pic- kleweed (Batis maritima), and salt marsh grass(DistichIts spicata) along the shore. It extended inland and mixed with exten- sive stands of salt marsh bunch grass (Spartina bakerit) and scattered stands of black needle rush (Juncus roemeria- nus) on the slightly higher elevations. Small stands of sea-ox-eye (Borrichia frutescens) and groundsel (Baccharis halimifolia) were scattered on elevation knolls in the marsh. Small black mangroves (Avicennia germinans) were also found widely spaced in places in the marsh (Baynard 1914, Nicholosn 1928, Trost 1964, 1968, Baker 1978). There is no detailed description of this large salt marsh community before extensivealter- ation by man. However, published pho- tographs (Baynard 1914, Nicholson 1928) give a general idea of the appear- ance of the original marsh. Under natural conditions the marsh was intermittently flooded by rains and fresh water sheet-flow from the uplands and periodic innundation by salt water from the Indian River, producing a pat-

Adult male on terri- tory, Impoundment T-24-C, Merritt Island IV. W.R., Brevard County, Florida, May 29, 1971.

Volume 34, Number 5 729 Oz

730 American Birds, September1980 conducted on the transects from mid- immediate vicinity of the Indian River The Dusky Seaside Sparrow is not April to mid-July 1969 through 1976 (• and tidal creeks for nesting and feeding. sedentary and will move relatively long = 3.6/yr). I discontinuedcensusing in By 1968 (Fig. 2C) the sparrow's range distances, although Trost (1968) stated T-24-C after 1972 because the sparrows on Merritt lsland had been reduced for that of the birds he banded, none were had disappeared from that area. I cap- the most part to T-10-K (14 singing found away from the vicinity in which it tured sparrowsin mist nets and banded males), T-10-J (7 males), T-24-C (8 was marked. Six of the individuals them with unique color combinationsin males), and 4-5 birds divided among (46%) I banded were seen in T-10-J in September1970 and 1972 to determine T-10-G, T-10q. and T-24-C (Sharp 1971, 1972, and 1974, a distance of 1.2 movements,age, and longevity. Sex was 1968, 1970). The distribution in 1972 km from the banding site in T-10-K. determined on the basis of behavior on (Fig. 3D) was confined to a small part of Two of these birds were later found in territory and age by checkingthe extent southern T-10-J (4 singing males) and T-10-K. Between May 16 and July 14, of the skull ossification; birds with fully the west-central sector of T-10-K (7 1972, a banded male was seen in both ossified skulls were considered adult, males). The range decreasedonly slightly T-10-J and T-10-K, at points about 1.6 and those with unossified skulls, imma- in T-10-J and T-10-K after 1972 and up km apart, straight line distance. Based ture. to the time the sparrowwas last recorded on observations of marked individuals, on Merritt Island in 1977. movement between the two impound- RESULTS AND DISCUSSION ments appeared to take place on a some- Distribution on Merritt Island Longevity and Movements what regular basis, although the exact frequency was not determined. Baker HEHISTORIC RANGE of theDusky HIRTEENSPARROWS were color (1978) reported that some of his marked Seaside Sparrow on Merritt Island banded in T-10-K, six in 1979, and birds moved up to 1.6 km from the before alteration of the salt marsh, ex- seven in 1972. Of these, eight were banding locality on the St. Johns River. cept for the road from Titusville to the adults and five were iramatures. Sex was Thus, there appears to be some regular beach, is shown in Fig. 2A (Maynard determined for seven individuals, four but poorly understood long-range move- 1881, Chapman 1.899, Nicholson 1928, males and three females. ment within and between aggregations Howell 1932, Trost 1968). Banana Creek Insufficient data exist to generate a (see Post [1974] for discussionof group- and Banana River populations were less life table for A.m. nigrescens.However, ing as related to SeasideSparrows). Such precisely known than that along Indian a color-marked adult male banded in movement may be related to water River. The marsh on the creek and the May 1972 on the St. Johns (Baker 1978) levels, rainfall, preferred feeding sites, north end of Banana River was frag- was observed in the spring of 1979 or perhaps a search for more suitable mented, resulting in a discontinuousdis- (Willard Leenhouts and Beau Sauselein, habitat. tribution of the sparrow. Other than its pers. comm.) making it 8+ years old general location, little is known of the and an adult female banded on Septem- What would be considered dispersal isolated population on the south shore ber 2, 1970 on Merritt lsland was seen has been recorded only twice, both dur- of Mosquito Lagoon. there on June 14, 1974, making it at least ing the non-breedingseason. Individuals Sharp (1970) and Trost (pets. comm.) 4.8 years old. These two birds consti- were found on Merritt Island 8 and 32 indicated that in 1961-1963 the birds tuted the oldest known individuals of km from the nearest known breeding (Fig. 2B) were concentrated in four this subspecies.The Northern Seaside areas in 1962 (Trost 1968). widely spaced aggregations centered Sparrow (A.m. maritima) has been around major tidal creeks. Trost (1968 found to live for at least 9 years(William and pers. comm.) found the birds using Post and Jon Greenlaw, pers. comm.). The Population Decline the narrow tidal zone along the creeks for feeding. The birds were often ob- served flying 180 m or more to reach these feeding areas. The recently-com- pleted dike system was in place and the impoundments were flooded at the time of Trost's (1964, 1968) study. Trost banded sparrows in the T-10-E part of his study area. The condition of that im- poundment as it appearsin 1979 (Fig. 3), has drastically changed since the 1961-1963 period. Following completion of the impoundments, the narrow relict natural marsh along the creeks probably offered the best, if not the only areas, where the birds were able to forage in their usual manner for long periods especially when the main marsh was deeply flooded. Baynard (1914), Nichol- Fig. 3. The northend of impoundmentT-10-E as it appearedJune 1979. In 1961-1963,Charles son (1928), and Trost (1968) stress the H. Trost {pets. comm.) bandedDusky SeasideSparrows in this area, at which time it was still importance of the pristine marsh in the salt marsh, although deteriorating rapidly.

