Date: 8/29/19 12:54 pm
From: Bennett, Chris (DNREC) <Chris.Bennett...>
Subject: [de-birds] Last Night's Evening Heronry Survey
Delaware State Parks staff with the help of three volunteers conducted the final evening heronry survey of the 2019 season last night in Delaware City. We once again dodged the iffy weather with only a very brief sprinkle that lasted about 2 minutes at the very beginning of the survey. As is usually for the August survey it started out very slowly with a grand total of 17 birds in the first hour. Things picked up considerably in the second hour with 118 in the first 30 half of that hour and 554 in the second half. Things tailed off in the last 25 minutes with 84 birds being recorded. We stopped five minutes short of the scheduled 8:10 stop time due to low light levels making it nearly impossible to see birds. As in the other surveys this year, the majority of the Cattle Egrets we counted were flying to the heronry from New Jersey. Most of those originated south of the island from the direction of Salem. This is a major shift from past years when most Cattle Egrets we counted were flying in from the west - many right down the branch canal. We ended with a total of 774 birds of eight species (only the third August survey with 8 species being recorded). It was pretty close to a direct count since only seven of those birds were counted leaving the island. This is the fifth highest total for an August count and about 100 birds over the average and nearly 200 over the median for all pervious August surveys. Additionally there were at least 25 to 30 white birds perched in trees in the heronry when we started along with a few birds feeding on the exposed beaches that we could see from Battery Park. We counted two Tricolored Herons - only the third time that we have recorded this species during an August survey (the others being 2018 and 2015). As is usual for an August survey Cattle Egret and Little Blue Heron made up the bulk of the total - 676 or 87% of the total. However seven of the eight species were counted in numbers that exceeded the average and median for all previous surveys. The eleven Great Egrets we counted was just a fraction below the average of 11.67 and above the median of 6. Typically by this time of year the majority of the birds that nest in the heronry have begun their southward migration or roost for the night near the areas where they feed during the day.

The first survey of 2020 is a mere six months away and will be conducted Wednesday, February 26 beginning at 3:51 pm. Below are the totals for yesterday's survey in the following format:

Species - total flying TO the heronry/total flying FROM the heronry:Total recorded - average of all previous August surveys/median of all previous August surveys

Great Blue Heron 6/1:7 - 2.07/1
Little Blue Heron 300/1:301 - 255.53/281
Tricolored Heron 2/0:2 - 0.2/0
Great Egret 10/1:11 - 11.67/6
Cattle Egret 375/0:375 - 349.8/257
Snowy Egret 25/1:26 - 8.47/4
Black-crowned Night-Heron 0/3:3 - 1.53/1
Glossy Ibis 19/0:19 - 11.07/10
Unidentified White Heron 30/0:30 - 32.67/10
TOTAL 767/7:774 - 685.73/585

We did have time in the first hour to look at other birds - though we did not see or hear anything out of the ordinary for this location at this time of year. If you are interested in what I noticed during the survey period here is a link to the eBird checklist:

Chris Bennett
Environmental Stewardship Program Manager
Division of Parks and Recreation

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