77.

New Zealand Long-tailed Bat

Chalinolobus tuberculatus

French: Chalinolobe de Nouvelle-Zélande / German: Neuseeland-Lappenfledermaus / Spanish: Calinolobo de Nueva Zelanda

Other common names: Long-tailed Bat, Long-tailed Wattled Bat

Taxonomy. Vespertilio tuberculatus Forster, 1844,

New Zealand.

Relationships unclear but perhaps closest to C. migrogriseus or C. morio, based on morphology. Populations of North and South Island were suggested perhaps to be distinct races, based on limited genetic data, size differences, and echolocation distinctions but more detailed genetic data show no consistent genetic differences; they maintain limited gene flow despite their fragmented range and regular population crashes. Monotypic.

Distribution. New Zealand, including Great Barrier, Little Barrier, Kapiti, and Stewart Is.

Descriptive notes. Head-body 42-63 mm, tail 30-46 mm, ear 7-2-14 mm, forearm 367-46 mm; weight 7-1-12-5 g. Head is broad with a high forehead and moderately hairy face. Pelage is variable and changes with age and sex, being relatively long (7 mm) dorsally; adult females are usually rich chestnut-brown dorsally (sometimes with white tips on fur), whereas adult males, and both sexes at 1-3 years old, are darker brown dorsally with blackish fur around the head; ventral pelage is pale brown in all and is paler in pubic regions. Limbs, membranes, ears, and face are blackish brown and nearly naked. Ears are short and broad, with ribbing on inner surface and small fleshy lobes on lower margin close to lips, extending below eyes; tragus is short, rounded, narrow at base, and widened at tip. Corner of mouth has moderately developed lobe that follows under lower lip as in congeners. Uropatagium extends to end of tail, and calcar extends to almost halfway between foot and tail on uropatagium, with rounded postcalcarial lobe near base of foot. Penis is relatively long and pendan-like. Skull is very short and broad; interorbital is broad whereas intertemporal area is constricted. I? lacks a posterior cusp; P? is very small; lower molars are myotodont.

Habitat. Mainly native temperate forest, such as Metrosideros excelsa (Myrtaceae) forest, Agathis australis (Araucariaceae) remnant forest, mixed southern beech ( Nothofagus, Nothofagaceae), podocarp, and podocarp-hardwood forests, and indigenous shrublands dominated by regenerating Leptospermum scoparium or Kunzea ericoides (both Myrtaceae). The New Zealand Long-tailed Bat has occasionally been found foraging in farmland, non-native plantations, and urban environments far from native forest, but frequencyis inversely correlated to distance from forest. The species was found in cities until 1920s and 1930s, but there are no records since. Recorded from sea level to tree line at ¢. 1000 m, but now rarer in lowland and coastal regions due to local deforestation.

Food and Feeding. The New Zealand Long-tailed Batis a fairly fast flier that forages by aerial-hawking;flight speed is recorded at 60 km /h. Feeding habits have not been well studied, but diet seems to vary with prey availability. Fecal samples from Grand Canyon Cave included Diptera (29%), Coleoptera (25%), and Lepidoptera (17-5%), with other insects less frequent, e.g. Mycetophilidae, Culicidae, Psychodidae, Calliphoridae, Hemiptera, Trichoptera, and Ephemeroptera. Similar variety was found in fecal samples collected in Eglinton Valley, with Tipulidae particularly common and other insects occurring at much smaller frequencies (including Coleoptera, Lepidoptera, Megaloptera, and Plecoptera).