Volume34, Number 5 731 28 28 [] Males ] Females 261• 26 24 24

22 • 22

20 20

18 18 76

14 1 4

C69 70. 71e 72I 73! 74ß 75e 761 77! 78! 79I 0{6•'• 7'•• 71a 72 • 73g 74 g 75 176 I 77178 179 ' Year Year Fig 4. Countsof singingmales on transectson Merritt Island, Fig. 5. Comparisonof bothsexes recorded during singing male cen- 1969-1979. suseson Merritt Island, 1969-1979. Number above each bar is the per- cent total for both sexesobserved per year.

mate of the original population, this next several years (Sykes unpubl.), but theHE DuskyRELATIVE SeasideABUNDANCESparrow on Mer-of would leave about 600 pairs or 600 sing- the sparrowscontinued to decline(F•gs ritt Island could be assessed at least into ing males. Trost found about 70 pairs 4 and 5). In 1969, I locatedonly 30 s•ng- the 1950s (Maynard 1881, Chapman during 1961-1963(Sharp 1970). An indi- ing males and by the following year the 1899, Baynard 1914, Vats 1926, Nichol- cation of the rapid deterioration of the number had decreased to 18, a loss of son 1928, Howell, 1932, Pettingill 1951, sparrow's habitat taking place under 40%. The downward trend continued Sprunt 1954). For example,on a collect- flooding was providedby Trost (1964) in No sparrows were found in T-24-C after •ng trip in May 1914, Baynard (1914) his study areas(T-10-D and T-10-E). At 1971; by 1973, only two males and an mentioned seeinga minimum of 20 birds that time flooding of the marsh was rela- undetermined number of females re- perched at one time within a small area. tively recent. Trost estimated that 35 mained. The two males apparentlyhved Nmholson (1928) found birds singing pairs were in T-10-D and T-10-E (which out their life span and were last seen •n around him in all directions in June 1926 were one impoundment until the rail- 1977, one in T-10-J and the other •n and located 14 active nests in one day. road causeway built in 1963 divided T-10-K (James Baker and Beau Sharp (1970), quoting Charles E. Carter, them into two cells) at the start of his Sauselein, pets. comm.). A census •n a friend of Nicholson, stated that the lat- study; by the end there were only two 1978 by Baker and Sauselein (pers ter would often find up to 30 of the spar- pairs remaining. Sharp (1970) could ac- comm.) and another in 1979 by rows' nests in the course of a day. Un- count for only 33-34 males in 1968, a de- Sauselein and Sykes revealed no spar- fortunately, no population estimates crease of roughly 50ø70in 5 years, and rows present. were made when the birds were plenti- four or five of the males did not appear When singing males were being cen- ful Sharp(1970) estimated {hat the to have mates. Obviously the sparrow sused, females were also recorded but no original population on Merritt Island population was undergoing a continuous concerted effort was made to locate all may have approached2000 pairs if all decline. the females that might be present. The sintable habitat were occupied;if the sex In 1969, the water level was lowered in number of birds identified as females •s rat•o was about equal, and if the densi- impoundmentsT-24-C and T-10-K in an givenin Fig. 5. The last female(sexed by ues were similar to several aggregations effort to rejuvenate the remaining stress- behavior) was seen on Merritt Island •n he found on the St. Johns River in 1968. ed salt-marshvegetation and to re-estab- 1976, and the last evidence of successful By 1957, the sparrowpopulation had lish it by natural means where it had nesting (young of the year seen away decreased on Merritt Island by 70ø7o disappearedas a result of flooding. The. from the nest) in T-24-C was in 1969, •n (Trost 1968). If one usesSharp's esti- vegetation slowly responded over the T-10-J in 1974, and in T-10-K in 1975

