Bat Conservation and Forestry in NH A PRESENTATION TO THE NH ASSOCIATION OF CONSERVATION COMMISSIONS
JESSE MOHR, CWB, CF CONSULTING ECOLOGIST LICENSED NH AND VT FORESTER NATIVE GEOGRAPHIC, LLC 177 FAIRVIEW ST. FAIRLEE, VT 05045 PHONE: 802-933-1614 WEB: WWW.NATIVEGEOGRAPHIC.COM What’s So Interesting About Bats?
• Numerous species worldwide • Bats represents 20% of the world’s mammals • Only true flying mammals • Feet and legs adapted for hanging upside down • Legs too weak to jump off of ground to initiate flight Bats Eat Bugs – Lots of them! A year in the life of a bat
Spring (mid-April) emergence
Pregnancy Maternity initiated colony formed
Fall Swarming Hibernation (Oct – April) Pups born (mid-June)
Mating (Aug-Oct) All NH Bats Are Declining Hoary Bat Little Brown Bat State‐endangered
P.D. Pratt Hoary Bat Silver‐ C. Stihler Haired Bat Big Brown Tricolored Bat M. Tuttle Eastern Bat State‐endangered Small‐footed Bat State‐endangered
C. Stihler
Northern Long‐eared Bat Eastern Red Bat Federally Threatened and M. Tuttle A. Hicks, NYDEC State‐endangered A New Threat – White-nose Syndrome Symptoms
• White fungus on nose, ears, wings or tail • Pseudogymnoascus destructans • Not visible on all affected individuals • Abnormal behaviors • Leaving hibernacula in winter • Moving to colder places in hibernacula Mortality
• Starving to death. WNS causes bats to wake more frequently and stay-awake longer, burning up stored fat • Dehydration. Dehydration causes the bats to wake and search for water. WNS damages wings, which may reduce air/water exchange. Aeolus Cave • Bats, cavers/miners, and Vermont human gear can transmit the fungus. Bat Wings • Bat wings come in many shapes and sizes • Creates specialization and differentiation in how and where bats fly Bats of NH SPECIES PROFILES AND CURRENT CONSERVATION STATUS Red Bat (Lasiurus borealis )
• Wingspan: 11-13 inches • Weight: 7-12 grams (larger bat) • Roost: hangs in or below foliage • Solitary • 2-3 young per year • Migrates to southeastern US Photo M. Tuttle • Fast, somewhat maneuverable flier (medium-to-low clutter adapted species) Hoary Bat (Lasiurus cinereus )
Photo P.D. Pratt
• Wingspan: 13-16 inches • Weight: 20 to 35 grams (very large bat) • Roost: hangs in or below foliage • Solitary • 2-3 young per year • Migrates south • Fast, less maneuverable flier (low clutter adapted species) Photo C. Stihler • Some calls may be heard by human ears Silver‐haired Bat (Lasionycteris noctivagans)
• Wingspan: 11-13 inches • Weight: 7-12 grams (larger bat) • Roosts in tree hollows and under bark • Often roosts closer to ground • May roost singly or in small groups • Typically 2 pups, but may have up to 4 • Two pairs of breats • Migrates south • Slow, less maneuverable flier (low clutter adapted species) Photo M. Tuttle Northern Long-eared Bat (Myotis septentrionalis) Federally Threatened and State Endangered
• Wingspan: 9-11 inches • Weight: 5-9 grams • Roosts in cavities, crevices, and under bark of dead and declining trees • Females form maternity colonies of 60 bats or fewer • Prior to WNS, one of the most common bats 5.6 • Since WNS, 99% population decline grams • Slow, very maneuverable flier (high clutter adapated species) Eastern Small-footed Bat (Myotis leibeii ) Endangered in NH
B. Clifford NHFG
• Wingspan: 8-10 inches A. Hicks, • Weight: 4-8 grams NYDEC • Roosts in rocky slopes, crevices, and hillsides • maternity colonies of 20 bats or fewer 5.6 • Only one known winter hibernacula in NH grams • Uncommon prior to WNS • Very maneuverable flier (high clutter adapated species) Tricolored Bat formerly Eastern Pipistrelle (Perimyotis subflavus ) Endangered in NH
• Wingspan: 8-10 inches • Weight: 4-10 grams • Roosts within foliage, often clusters of dead leaves • Females may roost singly or form maternity colonies of 30 bats or fewer • Prior to WNS, known to winter in 3 of NH’s known hibernacula • Uncommon prior to WNS • Slow, very maneuverable flier (high clutter species) Little Brown Bat (Myotis lucifugus ) Endangered in NH • Wingspan: 9-11 inches • Weight: 5-14 grams • Roosts Photo A. Hicks • Females form larger maternity colonies that roost in warmer sites and exposures • Prior to WNS, maternity colonies of hundreds or thousands • Roost in attics, barns and other manmade structures • May also roost in hollows and under bark of dead and declining tree • Most susceptible species to WNS • 100% mortality in some hibernacula • 98-99% decline across northeast • Slow, somewhat maneuverable flier (moderate-to-high clutter adapted species) Big Brown Bat (Eptesicus fuscus )
• Wingspan: 13-16 inches • Weight: 5-14 grams • Roosts in attics, barns and other manmade structures • May also roost in hollows, crevices and under bark of dead and declining trees • Maternity colonies of 20-500 bats • Hibernates in mines/caves and manmade Photo C. Stihler structures • Fast, less maneuverable flier (low clutter adapted species) Forestry Measures for Conserving Bats and Functional Bat Habitat ASSESSING BAT POPULATIONS AND HABITATS, CRITICAL HABITAT FUNCTIONS, CONSERVATION AND ENHANCEMENT MEASURES Bat Surveys
SURVEYING BATS SURVEYING BIRDS
Acoustics/Ultrasonic Breeding Bird Auditory Surveys Echolocation Surveys Mist Netting Mist Netting Visual Studies and Nest Surveys Telemetry Telemetry Winter Hibernacula Surveys
Ecosystem Function Ecosystem function refers to biological, geochemical and physical processes and components that take place or occur within an ecosystem.
