Boulder Jewel (Platycypha fitzsimonsi)

View the above photo record (by Bertie Brink) in OdonataMAP here.

Find the Boulder Jewel in the FBIS database (Freshwater Biodiversity Information System) here.

Family Chlorocyphidae

Platycypha fitzsimonsi – BOULDER JEWEL

Identification

Small size

Length up to 34mm; Wingspan attains 54mm.

Adult males are distinctive and easily recognised. The bright red and black colouration is diagnostic. Only the upper parts of the last four abdominal segments are vivid blue.

Females and immature males are very similar to those of Platycypha caligata. They are best identified by their association with the males.

Click here for more details on identification.

Habitat

This species frequents swift, rocky streams and rivers in both open or forested/wooded habitats. It is most common in fynbos and grassland. Often found alongside the more common Dancing Jewel (Platycypha caligata), but generally prefers more open habitats. The Boulder Jewel is the only Platycypha species in the Western Cape.

Behaviour

Territorial males perch low down, close to the water. They sit predominantly on rocks but will also rest on overhanging or emergent twigs, reeds and grass. The females are usually found alongside the males. Boulder Jewels are perch hunters, taking short, low flights across the water. Platycypha fitzsimonsi males are well noted for having an eye-catching courtship display. The male hovers in front of a perched female. His legs hang down vertically as he twists or waves them, alternately flashing red and white.

Active from October to May (See Phenology below).

Status and Conservation

Endemic to South Africa. It is a fairly common but localised species and is listed as Least Concern on the IUCN Red List of Threatened Species. It is moderately sensitive to habitat damage. It is intolerant of turbid and dirty water, but does occur on rivers with some alien plant growth.

Distribution

Platycypha fitzsimonsi occurs locally in cooler mid-altitude areas along the escarpment, from the Western Cape to Mpumalanga.

Below is a map showing the distribution of records for Boulder Jewel in the OdonataMAP database as at February 2020.

The next map below is an imputed map, produced by an interpolation algorithm, which attempts to generate a full distribution map from the partial information in the map above. This map will be improved by the submission of records to the OdonataMAP section of the Virtual Museum.

Ultimately, we will produce a series of maps for all the odonata species in the region. The current algorithm is a new algorithm. The objective is mainly to produce “smoothed” maps that could go into a field guide for odonata. This basic version of the algorithm (as mapped above) does not make use of “explanatory variables” (e.g. altitude, terrain roughness, presence of freshwater — we will be producing maps that take these variables into account soon). Currently, it only makes use of the OdonataMAP records for the species being mapped, as well as all the other records of all other species.

The basic maps are “optimistic” and will generally show ranges to be larger than what they probably are. These maps use the data in the OdonataMAP section of the Virtual Museum, and also the database assembled by the previous JRS funded project, which was led by Professor Michael Samways and Dr KD Dijkstra