732 American Btrds, September1980 Human Impact on the Marsh continued during the mosquito breeding began as each cell was closed. Present season from 1973 to 1979. T-24-C was water levels in the impoundments are the reflooded startingin ! 972 after the spar- resultsof rains, storm tides, or pumping. tionHE toFIRST the marshPERMANENT on Merrittaltera- Island rows had disappeared. With the completion of the dike system, was the constructionin the late 1920sof The harmful effects of insecticides on almost 100% of the sparrow's habitat on what is now State Road (S.R.) 402 from birds is well known (Hickey 1961, Hick- Merritt Island, including that along Titusville to the ocean beach. The road, ey and Anderson 1968, Stickel, L. 1973, Banana Creek and the upper part of unpaveduntil 1942,crossed the marsh Dustman and Stickel 1969, Heath et al. Banana River, was impounded. Only between Puckett and Gator Creeks and 1970, Ohlendorf et al. 1974, Stickel, W. small narrow strips of the original marsh had little effect on the sparrow habitat 1975). Hickey (1961) revealedthe serious were left in places between the dike and exceptfor that lostto thehighway corri- problemsposed by the useof insecticides the open water of the river to protect the dor and the slightinterruption of drain- in the habitats of birds with limited dis- dike system from wave action, but were age in its vicinity. tribution. Donald J. Nicholson estimat- too small to support the sparrows. Since the first settling in Brevard ed that by 1957 the sparrow population A railroad causeway was constructed County, man has beenbothered by bit- had been reduced on Merritt Island by at across the marsh north of Roach Hole in ing insectsduring the warmer months, least 70% and attributed this reduction 1963 (Trost 1964) further subdividing particularlysalt-marsh (pri- to the aerial spraying of insecticides. the wetland and forming impoundments marilyAedes taeniorhynchus and A. sol- (Trost 1968). The Dusky Seaside Spar- T-10-D, T-10-E, T-10-F, and T-10-G. licitans). Attempts to control these in- row has probably been affected by ap- The dependenceof the Dusky Seaside sects were not successful until the 1940s. plicationsof various insecticideson Mer- Sparrow upon a high salt marsh (Figs. 6 Treatment for control of adult and lar- ritt Island over the last 30 years, and 7) with its aforementioned plant as- val mosquitosin the marshon Merritt although the precisenature of the effect sociations and their associated fauna is Island was initiated in 1946 by the (Le., direct or indirect poisioning, vari- well recognized (Baynard 1914, Nichol- Brevard Mosquito Control District. ous physiological problems, reproduc- son 1918, Trost 1964, 1968, Sharp 1970, Infrequent aerial sprayingof 0.2 kg/ha tive failure, reduction of food supply, or Baker 1973, 1978, Baker and Kale 1978). of DDT in a Number 2 diesel fuel carrier other factors) is not known. Those plant speciescan tolerate flooding was carried out from June through Oc- The impounding and flooding of salt for only a relatively short period. Histor- tober to alleviate the mosquito problem marshes has been demonstrated to be a ically, S. bakerii appears to be more in Titusville and adjoining communities. highly effective mosquito control tech- common on the St. Johns River, where it The frequencyof applicationwas in- nique (Provost 1959). Low dikes, that is the dominant species,than on Merritt creased in 1947 and its use was contin- were open at the creeks, were construct- Island with its heterogeneousvegetation. ued through 1951, after which its use ed along the shore of Indian River dur- The impounding and flooding of the was greatlyreduced because the mosqui- ing 1955-1958. The building of higher, marsh on Merritt Island primarily with tos had become resistantto it (Deonier et permanent dikes that completely en- fresh water, has now eliminated approx- aL 1950). In 1951,the districtstarted us- closed the salt marshes on Merritt Island imately 91% of the sparrow's former ing benzenehexachloride(BHC) mixed began in 1959 and was completed in habitat in that area. Only impoundment with dieselfuel and experimentedwith a December 1962. Flooding with rainwater T-10-K and a very small area in the number of other chemicals, including dieldrin, through 1957. The use of malathion to control adult mosquitos was begunin 1956 and discontinuedin 1962. No larviciding was done during this period. Chemical treatment for adult mosquitoson Merritt Island was terminated in 1962 when the marsh im- poundmentswere completed.There was essentially no chemical treatment for mosquito larvae in the impoundments until 1969, when water levels were lowered in 3 impoundments (T-10-J, T-10-K, T-24-C) in connectionwith the Dusky SeasideSparrow habitat manage- ment programand study. Periodictreat- ment for mosquitolarvae from 1969 to 1972 in theseimpoundments consisted of various aerial applicationsof (1) flit (a petroleumderivative) at 56 !/ha; (2) paris green (5%) at 0.7 kg/ha with a granularvermiculite carrier; and (3) 187 Fig. 6. High salt marshin impoundmentT-10-K, Merritt IslandN.W.R., as it appearedin 1979 liters of diesel fuel/ha. Periodic aerial after marshresloration. The taller vegetationis Spartinabakerii intermixedwith standsof treatment with chemicals in two im- Distichlisspicata. Small mangroves(Avicennia germinans and Lagunculariaracemosa) border poundmenls (T-10-J and •l-10-K) was the canal in the foreground.