This may include a good or service that provides benefit to people (ecosystem services)
Biologists often apply this concept to habitats and their ability to provide a service to wildlife Habitat and Function Example
Large wetland habitat functions as a feeding area and drinking area for 8 species of bats. The riparian forest habitat along the edge of wetland may also function as a roosting area for 5‐6 species of bats.
The warm talus slopes and/or nearby ledges may function as a roost for small‐footed bats. Critical Habitat Functions for Bats Forage Drink Forage- • Bats primarily hunt insects on the wing Roost • Require healthy insect populations • Variable in how much vegetation or clutter free space Hibernacula is needed for flying and hunting Drink- Fall • Bats drink on the wing Swarm/Spring • Require still or slow moving surface waters free or Staging partially free of emergent and overhanging vegetation • Variable in how much vegetation or clutter free space is needed for flying and drinking Critical Habitat Functions for Bats Forage Drink
Roost Roost- Throughout the summer, migratory and nonmigratory bats sleep Hibernacula and raise young in roosts. Roosts vary depending on species Fall Cavities, crevices, and under exfoliating bark in dead and Swarm/Spring declining tree Other bats roost in or under pockets of dense foliage Staging Little and big brown bats also roost in structures. Pregnant and lactating bats generally roost in groups Males and non-breeding females are more likely to roost singly or in small groups Critical Habitat Functions for Bats Forage Drink Roost Hibernacula Hibernacula- Fall Hibernacula are shelters occupied during the winter Swarm/Spring by a dormant animals Require stable environments with suitable Staging temperature and humidity for hibernation Some variance between species, but mines, caves, and occasionally structures may function as hibernacula Critical Habitat Functions for Bats Forage Drink Roost
Hibernacula Fall Swarm/Spring Staging- Fall Late summer and fall, bats assemble and mate around hibernacula Swarm/Spring Spring, bats emerge from and stay near hibernacula Staging Concentrated use of the hibernacula entrance and feeding, drinking, and roosting resources in the surrounding landscape Bats may visit multiple hibernacula during fall swarm Common Habitats and Features of NH’s Forested Landscape and their Function for Bats
Mines and Structures Forest Ponds, Rivers, Streams, and Openings Trails and Forest Caves Wetlands Roads Hibernacula Hibernacula Roost Forage Drink Forage Roost, Forage, Forage Commute and Fall and Roost Commute Roost Swarm/Spring Staging Mines and Caves Limited resource in NH Only 7 mines provide hibernacula function More abundant in VT Winter hibernacula function for little brown bat, big brown bat, northern long-eared bat, eastern small-footed bat, and tricolored bat Swarming and staging site for same species Human disturbances can degrade function Further the spread of WNS Wake up hibernating bats Mines and Caves
CONSERVATION AND ASSESSING YOUR PROPERTY ENHANCEMENT Probably already know if you own Gates to limit access a bat mine Conservation easements to protect mine/cave, entrance, and surrounding Check for hibernacula within habitats for Fall Swarm/Spring Staging surrounding 1 mile using the NH Within 1 mile of hibernacula, retain Heritage Bureau DataCheck tool potential roost trees. Consider creating additional roost trees (see forests) If within 1 mile, assume that any habitats that provide foraging, Within 1 mile of hibernacula, protect all drinking, or roosting functions could surface waters and wetlands (see Ponds, Rivers, Streams, and Wetlands) be important for the Fall Swarm/Spring Staging Property owners with a mine entrance or within .25 miles of known mine hibernacula should consult with USFWS Mines and Caves
RESOURCES
NH Heritage Bureau DataCheck tool United States Fish and Wildlife Service New England Field Office Nongame and Endangered Wildlife Program of the NH Fish and Game Department (Sandra Houghton, Wildlife Diversity Biologist) Local NRCS Office Ponds, Rivers, Streams, and Wetlands Slow moving waterways free or partially free of vegetation function as drinking areas for all species of bats Larger bodied, less maneuverable bats (big brown, hoary, red, and silver- haired) require more open space with less clutter Smaller bodied, more maneuverable bats (NLEB, little brown bat, small-footed) require less open space and can navigate more clutter Air space above important foraging areas for all species Higher insect diversity and concentration Riparian areas may be a preferred roosting location for NLEB, Little Brown Bat (males and non reproductive females), Big Brown Bat (males and non reproductive females), Red Bat, and Silver-Haired Bat Higher concentration of declining and dead trees Increased solar radiation Adjacent flyways Partially forested pond with clear flyways. Extensive little brown and big brown activity. Also NLEB, silver-haired, hoary, and red bat. Vernal pool surrounded by closed canopy forest with lots of clutter in the midstory and with no clear flyways. No bat activity at pool. Ponds, Rivers, Streams, and Wetlands
