24 Greenwell Court Lynchburg, Virginia 24502 A studyof the local bird population was started in April of 1986 using the technique of bird banding. The purposes of the study were (1) to determine the local occurrence of birds, particularly those species in residential habitats (i.e., ground and low brush); (2) to determine the seasonal occur- rence of these species; and (3) to follow up on Freeifs (1973) suggestion that Am. Robins (Turdus migratorius) considered permanent residents here, move into and away from the local area during thechanging seasons. After the summer of 1988, examination of the banding data suggested an irruptive occurrence of Pine Siskins (Carduelispinus) had taken place. STUDY SITE AND METHOD The banding station is 1-1/4 mile from the intersection of State Route 460 and CountyRoute 622 (WaterlickRoad) in a residential section of Campbell County. Campbell County is on the western edge of the Piedmont region in central Virginia. The mist nets are placed in the backof our 75'x 125' lot. Bird feeders with sunflower, mixed wild bird, and niger seeds are placed in the back section of the lot during the fall, winter and spring. In an effort to detect as much of the annual bird population as possible, the banding station is opened and closed in a random fashion throughout a twelve- month period. Strong windy conditions, extreme heat or cold, rain or snow, in addition to both family and work responsibilities prevent the nets from being opened on a more regular basis. For this study, we defined a banding time period as a station day, which is any day or portions of a day the station is open regardless of the number of nets used. One or two nets usually were used, occasionally as many as four. Each nylon net has four shelves of 1-1/4" mesh and is 12 feet long. After banding a bird, the (unflattened) wing chord was measured to the nearest millimeter using a rule with an end stop. The bird was aged and sexed before release. RESULTS Table 1 summarizes the status, early and late dates, and peak counts for Pine Siskins within Virginia. Table 2 lists the number of station days per month the station was open. Table 3 lists the number of Pine Siskins banded monthly over the time period. Table 4 lists in descending order by number banded the species captured. BACKGROUND The status, early dates, la. te dates, and peak counts for Pine Page 6 Siskins in the Piedmont and mountains and valleys physi- ographic regions of Virginia (Kane, 1987) are given in Table 1. Kinzie (1985) and Hansrote (1987), local annotated lists, agree with the status as given in the VSO guide. Freer (1973) listed the status of the pine Siskin as irregular winter visiter, usually uncommon but sometimes in large flocks. Early dates for sighting Pine Siskins generally agreed with the 15 October date found in the VSO guide. In recent years, there have been no October sightings reported in Lynchburg and vicinity. Late dates range into June, well past the VSO accepted 15 May date. Peak count numbers vary widely. John Dalmas (pets. comm.) has compiled the 47 Lynchburg Christmas Bird Counts on computer. Pine Siskins appeared on 27 (53%) of the CBCs. The highest number recorded (207) was in 1987. Dalmas found for the last fifteen years there were an average of 23 but only a medium of three Pine Siskins per Lynchburg CBC. For the 1987-1988 invasion, the earliest reported sighting of a Pine Siskin in Lynchburg and vicinitywas 1 November 1987 (Thiesinger, pcrs. comm.) and the latest date they were seen was 23 May 1988 (Moore, pets. comm.). The peak count of 2,450 was recorded on 14 February 1988. Evidence that the Pine Siskin invasions of 1987-88 was widely spread over Atlantic Coast States is found in regional write-ups in American Birds. George Hall (1988) described the invasion in the Appalachian region as follows: "The winter of 1987-1988 can best be described by calling it a Pine Siskin season. Starting in mid-December and con- tinuing past the end of the period, siskins staged an invasion of unprecedented size. Flocks of 50-100 were going to feeders throughout the region, flocks of 