Toad nursery in way of improvements at airport
Biologist Tim Shields recently let the Haines Borough Planning Commission in on a little secret – there’s a pond at the airport teeming with toads.
One sunny day two weeks ago, Shields pulled back some brush at the pond to expose a pile of baby toads – as many as 500 heaped up in a softball-sized mound – in tall weeds close to the water.
The discovery was an affirmation for Shields that the pond, hidden from view behind a screen of trees and surrounded by airplane traffic, is rich breeding habitat for western toads, a species he and others believe experienced a sharp population decline here in recent decades and may only be starting to recover.
For now, the one-acre pond – which is part of Yendeistakye Creek and provides habitat for spawning and rearing coho salmon and for spawning and rearing Dolly Varden, according to the state’s catalogue of anadromous waters – appears likely to go away.
Citing an FAA policy against standing, open water at airports that attracts wildlife and increases the likelihood of collisions between birds and planes, the state Department of Transportation plans to fill the pond and pave it.
The state is starting to prepare an environmental assessment on a broader project there aimed primarily at improving drainage, part of the 2004 airport master plan, that calls for expanding the apron east to the pond.
The Haines Borough Planning Commission voiced support for airport improvements Aug. 8, but also will ask the state to investigate mitigation for loss of the pond, or to consider saving it entirely. A public hearing on the project in Haines is tentatively scheduled for October.
An independent reptile and amphibian biologist, Shields has been researching toads here for 11 years, specifically the reproductive success at some 25 road-connected ponds in the valley. The airport pond, called the East Pond, is the most reliably productive one he’s looked at, he said. The stream and pond are connected through a series of culverts to the Chilkat River.
“It has a consistent water supply. They lay their eggs there and know that the water will remain. If you’re an adult toad, that’s what you’re after. (The pond) produces tens of thousands of juvenile toads,” Shields said.
The decline of western toad populations in the species’ southern range in Colorado and New Mexico, due to a fungus, has been documented.
Toad numbers in Southeast also dropped in the 1980s and 1990s, also apparently due to the fungus.
Samples from toads around Southeast found the fungus here as well. A Fish and Game funded study from 2003-2005 found seven spawning ponds along the Juneau road system, one-tenth or possibly one-hundredth of the toad’s former habitat, said Richard Carstensen, a researcher on the project. “They really went downhill.”
Shields said evidence of a local decline here is anecdotal. It includes accounts he’s heard about large numbers of toads a decade or more ago in basements in Klukwan, on the beach at Chilkoot Lake and flattened by cars on streets downtown. Also, old timers often say they haven’t seen a toad in years, he said.
The toads are “incredible, insect-eating machines” that play an ecological role in limiting numbers of insect prey, an “important force in forest ecology,” Shields said. “If you remove them from the ecosystem, you remove a check on the populations of other creatures in the ecosystem.”
Shields said he doesn’t want the pond destroyed if it doesn’t need to be.
Cheryl Benson, an environmental specialist for the state Department of Transportation, said one of the factors behind the proposed action to fill the East Pond is to address potential safety concerns.
“Having standing water on an airport is never a good idea. It attracts wildlife. For the safety of both wildlife as well as users of the airport, we don’t want to provide an element that has the potential to cause a wildlife strike.”
Further, she said, toads exiting the pond end up getting squished by airport maintenance vehicles as well as aircraft traffic when they leave it, attracting birds and increasing the hazard of a strike.
Shields said waterfowl use the pond because of the protection from predators afforded by the screen of trees. Removing the trees might reduce bird traffic and improve habitat for the toads, he said.
Shields said the massive ball of juvenile toads or “mounding behavior” he discovered last week may be used to regulate body temperature, although researcher Carstensen said it may be a strategy toads use on sunny days to keep from drying out.
Benson, who has toured the site with Shields, said DOT is sensitive to environmental concerns with the project and already has dropped plans to build a shed for storage of snow-removal equipment during this stage of the project, due to space and environmental concerns.
Currently, the state Department of Fish and Game recommendations for the project include that DOT build a new pond “designed for rearing juvenile coho salmon and western toads” near the airport’s helicopter pad.
“How do you relocate a toad pond? You have to do it at a certain time of year when they’re at the right stage. We’re definitely not taking this lightly. We understand there’s a high level of interest in that pond,” DOT’s Benson said. She expressed confidence, saying that results of mitigation projects after the addition of a runway to the airport in 1992 showed the state could do major work in the area without negatively impacting fish.
As the toads don’t have protected status, DOT “is not under any legal mandate to give a fig” about them, Shields said. He said he got the impression from Benson that filling the pond is a done deal, reinforced by planning commissioners who said that, in the face of a bird-strike hazard, saving the pond would be a “hard sell.”
“With this pond destroyed, we can create other habitat,” Shields said. “It’s possible to do it, but replicating that pond, it’s not going to happen. We’re not going to make it. There’s no way we’re going to engineer something that’s that ideal.”
Shields said he’d like to have some say on the design of the mitigation project. “I’ve looked at what characteristics work for a successful breeding site.”