ASSESSING YOUR PROPERTY Identify all surface waters and open wetlands on property. Also consider these features in the surrounding landscape (1 mile buffer) Can be done in Google Earth Range Rings and other extension allow you to create a 1 mile buffer Identify locations were riparian forest cover is limited or lacking Areas lacking riparian forest cover can easily be identified in Google Earth Narrow bands of riparian forest cover are also easily identified Also identify locations with extensive or more mature riparian forest cover Areas with extensive forest cover can also be identified in Google Earth Visit riparian areas looking for more mature looking forest Identify disjunct surface waters and wetlands on your property. Evaluate the distance and land use between the surface water or wetland and the closest forest patch or hedgerow Ponds, Rivers, Streams, and Wetlands
CONSERVATION AND ENHANCEMENT Maintain or establish continuous riparian forest and wetland buffers. The bigger the better During a timber harvest 25ft of no vegetation removal or harvesting Additional 100-125ft of partial harvest buffer (no more than a 25% canopy removal) Meet or exceed all state BMPs/AMPs for erosion control and water quality protection Within forested buffers, consider enhancing roosting functions by creating 6-8 snags per acre If large diameter cavity trees are limited, consider placing a bat box or multiple boxes along or near the shoreline If your property includes a high quality surface water, wetland, or riparian area, consider conserving your land If your property lacks a forested or otherwise relatively natural riparian buffer, consider a riparian buffer planting Consider connecting disjunct water sources to existing forest patches by allowing natural regeneration and/or a riparian forest buffer planting Ponds, Rivers, Streams, and Wetlands
RESOURCES
Local NRCS Office. Technical and financial support for bat boxes, riparian forest buffers, and wildlife management plans. UNH Extension County Forester Land Trusts for inquires and support for land conservation Good Forestry in the Granite State publication (available for free online) Google Earth Range Rings Extension: http://www.metzgerwillard.us/rings/rings.html Forests Forests function as roosting areas for seven species of bats. Roost preferences vary by species NLEB roost in cavities, crevices, and under exfoliating bark Often in dead and declining trees. Reproductive females and male/non-reproductive females both roost in forest Generally prefers deciduous trees and white pine in deciduous or mixed forests Tri-colored bats, red bats, and hoary bats roost by hanging in foliage Hoary bats prefer coniferous trees and coniferous or mixed forest types Tri-colored and red bats generally prefer deciduous trees. Tri-colored bats prefer deciduous forest types while red bats will utilize a variety forest types Little brown and big brown bats also roost in forest Maternity colonies generally in heated structures Males and non-reproductive females in cavities, crevices, and under exfoliating bark Forests Not all roost trees are created equal. Generally bigger is better. Some evidence that multiple species show a preference for the largest/tallest trees Better able to accommodate maternity colonies More micro-sites More likely to support a greater diversity of all wildlife species Large snags and cavity trees often remaining standing longer than smaller snags Supracanopy trees or trees taller than surrounding forest are an important roosting resource More open flyways More solar radiation Long-live deciduous trees (maple, oak, yellow birch) persist longer and are better at forming large cavities Evidence that multiple species of bat prefer a more mature forest for roosting NLEB Lower Canopy Roost Tree NLEB Upper Canopy Roost Hoary Bat Roosting in Foliage
Red Bat Roosting in Foliage Forests Forests function as foraging areas for NLEB and other more maneuverable bats (small-footed, tri-colored and little brown bats) Some evidence that NLEB foraging activity is higher in slightly more open forest Forest trails and roads may be used as foraging areas and travel corridors for multiple species of bats NLEB and other more maneuverable able to forage along smaller more cluttered roads and trails Large bodied, less maneuverable bats primarily restricted to larger, less cluttered forest roads Partially harvested forest and logging trail with NLEB, Little Brown, Big Brown, Hoary, and Silver-haired activity. NLEB activity includes foraging, while most of the other species appeared to be mostly commuting along the trail or above the canopy. Closed canopy forest and older logging trail with moderate to high amounts of clutter in the trail and surrounding forest. No activity recorded along trail. Big Brown, Hoary, and Silver-haired activity above the main canopy . Forests