Volume34, Number 5 733 1973 and again in early December 1975 killed back the above-ground portion of some shrubs, but they returned within a year or so. Apparently, the combination of absence of alternate periods of flushing by fresh water from the uplands and salt water from the Indian River has favored establishmenl of Baccharis. With a readily available seed source along the dikes these plants continue to be a problem, and have altered the marsh physiognomyby creatingwalls of vegetation crisscrossingthe marsh. Such conditions are very different from the sparrow's preferred habitat (Maynard 1895, Baynard 1914, Nicholson 1928, Howell 1932, Trost 1968, Sharp 1969a, 1969b, 1970, and Baker 1973, 1978). The sparrowstend to vacate the marsh when it is dominated by shrubs and are not Fig. 7. Typicalhabital of the DuskySeaside Sparrow on Merritt IslandN.W.R. in 1979in im- generally found closer than 50 m to poundmentT-10-K after removalof flood watersand part of the dike system.The tall Spartina dense stands of trees and shrubs, or up- bakerii interdigitateswith the shorterDistichIls spicata. lands (Baker 1978). southern part of T-10-J vaguely resem- remain alive for years but are in a stress- The dike system has created condi- ble the original salt marsh. ed condition; reproduction is vegetative tions that enable upland vegetation to Drastic vegetation changescaused by and confined to the area on top of the invade the most distant fringes of the long periods of flooding have taken pedestal. The last Dusky Seaside Spar- marsh. This may facilitate visitation by place in the marsh over the last 17 years. rows recorded in T-10-J and T-24-C upland predators (i.e., snakes, rodents, Among the first halophytesto disappear were found in S. bakeri growing under racoons) that would otherwise be ab- from the flooded marsh, usually within such conditions. sent, or whose numbers would be small, the first 1 to 3 years, were Batis and Sali- and whose visits into the marsh would be cornia (Provost 1959, Trost 1964). It is less frequent under the original natural evident from Baynard (1914) and Nich- conditions. As the number of sparrows olson (1928) that these specieswere im- .4 dditional Problems grew smaller, each interacting negative portant to the sparrow, particularly for factor, such as predation, became more nesting. Also soon after flooding, dense HORTLYAFTER ITS completion, the significant. stands of Distichlis became thin and dike systemon Merritt Island was in- The enroachment of shrubs on the scattered, and stands of Spartina de- vaded by shrubs, primarily Baccharis dikes and in T-10-K have made those creasedin both density and in distribu- halimifolia and B. angustifolia. This en- areas more attractive to nesting Red- tion (Trost 1964). Such conditions ex- croachment by the two speciesof Bac- winged Blackbirds (.4gelaius phoeni- isted in T-24-C, (Fig. 8) and the southern charis has been a continuing problem in ceus). On many occasions I have re- part of T-10-J in 1979. As the transition the higher central part of T-10-K. A pre- corded Red-wingedschasing male spar- from saline to fresh conditions took scribed burn in the area in mid-February rows from their song perches. The densi- place, many of the impoundments were invaded by cattails (Typha spp.) (Pro- vost 1959, Trost 1964). T-24-D, the larg- esl impoundment, is now dominatedby cattails; which have invaded gradualy since 1969. Someimpoundments have been flood- ed almosl continuously to a water depth of 2-40 cm, and in many areas the emer- gent vegetationhas disappeared,turning the impoundments into open ponds (Table I and Fig. 9). In four impoundments some widely scattered clumps of S. bakerii and J. roemerianus continue to grow on the tops of pedestals elevated above the marsh substrate (Fig. 9). These pedestals Fig. 8. Deterioratedhigh salt marshas the result of long periodsof flooding as seenin the east end of T-24-C in 1979.Most of the marshvegetation has died out and only a few stressedclumps consistof both organic and mineral ma- of Spartinabakerii remain. Theseare confinedto the tops of widely spacepedestals that are terials and appear to be the result of abovewater. The sparrowsin Figures1 and 10were photographed in the centralpart of thispic- work by ant colonies. These clumps may ture in 1970 and 1971.

