Birder Information

​​​​​​Below are bird count reports made by birders at the now closed research wetlands. When the new wetlands is open to the public, we will encourage birders to visit and make reports like those below. Meanwhile, the reports below can be used as reference as to the type and number of birds that have visited Tres Rios in the past, and perhaps the future.

Tres Rios Bi​rd List

Download a map of the Tres Rios Wetlands, which includes parking information

Tres Rios Waterbird Census Report
Saturday, January 18, 2014
Survey conducted by Justin Jones and Melanie Herring

View the Report

Tres Rios Christmas Bird Count
Friday, December 20, 2013 
Survey conducted by Melanie Herring, Barb Meding, and Laura Ellis 

View the Report

Tres Rios Waterbird Census Report
Saturday, January 19, 2013
Survey conducted by Justin Jones

View the Report

Tres Rios Christmas Bird Count Report
Monday, December 17, 2012
Survey conducted by Troy Corman and Justin Jones

Justin Jones and I spent the past weekend scouting for the Phoenix-Tres Rios CBC. The count was December 17, 2012 under clear skies and cool temperatures. While scouting a mile or so section of the 91st Avenue Wastewater Treatment Plant's effluent channel along the north edge of the lower Salt River bed, plus the adjacent Tres Rios Wetlands, we were surprised to find 10 species of warblers. The pressure was now on to try to relocate as many as we could for the count. Well long-story short, we did not find 10 species, we found 11! It took a coordinated effort from two teams to do it, which included Tommy DeBardeleben, Justin Jones and Tom Lewis. Among the hordes of YELLOW-RUMPED WARBLERS (we counted over 400!), we found the following other warblers: ORANGE-CROWNED, COMMON YELLOWTHROAT, BLACK-THROATED GRAY (5) and individual YELLOW, WILSON'S, NORTHERN PARULA, AMERICAN REDSTART, CHESTNUT-SIDED, and BLACK-AND-WHITE. Our final surprise warbler came just before sunset when Justin heard an odd chip coming from an exotic pine at the edge of an isolated wooded grove. This proved to be a very late HERMIT WARBLER.

Another interesting observation was the current nesting activities of hundreds of NEOTROPIC CORMORANTS at the Tres Rios Flow-Regulating Wetlands (FRW). This is the 200+ acres of fenced in wetlands that is immediately west of the Phoenix 91st Avenue wastewater facility. My understanding is that due to regulatory agencies permits, these wetlands are primarily closed to the public and are different than the adjacent Tres Rios Overbank Wetlands (OBW). The latter wetlands only require a Parking and Ingress Permit from the City of Phoenix*and you can then enter via walking or biking to explore the 2.5 miles of wonderful marshes, ponds, riparian, and brushy areas. Since there has been some confusion, I just wanted to clarify the difference regarding these two adjacent wetlands. Anyway, back to the cormorants. Apparently, during the late summer or early fall, these cormorants began to construct nests in the young willows and cottonwoods on several of the islands. Likely due to the unseasonable warm temperatures the past few months, this colony has continued to breed with many new pairs joining in. Over the weekend, we estimated there were still at least 250 active nests. Some nesting pairs were just getting started with nest construction, while others appeared to be incubating eggs, and still other nests contained very large nestlings that will soon fledge. With likely well over 1000 Neotropic Cormorants already within this area of the Valley, it will be interesting to see how large this colony will become.

Hope to see you in the field...

Troy Corman, Phoenix, AZ       

*Birders and wildlife photographers interested in obtaining a Parking and Ingress Permit should send their postal mailing address to