An "Upright and Spread Wing" Feeding Ground Threat Display
Observed: Friday November 25, 2011
Updated: June 2, 2012
This page provides a description of an "Upright and Spread Wing" feeding ground threat display by two Great Blue Herons at Blackwater National Wildlife Refuge, MD. Photographs of the entire display sequence can be viewed here or by clicking any of the thumbnails that accompany the narrative.
I would like to thank Dr. James Kushlan of the Heron Conservation organization for confirming my interpretation of the Great Blue Heron behavior that I had photographed. The Heron Conservation organization is "the world’s leading body of scientific, practical, and conservation expertise on the biology, status and conservation of the herons (Ardeidae) of the world". Dr. Kushlan is the co-founder and Chair of the IUCN Heron Specialist Group. To learn more about the organization's work, visit them on line at www.HeronConservation.org. General information about the Great Blue Heron can be found at the Heron Conservation's web page. The "Upright and Spread Wing" and other heron behaviors are described by Dr. Kushlan in .
I would also like to thank Arthur Morris (www.birdsasart.com) for his suggestion that I reword part of my original description to clarify that this is a form of threat display. As is noted in Dr. Kushlan's paper, herons will defend their feeding areas. Herons exhibit several forms of defensive and territorial behaviors in addition to this particular feeding grounds interaction.
I was photographing the marsh wildlife and scenery along Wildlife Drive at the Blackwater National Wildlife Refuge (BNWR). The weather that day was unseasonably warm: the temperature reached approximately 70F, and the sky was virtually cloud-free. At approximately 4:00PM (EST) I glimpsed a single Great Blue Heron flying overhead (in an approximately southwesterly direction) toward the marsh. I started to take a sequence of shots to capture it in flight since it appeared it would land in the marsh and the golden side-light of the late afternoon sun. It landed in very shallow water approximately 200 feet from my location on the drive.
With its back to my camera (Canon 50D, 100-400mm f4.5/5.6 lens) I continued to take photographs as it extended its wings horizontally to its maximum wing span. With its wings held up high above the water surface, it turned parallel to the road and began to “trot” across the water quickly slowing down to a “walking pace”. It initially held its left wing arched up at the elbow while keeping its right wing stretched out and held somewhat parallel to the water.
Its wingtips were then lowered and they began to skim the surface of the water: initially the left wingtip and then both wingtips (simultaneously) skimmed or “dragged” along the surface of the water as the heron continued at a walking pace.
At this point a second Great Blue Heron appeared in the marsh to my left.
I had been paying attention to photographing the first heron, so I did not see when the second heron appeared on the scene. The second heron was approximately 20-25 feet away from the first. It was at this point that I noticed that both herons had raised their heads by stretching their necks to what appeared to be their full extent. Their bills were pointed up towards the sky at about a 45 degree angle. As they approached one another their wings skimmed/dragged along the water surface. The first heron then appeared to navigate somewhat behind the second heron: both were generally moving toward the shore and Wildlife Drive. As it closed the distance behind the second heron (perhaps within 10-15 feet), the first heron’s behavior changed somewhat: it raised its left wingtip out of the water, dragged more of its right wingtip in the water, and proceeded to walk “behind” the first heron. Eventually each heron walked away from one another and went their separate ways.
The entire sequence from the landing of the first heron to the conclusion of their “dance” was about 30 seconds. The herons never came into physical contact with one another, nor did they make any vocalizations. If any sounds were made I may not have heard them due to their distance and/or due to the sounds from other wildlife that were in the vicinity (e.g., Canada geese).
 Kushlan, J. A. 2011. The terminology of courtship, nesting, feeding and maintenance in herons; which can be downloaded here.
BNWR activities and recent sightings can be found at the Friends of Blackwater Facebook page.