of the largest breeding colonies in Europe, the bats are in danger of obliteration. Rose-ringed parakeets (Psittacula krameri), an invasive species, compete for homes in tree hollows, and will attack and kill adult noctules before colonising their habitat. There has been an 81% decrease in trees inhabited by the bats since researchers first began keeping track. Conservation The greater noctule bat is currently classified as Vulnerable on the IUCN Red List of Threatened Species. It is classified as 'vulnerable' in Spain (Ministerio de Medio Ambiente, 2006). No other country in Europe has a specific endangered status for the greater noctule bat. Conservation proposals The organism separates itself socially and spatially with roosts. A colony has several roosts, with most of the populations centered in one large roost and several fringe roosts which other bat species may share. These are useful for sharing information between colonies. These roosts however can communicate disease and parasites. The individuals often fly from one roost to another to exchange information, and this also creates a pathway for infection. For reasons uncertain, such as being perhaps too advantageous to the colony, they continue to roost within these trees despite the disadvantages to themselves. It would be beneficial to the conservation of the species to locate the trees with roosts that have high levels of disease/ parasite infections in addition to high rates of transfers between roosts and cut them down to lessen the rate of infection among them. The functions of each roost also needs to be identified, as to understand which roosts would be better left intact. However, only day roosts studies were performed, and further research into their nocturnal habits may be required. The species has not yet been well defined in their areas of roosting. Some have even been found to roost in caves and possibly housing, though whether this is typical behavior or an effect of displacement is uncertain. Tracking the species by radio signals, it was found that the species prefers older, larger trees, specifically beeches, perhaps due to possessing relatively spacious trunks and branches, allowing for ease of entry. The species does not have one specific roost, but a network through which the colony can rotate individuals. Recent years have seen less reliance on fossil fuels and rather relying on wood as a source of energy, and consequently an increase in logging, therefore it is important to locate the areas