459
the effort of collection, maintenance and analysis of large amounts of photoidentification data.
16.6 The Brazilian Right Whale Photo-Identification Catalog
The Brazilian Right Whale Photo-identification (BRWP) Catalog was created after
the first aerial surveys conducted in Brazil, in 1987. Each whale photographed in a
new aerial survey is compared to the existing catalogue to look for matches. If a
whale is not found in the catalog, it is given a new number and added to the catalogue.
Photographs are analyzed with the aid of the “Right Whale Photo- identification
Software” (Hiby and Lovel 2001), and the information associated to each whale
sighting is stored in the database associated to the system.
The BRWP Catalog has over 2300 photos from 670 individual whales identified
up to 2010. From the total, 38.2% (n = 256) are mature females (whales sighted at
least once accompanied by a calf), 18.5% (n = 124) are calves identified in the year
of birth, 3.6% are (n = 24) juveniles, and 39.7% (n = 266) are adult whales never
seen accompanied by calf. The catalog includes 8.4% (n = 56) of whales presenting
dorsal marks and 1.6% (n = 11) of whales with a partial albinism.
16.7 What Have We Learned from the Catalog?
The number of right whales on the Brazilian breeding ground was low in the first
years of aerial surveys with a mean of 11 new whales added to the catalog by year
up to 2001. However a rapid increase in the population was observed in 2002 (Groch
et al. 2005), and so the number of right whales in the BRWP Catalog. The year with
the highest number of new whales added to the catalog was 2002 (n = 124 whales)
(Fig. 16.16). From 2002 and 2010 a mean of 57 new whales were added to the catalog each year. Resightings of individuals begun to occur in 1994 but 95% were
recorded from 2003, when a pattern emerged. From 2003 to 2010, an average of
39% of whales identified each year were resightings. The year with the highest
number of resightings in relation to the total identified individuals was 2007, when
56.5% (n = 35) of individuals sighted were known whales.
The greater number of new whales added to the catalog every year in relation to
the number of resightings indicate that this population is being ´discovered´. The
number of whales added to the catalog vary between years, but some individual
whales have been providing valuable information on patterns of occurrence and site
fidelity to this area. Twenty-five percent of the catalogued whales up to 2010 were
seen in two or more years. The longest sighting interval is 18 years, shown by the
whale B016, first sighted in 1988 and resighted in 2006 (Fig. 16.17). In both opportunities she was sighted with a calf. This whale had been previously sighted in
Argentina (PV256) (Best et al. 1993), where she was also sighted with a calf, in
16 Conservation Advances for the Southern Right Whales in Brazil
the effort of collection, maintenance and analysis of large amounts of photoidentification data.
16.6 The Brazilian Right Whale Photo-Identification Catalog
The Brazilian Right Whale Photo-identification (BRWP) Catalog was created after
the first aerial surveys conducted in Brazil, in 1987. Each whale photographed in a
new aerial survey is compared to the existing catalogue to look for matches. If a
whale is not found in the catalog, it is given a new number and added to the catalogue.
Photographs are analyzed with the aid of the “Right Whale Photo- identification
Software” (Hiby and Lovel 2001), and the information associated to each whale
sighting is stored in the database associated to the system.
The BRWP Catalog has over 2300 photos from 670 individual whales identified
up to 2010. From the total, 38.2% (n = 256) are mature females (whales sighted at
least once accompanied by a calf), 18.5% (n = 124) are calves identified in the year
of birth, 3.6% are (n = 24) juveniles, and 39.7% (n = 266) are adult whales never
seen accompanied by calf. The catalog includes 8.4% (n = 56) of whales presenting
dorsal marks and 1.6% (n = 11) of whales with a partial albinism.
16.7 What Have We Learned from the Catalog?
The number of right whales on the Brazilian breeding ground was low in the first
years of aerial surveys with a mean of 11 new whales added to the catalog by year
up to 2001. However a rapid increase in the population was observed in 2002 (Groch
et al. 2005), and so the number of right whales in the BRWP Catalog. The year with
the highest number of new whales added to the catalog was 2002 (n = 124 whales)
(Fig. 16.16). From 2002 and 2010 a mean of 57 new whales were added to the catalog each year. Resightings of individuals begun to occur in 1994 but 95% were
recorded from 2003, when a pattern emerged. From 2003 to 2010, an average of
39% of whales identified each year were resightings. The year with the highest
number of resightings in relation to the total identified individuals was 2007, when
56.5% (n = 35) of individuals sighted were known whales.
The greater number of new whales added to the catalog every year in relation to
the number of resightings indicate that this population is being ´discovered´. The
number of whales added to the catalog vary between years, but some individual
whales have been providing valuable information on patterns of occurrence and site
fidelity to this area. Twenty-five percent of the catalogued whales up to 2010 were
seen in two or more years. The longest sighting interval is 18 years, shown by the
whale B016, first sighted in 1988 and resighted in 2006 (Fig. 16.17). In both opportunities she was sighted with a calf. This whale had been previously sighted in
Argentina (PV256) (Best et al. 1993), where she was also sighted with a calf, in
16 Conservation Advances for the Southern Right Whales in Brazil