Bat Distribution & Abundance in the East Bay Regional Park District

David “Doc Quack” Riensche Wildlife Biologist II, Certified Wildlife Biologist ® [email protected] Acknowledgements – Bat Brigade

More than 16,000 volunteers More than 100,000 hours of volunteer service Acknowledgements - Institutions Regional Parks Foundation Alameda County Fish & Wildlife Commission Contra Costa County Fish & Wildlife Commission U.S. Fish and & Wildlife Service California Department of Fish & Game Key Messages • Background on Bats: Physical descriptions, natural history and conservation status. • Methods & techniques: visual/roost exit surveys, thermal imaging and acoustic surveys. • Results and Bat Distribution in EBRPD. • Discussion, conclusion & next steps. • Communicating science to help these special status species on their road to recover (“Bat Song” & Bat Quiz). Background

• Ecological services: Insect consumption and nutrient cycling (and pollination and seed dispersal in the tropics) • Threats: Habitat loss and fragmentation, climate change, pesticides, persecution by humans, toxic wastewater, wind farm development, and white-nose syndrome

Brazilian free-tailed bat eating a corn earworm moth

A bat affected by white-nose syndrome Background

• Order Chiroptera = “hand wing” • San Francisco Bay Area: 9 genera and 15 species • East Bay Regional Park District: From 2004 – present, staff conducted visual and acoustic surveys between April and November at 10 locations Pallid Bat • 7 genera and 8 species • 2 California Special Status Species • Pallid Bat (Antrozous pallidus) • Townsend’s Big-Eared Bat (Corynorhinus townsendii) Townsend’s Big-Eared Bat Vespertilionidae Family Vesper Bats, Evening Bats

• Largest family of Chiroptera • Mostly insectivores, rely on echolocation • Contains 7 of the 8 bat species recorded in EBRPD California Myotis • Pallid Bat (Antrozous pallidus) • California Myotis (Myotis • Townsend’s Big-Eared Bat californicus) (Corynorhinus townsendii) • Yuma Myotis (Myotis • Big Brown Bat (Eptesicus yumanensis) fuscus) • Canyon Bat (Parastrellus • Hoary Bat (Lasiurus cinereus) hesperus) Molossidae Family Free-Tailed Bats

• Free tail extends beyond the tail membrane (uropatagium) • Mostly insectivores • Only 1 species in this family recorded in EBRPD • Brazilian Free-Tailed Bat (Tadarida brasiliensis) Tail extends beyond membrane Brazilian Free- Tailed Bat Uropatagium (tail membrane) Mouse-Eared Bats Myotis ssp.

• Several species, difficult to distinguish • 2 species identified in EBRPD: California Myotis and Yuma Myotis. • Key characteristics: Myotis = “mouse-ear”, ears longer than wide, with a pointy tragus California Myotis • Known Locations: Del Valle, Sunol, Ardenwood, Anthony Chabot, Sibley, Cull Canyon

Yuma Myotis Pointy tragus California Myotis Myotis californicus

• Key characteristics: Small, 9” (22-23cm) wingspan. Fur is dull, light tan to dark brown. Ears and wing/tail membranes are dark brown to black ears. Keeled calcar (cartilage extending from ankle has a membrane flap).

Keeled calcar California Myotis Myotis californicus

• Habitat: Desert, chaparral, woodland, forest. Black ears • Emergence: Shortly after sunset. Activity peaks 1 hour after sunset. • Feeding habits: Slow, erratic flight. Hunts over water in open areas, along margins of tree clumps and canopies. • Diet: Moths and flies. Tan fur California Myotis Myotis californicus

• Activity: Roosts in crevices, hollow trees, under loose bark, in small groups or alone. May be found roosting or feeding with other species. Hibernates. • Known Locations: Anthony Chabot Dark ears and wing membranes

