Randall’s Island Park Alliance Natural Areas Department Harbor Heron Conference 2019 Randall’s Island

Interesting Sightings from 2019

• American eels & previously undocumented species of fish • Resident Great Blue Heron in West Bronx / • Many juvenile Yellow-Crowned Night Herons in late summer/fall Are Foraging Heron Populations Declining on Randall’s Island?

Harbor Heron Totals Per Site Heron Totals Over Time 2011 2012 2013 2014 2015 2016 2017 2018 Rand 7a 8 4 3 19 4 20 4 100 Rand 08 6 1 6 2 4 5 6 4 90 Rand 02 8 6 0 0 0 0 1 1 80 Rand 01 22 4 1 0 0 1 1 0 70 Rand 09 15 27 7 2 5 5 2 4 60 Rand 10 0 0 0 1 0 0 0 0 50 Rand 06 14 9 2 8 3 2 5 5 40 Rand 05 8 7 2 3 5 1 1 4 30

Rand 04 3 2 1 0 8 0 0 0 NumberIndividuals of 20 Rand 03 8 15 6 9 8 0 0 2 Randall's Island 10 Harbor Heron Totals 91 79 29 28 52 18 36 24 0 2011 2012 2013 2014 2015 2016 2017 2018

Post-Hurricane Sandy Are Foraging Heron Populations Declining on Randall’s Island?

Harbor Heron Totals Per Site Heron Totals Over Time 100 2011 2012 2013 2014 2015 2016 2017 2018 2019 Rand 7a 7 8 4 3 19 4 20 4 0 90 Rand 08 6 1 6 2 4 5 6 4 0 80 Rand 02 8 6 0 0 0BUT0 1 1 0 70 Rand 01 22 4 1 0 0 1 1 0 1 Rand 09 15 27 7 2 5 5 2 4 0 60 Rand 10 0 0 0 1 0 0 0 0 0 50 Rand 06 14 9 2 8 3 2 5 5 0 40 Rand 05 8 7 2 3 5 1 1 4 0 Rand 04 3 2 1 0 8 0 0 0 2 NumberIndividuals of 30 Rand 03 8 15 6 9 8 0 0 2 1 20 Randall's Island Harbor Heron Totals 91 79 29 28 52 18 36 24 4 10 0 WAIT2011 2012 2013 2014 2015 2016 2017 2018 2019 Whatabout ? Harbor Heron Surveys Compared to eBird

600

500 400 r=0.105 300 Randall's Island Harbor Heron Totals p-value=0.822 200 eBird No significant correlation 100

0 2013 2014 2015 2016 2017 2018 2019

Harbor Heron Survey and eBird in the LHGSM 50 40 r=-0.003 30 Harbor Herons p-value=0.994 20 eBird No significant correlation 10

0 2013 2014 2015 2016 2017 2018 2019

Harbor Heron Survey and eBird in Kill 400 350 300 r=0.181 250 200 Harbor Herons p-value=0.571 150 eBird No significant correlation 100 50 0 2013 2014 2015 2016 2017 2018 2019 Heron Totals Over Time 60

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0 2013 2014 2015 2016 2017 2018 2019

Heron Totals Over Time 600

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0 2013 2014 2015 2016 2017 2018 2019 Randall's Island Harbor Herons and Nearby Wader Nest Counts 450

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350 alpha=0.05

300 Significant correlation between Mill Rock Nests and Heron Totals on 250 Randall’s Island? r=0.813 Individuals 200 p-value= 0.014

150 No significant correlation between South Brother Nests and Heron Totals 100 on Randall’s Island r=0.029 50 p-value= 0.945 Bonferroni adjustment for 0 multiple comparisons 2011 2012 2013 2014 2015 2016 2017 2018

Randall's Island Harbor Heron Totals Mill Rock Wader Nests South Brother Wader Nests lowers our alpha value to 0.025 We need a better way to survey Randall’s Island! Bronx South Brother

Bronx Kill

Manhattan Total Area: 516 acres

Mill Rock to Rand 03: 300 m

Seining Sites South Brother to Rand 7a: 1.5km Little Saltmarsh

Queens Mill Rock How do we improve our methods to study wading birds on Randall’s Island? • Phenology study • including eBird & iNaturatist data

• Methods • Observations only at low tide

Help us! randallsisland.org/park-as-lab/

Resources and Contacts

Jennifer Adams– Restoration Help Us Help Our Wildlife: Associate eBird [email protected] iNaturalist Park-as-Lab (PAL) Jackie Wu– Park-as-Lab Coordinator www.randallsisland.org [email protected]

Christopher Girgenti – Natural Areas Manager [email protected] Thank you! How do we improve our methods to study wading birds on Randall’s Island? • Phenology study • including eBird & iNaturatist data

• Methods • Observations only at low tide

Help us!

Breakdown by Species Little Hell Gate Saltmarsh

GREG SNEG BCNH YCNH GBHE GRHE 2011 0 1 7 15 1 0 2012 5 7 2 4 0 0 2013 0 1 1 1 0 0 2014 3 2 1 4 0 1 2015 14 0 1 1 0 0 2016 2 0 1 0 0 0 2017 4 2 0 0 0 0 2018 3 2 0 4 0 0 Totals 31 15 13 29 1 1 Diets of Great Egrets and Yellow Crowned Night Herons What are in the waters around Randall’s Island?

Blue crab Bluefish Asian shore crab Alewife Fiddler crab Window pane Green crab Summer flounder American eel Winter flounder Comb jelly Killifish Lion’s mane jelly Grass shrimp Mummichog Sand shrimp Atlantic silverside Eastern mudsnail Scup Periwinkle Tomcod Naked goby Needlefish Bay anchovy Northern pipefish Striped bass Atlantic menhaden Is there a correlation between herons and fish or herons and crustaceans?

alpha= 0.025 Heron, Fish, and Crustacean Counts 350 16 No significant correlation between Crustaceans and Herons on Randall’s 300 14 Island. 12 250 R=-0.14 10 200 p= 0.67 8 150

6 Count Heronsfor 100 4 Significant correlation between Fish Count Fish for andCrustaceans and Herons on Randall’s Island! 50 2 R=0.75 0 0 p= 0.0051 Bonferroni adjustment for Crustaceans Fish Herons multiple comparisons lowers our alpha value to 0.025