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Fermilab Grassland Birds http://home.fnal.gov/~kasper/talks/GrasslandBirds.ppt Peter Kasper
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6,800 acres with a variety of “natural” habitats Restored Prairie Non-native Grasslands Woodlands Wetlands Man-made Lakes Agricultural Tracts 6,800 acres with a variety of “natural” habitats Restored Prairie Non-native Grasslands Woodlands Wetlands Man-made Lakes Agricultural Tracts FERMILAB World’s Highest Energy Particle Accelerator
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The Fermilab Bird Survey Started in 1987 by Vicki Byre (C.A.S) and P.K. Goals What birds use the site? At what time of year? Use knowledge obtained to permit bird friendly land management –E.g. When to mow and when to burn grasslands. Started in 1987 by Vicki Byre (C.A.S) and P.K. Goals What birds use the site? At what time of year? Use knowledge obtained to permit bird friendly land management –E.g. When to mow and when to burn grasslands.
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The Fermilab Bird Survey Technique Divide year into 48 quarter months –Shortest time interval over which I can hope to achieve reasonable coverage of the site –Provides at least one weekend in each division Divide survey into 5 year periods –Averages over weather conditions –Averages when the weekend occurs in a quarter month –Provides an opportunity to fill gaps in my coverage … e.g. vacation, work, illness Record presence not numbers – Too time intensive Technique Divide year into 48 quarter months –Shortest time interval over which I can hope to achieve reasonable coverage of the site –Provides at least one weekend in each division Divide survey into 5 year periods –Averages over weather conditions –Averages when the weekend occurs in a quarter month –Provides an opportunity to fill gaps in my coverage … e.g. vacation, work, illness Record presence not numbers – Too time intensive
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The Fermilab Bird Survey Supplementary Data Breeding status in each period –Confirmed ( nest, recently fledged young, or carrying food ) –Likely ( singing male on territory …same location for a week or more) –Possible ( seen in the right sort of habitat at the right time of year ) Year last seen Notes on rarer observations Supplementary Data Breeding status in each period –Confirmed ( nest, recently fledged young, or carrying food ) –Likely ( singing male on territory …same location for a week or more) –Possible ( seen in the right sort of habitat at the right time of year ) Year last seen Notes on rarer observations
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Summary of Results 4 survey periods covering past 18+ years 1987 to 1991 1992 to 1996 1997 to 2001 2002 to now 277 species recorded on site 91 confirmed breeding, plus 6 likely and a further 12 possible 3 are pre-survey records Red Phalarope - 1981 Garganey - 1982 Snowy Owl - 1984 4 survey periods covering past 18+ years 1987 to 1991 1992 to 1996 1997 to 2001 2002 to now 277 species recorded on site 91 confirmed breeding, plus 6 likely and a further 12 possible 3 are pre-survey records Red Phalarope - 1981 Garganey - 1982 Snowy Owl - 1984
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Cooper’s Hawk Resident Increasing Resident Increasing Rough-legged Hawk Winter Visitor Decreasing Winter Visitor Decreasing Bobolink Summer Visitor Stable Summer Visitor Stable Yellow-bellied Sapsucker Migrant Stable? Migrant Stable? Common Merganser Spring Migrant → Winter Visitor Increasing Spring Migrant → Winter Visitor Increasing Example Species Data
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Number of species versus time of year Wintering species have increased New species continue to be added Number of species versus time of year Wintering species have increased New species continue to be added
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Categorized according to “normal” site usage. Some summer visitors are becoming year round residents Categorized according to “normal” site usage. Some summer visitors are becoming year round residents
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Migrants categorized by family... –Waterfowl are earliest and latest –Shorebirds are heading south in late June Migrants categorized by family... –Waterfowl are earliest and latest –Shorebirds are heading south in late June
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Grassland Birds The survey tells us what grassland birds have occurred on site and roughly when they were there Upland Sandpipers were regular breeders until 2002 Henslow’s Sparrows were absent until 2000, but have been regular since It does NOT provide quantitative data on abundances Grasshopper Sparrows are declining but have been regular throughout the survey The survey tells us what grassland birds have occurred on site and roughly when they were there Upland Sandpipers were regular breeders until 2002 Henslow’s Sparrows were absent until 2000, but have been regular since It does NOT provide quantitative data on abundances Grasshopper Sparrows are declining but have been regular throughout the survey
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Grassland Areas Prairies Various sizes and stages of succession Maintained with fire Various sizes and stages of succession Maintained with fire Introduced Grasses Introduced Grasses Maintained with late summer mowing Maintained with late summer mowing Where do the birds breed? Upland Sandpiper Henslow’s Sparrow Grasshopper Sparrow
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Henslow’s Sparrow Historical data indicates they were present on site as late as 1978 Not recorded in the survey until 2000 ( ~ 10 territories) Regular since then Mainly in non-native grasses Historical data indicates they were present on site as late as 1978 Not recorded in the survey until 2000 ( ~ 10 territories) Regular since then Mainly in non-native grasses In 2002 and 2004 breeding territories were located in restored prairie sites – “Won’t use areas that were recently burned” – 2002 was at the end several years of a burning moratorium – 2004 was in spite of a burn in Spring of 2003 In 2002 and 2004 breeding territories were located in restored prairie sites – “Won’t use areas that were recently burned” – 2002 was at the end several years of a burning moratorium – 2004 was in spite of a burn in Spring of 2003
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Grasshopper Sparrow Never were very common Have been recorded on site every year of the survey Numbers have declined significantly in last 5 years Now outnumbered by Henslow’s Sparrows. Never were very common Have been recorded on site every year of the survey Numbers have declined significantly in last 5 years Now outnumbered by Henslow’s Sparrows. Also seems to prefer non-native grasses Why are these birds decreasing while Henslow’s are increasing? –Is our grassland management the cause? Also seems to prefer non-native grasses Why are these birds decreasing while Henslow’s are increasing? –Is our grassland management the cause?
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THE END http://www.fnal.gov/pub/about/campus/ecology/wildlife/birds.html
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Christmas Count Data The Fermilab Christmas Count has been held annually in mid December since 1976. Count circle is 15 mile diameter roughly centered on Fermilab All the data is available on the “Birds of Fermilab” web site. Indicates some interesting long term trends … The Fermilab Christmas Count has been held annually in mid December since 1976. Count circle is 15 mile diameter roughly centered on Fermilab All the data is available on the “Birds of Fermilab” web site. Indicates some interesting long term trends …
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Number of species recorded has increased
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Number of birds counted has also increased
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The Big Five!
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Some interesting trends.. Canada Goose numbers have stabilized
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Southern migrants are staying.. Great Blue Herons have started wintering over!
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Northern migrants are not returning.. Rough-legged Hawks are declining!
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Predators are moving into the ‘burbs.. Pheasant numbers have taken a dive.. coyotes?
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What about West Nile Virus? American Crows took a big hit..
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Some claims are perhaps exaggerated? Black-capped Chickadees are not so bad off.
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