Pipistrellus hanaki Hulva et Benda, 2004 is one of the most recently described bat species in the western Palearctic. It was originally described from Cyrenaica, Libya and it was later discovered also in Crete.

P. hanaki has a rather limited distribution, since it occurs only in the Cyrenaica Peninsula and Crete and according to the IUCN criteria, it was listed as Vulnerable in the Red Data Book of the Endangered Animals of Greece. Also, it is listed under EUROBATS and in the Annex IV of the Habitats Directive (92/43/EU).

Preliminary work had shown that P. hanaki occupies several different habitat types, but most of its activity concentrates on mature oak forests and riverine habitats with old trees. So far, there are no published information on its roosting habits, although protection of roosts is a key element for the conservation of the species.

The aims of this study were:

1.   To investigate the foraging and roosting habits of the species.

2.   To draw guidelines for the conservation of the species in its whole distribution range.

Study area and methods

In September 2012 and partially in June - July 2013 field work took place in the Aravanes forest in the northwest of Psiloritis Mountain (central Crete). The forest has a mean elevation of ca. 950m a.s.l. and consists mainly of Quercus coccifera, Q. ilex, Q. macrolepis, Q. pubescens and Acer sempervirens. Aravanes forest covers an area of ca. 1500 hectares and is surrounded by shrub land. Previous fieldwork (with acoustic surveys and mist netting) has shown that it is one of the five most important foraging areas for P. hanaki on Crete.

In summer 2013 the study was focused on lactating females. Since in 4 netting efforts many males but no female bats were trapped in the Aravanes forest, we tracked 2 males and then moved to the area around the villages Pigouniana, Margarites, Kynigiana, Eleftherna and Plevriana (mean elevation of ca. 450m a.s.l., ca. 1500 hectares). The area comprises a mosaic of oak trees (mainly Quercus pubescens), cypresses (Cupressus sempervirens), olive trees (Olea europea), carob trees (Ceratonia siliqua) and to a lesser extend other cultivated trees (including Ficus carica and Prunus spp.). 

23 bats were tagged with radio tags (Biotrack Ltd, UK) attached between the shoulder blades with Salts Healthcare adhesive after clipping the fur. Bats were released in situ after processing and were tracked on foot and by car.

Photomap of Crete with the study areas in the red rectangles (south: Aravanes, north: Margarites).

Results - Roosts

September 2012

Twelve roosts (four in rocks and 8 in trees) of 7 bats were located during the study.

June – July 2013

In June 2013, in the Aravanes forest we located the roost tree of one of the two males tracked. In Margarites area we located 22 roosting places of 10 females. These included old trees. Additionally, bats were found roosting in wooden electricity posts, one metal post (street light) and buildings.

The feeding activity of all tracked bats was strictly confined above and around big trees. Although most of the roosts were located close to scrublands and villages, these habitats were avoided by feeding bats.

The results of this study, together with the results from previous studies (habitat selection with acoustic method and modeling with MAXENT software) will be combined to an integrated assessment of the species ecological requirements.

Searching for day roosts in Aravanes forest.                

The roost cliff of Kokolis and the tag antenna protruding from its cavity.

A roost tree (in the middle).

The Natural History Museum of Crete / University of Crete (NHMC-UOC) thanks the donors who made this project possible, these were: 

The German Ministry for the Environment, Nature Conservation, Building and Nuclear Safety as well as 

Le Gouvernement du Grand-Duché de Luxembourg, Administration de la nature et des forêts.