|Scientific Name:||Mystacina tuberculata|
|Species Authority:||Gray, 1843|
|Taxonomic Notes:||There are three subspecies and five evolutionary significant units (ESUs) recognized by the New Zealand Bat Recovery Group and the New Zealand Department of Conservation (Lloyd 2003a, b; Hitchmough et al. 2007).|
|Red List Category & Criteria:||Vulnerable B1ab(i,ii,iii,iv,v)+2ab(i,ii,iii,iv,v) ver 3.1|
|Reviewer(s):||Lamoreux, J. (Global Mammal Assessment Team), Racey, P.A., Medellín, R. & Hutson, A.M. (Chiroptera Red List Authority)|
Listed as Vulnerable, because its extent of occurrence is less than 20,000 km2 and the area of occupancy is less than 2,000 km2, the population is severely fragmented, and there is a continuing decline in: the extent of occurrence, area of occupancy, quality of habitat, number of locations and subpopulations, and the number of mature individuals. Additionally, further research is needed to determine whether or not the area of occupancy is <500 km2, which would qualify this species as Endangered under criterion B2.
|Range Description:||New Zealand lesser short-tailed bat is endemic to New Zealand where it was once widespread on North Island and South Island. It now occupies less than 30% of its historical geographic range (C. O'Donnell pers. comm.). The species is currently distributed on North Island in the Omahuta-Puketi Forest, the Waipoua and Warawara Forests, and throughout tracts of indigenous forest remnants ranging from Taranaki to East Cape and south to the Tararuas (Lloyd 2001, 2005). On South Island, populations are known from the Oparara Basin and Eglinton Valley, with calls recorded from Punakaiki (Lloyd 2001, 2005) and the Dart Valley (B. Lawrence pers. comm.). Large populations of this species are also present on the offshore islands of Little Barrier Island and Codfish Island (Lloyd 2001, 2005). Lesser short-tailed bats range from close to sea level to the upper altitudinal limits of forest cover (Lloyd 2001, 2005).|
Native:New Zealand (North Is., South Is.)
|Range Map:||Click here to open the map viewer and explore range.|
Large numbers have been recorded in undamaged old-growth forest (Lloyd 2001, 2005). The largest colonial roost recorded consisted of >6,000 animals (Lloyd 2005). The overall population of lesser short-tailed bats probably exceeds 30,000 individuals with several populations containing more than 1,000 bats (Lloyd 2005).
The geographic ranges of the colonies are c.150 km2 a piece, and only about a dozen subpopulations are known (O'Donnell et al. 1999; Christie 2003; Lloyd 2005). Within these, the range of the 'irreplaceable colonial breeding sites' are much smaller (17 ha in one study; Christie 2003). Colonial breeding trees per colony number only 20-30 and they have very specific physical and microhabitat charcteristics, which are now very rare in New Zealand forests because of the history of logging (Sedgeley 2003, 2006).
The central North Island populations are large, but they are fragmented and we have little understanding of current trends there. Two of the three subpopulations that are being studied continue to decline (i.e., Oparara and Tararua). In fact, the Oparara bats (only 1 of 2 subpopulations in South Island) have not been detected for a few years now, despite considerable survey effort.
|Habitat and Ecology:||
Lesser short-tailed bats are associated with old-growth temperate forest, with large trees available for colonial roosts, abundant epiphytes and deep leaf-litter (Lloyd 2005). Colonial breeding trees per colony number only 20-30 and they have very specific physical and microhabitat charcteristics, which are now very rare in New Zealand forests because of the history of logging (Sedgeley 2003, 2006). The species has been recorded at low numbers in logged forest, shrubland, pine plantations, and farmland in areas adjacent to undamaged old-growth forest (Lloyd 2005). Although the species primarily roosts in tree cavities, there are records of the species using caves for roosting (Lloyd 2005).
It is primarily insectivorous but also comsumes nectar, pollen, and fruit (Lloyd 2005). Lesser short-tailed bats undergo periods of torpor and seasonal hibernation (Lloyd 2005). The species is thought to undertake a lek mating system, but this has yet to be proven (C. O'Donnell pers. comm.). Females annually give birth to a single young (Lloyd 2001, 2005).
Old-growth roost trees are very important to the species. Lesser short-tailed bats are thought to have declined through forest clearance following human settlement of New Zealand.
Predation by introduced stoats and rats has also been, and continues to be, a major threat to this species. This is evident from the increase in bats on Codfish Island following the removal of Pacific rats, as well as increases in the Eglinton Valley following the initiation of comprehensive rat and stoat control. Stoats and rats are also known to visit colonial roosts, and are suspected as the reason for the critical status of the Tararua, Oparara, and Northland subpopulations in areas where no logging has occurred. Furthermore, these bats disappeared from the southern Titi Islands when ship rats were introduced.
Populations of this species also appear to be minimally impacted by poisoning through consumption of bait distributed in New Zealand forests to control invasive vertebrate species, and also through secondary poisoning resulting from consumption of invertebrates that have fed on poisoned bait (Lloyd 2005).
Mystacina tuberculata is protected by New Zealand's Wildlife Act of 1953. Conservation is occurring using guidance from a national Bat Recovery Plan (Molloy 1995), with on-going assessments and annual work plans being co-ordinated by the national Bat Recovery Group. Management includes eradications of introduced predators from offshore islands (rats have already been eliminated from islands containing two large offshore populations), predator control at mainland sites (this is just beginning), habitat protection, trial translocations to new habitats, and general advocacy. This species occurs in a number of protected areas. More research is needed to determine the area of occupancy for the species.
There are three subspecies and five evolutionary significant units (ESUs) recognised by the New Zealand Bat Recovery Group and the New Zealand Department of Conservation (Lloyd 2003a,b). The national (non-IUCN) listings for these populations are as follows (Hitchmough et al. 2007):
Northern lesser short-tailed bat Mystacina tuberculata aupourica, nationally endangered
Eastern lesser short-tailed bat Mystacina tuberculata rhyacobia, at risk
North-western lesser short-tailed bat Mystacina tuberculata rhyacobia, at risk
Southern North Island lesser short-tailed bat Mystacina tuberculata tuberculata, nationally critical
South Island lesser short-tailed bat Mystacina tuberculata tuberculata, nationally endangered
Fortunately, the population of Mystacina tuberculata rhyacobia on the central North Island is much bigger than originally thought. Other populations, however, cannot be considered secure such as northern and southern subspecies (C. O'Donnell pers. comm.).
|Citation:||O'Donnell, C. 2008. Mystacina tuberculata. The IUCN Red List of Threatened Species. Version 2014.2. <www.iucnredlist.org>. Downloaded on 22 October 2014.|