Breeding. The short, highly synchronous breeding season lasts less than three months, from late autumn and probably through winter. Spermatogenesis seems to occur in late summer or early autumn and sperm is stored in the epididymis through winter. Males may arouse from hibernation to mate with females while they hibernate, and females probably store sperm in their reproductive tracts through winter. Ovulation and fertilization are delayed until spring, although the exact timing of ovulation is uncertain, as is the gestation period. Pregnant females are seen from early to late November, with births from mid-November to mid-December;litter size is one. Births at Hawke's Bay (39° S) had a median timing oflast week of November, with volant young appearing in earlyJanuary. In Eglinton Valley (45° S), 70% ofbirths occurred during a ten-day period in mid-December, with most of the rest through the rest of December. Females carry their non-volant young until they weigh up to 80% of their body weight, after which they are left in the roost while the female forages. Most lactating females will stay out to forage during the first 1-3 hours of the night returning to feed the young. Young develop fast and begin to fly at 5-6 weeks old. Females nipples regress two weeks after the young become volant. Males become sexually mature at 1-2 years old (mean 1-6 years); females produce their first young at 1-3 years old. The ratio of volant juveniles to females in one population was 0-91:1, indicating low mortality for non-volant young. The oldest known banded female was at least 20 years old, but most bats do not survive past nine years. In Eglinton Valley, the survival of 107 reproductive females was followed over a seven-year period: 54% were still alive aftersix years, and 32% after seven years. The survival rate of adult females over a four-year period was also tested at Hanging Rock and Grand Canyon Cave, with annual survival of 0-75 and 0-53, respectively.

Activity patterns. New Zealand Long-tailed Bats emerge from the day roost just before or after sunset, the exact timing varying from one roost to another; solitary bats and those aroused while hibernating emerge significantly later. They remain active throughout the night, with some geographic and seasonal variation. In Eglinton Valley, during spring and summer most activity was recorded in the first two hours after sunset, but during winter most activity happened in the last four hours before sunrise. Most other regions have a similar activity spread, although in Puketitiri, they are bimodally active with peaks at dawn and dusk. Throughout the night, they will find night roosts to rest in between bouts of foraging, and in Eglinton Valley radio-tagged bats had an average offour foraging bouts and three roosting periods per night. Activity levels were about the same regardless of sex, reproductive condition, or weather, suggesting that cold temperatures and energy demands limit all individuals equally. New Zealand Long-tailed Bats were active for an average of 71% of the night and remained stationary for 29% of the night. During winter, they hibernate and reduce their activity substantially. They arouse during winter to forage and probably to mate, and have been seen foraging in temperatures as low as —1-5°C. They also enter torpor during the day in summer, to save energy. Adult males and females roosting solitarily were reported entering torpor on 80% of days for the whole day (twelve hours), but when roosting in groups they would only enter a torpid state on 35% of days, and not for the whole day (nine hours). Body temperature of captive torpid individualsfell to nearly the ambient external temperature at 10°C. Day roosts are primarily found in cavities in trunks and large limbs oftrees, and can occasionally be found in caves,in buildings, under bridges, and on cliffs; trees provide a warm environment for roosting throughout winter. Some notable caves have been used for many years, e.g. Grand Canyon Cave, which has been in use for at least 40 years but only in large numbers during spring and early summer, when cave temperature is 10-13°C. Tree day roosts are typically in knot-hole cavities in large, old trees and are relatively high aboveground, with a small to medium-sized opening; they are dry internally with good insulation, making them warmer at night. In South Canterbury where 97% of the forest cover is gone, 23% of breeding roosts are in small cracks in limestone bluffs. Call shape is a steep FM/QCF sweep with up to three harmonics; peak frequencies are 36-40 kHz (varying with population), sweeps generally 65-34 kHz, and duration averages 6-3 milliseconds.

