Hi Mike
There are quite a few scientific papers relating to Bats on Mallorca. I've extracted a list that might be of interest:
Title: [Chiropterological catalogue of Albufera de Mallorca nature park.]
Author(s): Trujillo, Domingo; Garcia, David; Pons, Guillem X.
Pages: 132-133 Published: 2008
First record of seasonal over sea migration of
Miniopterus schreibersii and
Myotis capaccinii between Balearic Islands (Spain)
Author(s): Amengual, B; Lopez-Roig, M; Serra-Cobo, J
Source:
ACTA CHIROPTEROLOGICA Volume: 9 Issue: 1 Pages: 319-322 Published: 2007
[Fifteen years of chiropterological studies in the Balearic Islands (1993-2007).]
Author(s): Serra-Cobo, Jordi; Amengual, Blanca; Lopez-Roig, Marc; et al.
Source:
Endins Volume: 31 Pages: 125-140 Published: 2007
[The Chiroptera of the S'Albufera Natural Park in Majorca.]
Author(s): Noblet, Jean Francois
Source:
Monografies de la Societat d'Historia Natural de les Balears Volume: 4 Pages: 169-173 Published: 1995
Apunts sobre els avencs del Puig Major (Escorca, Mallorca).
Author(s): Trias, M.
Source:
Endins Pages: 21-26 Published: 1987
Una captura de
Nyctalus noctula Schreber (Chiroptera: Vespertilionidae) en Mallorca.
Author(s): Munar Bernat, J.
Source: Bolleti de la Societat d'Historia Natural de les Balears Volume: 26 Pages: 233-236Published: 1982
Some, if not all of these will be kept in s'Albufera.
There's also a list of the bats of s'Albufera in the 2002 published catalogue (p. 77).
See:
http://www.mallorcaweb.net/salbufera/docs/cataleg_biodiversitat_2002.pdf
I hope this helps
Martin