200-300 were com- mon, and some CBC counts topped 1000. A bander near Huntington, W.Va. banded over 500 birds in just over 100 net hours (LW), and dealers in niger seed made a killing. The total number of Pine Siskins in this region alone was extraor- dinarily high. If nearby regions experienced anything simi- lar, the total numbers are mind-boggling." Examination of American Birds regional reports from 1982 reveal seasons with high regional activity of Pine Siskins. Two major periods--December 1986 to May 1987 and De- cember 1987 to May 1988--indicate large numbers of Pine Siskins in the Hudson/Delaware region (NY, Pa, Del, N J), the mid-Atlantic region (Md, Va, DC, Del), and the South- ern Atlantic region (NC, SC, 6a). Pine Siskins were also found in large numbers in the Appalachian region (W.Va, W. Md, W. Pa) throughout March to May 1987 and Decem- her 1987 to May 1988. Yet, from May 1982 through February 1986, the numbers of Pine Siskins in these four mid-Atlantic regions were either not mentioned or reported as scarce, absent, few, low, etc. December 1981 to May 1982 was a major Pine Siskin season in the Hudson/Delaware region (NY, Pa, Del, N J), but not in the other surrounding regions. No pattern developed from this limited examination. Per- haps Potter et al. (1980), who suggested Pine Siskins are ex- tremely abundant one winter and almost impossible to find the next, comes closest to capturing the status for the species in the states surrounding Virginia. DISCUSSION Howard et al. (1989) noted that Pine Siskins are nomadic, wide-ranging birds during the non-breeding season. Both Bent (1968) and Ehrlich et al. (1988) offer discussions con- cerning the irruptive nature of Pine Siskins. One of the most widely accepted explanations for this tendency of Pine Siskins to wander is lack of food supply. No information concerning the food supply for Pine Siskins during the period of time covered in this study has been located by the authors. By December 1987 members of the Lynchburg Bird Club (LBC) had reported the early appearance and larger-than-normal numbers of Pine Siskins at their home bird feeders. In addition, the 1987 Lynchburg Christmas Bird Count (CBC) reported 205 Pine Siskins. This was a major increase over the 1986 CBC when only one Pine Siskin was detected (Dalmas, pers. comm.). In January 1988, Myriam Moore (pets. comm.) suggested LBC members undertake a "Super Siskin Sunday" (SSS) count of Pine Siskins. The method was simply to observe your backyard bird feeder on the selected day and report the largest number of Pine Siskins seen at one time. Hansrote and Hansrote (1988) reported 60 participants saw 2,450 Pine Siskins on 14 February 1988 (SSS). Examination of banding data in Table 3 show Pine Siskins appeared in increasing numbers starting in December 1987 and continuing into May 1988. TWelve hundred and eighty (1280) Pine Siskins were banded from December 1987 through May 1988. Using data from Tables 2 and 3, the following expression can be solved. No. of Pine Siskins bander per month number station days per month =a Numerical Index The resulting monthly indices Dec Jan Feb Mar Apr index = 0.9 34.7 59.1 38.5 22.1 suggest the invasion peaked in late February or early March. On two occasions, all size zero bands were used and we had towair for resupply. The U.S. Fish and Wildlife Service was very helpful in getting additional bands to us. Because of these times when we could not band, our data under-esti- mates the magnitude of the invasion. Jan.-Mar. 1990 Table 4 reveals Pine Siskins made up 52% (1,347) of all the birds banded (2,585) from April 1986 to December 1988. Ninety-five percent (1,280) of the 1,347 banded Pine Siskins were netted between December 1987 and May 1988. Our bird banding data plus the information from Super Siskin Sunday document the irruption (invasions) by Pine Siskins that occurred in Lynchburg and vicinity throughout the winter of 1987 and spring of 1988. CONCLUSIONS AND SUMMARY 1. Banding provided a method of detecting an irruption (invasion) in the local bird population. 