Movements, Home range and Social organization. Colonies can number over 132 bats, while some individuals are solitary. Night roosts are usually different from day roosts, and can be high-traffic areas, with up to ¢.360 individuals entering Grand Canyon Cave. All ages and both sexes switch between solitary and colonial day and night roosts regularly and form complex social groups, so the size of a roost may change from day to day. In Eglinton Valley, individuals used colonial roosts 63% of nights and solitary roosts 37% of nights over a span of three years. During breeding, average colonial roost size was 34-7 bats, with a maximum of 123. In the same region, colonial roosts contained 62:8% reproductive females, 22-1% non-reproductive females, and 15-1% males. When moving between roostsites, New Zealand Long-tailed Bats move in small, highly structured social groups. They usually do notstay at a roost for long (1-8 days); they occupy roosts longer during winter, and males, juveniles, and solitary bats seem to stay in roosts longer than breeding females (16 days per roost vs. 1-2 days). Breeding females carrying young shifted roosts nearly every day and moved simultaneously as a group, rarely using the same roost during one season but often returning to the same roost at the same time the next year. The reason they shift roosts so often is uncertain, but predation risk may be a factor. Within the same area, they can form several social groups that roost colonially, together with individuals regularly leaving to roost solitarily but later returning. Individual home ranges are among the largest published for yangochiropteran bats. A group of 50 radio-tagged bats occupied an area over 11,700 ha collectively, with a median home range of 1589 ha in males (maximum 5629 ha), 1361 ha in post-lactating females, and 657 ha for non-breeding females. Juveniles that had been volant for less than two weeks had a much smaller home range (median 237 ha); they began to disperse more readily after the first two weeks, increasing their home ranges with a median of 2006 ha; despite the very large home ranges, most of their activity (85%) occurred in a small core area that represented a mean of 5-7% oftheir range (Eglinton Valley). Roosting sites for each individual were relatively close together, all being within 20-129 ha, and averaged 9-4% of their home range area. They faithfully foraged in the same area of forest each year and followed similar movement patterns each night, always returning to the day roost area in the morning.

Status and Conservation. Classified as Vulnerable on The IUCN Red List. The New Zealand Long-tailed Bat is one of only three terrestrial mammals native to New Zealand. It was formerly common throughout much of the archipelago, but populations have become largely fragmented. It is now found in suitable habitat only on North Island, South Island, and Steward Island. Major population declines occurred during the 1990s, 2000s, and 2010s, and it has recently disappeared from Banks Peninsula of South Island, and has become rare or absent at many othersites. As with most of the other native wildlife of New Zealand, introduced predators are one of the greatest threats, and Ermines (Mustela erminea), rats ( Rattus spp.), Common Brush-tailed Possums (Trichosurus vulpecula), and feral cats often prey on New Zealand Longtailed Bats. New Zealand Long-tailed Bats are vulnerable to introduced predators year-round since they congregate during summerin large numbers to breed, and are mostly sedentary in a torpid state during winter. The eruption of rat and mustelid populations has coincided with major declines, and eradication of these introduced predators is a high priority. In two subpopulations, bat survival increased significantly after rats were eradicated from the area. Habitat fragmentation from urban and agricultural expansion is also a major concern, as the species relies on native temperate forests. It seems mildly adaptable and has been seen foraging in plantations and urban environments, but it roosts mainly in remnant native forest patches, and its frequency decreases in areas further away from forests. It has largely disappeared from lowland and coastal regions due to lost forest cover, and in some areas has had to adapt to roosting in limestone crevices rather than tree hollows as most of the area has been deforested (e.g. South Canterbury); 20™ century logging typically targeted the bats’ preferred roosting trees. The only population that is considered significantly isolated from all others is the Hanging Rock Colony on South Island. Maintaining gene flow between populations by reducing habitat fragmentation and creating corridors for traveling between subpopulations and populations is a primary conservation goal. The species is protected by the New Zealand Wildlife Act of 1953 and the conservation of the species is proceeding using recommendations from the national Bat Recovery Plan, with population assessments coordinated by the national Bat Recovery Group. Conservation priorities are focused on protecting roosting sites, creating suitable habitat, controlling introduced predators, and educating the public about this species. Luckily the species has become well known, as there has been a lot of focused research on this and the two native short-tailed bats ( Mystacina) over the last 30 years. In 2018 it was listed as critical overall in New Zealand. Estimated numberofviable populations is under 15 on North Island and ten on South Island, with estimated total populations of 20,000 -100,000 on North [sland and under 5000 on South Island. Projected population declines over the next three generations (one generation is conservatively estimated at twelve years) are predicted to be very steep, at 50-70% for North Island and over 90% for South Island. As a result, the species may require reassessment as Critically Endangered.

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