734 American Birds, September 1980 ty of blackbirdsin the sparrow areaswas high during the period 1969-1976. In 1971 and 1972 four counts of territorial male blackbirds in the sparrow habitat averaged5.3, 3.3, and 1.2 birds/ha for T-10-J, T-10-K, and T-24-C, respective- ly. Increaseddensity of blackbirdsmay have been detrimental to the maintenance of normal territorial behavior by the dwindling number of sparrows.

CONCLUSIONS

N RETROSPECT,efforts to aid the Dusky Seaside Sparrow on Merritt Island appeared to have begun too late, and too little has been done (i.e., not enough habitat provided, no predator control, too much flooding for mosqui- to control and insufficient control of in- Fig. 9. View lookingwestward toward Titusville across an openpond fringed by mangrovesthat is impoundmentT-214-A along the southside of S.R. 402 (alongutility line in the right vading shrubs). It is possible that the background)on Merritt Island,June 7, 1979.This washigh salt marsh habitat before being im- population decline may have progressed poundedand is thesite where Pettingill (1951), in the firstedition of hisA Guideto Bird Finding too far by 1969 to permit recovery with East of the Mississippi,suggested one look to find the Dusky SeasideSparrow. the condition of the habitat, and the re- sponseof the marsh to management was (Figs. 6 and 7) been available in the late island. In addition to providing sparrow evidently too slow to check that decline. 1960s, a small population of sparrows habitat, this salt marsh provides nesting The nearly complete destruction of might have survived on Merritt Island. habitat for the Mottled Duck (Arias habitat by the mosquito control project fulvigula), Clapper Rail (Railus was more than the sparrows could en- RECOMMENDATIONS longirostris), Black Rail (Lateral!us dure. The minimum number of sparrows jamaicensis), Willet ( Catoptrophorus above the threshold needed to LTHOUGHTHE Dusky Seaside semipalmatus), and several other spe- permit continued breeding successis not Sparrow has disappeared from cies. This marsh type is the winter home known for Merritt Island; when habitat Merritt Island, the possibility exists for of the Clapper Rail, Sora (Porzana caro- deterioration was stopped on a limited reintroducing it into the area. Even if the lina), Black Rail, Short-eared Owl (Asio scalein the early 1970sless than a dozen effort were to fail, it would still be highly fiammeus], Long-billed Marsh Wren pairs remained. Had sufficient suitable desirable to preserve some examples of (Cistothorus palustris), Short-billed habitat as is present today in T-10-K the original high salt marsh on the Marsh Wren (Cistothorus platensis), Common Yellowthroat (Geothylpis trichas), Sharp-tailed Sparrow (Am- Table 1. General condition of impoundmenlsin 1979 along Ihe Indian River on Ihe Merril! mospiza caudacuta), Swamp Sparrow Island N.W.R. (Melospiza georgiana), and many other birds. A number of other vertebrates Impoundment Condition found in this high salt marsh include T-10-A Open pond Marsh Rabbit (Sylvilagus palustris), -B Open pond Rice Rat, (Oryzomys palustris), -C Open pond Alligator Snapping Turtle (Macyochelys -D (Roach Hole) Open pond -E Open pond temmincki), Diamondback Terrapin -F Open pond (Malaclemys terrapin), Atlantic Salt -G Open pond with some widely scattered heavily stressed Marsh Snake (Nerodia fasciata emergent vegetation taeniata), and a host of fish species.The -H (Salt Cell) Mostly bare mud flats with some open pond and a stressed array of invertebratesis impressive.The stand of Salicornia that has attempted to re-establishin the central portion major plant speciesof this type of marsh -1 Open pond being invaded by mangroves were discussedearlier and the important -J (Black Point) Heavily stressedsalt marsh vegetation with mangroves in- function of salt marshes in the estuarine vading the central portion ecosystemand littoral zone of the ocean -K (restored marsh) Best salt marsh vegetation remaining on Merritt Island but is well known. invasion by Baccharis and Schinus is serious problem -L Much salt marsh vegetationremains but heavily stressedand I recommend the following: in poor condition 1. Remove all of the remaining dike T-24-A Open pond system around T-10-K, and all of the -B Open pond diking around T-10-J. This includes -C Heavily stressedvegetation with open pond condition in many places both the river and creekedge and the up- -D Extensivestand of Typha and open ponds land dikes. The ditches created when the dikes were built should be filled. These

