The Great Egret Roost Blitz 2012 Mapping and Monitoring Autumnal Waterbird Roosts in the NY/NJ Metro Area

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1 The Great Egret Roost Blitz 2012 Mapping and Monitoring Autumnal Waterbird Roosts in the NY/NJ Metro Area Mike Allen 1, Nellie Tsipoura 1, Susan Elbin 2, John Rowden 2, and Chip Weseloh 3 1 NJ Audubon, 2 NYC Audubon, 3 Canadian Wildlife Service

2 What is an Autumnal Roost? Communal sleeping area (usually in trees) Occupied from after breeding through Fall A time of wandering & migration for egrets Sizes vary, but often several dozen egrets Roosts ranging from 2 to 700+ reported in Ontario Often mixed-species Mainly egrets, cormorants, and night-herons Used perennially One in NJ active since at least since the 70 s (Rich Kane, pers. comm.).

3 What is an Autumnal Roost? Habitat characteristics Treed islands, trees over water (similar to breeding colonies) Can also be in shallow water or on mudflats (Ontario) Often central to good foraging areas May help newcomer migrants find food? In ON, whole roosts sometimes depart together for the same feeding area Sensitive to disturbance Known to abandon roosts, often temporarily

4 Photo by Allen Woodliffe

5 Methods: The Blitz Roost Blitz: September 14 th - 23 rd Asked NYC Audubon and NJ Audubon Harbor Herons volunteers to visit their sites from dusk to dark Note numbers of egrets, flight direction Visit again and triangulate A twilight fly-over of the Raritan Bay area Volunteer pilot working with LightHawk Post-blitz efforts: Followed up on tips from volunteers Reached out to other birders, professionals Additional scouting by car and by boat

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7 Methods: Monitoring Based on Chip W s Ontario protocol Visit 2x weekly if possible (not this time!) Count arrivals/departures in 10 min intervals Evening: min before sunset until dark Morning: min before sunrise until all birds leave Counts by staff and volunteers Mike Dixon, Debbie Schmidt, Liv Vreeland, Dan Morley and others

8 Results

9 Foraging Birds

10 Sites searched* / Roosts found Staten Island: Bridge Creek, other sites Queens: Jamaica Bay Meadowlands: Kearny Marsh, Sawmill Creek WMA, Laurel Hill, DeKorte Park, Harrier Meadow, Clay Ave. Raritan Bayshore: Cheesequake Creek, Natco Lake, Lake Matawan, Compton s Creek Bayonne / Jersey City: Lefante Walkway, Lincoln Park *Visited at dusk by NYC Audubon and NJ Audubon citizen scientists during blitz.

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12 Thanks to the NYC and NJ Audubon volunteers who helped find roosts! Joe O Sullivan Catherine Barron Jeff and Lynn Krauss Mike Dixon Liz Vreeland Debbie Schmidt Dan Morley Jim Ceravolo Bill Schultz Pat and Mike Hilliard George Pitcher Kirk Weber Ernie Lowenfels Lorraine Ninski Ian Garrison Jorge Monteagudo Lena Kelly Mike Britt Charlene Burke Tom Shinskey Lene De Coursin Camille Gutmore Jerry Golub Becky James Mike Fedosh Joe Fischetti (pilot) LightHawk (non-profit) Eileen and Stanley Smith Steve Gruber John Tyler Mike Fedosh Regina Sieben Special thanks to Laura Stern and Tom Smith for handling all the data!

13 Roost Characteristics All 8 were in mid-sized trees All 8 were next to water 6 of 8 near ~ freshwater Observed drinking Only 2 of 8 were on an island Closest together: 2.5 km

14 Species Composition In addition to Great Egrets: Gr. Blue Heron: at least 4 of 8 roosts (low # s) B.C. Night-heron: at least 4 of 8 roosts (# s varied) D.C. Cormorant: 2 of 8 (large # s at one, not other) Snowy Egret: 2 of 8 (separate area in Kearny) Cormorants outnumber Great Egrets at the Lake Matawan roost Snowy Egrets at the Kearny Roost sleep Separately from the Greats. Great Egrets at the Kearny Roost.

15 Roost Profiles

16 Kearny Roost Our largest roost, it has been in use since at least the 1970 s! (R. Kane, pers. comm.)

17 Lake Matawan Roost Our 2 nd largest roost, in use for at least several years. (L. Vreeland, pers. comm.)

18 Cheesequake Roost Our 3 rd largest roost, in use for at least several years. (B. Schultz, pers. comm.)

19 Seasonal Patterns Roost 11 evening counts, all starting min before sunset 4 morning counts, all starting min before sunrise

20 Reaction to Disturbance Cheesequake Roost 6:37 pm 6:39 pm Entering roost as boat approaches Most flushed as boat passed 6:41 pm 6:48 pm Waited it out in the marsh Back to normal

21 Reaction to Disturbance Kearny Roost: two duck hunters continually flushing the [BCNH] on the near abandoned RR bed Oddly enough, I don't think the hunters spooked any egrets once they got to the roost. Mike Dixon, Oct 6 th This roost had moved permanently 0.5km away by next visit on Oct 14 th

22 Timing of Roost Entry & Exit

23 Conclusions Roost characteristics / species composition Freshwater seems to be important Proximity to good foraging areas No clear species patterns, but mix similar to breeding colonies Seasonality / timing Need better coverage in future years Not a typical year? (Sandy) Timing info will help in planning next year Disturbance Reason Cheesequake & Kearny Roosts apparently moved? Is duck hunting a factor? It is in Ontario.

24 Next Year Find more roosts! Monitor the 8 known roosts Ideally, weekly starting in June-July and biweekly once they are active Try spring monitoring at largest roosts? Roosts are occupied more sparsely in spring

25 Thanks! Any questions?