Surveying White Memorial's Bat Population

 

 This summer, White Memorial adds its efforts to an ongoing survey of Connecticut's bat species. Begun in 2010 by the Department of Energy and Environmental Protection, the survey uses sound recordings to monitor bat activity. Starting a half-hour after sunset and continuing until late at night, White Memorial's research technicians drive a 24-mile route through the woods roads of the property, using a truck-mounted microphone to record high-pitched sounds. The microphone is sensitive to sounds well above the range of human hearing, and records the calls of bats as they seek out insects for food, along with any high-pitched background noise from nearby telephone wires, insects, and radio transmissions. We'll pass these recordings on to the DEEP, where computer analysis will distinguish the bat calls from surrounding noise and identify the bats by species based on their unique sound patterns. We'll likely find evidence of big brown bats (Eptesicus fuscus), little brown bats (Myotis lucifugus), and northern long-eared bats (Myotis septentrionalis), all known to inhabit White Memorial's property.


     Relying on acoustic recordings of bats allows us to form a much more detailed picture of bat populations, distributions, and activity than do older methods such as counting bats caught in mist nets. Furthermore, as white nose syndrome continues to decimate bat populations in the eastern United States, bat monitoring has become increasingly important. The white nose fungus (Pseudogymnoascus destructans) has been present in Connecticut since the winter of 2007-2008, when it was found among hibernating bats in northern Litchfield county. Bats affected by the fungus exhaust their fat reserves and die during their winter hibernation. Monitoring efforts at White Memorial and in towns around Connecticut will help measure surviving bat populations, determine which species are affected and not affected, and provide long-term data against which management efforts can be judged.

BioBlitz 2016

     The White Memorial wildlife research team participated in this year's Connecticut BioBlitz, which was in Hartford. We are especially proud to have contributed this year, as Connecticut BioBlitz 2016 has set a new world record for most species identified in a 24-hour period!  A total of 2,765 species were identified in a variety of taxa including including plants, fungi, invertebrates, reptiles, amphibians, birds, and mammals.


Although we were focusing on mammals, it was hard not to get distracted by other wildlife, like this leopard frog.
      BioBlitz lasted from 3:00 pm on June 3rd to 3:00 pm on June 4th.  Scientists from a variety of fields participated, as well as members of the Hartford community. James Fischer, Molly Mullen and I, as well as several others from outside of White Memorial, focused our attention on mammals.  The goal was to determine what species were present in the area, so tracks or scat left behind by animals counted as much as seeing the animal itself.  We were very surprised by the variety of species living in and around the Hartford area.  Members of the mammal team saw woodchuck, white-tailed deer, gray squirrel, red squirrel, beaver, muskrat, and fisher.  Tracks and signs identified included red fox, flying squirrel, weasel, bobcat, and bear, as well as a variety of small mammals.  In all, 23 species of mammals were identified.  


Since we had to rely so much on tracks and scat, it was very exciting to see the animal itself.
    
     For more information on BioBlitz, check out their official website.  To see a complete list of the species identified this year, look at the iNaturalist BioBlitz page.





Amphibian Coverboard Monitoring

Spotted salamander
     
      Scattered throughout White Memorial in forested areas near wetlands are nineteen grids of coverboards, which are simply boards of untreated wood that are left on the ground. They have been in place for many years as part of a long-term amphibian monitoring program.  Amphibians like salamanders often shelter under rotting logs; the greater surface area provided by the coverboards allows us to find amphibians more easily than checking naturally occurring logs. 
     Amphibians are sensitive to a variety of environmental factors.  Unlike mammals, who gain minerals like electrolytes by eating, amphibians absorb those minerals through their skin.  Unfortunately, harmful things can also pass through their skin; they are extremely vulnerable to both local pollutants like farm runoff and  global ones like acid rain.  Climate change and diseases also threaten many species.  The parasitic fungus chytrid has been causing extinction in amphibian species all over the world, and a new flesh-eating fungus discovered on salamanders in England may be spreading internationally.  
     By monitoring our amphibian coverboards regularly, we will notice changes in amphibian populations and can use this information to try to determine a cause.  While we at White Memorial cannot end global climate change or acid rain by ourselves, we can attempt to stop the spread of diseases or address the sources of local pollutants.  
    Of particular interest to us are Jefferson salamanders, blue-spotted salamanders, and the hybrids that can result from those two species interbreeding.  Blue-spotted salamanders are endangered in the state of Connecticut, and are limited to several small, isolated populations.  The hybrids are state listed as species of special concern.  While blue-spotted salamanders and hybrids look very similar, hybrids tend to be slightly lighter in color, dark gray rather than black, and both have striking, sky blue spots.

Jefferson/Blue-spotted salamander hybrid
     We check coverboards once a month, and it takes a team of 3-4 people a day and a half to check all nineteen grids.  The most common salamanders we encounter are red-backed salamanders, which also have a "led" phase, meaning that while most individuals have reddish-brown backs, others appear gray-blue.  We also record any other amphibians that happen to be in the grids, like red-spotted newts, whose bright orange eft life-stage we usually see walking through leaf litter, as well as wood frogs, spring peepers, and American toads.  While checking coverboards, we try to disturb the amphibians as little as possible.  We do not handle the amphibians, and we try to cover salamanders quickly and gently after identifying them.
Led phase red-backed salamander