Volume 34, Number 5 735 two impoundments are the most distant able. I estimate that 20 or more pairs will ACKNOWLEDGEMENTS from the residential, recreational, and be required to re-establisha viable popu- Space Center work areas, so that the lation on Merritt Island. PPRECIATIONis expressed for problemsresulting from a population in- Unfortunately in the last four years assistance with the field work and crease of mosquitos should be small. the population on the St. Johns River other aspectsof the study to James L. With both impounded areas (a total of has rapidly declined (Baker 1978); 13 Baker, Glen W. Bond, Lois E. Brown, 462 ha or 1,143 acres)restored to natural singing males were found in 1979 (Wil- J. C. Bryant, Jerome T. Carroll, Wil- marsh, sufficient habitat to support a lard Leenhouts and Beau Sauselein, liam David, Edward G. Duffy, Robin small viable sparrow population should pets. comm.), and by July 1980 only H. Fields, Hugh V. Hines, Elwood E result. four singing males remained and no Hurte, Herbert W. Kale, II, Harold J. 2 Remove most of the black man- femaleshad been found after a thorough O'Connor, Beau W. Sauselein, Richard grove (A vicennia germinans), white searchof the remaining habitat (Michael L. Thompson, John Venegoni, Larry mangrove (Laguncularia racemosa), Delany, Herbert W. Kale II, Leenhouts, West, S. Lawrence Wineland, and Jim- Brazilian pepper (Schinus terebin- and Sauselein,pers. comm.). Thesefour mie S. Woodall. Jack Salmela kindly th•folius), both speciesof Baccharis,and birds and the two males at the captive furnishedinformation on mosquitocon- leather fern (Acrostichum aureum) that propagation facility of the Florida Game trol and Charles H. Trost provided data have invaded the two impoundments and Fresh Water Fish Commission at on locations of the sparrows •n since the dike system was constructed. Gainesville, Florida, now constitute the 1961-1963. Logistical support was pro- Following initial removal of these in- extant population of the Dusky Seaside vided by Harold J. O'Connor and vaders, any regrowth should be routine- Sparrow (Michael Delany, William Post, Robert G. Yoder. I am indebted to ly controlled until such time as a simula- and Lois Wood, pets. comm.). The only James L. Baker, Herbert W. Kale, II, tion of the original salt marsh has been hope of perpetuating the gene pool of Willard P. Leenhouts, William Post, restored. Except for the persistenceof the Dusky is to capture the remaining Brian Sharp, and Charles H. Trost for shrubs, the response of the natural wild birds, create a semenbank from the reading an early draft of this paper and marsh vegetation in T-10-K following existing six males to preserve as much making suggestionsfor its improvement ehmination of the long periods of flood- genetic diversity of the population as •ng has been most encouraging (Sykes possible, backcross these males with LITERATURE CITED ms in prep.) females of one of the other races of the 3 Use fire as a management tool SeasideSparrow (i.e., A.m. macgillivraii AOU Check-list Committeeß 1973. Thirty- second supplement to the American Or- (Baker 1973, 1978) to achieve the opti- might be the bestchoice), and artificially nithologists' Union Check-list of North mum density of S. bakerii (Sharp 1968). inseminate females of another race. American Birds. Auk 90:411-419. Standsof grasspreferred by the spar- After six backcrossesthe F6 generation BAKER, J.L. 1973. Preliminary studies of