2. Pine Siskins staged an irruption in Lynchburg and vicinity during the period from December 1987 to May 1988. LITERATURE CITED Bent, A.C. 1968. Life histories of North American cardinals, buntings, towhees, finches, sparrows and their al- lies. ed. O. L. Austin. U.S. Natl. Museum Bulletin 237: 427-444. Ehrlich, P.R., D.I. Dobkin, and D. Wheye. 1988. The birder's handbook. Simon & Schuster, Inc., New York. Freer, R.S. 1973. The Birds of Lynchburg, Virginia and vicinity. Lynchburg College Press. Hall, G.A. 1988. Appalachian region. American Birds 42:266. Hansrote, C.J. 1987. The birds of Lynchburg, Virginia and vicinity, update 1987. Lynchburg Bird Club. Hansrote, Charles and Melva Hansrote. 1988. 1988 winter invasions of Pine Siskins. Jr. of the Va. Soc. of Ornith. 53: 16. Howard, G.E., A. McCormick, and P.B. Hamel. 1989. Measurements of 677 Pine Siskins banded one spring in South Carolina. No. Am. Bird Bander 14:9-10. May Kane, T. ed. 1987. Virginia birdlife: an annotated check 9.3 list. Va. Avifauna No. 31, Virginia Society of Ornithology. Kinzie, B.L. 1985. Birds of the Roanoke Valley: an anno- tated checklist. Potter, E.F., J. F. Parnell, and R.P. Teulings. 1980. Birds of the Carolinas. University of North Carolina Press. Table 1. References from State and Local Annotated Lists. PART A: STATUS OF PINE SISKIN IN VIRGINIA (Kane 1) Piedmont: Irregularly common to rare transient and winter resident (15 Oct-15 May) Mtns. & Valleys: Irregularly common to rare transient and winter resident (15 Oct-15 May). Rare summer visitor at high elevations. PART B: PINE SISKIN EARLY AND LATE DATES, PEAK COUNTS Kane 1 Freer 2 Hansrote 2 Kinzie 3 EARLY DATE Piedmont: 15 Oct 16 Oct 26 Nov 1984 ......... Mtns & Valleys: 23 Oct. 1965 ....................... 15 Oct 1977 LATE DATE Piedmont: 15 Jun 1978 14 May 30 May 1986 ......... Mtns & Valleys: 8 Apr 1966 ....................... 12 May 1977 PEAK COUNTS Piedmont: (596)19 Dec 1981 Mtns. & Valleys: (700+)28 Feb 1982 ......... (48)17Dec 1977 ......... (150) 22 Oct1977 State of Virginia (Kane, 1987). In the Piedmont region of Virginia-Lynchburg & Vicinity (Freer, 1973); (Hansrote, 1987). In the Mountains and Valley region of Virginia- Roanoke (Kinzie, 1985) Table 2. Station Days/Month from April 1986 to May 1989. Month 1986 1987 1988 1989 Total January * 15 4 5 24 February * 9 9 8 26 March * 7 4 14 25 April 12 11 18 7 48 May 3 5 10 18 June 6 9 1 16 July 9 7 5 21 August 2 11 7 20 September 7 10 14 31 October 23 10 13 46 November 17 8 9 34 December 7 ß 8 6 21 Days Banding 86 110 100 34 %Station Days 26% 33% 30% 10% 339 NOTE: A station day is defined as any day or part of a day the banding station is open. It does not depend upon the number of nets opened. Table 3. Pine Siskins Banded/Month from April 1986 to May 1989. YR. JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC 1986 * * * 14 2 1987 1 30 13 7 1988 139 496 154 398 93 1989 # NOTES: 1. * represents no banding that month. 2. - represents no pine siskins banded that banding month. 3. # represents no pine siskins banded to 16 May 1989. Table 4. Percentage of Bird Species Banded April 1986 to 30 December 1988, Campbell County, Virginia. BIRD SPECIES TOTAL BANDED % TOTAL Pine Siskin 1347 52.32 (Carduelis pinus) House Finch 406 15.77 (Carpodacus mexicanus) American Goldfinch 176 6.84 (Carduelis tristis ) Northern Cardinal 103 4.00 (Cardinalis cardinalis) White-throated Sparrow 82 3.19 ( Zonotrichia alb icollis ) Song Sparrow 80 3.11 (Melospiza rnelodia) American Robin 69 2.68 (Turdus migratorius) Blue Jay 38 1.48 ( Cyanocitta cristata ) Tufted Titmouse 33 1.28 (Parus bicolor) Gray Catbird 33 1.28 (Durnetella carolinensis ) Carolina Chickadee 28 1.09 (Parus carolinensis ) Dark-eyed Junco 28 1.09 (Junco hyernalis ) Common Grackle 20 0.78 ( Quiscalus quiscula ) Purple Finch 20 0.78 (Carpodacus purpureus ) Field Sparrow 19 0.74 (Spizella pusilla ) House Wren 16 0.62 (Troglodytes aedon ) Carolina Wren 15 0.58 (Thryothorus ludovicianus) Downy Woodpecker 12 0.47 (Picoides pubescens ) Northern Mockingbird 9 0.35 (Mirnus polyglottos ) 20 additional species 50 1.94 Total Banded Individuals Total Species Banded 2584 39