A Rocha Portugal Observatory Report 2009-2010

46 A Rocha Portugal Observatory Report 2009-2010
Figure 2 Polygonia c-album (Comma).
Data from 2009, comparison of the transects in Abicada and Mexilhoeira Grande with the
transects on Foia
Comparing data collected at the same time of year enables us to conclude that the two areas are
very different regarding butterfly diversity. The transect on Foia, in the Monchique hills, provided
both a higher number of species recorded and a higher number of individuals observed than any of
the transects in the near vicinity of the Alvor estuary (see Butterfly Monitoring Around The Alvor
Estuary, June – October 2009 in this report by the same author).
The number of individuals recorded in September on the Foia transect was higher than the sum of
the number of individuals recorded on the other transects. A summary is provided in Table 2.
Table 2 Comparison between the transects in Abicada and Mexilhoeira Grande with Foia
Site and date
Abicada / M. Grande
(total of transects 1-4)
Pyronia tithonus sub spp. decolorata (Gatekeeper) is
considered to be scarce in the Algarve, but is more
abundant in the Monchique area. The observed
individuals all belonged to the subspecies decolorata
common in Southern Europe (Tolman, 1997).
Another point of interest was the presence of Polygonia
c-album (Comma) in the same area near the reservoir,
although not recorded during the survey. On 18 th August
two individuals were observed, and one on 26 th August.
This species is not known to have populations in the
Algarve, however, the territorial behaviour observed on
the forest path close to its main breeding plant (Urtica
sp.) suggests that this may be an isolated population
which has been overlooked in the past. The photograph
taken of this species on 18 th August (see Photo 1), is the
first in the Algarve (N. Fonseca pers. comm.). It would be
of interest to continue to monitor this species in the
future.
Number of
individuals
Number of
species
25-08-2009 20 7
22-09-2009 20 6
13-10-2009 32 8
Foia
01-09-2009 54 13
08-09-2009 47 14
16-10-2009 24 7