ASSESSING YOUR PROPERTY Ask forester to tally snags, cavity trees, and potential roost trees during inventory Done with limited additional cost in modern forest inventory softwares Identify locations with larger diameter cavity trees, supracanopy trees or pockets of mature forest Identify locations that have a high density of dead or declining trees and other potential roost trees Utilize NHB datacheck tool to assess for the presence of any known NLEB roost trees on the property or surrounding 1 mile landscape If within 1 mile if a known NLEB roost tree, assume that forest may provide roosting function Forests
CONSERVATION AND ENHANCEMENT Keep forests as forest. If you have a large forestland consider conservation Plan the timing of any tree cutting to minimize potential additive loss of adults and impacts on young bats when they are not yet capable of flight by: (1) cutting trees only in the winter (best for the bats) or (2) cutting trees anytime but June and July (good for the bats). If a June or July harvest or tree cutting is necessary , conduct a bat survey to determine bat presence/absence. If NLEB, tri-color, or undetermined myotis is present, consider a winter operation Seek to maintain a mature forest across the majority of the property, but utilize timber harvesting in some locations to encourage a variety of tree sizes, ages, and opening sizes. Forests
CONSERVATION AND ENHANCEMENT Set aside some forest as a reserve, allowing old forest conditions to develop Except where safety or forest health risks are any issue, retain all snags, cavity trees, and other potential high value roost trees. Larger diameter and supracanopy trees are a priority During a commercial timber harvest, maintain or enhance roosting functions by creating clusters of 6-8 snags per acre If habitat assessment indicates these features are poorly represented on the property and commercial harvest is not planned, consider a standalone treatment to create snags Do not cut trees within 150ft of a known NLEB roost tree Property owners within 150ft of a known NLEB roost tree should consult with USFWS Openings Openings in forested landscapes may include Log landings, areas of brush or regenerating forest, clearcuts, patch cuts Old or active fields, wildlife food plots, or other mowed areas lacking tree cover Varied preference among species, but openings important foraging areas for all species. Lush growth can foster insect diversity and mass NLEB may avoid larger openings or center of larger openings Little brown and tri-colored bat appear to forage in a variety of opening sizes Larger bodied, less maneuverable bats (big brown, hoary, red, and silver- haired) require larger openings and openings with less retention/clutter Small, cluttered seepage opening with NLEB Activity Large log landing (~1-acre) with no clutter. Big brown, hoary, and red bat activity Openings
ASSESSING YOUR PROPERTY Evaluate the abundance of larger temporary openings (clearcuts, patch cuts, windthrow) and areas of regenerating forest cover on the property. Also consider these features in the surrounding landscape (1 mile buffer) Can be done in Google Earth Range Rings and other extension allow you to create a 1 mile buffer Evaluate the abundance of permanent openings (fields, log landings) and areas of open herbaceous vegetation. Also consider these features in the surrounding landscape (1 mile buffer) Openings
CONSERVATION AND ENHANCEMENT Larger openings should be created in moderation and with due diligence Openings represent a loss in NLEB roosting function Other ecological consequences, including spread of invasives, fragmentation, nest parasitism If openings, regenerating areas and associated foraging functions are limited on the property and surrounding landscape, consider creating some larger openings with patch cuts of 1-3 acres in size maintaining old fields with rotary mowing creating a new herbaceous opening or shrubland Openings CONSERVATION AND ENHANCEMENT When creating larger openings through timber harvesting: retain scattered live trees, snags, and islands of uncut supracanopy, overstory and midstory trees try to time harvest so it does not occur in the same year as other harvesting and/or land clearing in the surrounding landscape (1 mile buffer) conserve roosting functions by creating clusters of 6-8 snags per acre place opening near existing edges to maximize interior forest Consider making openings by creating clusters of snags through girdling, rather than creating openings through timber harvesting Maximize the foraging function of openings by creating feathered and non-linear edges between forests and openings If large diameter cavities are limited, consider placing a bat box(es) along or near the edge of an opening Forests and Openings
RESOURCES
Local NRCS Office. Technical and financial support Consulting foresters and biologists UNH Extension County Forester Good Forestry in the Granite State publication (available for free online) Google Earth Range Rings Extension: http://www.metzgerwillard.us/rings/rings.html