by Lynne Jackson
The first part of this series was printed in the February/March, 2005 newsletter and is a summary of a presentation given by Neil Gifford at the October, 2004 SPB lasagna dinner.
The Karner Blue Butterfly Federal Recovery Plan has three priorities. In New York State, scientists are focussing on priority one, which is doing those things necessary to prevent extinction of or the irreversible decline of the species, everything from monitoring populations to creating and implementing a management plan for the butterfly, to purchasing land.
The question for the Albany Pine Bush Preserve Commission to answer is, “how do we interpret this federal document and implement it here, in the Pine Bush and bring recovery to fruition?”
There are three sub-populations left of Karner Blues remaining in the Pine Bush: the Crossgates sub-population which contains about 5.5 acres of occupied habitat; the Apollo Drive cluster of sites, which makes up one sub-population (a patch of lupine within 200 meters of each other is considered the same sub-population); and the Curry Road site. Unfortunately, no butterflies have been seen at the Willow Street site in the past four years.
The current challenge at the Commission is to ensure that there is a suitable number of butterflies and a suitable amount of occupied habitat. The current Preserve size is about 2,940 acres; and the goal is to have 4,650 acres in the Preserve.
To meet this challenge more butterfly habitat must be created. Five years ago, there was only 10-15 acres of occupied habitat. The amount of habitat has tripled in the past couple of years.
Another goal is to have Karner Blue populations spread throughout the Pine Bush preserve.
The Commission began monitoring Karner Blue butterfly sites in 1991. The monitoring is financially supported by the NYS Department of Environmental Conservation, The Nature Conservancy, and US Fish and Wildlife Service. The method used to count the butterflies is one where the researcher walks a set path through a lupine patch and counts butterflies. These same paths are walked in the same patches every year. This allows comparison of numbers from year-to-year in the same patch.
The overall trend from 1995 to today is a decline in the numbers. For example the Crossgates site is definitely in trouble. Peek butterflies counted at this site in 1996 were around 150. By 2002, 5 butterflies were counted in the spring brood. The 18-theaters were built adjacent to the Karner Blue butterfly hill in 1997 – it is after this time that the number of butterflies declined so dramatically.
Typically, the summer brood of butterflies is three times the number as the spring brood. Small populations, over-time, are trending toward extinction.
Over the 13 years the Commission has been monitoring sites, there are a number of things the Commission has noticed. Populations of butterflies tend to fluctuate. Small, isolated sites are extremely vulnerable to stochastic or random events. The trick to surviving the bad years, is for a site to have enough butterflies to deal with the stress.
Site expansion, making the sites bigger and connecting them, is the key to survival of the butterfly. Currently, there is not enough habitat, high-quality habitat or connected habitat in the Pine Bush.
In regards to butterfly populations, how do we know where we are and where we need to go? The Nature Conservancy has developed a tool called “measures of success” that tries to do just that. Starting with an ecological conceptual model of the Karner Blue, which include dozens of factors affecting the viability of the butter, we boil this down to a couple of key critical factors that affect the survival of the Karner Blue and that we can do something about.
The factor that we can do the most about in the short term is habitat. The next question to answer is “what is it about habitat that we need?”
Variables which affect Karner Blue habitat include availability of larval food, shade, places to hide when raining, when its cold, at night, and adult food.
The Federal Recovery Plan, as big as this document is, gives general guidelines about habitat, but does not give a lot of detail about how to achieve the goals. Here in New York, the Commission is trying to develop a proscriptive tool that will rate the status of individual habitat.
For example, the Federal Recovery Plan outlines that for the overall population in Glacial Lake Albany to be considered recovered, a certain number of viable populations are needed, with each one needing to consist of a certain number of subpopulations consisting of a certain number of individual butterflies. These then need to be a certain distance from a neighbor, and they need to be connected.
The Commission has adopted an adaptive management strategy to develop a system to identify suitable habitat for the Karner Blue. Scientists need to know what needs to be done to habitat to encourage the butterflies. Is there enough lupine? enough nector? too much shade? not enough shade? After the habitat is modified, by planting lupine, nector plants, grasses and other species, the number of butterflies found will tell whether the modification worked or not.
So, what is being done for Karner Blue habitat restoration in the Pine Bush? The Commission is focusing on the federal strategy which includes expanding existing sites, linking sites together, and building the population numbers up to a point where they are viable. The habitats being worked on now include high quality pitch-pine scrub oak barrens, disturbed and invaded sites, such as old agricultural fields such as is found in Guilderland and Colonie, and locust clones found in high quality pine barrens around the existing Karner Blue butterfly sites.
The Commission is developing a supply of local seeds, and is not planting lupine from the Midwest or New Hampshire. The Commission uses a large machine to plant the seeds. This year 40 acres were planted, 55 acres are planned for next spring. The plan is to plant 20-50 acres of Karner Blue habitat for the next 20 years.
The habitat changes the Commission has implemented around Apollo Drive site include removing locust clones around SEFCU building and west of Rt 155. Next, they are planning to plant lupine in high quality barrens that have been burned. In the past, the controlled fires have not created conditions that allowed lupine to be planted. This year, for the first time they have. The site was burned and planted lupine in July. By August, there were lupine seedlings.
Part Three will be published in the June/July Newsletter