rows are those that shade about 80-90% would have a Dusky genotype of over 98 the Dusky Seaside Sparrow on the St. Johns National Wildlife Refuge. Proc. SE Assoc of the ground. As a general "rule of percent and would in fact be a Dusky Game & Fish Comm. 27: 207-214. thumb," such stands are relatively easy phenotypically. Birds propogated in this ß 1978. Statusof the Dusky SeasideSpar- for a person to walk through. If the S. manner would then be used to re-estab- row. Rare and Endangered Wildl. Symp bakerii is difficult to walk through,it has lish a population on Merritt Island and Georgia Dept. Nat. Resourc. & Georgia become too denseto be good habitat for eventually on the St. Johns. Whether or Chapter Wildl. Soc., Athens. and H. W. KALE, II. 1978. Endangered the sparrows. Burning of up to 25 ha of not this approach will be taken has not Dusky Seaside Sparrow. In Rare and En- marsh during August or early September been decided. Time is of the essence if dangered Biota of Florida 2: 16-19, H W of each year, on a rotation basis, or as we are to preserve this unique sparrow Kale, II. Ed. Florida Game and Fresh Water conditions warrant, is suggested for that is now almost extinct in the wild. Commission, Tallahassee. BAYNARD, O.E. 1914. The Dusky Seaside T-10-K. Summer or early fall patch bur- 5. Reduce the Red-winged Blackbird Sparrow. Oologist 31: 130-134. rang should increasethe amount of edge population in the release areas just CHAPMAN, F. M. 1899. The distribution that is heavily used by the sparrows and before releaseof the sparrowsto reduce and relationships of Ammodramus wall aid in control of shrubs. Pure stands competition for food and harassment. maritimus and its allies. Auk 16: 1-12. of Spatrina are not suitable habitat for Control of the blackbirds should be con- Committee on Rare and EndangeredWildlife Species. 1966. Rare and endangeredfish and the sparrows; some open areas are need- tinued until the sparrows have become wildlife of the United Statesß Resource Publ ed It is essentialthat the Spatrina stands established, and thereafter if warranted. 34, Bur. Sport Fisheries & Wildl , be intermixed with stands of DistichIls, 6. Monitor the transplanted sparrows Washington, D.C. Batts, and also have scattered salt pans, to determine success.If the transplant is DEONIER, C. C., T. L. CAIN, JR. and W C. MCDUFFIE. 1950. Aerial spray tests on exposed areas of mud, and include small successful, census thereafter should be adult salt-marsh mosquitos resitanl to DDT t•dal creeks or creek edge. accomplishedon a permanent grid. J. Econ. Entom. 43: 506-510. 4 Reintroduce the Dusky Seaside 7. Convert other impoundments (i.e., DUSTMAN, E. H. and L. F. STICKEL Sparrow in T-10-K on Merritt Island as T-10-L and T-10-H) to salt marsh for in- 1969. The occurrence and significance of soon as the shrubs have been removed clusion in a management program to in- pesticide residues in wild . Annals New York Acad. Sci. 160(1): 162-172. crease the amount of habitat for the from within the impoundment. This can HEATH, R.G., J. W. SPANN, J. F be done using birds produced through Dusky Seaside Sparrow on Merritt Is- KREITZER and C. VANCE. 1970. Effects captive propagation. The sparrows land, if the sparrowsare successfullyre- of polychlorinated biphenyls on birds. 1X should also be re-established in T-10-J established in T-10-K and T-10-J. lnt. Ornith. Cons., The Hague, Netherlands once the habitat is determined to be suit-