Tan to brown fur Yuma Myotis Myotis yumanensis

• Key characteristics: Small, 9” (22-24cm) wingspan. Tan to gray to brown fur on back, lighter fur on belly. Pale gray to brown ears and wing membranes. • Habitat: Open forest and woodland with water source. Fur is gray to brown to tan

Belly is lighter than back Yuma Myotis Myotis yumanensis

• Emergence: Just after sunset. • Feeding habits: Forages just above streams and ponds. • Diet: Small flying insects, Pale gray ears and beetles. Drinks water. wing membranes Yuma Myotis Myotis yumanensis

• Activity: Roosts in large groups. May roost or feed with other species, including the Pallid Bat and Brazilian Free-Tailed Bat. Hibernates. • Known Locations: Sunol, Del Valle, and Ardenwood

Darker back

Pointy tragus

Lighter belly Pallid Bat* Antrozous pallidus • * California Species of Special Concern • Key characteristics: Large size,15” (37-39cm) wingspan. Large ears and eyes. Light color, blonde to tan fur. Piglike snout. Skunk-like odor. • Habitat: Various. Most common in xeric habitats with rocky areas.

Large ears

Large eyes

Fur blonde to tan Pallid Bat* Antrozous pallidus

• Emergence: 30-60 min after sunset. Activity peaks 90-190 min after sunset and shortly before dawn. • Feeding habits: Forages 0.5- 2.5m (1.6-8 ft) above open ground. Slow, maneuverable flight with dips, swoops, glides. Gleans prey from ground or vegetation. Gleans prey from the ground • Diet: Adapted to hard-shelled prey. Insects, arachnids. Pallid Bat* Antrozous pallidus

• Activity: Social, usually in groups of at least 20. Hibernates in winter. • Very sensitive to disturbance. • Known Locations: Sunol, Black Diamond Mines, Cull Canyon Brazilian Free-Tailed Bat Tadarida brasiliensis

• Key characteristics: 11-14” (29-25cm) wingspan. Dark brown or gray. Free tail extends beyond the tail membrane (uropatagium). Wrinkled upper lips. Fast flier. Tail extends beyond membrane Wrinkled upper lip

Uropatagium (tail membrane) Brazilian Free-Tailed Bat Tadarida brasiliensis

• Habitat: Various. Prefers open woodlands, grasslands, shrublands. • Emergence: Shortly after dusk. • Feeding habits: Forages 30m (100ft) above ground. Rapid flight, ~25mph. • Diet: Mainly moths. Uses echolocation. Eating a corn earworm moth Brazilian Free-Tailed Bat Tadarida brasiliensis

• Activity: Small groups of males, or larger maternity colonies. Coastal and Central Valley populations hibernate. Roosts with other species. • Known Locations: Ardenwood, Anthony Chabot, Camp Arroyo Big Brown Bat Eptesicus fuscus

• Key characteristics: Medium to large size,13-15” (32-39cm) wingspan. Dark brown fur. Black ears and wing membranes. Rounded ears. • Habitat:Various. Common near human structures. Brown glossy fur

Black ears/ wing membranes

Rounded ears Big Brown Bat Eptesicus fuscus

• Emergence: At dusk. • Feeding habits: Forages 20-30 ft over open areas and near water sources. Slow, straight, steady flight. Territorial, forages along the same route. • Diet: Flying insects, primarily beetles.

Catching a moth in flight Big Brown Bat Eptesicus fuscus

• Activity: Hibernates in winter in the north part of its range. • More tolerant of human disturbances. • Known Locations: Redwood (Piedmont Stable), Cull Canyon (Formerly Western Canyon Bat Pipistrelle)

Parastrellus hesperus (Pipistrellus)

• Key characteristics: Smallest North American bat, wingspan 7-9” (19-22cm). Yellow to light gray to reddish brown fur. Black ears and wing/tail membranes. Keeled calcar. Emerges early. Similar to California Myotis, but tragus is club shaped, not pointy. Black ears Club-shaped tragus

