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3400 Wildlife Preservation - Bird Count 30 Year Summary PVP Christmas Bird Count03/13/98 11:11 FAX 1310 541 3030 D.M. & C. GALES [i001 PALOS VERDES PENINSULA AUDUBON CHRISTMAS BIRD COUNT p Red -Shouldered Hawk 4 p Red -Tailed Hawk 38 p American Kestrel 70 p Sharp -Shinned Hawk 7 s California Quail 10 s Rock Dove 1871 s Spotted Dove 164 s Mourning Dove 1006 1887 p Barn Owl p Great Horned Owl i Anna's Hummingbird i Costa's Hummingbird i Allen's Hummingbird s Red -Shafted Flicker s Black Phoebe s Says Phoebe s Scrub Jay p American Crow p Common Raven . s Bushtit s Cactus Wren s Rock Wren s Bewick's Wren s House Wren Since about 1967 volunteers from the Audubon Society have taken one -day bird counts in various areas on the Peninsula. Herewith is an extract from a report by Prof_ David Bradley listing the more common birds by species, the maximum in any one year, and an indication of the trend for the past 10 to 15 years. Successive years can vary greatly, but we are trying to show a current trend for the more common species of ]and birds on PVP. 30 -year 10 to 15 yr 30 -year 10 to 15 yr. Species Median & Max Species Median & Max. Trend p Cooper's Hawk 5 11 s Ring Necked Pheasant 1 14 Dcrsg 22 57 Dcrsg 72 135 Steady 119 132 Incrsg 11 147 Steady 130 43 Vrbl 3444 468 Steady 287 2620 Steady 1 10 6 14 3108 599 2 1 75 243 100 210 30 125 33 59 138 396 96 542 16 273 401 912 8 32 4 1 17 43 14 49 s Ruby -Crowned Kinglet 129 420 s Blue -Gray Gnatcatcher 37 96 s California Gnatcatcher 7 21 s Hermit Thrush 110 306 p Brown Pelicans 214 1228 s American Robin 217 1705 s Mockingbird 221 252 s American Pipit 115 210 s Cedar Waxwing 312 1038 p Loggerhead Shrlke 59 98 s European Starling 1848 5925 s Orange -Crowned Warbler 48 1411 s Myrtle Warbler 4 411 sAudubons Warbler 774 2835 s Townsend's Warbler 10 103 s Common Yellowthroat 19 107 s Western Tanager • 2 111 s Rufous -Sided Towhee 69 173 s Calif. Brown Towhee 208 515 Trend lncrsg Incrsg Incrsg Incrsg Incrsg Dcrsg Incrsg ! Tncrsg Incrsg Dcrsg Steady Incrsg ! Incrsg Incrsg ! Dcrsg Incrsg ! Steady lncrsg Incrsg lncrsg ! Incrsg Steady Dcrsg Steady Incrsg Steady Steady Steady Incrsg Ingrsg ! Dcrsg Steady Steady Dcrsg Dcrsg ! Incrsg ! Incrsg ! s Lark Sparrow 10 s Savannah Sparrow 28 s Fox Sparrow 23 s Song Sparrow 96 s Lincoln's Sparrow 10 s Golden -Crown Sprw 148 s White -Crowned 1254 s Oregon Junco 170 s Red -wing Blackbird 168 s Tri-Color Blackbird 170 s Brewers Blackbird 748 p Cowbird 38 s Bullocks Oriole 2 s Purple Finch 20 s House Finch 1466 9806 Steady s Lesser Goldfinch 68 354 Dcrsg s American Goldfinch 76 380 Steady s House Sparrow 400 1854 Incrsg s Meadowlark 397 1588 Dcrsg Great -Tailed Grackle 0 38 Incrsg I (Grackles were not seen at all until about 1988) Canary -Winged Parakeet 12 45 Incrsg NOTES: p means a predator bird s means a songbird i means insect eating bird 4 Ax the time of the Christmas Count, the migratory birds may be early or late, thus giving that year a small count_ If the species is on time~ a larger count results. This can skew the statistical analysis regarding medians, maximums & trends . 4 Swallows and many other insect -eating birds are not seen at Christmas. 4 After me Trend, an exclamation point [!] means a rather rapid increase or decrease. Incrsg = Yellow Rumped Warbler Incrsg = Yellow Rumped Warbler Incrsg Incrsg Steady Dcrsg Steady 664 Steady 767 Steady 460 Steady 1477 Incrsg 200 Incrsg 12 Dcrsg 81 Dcrsg Prepared by Don Gales February 12. 1998 03/19/98 14:11 FAX 1310 S-11 3030 D.M. & C. GALES g)001 DONALD MOORE GALES Marchh; 18, 1998 PALOS VERDES PENINSULA BIRD COUNT ANALYSIS For 30 years the Audubon Society birders have counted birds in various areas on the Peninsula. Statistics Professor David Bradley of CSULB has furnished the Wildlife Preservation Committee with a 30 -year summary graphically and numerically showing for each of the 180 species the yearly count plus the median and maximum over the years. Some 40 to 80 individuals take part in the count after splitting up into small parties for different areas. Being a winter -time bird count, some popular species have already migrated south and are not seen Other migrants may have arrived and are counted; others may still be on their way and are uncounted, at least in some years. I have analyzed the statistics to determine whether bird species are decreasing as many people report from their own observations. I eliminated the 80 or so shorebirds which are rarely seen in Rolling Mils and the some of the relatively uncommon birds where less than 30 are seen. That still left many species, six of which the birders counted over 1000 as the median number sighted and with rock doves topping the list at 1871 and starlings next at 1848. The maximum sightings fora single year is the house finch with 