736 American Birds, September 1980 HICKEY, J. J. 1961. Some effects of insecti- finch from Florida. Amer. Sportsman 5: 248. toxic environments,pp. 53-81, M. A. Q. cides on terrestrial birdlife in the Middle ß 1881ß The birds of Eastern North Khan and J. P. Bederka, Jr. Ed. Academic West. Wilson Bull. 73: 398-424. America. C. J. Maynard and Co., Newton- Press, Inc., New York. __ and D. W. ANDERSON. 1968. Chlori- ville, Mass. PETTINGILL, O. S., JR. 1951. A guide to nated hydrocarbonsand eggshellchanges in NICHOLSON, D. J. 1928. Nesting habits of bird finding east of the Mississippi. 1st. ed., raptorial and fish-eating birds. Sci. 162: the SeasideSparrows in Florida. Wilson Bull. Oxford Univ. Press, New York. 271-273. 40: 225-237. POST, W. 1974. Functional analysis of HOWELL, A. H. 1932. Florida bird life. OHLENDORF, H. M., E. E. KLAAS and T. space-related behavior in the Seaside Spar- Coward-McCann, Inc., New York. E. KAISER. 1974. Environmental pollution row. Ecology 55: 564-575. MAYNARD, C. J. 1875. A new speciesof in relation to estuarine birds. In Survival in PROVOST, M. S. 1959. Impounding sail marshes for mosquito control--and its ef- fects on bird life. Florida Naturalist 32: 163-170. SHARP, B. 1968. Numbers, distribution, and managementof the Dusky SeasideSpar- row. MS thesis, Univ. of Wisconsin, Madi- son. ß 1969a. Conservation of the Dusky Sea- side Sparrow on Merritt Island, Florida. Biol. Conserv. 1: 175-176. __. 1969b. Let's save the Dusky Seaside Sparrow. Florida Naturalist 42: 68-70. ß 1970. A population estimate of the Dusky Seaside Sparrow. Wilson Bull. 82: 158-166. SPRUNT, A., JR. 1954. Florida bird life. Coward-McCann, Inc., New York and Natl. Aud. Soc. STICKEL, L. F. 1973. Pesticide residues in birds and mammals. Chapter 7. In En- vironmental pollution by pesticides, pp. 254-312, C. A. Edwards, Ed. Plenum Press, London and New York. STICKEL, W. H. 1975. Some effects of pol- lutants in terrestrial ecosystems. In Ecological toxicology research, A.D. Mcin- tyre and C. F. Mill, Ed. Plenum Publ. Co., New York. TROST, C. H. 1964. Study of wildlife usage of salt marsh on east coast of Florida before and after impoundment for mosquito and sandfly control. Final Rep. (mimeo) 61 pp., Florida State Board of Heahh, Entomol. Res. Cent., Vero Beach. ß 1968. Dusky SeasideSparrow. In Life histories of North American cardinals, gros- beaks, buntings, towhees, finches, sparrows, and allies. O. L. Austin, Jr., Compil. and Ed. U.S. Nail. Mus. Bull. No. 237, Part 2. VARS, H. N. 1926. Florida notes. Oologist 43: 2-9.

--U.S. Fish and Wildlife Service, Patux- ent Wildlife ResearchCenter, Field Sta- Fig. 10. Dusky SeasideSparrow photographedat Merritt Island N.W.R., May 29, 1971. All tion, P.O. Box 2077, Delray Beach, photos by the author. Florida 33444.

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