New Important Bird Area Proposal in Addison County VT

 Snow Geese at Dead Creek Wildlife Management Area by Bryan Pfeiffer

Snow Geese at Dead Creek Wildlife Management Area by Bryan Pfeiffer

Maintaining biodiversity is an essential part of mitigating and adapting to the consequences of climate change. However in measuring biological diversity, we need to consider measures beyond species richness and look at functional and phylogenetic diversity as well. Functional diversity looks at the diversity in traits between species such as diet and how they travel. Phylogenetic diversity on the other hand looks at the evolutionary history of a species to determine the distance between species and their ancestors.

In an effort to conserve bird biodiversity, Audobon Vermont has worked with local agencies and individuals to identify and nominate Important Bird Areas (IBAs) throughout the state. These IBAs do not grant a specific legal status, but serve as a guide to identify priority areas for protection and conservation actions. Dead Creek Wildlife Management Area is the IBA identified in Addison County which spans 3000 acres of state managed wetlands, fields and forests. 

Above left left is a map of newly proposed IBAs within the Town of Middlebury. This was chosen because of the three biodiversity hotspots within Addison county, this was the area within a town that lacked specific management plans for the land. One of the hotspots was split between two towns which would have made it difficult to implement a management plan, and the other was within Green Mountain National Forest, putting it at less risk than these privately owned pieces of land. While involving multiple stakeholder may seem less ideal than a place like the Dead Creek Wildlife Management Area, I argue that efforts to do so will bring in a wider community together.

Management Plan for Middlebury IBAs

Since designation of land as IBAs does not grant an official legal status, conservation efforts depend entirely on volunteer efforts by local community members and landowners. With the specific make up of these particulars IBAs, stakeholders involved would be local community members, Middlebury Area Land Trust, Vermont Land Trust, Middlebury College, Middlebury Union Middle School and the Otter Creek Audobon Society.

This would be possible especially with Otter View Park and its proximity to Middlebury College, opening it up to possibilities of research and policy proposals through courses like the Environmental Studies Senior Seminar and other science classes. Jeffrey Murdock Nature Preserve is also directly opposite Middlebury Union Middle School and frequently used by its students for classes. Identifying these two areas as IBAs would incentivize existing education programs to invest more in these areas and heighten the sense of local agency in avian conservation. 

Other areas have conservation easements from either the VT Land Trust or Middlebury Land Trust. With these organizations intent on protecting these lands, identifying these areas as IBAs may incentize them to put into managerial policies in place (the data I collected indicated there was no plan in place). Since these lands were protected for farm land use, it would be important to either implement programs to steer away from that or write up recommendations for farmers using that land so as to mitigate the impacts of cultivating the land. Alternative ideas include building a recreation center near the wetland areas to attract ecotourism and allow for the local community to engage in these areas in a new way.

The Otter Creek Audobon Society already has a strong base in the Middlebury Community and could direct a lot of these volunteer efforts, pushing for local government to increase capacity to manage these lands and writing grants to maintain these areas. Middlebury College in particular could be an essential part of monitoring and evaluating the success of identifying these areas as IBAs with classes taught on GIS that could look at this as a case study periodically. Field work could also be done by college students and other schools in the area to increase the amount of data available on eBird. Community events held in these areas could also help raise community awareness.

Methodology and Limitations

In order to evaluate the biodiversity of birds, I looked at data on the location of different bird species in Addison County from eBird--a citizen science database for reporting bird observations. This gave me information at the species level but in order to assess functional diversity, I used data which sorted the species into guilds based on how they forage, migratory patterns and where they nest. Phylogenetic diversity was then assessed based on looking at the locations of families of birds. I created raster layers from running an Optimized Hotspot Analysis on each dataset to produce raster layers indicating hotspots of avian biodiversity. I then created a raster layer containing a weighted sum of these three raster layers to produce the colored raster layer seen in the map below.

I then looked at existing protected areas from the National Conservation Easement Database and Protected Areas Database to identify land that overlapped with the hotspots identified above. The particular IBAs above were chosen, as explained previously, mainly because they were most the areas that fell within a hotspot within a single town. I did not choose land with conservation easements which already had management plans in place. Being in Middlebury, it would also benefit from involvement with Middlebury College to monitor and manage the areas. These choices meant a strong base to build infrastructure to further protect these areas.

I was limited mostly by the timescale of the data, digitizing points from eBird from April to July of 2016. Comparing numbers during different times of the year could yield different results and further refine which lands should be declared IBAs. Data from different time periods could be compared and overlapped to identify biodiversity strongholds. I could also consult the Otter creek Audubon Society to get a sense of what the local community felt about the areas delineated by my data analysis and how that correlated with their understanding of potential areas in Middlebury. Involving local stakeholders in the process would also allow people to feel more invested in avian conservation action in the region.

Using data from eBird, a global citizen science database for reporting bird observations, I used GIS software to identify another potential IBA for Addison County. Through this I found that while the Dead Creek Wildlife Management Area covered a hotspot for species richness, when other dimensions of diversity were factored into the equation, it was not an area I would have prioritized as an IBA according to that criteria.

Nicole ChengComment