9806 some 25 years ago. In recent years they seem to have more like 1500 sightings Down now to 66 species, I found 32 of them are increasing, 14 are decreasing and 20 species are holding steady. Bear in mind that the annual counts can vary greatly from year to year, but the figures above are determined for general trend over the last ten to 15 years as seemed appropriate. Of the abundant species, those with a median count of 30 or more, 19 species are increasing, 7 species decreasing and 14 holding steady. Perhaps of most concern by many residents is the American crow which over the last 30 years has steadily increased from just a few to a maximum of 542 sighted in 1996. The larger and scarcer raven had a median of only 16 while peaking at 273 in 1995. The unwelcome starling is another one increasing Quail and Meadowlarks are decreasing and the Roadrunner has not been seen for many years. The trend curves of individual species do not show an easily recognized pattern of a decrease as was suspected. Some species are steadily increasing, and many that are now increasing suffered a decrease in the '80s and are making a comeback or holding steady. In conclusion, among land birds in Rolling Hills, more species seem to be increasing than decreasing according to the annual Christmas Bird Count by the Audubon Society, though they might not all be the species people would most like to have around. 19 NORTH YIDDLII1IDGE T_AIgE ROLLING MILLS, CALIFORNIA 0027a To: Rolling Hills WPC (Wildlife Committee) Attn: Don Gales From: David Bradley, ACS, CSULB Here are the graphs of the 30 year Summary of the Palos Verdes Peninsula Christmas Bird Count results. I still haven't been able to re -liven the program to incorporate last year's count, but this will give the overall trends. I hope to get the program fixed soon. The raw listings printed out with such fine print that I fear they won't work very well over fax. Perhaps once the additional data gets incorporated I can send you good prints of the whole thing...Dave ET 39dd 9NI ndW00 DIWaNDti 9935-536-Z95 TT:LT L66I/ET/99 Brewers Blackbird Max: 1477 Normal: 748 % of years: 100% TO 39dd 9NIIIldW00 OIN a'DV 0085-536-Z95 TT:LT L66T/ET/90 Z9 39dd 9NIIOdW00 OIW3QvDd 9035-S86-Z9S TT:LT L66T/ET/99 Bewick's Wren • House Wren Marc 49 Normal: 14 % of years: 100* • Marsh Wren Mar 44 Normal: 11 % of years: 100% • CO 39Vd 9NIlf1dW00' DIW3 NDV 0035-536-Z95 II:LT L66T/£T/90 Belted Kingfisher Mac 9 Normal: 4 % of years: 87% 170 39dd. 9NIlfldW00 DIW3Qt1Da 0005-536-Z9S TT:LT L66T/ET/90 S0 39dd 9NIlfdW00 OIW3QdDd 0065-536-Z9S TT:LT L66T/ET/90 Thayer's Gull Max: 17 Normal: 2 % of years: 73% 90 39dd 9NIlldL00.DIW3QiDd 0005-S36-Z9S TT:LT L66T/ET/90 r w 0085-586-Z95 L0 39dd 9NIlOdWOO OIW3Q\Od IT:LT L66T/ET/90 White -winged Scoter Marc 198 Normal: 2 % of years: 57% Northern Harrier Marc 4 Normal: 1 % of years: 60% • 80 39Vd 9NIlfdWOO OIW3QdOd 0085-596-Z9S TT:LT L66T/EI/90 60 39dd 9NILfdWOO OIW3QkOd 0035-536-Z9S TT:LT L66T/cT/90 J TT:LT L66T/ET/90 OT 39tid 9NIlldW00 DIW3a Dd 0085-536-Z95 PALOS VERDES PENINSULA CHRISTMAS BIRD COUNT 30 Year Summary This summary uses small multi -component graphs to quickly summarize the abundance, reliability, and trends for the most frequent species on the count. Three summary statistics are displayed by number, and are described in reference to the example of Green Heron below: Max: Normal: % of years: 32 The largest count we've ever had for this species 6 The median (half the counts are above and half below this number) 90% The percentage of years where this species has been seen The graphical elements are described below: Trend Graphs These chart the relative abundance per species over the years, adjusted for total party hours, with vertical bars marking the actual data, and a cubic smoothing spline (with 4 degrees of freedom) superimposed to illustrate the general trend through time. These graphs are scaled to fill the available space, so the height of the tallest bar is the same for all species (whether it's 32, 452, or 9806). Consequently, avoid comparing bar heights between spe- cies. The alternative of a common vertical scale was rejected because almost all of the plots would be mashed down at the bottom, and nearly useless for interpreting the time trend within the species. Green Heron Marc 32 Normal: 6 % of years: 90% Black -bellied Plover Max Normal: % of years: 452 162 100% Abundance Dots These allow you to judge a species' normal (median) abundance at a glance. They match the scale indicated below: Zero 0 1-9 10-99 • House Finch Max 9808 Normal: 1486 % of years: 100% Frequency Pies These display the percentage of years in which the species has been found on the count. Solid circles accompany those species that have not yet been missed. 100-499 500-999 1000+ ZT 391Vd 9NIlldW00 DIW3a V 9085-S86-Z9S TT:LT L66T/ET/99