Yellowish fur Very small size (Formerly Western Canyon Bat Pipistrelle)

Parastrellus hesperus (Formerly Pipistrellus) Black ears • Habitat: Deserts, grasslands, brushlands, woodlands. Rocky Yellowish canyons, cliffs, outcroppings. fur • Emergence: As early as 45 mins before sunset. Most active 1-2 hrs after sunset. Remains active after dawn. • Feeding habits: Forages on swarming insects 5-80’ (2-25m) above ground. Slow, fluttery flight. Sensitive to wind. Forages with other species. • Diet: Swarming insects, caddisflies, stoneflies, moths, small beetles, soft-bodied insects. (Formerly Western Canyon Bat Pipistrelle)

Parastrellus hesperus (Formerly Pipistrellus)

• Activity: Roosts alone or in groups, maternity colonies no larger than 12. Day roosts usually in rock crevices. Hibernates in winter in caves, mines, rock crevices. • Known Locations: Sunol, Black Diamond Mines Townsend’s Big-Eared Bat* Corynorhinus townsendii

• * California Species of Special Concern • Key characteristics: Medium size,12-13” (30-32cm) wingspan. Very long ears over 1” long, can be coiled up. Pale to black fur with lighter belly. Lumps on snout.

Very long ears, over 1”

Lumps on both sides of snout Townsend’s Big-Eared Bat* Corynorhinus townsendii

• Habitat: Mesic habitats. • Emergence: ~1 hour after sunset • Feeding habits: Forages along streams, forest edges. Slow, Catching a maneuverable flight; capable of moth in flight hovering. Captures prey in flight or gleans from foliage. • Diet: Mainly small moths. Townsend’s Big-Eared Bat* Corynorhinus townsendii

• Activity: Hibernates in caves or mines in clusters of few to 100s of individuals. Very long ears • Very sensitive to human disturbance, may abandon roost in large numbers. • Known Location: Sunol.

Lumps on snout Hoary Bat Lasiurus cinereus

• Key characteristics: Large, wingspan 13-16” (34-41cm). Thick, frosted fur, golden around face. Round ears. • Habitat: Woodlands and forests during breeding. Males in foothills and mountains, females in lowlands and coastal valleys during migration. Round ears

Golden fur around face Thick, frosted fur Hoary Bat Lasiurus cinereus

• Emergence: Late in evening. Activity peaks 3-5 hrs after sunset. May fly in late afternoon on warm winter days.

• Feeding habits: Fast, straight Golden face flight while foraging. • Diet: Moths, true bugs, mosquitoes, other insects, Thick, occasionally other bats. Drinks frosted fur water. Hoary Bat Lasiurus cinereus

• Activity: Solitary. Roosts in trees with dense foliage. Migrates. Winters along coast and in S. California. Hibernates in cold climates. • Known Locations: Tilden, Redwood Number of Bats by Park 2004 - 2019 Total Number of Bats by Species in EBPRD Future Efforts • Continued monitoring of bat abundance and distribution. • Development of a standard bat surveying protocol to improve survey data. • Mapping locations of all known existing bat colonies and bat houses. • Special attention given to the two special status species. Questions?

David “Doc Quack” Riensche Wildlife Biologist II, Certified Wildlife Biologist ® [email protected] Sources

• California Department of Fish and Wildlife, California Wildlife Habitat Relationships Life History Accounts, https://www.wildlife.ca.gov/Data/CWHR/Life-History-and-Range. • The IUCN Red List of Threatened Species™, www.iucnredlist.org. • NorCal Bats, http://www.norcalbats.org/aboutbats.shtml. • Western Bat Working Group, Western Species Accounts, http://wbwg.org/western-bat-species/. • Harvey, M. J., J. S. Altenbach, and T. L. Best. 2011. Bats of the United States and Canada. The Johns Hopkins University Press.