The following article describes threats to whooping cranes from habitat loss and human disturbance. In recent years, there have been ongoing habitat losses and we thought our viewers would benefit from articles by biologists who work closely with the birds. This article was originally published in our Whooping Crane Conservation Association’s (WCCA) Grus Americana newsletter. We thought you may like to review it to learn what prompted WCCA to recently purchase whooping crane habitat in Texas.
Land development is happening on the Texas coast, and happening quickly. I know of 4 developments planned for lands on which I have observed whooping cranes foraging. The proposed developments are waterfront canal lot subdivisions, places for folks from Houston and San Antonio to keep a boat on the coast and have a second house. This pressure near the crane wintering area has literally sprung up in the last 3 years; I don’t know of anyone that expected it to happen this rapidly.
This type of development is not unprecedented. The small town of Holiday Beach on the Lamar Peninsula was built next to salt marsh that is now occasionally used by whooping cranes. When that development was built, whooping cranes numbered less than 70 in the Aransas-Wood Buffalo flock and the cranes had no need back then to use the salt marshes next to what is now Holiday Beach.
What does all the impending development mean for whooping cranes, and can the species be adequately protected? Let me give you some examples of what is happening. Two developments will potentially impact the 24 whooping cranes that utilize Welder Flats which is located across San Antonio Bay north of Aransas. In 2006, a developer applied to build 776 homes on 680 acres in a development to be called “The Sanctuary” located across the Gulf Intracoastal Waterway from one whooping crane winter territory near Port O’Connor. I had seen whooping cranes on a few occasions using the salt marsh on the edge of the proposed development, and once watched a family group walk from the marsh into the uplands to forage. In the process of formal consultation under Section 7 of the Endangered Species Act, the USFWS decided that the development would not likely jeopardize the continued existence of the whooping crane.
The Service negotiated with the developer who agreed to do certain things to avoid and/or minimize impacts to the cranes. These included not building any houses in the salt marsh, protecting the salt marsh with a non-development easement, creating freshwater wetlands on one edge of the development to replace wetlands impacted, and providing $200,000 to a conservation group to be used to purchase non-development easements on lands important to whooping cranes. Although a salt marsh and freshwater marsh will be created and include a buffer between them and the homes, no buffer was established along the existing salt marsh strip, so I anticipate that whooping crane use in the remaining narrow strip of salt marsh will be very low due to human presence. A permit for this development was granted by the Corps of Engineers and construction is ongoing.
“The Sanctuary” development near Port O’Connor, Texas that has begun construction. The photo shows the close proximity of the developed area (light color) to a whooping crane territory on nearby Dewberry Island. Photo by Tom Stehn, taken 8/3/07.
Currently, the pending application by a developer to build 918 residential lots and marina on 700 acres near Seadrift, Texas will remove 136 acres of whooping crane critical habitat. However, that habitat is not the valuable salt marsh used by the cranes on a daily basis. Instead, it is more of an upland/drier marsh habitat, the type of habitat that the cranes only occasionally use to search primarily for wolfberries in the fall or for other food items when foods in the marsh are scarce. Again, I anticipate some kind of conservation easement will be provided to create a buffer between the houses and the salt marsh used by the cranes. I have recommended 300 yards as a reasonable buffer that the cranes need for areas they use to be mostly protected from human development. The developer will also create some small freshwater marshes and provide a permanent source of drinking water needed by the cranes.
It is important to note the size of these two developments (918 homes and 776 homes). Presently, the only 2 towns in that immediate area are Port O’Connor (population 1,184) and Seadrift (population 1,352). Each development will basically be adding another small town to the Texas coast, increasing demand for fresh water and electricity, and putting more recreational pressure on the lands where the whooping cranes winter. So far, the 2 developments have not physically destroyed the valuable salt marsh habitat preferred by the cranes, but the presence of so many houses near the marsh has me very concerned about human disturbance issues. The purchase of non-development conservation easements on salt marsh and adjacent upland properties used by the cranes would adequately provide needed habitat with a minimum of human disturbance and is an action needed to protect the cranes.
I hope in the next year to update a paper I wrote in 1985 about territory size and the slow expansion of the crane range at Aransas that I have observed in 25 years of doing census flights. With the help of our refuge GIS person, we will measure the acreage of the current crane range, assess how it has changed in size over the years, measure how much adjacent unoccupied habitat is available, and come up with a figure of how many whooping cranes the existing habitat at Aransas will support. I’ve always said there is enough habitat to support 500 whooping cranes at Aransas as the cranes continue to spread out the length of Matagorda and San Jose Islands. But I’m anticipating that our analysis will show that there is not enough existing habitat to provide for 1,000 whooping cranes, the minimum number required for downlisting from endangered to threatened status. And as the Texas coast gets developed, will enough habitat be preserved to winter 5,000-7,000 whooping cranes, possibly the minimum number needed for recovery?
Whooping cranes face many threats including development, reduction of fresh water inflows that will reduce blue crab populations, sea level rise that is expected to make much of the crane marshes too deep for the cranes to use, increasing development in the migration corridor (power lines, wind farms, cell towers), and introduced diseases. I am working closely with the USFWS –Ecological Services to analyze the cumulative impacts that the cranes are facing to determine at what level jeopardy would occur. Currently, I feel strongly that the whooping cranes are facing “death by 1,000 cuts” which is hindering the recovery of the species.
****Tom Stehn, Whooping Crane Coordinator, USFWS****
(From WCCA’s Newsletter section, Fall 2008)