Papilio hornimani mbulu Kielland, 1990

Vane-Wright, Richard I. & Liseki, Steven, 2008, The type material, taxonomy and conservation of Horniman’s Swallowtail, Papilio hornimani (Lepidoptera: Papilionidae), Journal of Natural History 42 (19 - 20), pp. 1333-1348 : 1343-1346

Papilio hornimani mbulu Kielland, 1990

Papilio hornimani mbulu Kielland, 1990:40 , pl. 3. Holotype male, Tanzania: Mamaisara , Mbulu, Hasama Forest, 2000 m, 20.iv.1979 (Kielland), BMNHE # 147802 [examined].

Kielland (1990) based subspecies P. h. mbulu on 18 male and one female specimens from Mbulu , Ngorongoro (Oldeani) and Mt Kwaraha , collected between 1973 and 1987. The holotype male (Figure 2E), which bears the labels // Mamaisara, Mbulu, 2000 m, 20.iv.1979, J. Kielland // BM 1990-166 // BMNHE # 147802 //, is deposited in the BMNH. Forewing length: 55.7 mm; forewing band width: 7.0 mm; hindwing band width: 9.5 mm. The female paratype (‘‘allotype’’; Figure 2F), also deposited in the BMNH, bears labels // Mbulu, Marang F., ii.1980, J. Kielland // BM 1990-166 // BMNHE # 147803 //. Forewing length: 56.7 mm; forewing band width: 4.6 mm; hindwing band width: 8.2 mm .

Fourteen of the male paratypes are now in ABRI, ex Jan Kielland collection. Steve Collins (pers. comm.) has identified these and added paratype labels. The data are as follows: 1 male, Oldeani, Mbulu , 1860 m, 22.ii.1957 (J.K.) ; 1 male, Oldeani , 2000 m, 1.ii.1959 (J.K.) ; 1 male, Oldeani, Mbulu , 5.x.1972 (J.K.) ; 1 male, Oldeani Mtn , Arusha R., 2000 m, 18.iii.1973 (J.K.) ; 1 male, Oldeani , 18.x.1974 (J.K.) ; 1 male, Mbulu, Marang , ii.1980 (J.K.) ; 5 males, Mbulu, Marang Forest , 1800 m, 15.iv.1987 (J.K.) ; 2 males, Galappo, Babati, Mt Kwaraha , 1850 m, 19.iv.1987 and 30.iv.1987 (J.K.) ; 1 male, Ngorongoro , 1850 m, 2.iv.1979 (J.K.).

According to Steve Collins, it is possible that the three unaccounted paratypes are now in the collection of Anders Bjørnstad ( Norway).

The type locality of P. hornimani

Distant (1879) recorded the original type locality for his new species, P. hornimani , simply as ‘‘Magila, East Africa’’. There are two possible locations for Magila, both in the Usambara Mountains of northeast Tanzania. One is a village in the West Usambaras at 04 ° 489 000 S, 038 ° 199 000 E, 1600 m altitude, close to Mt Kwa Mongo and the towns of Soni and Lushoto. The second is the site of an old missionary station near Amani, at 05 ° 089S, 38 ° 469E, quite close to the major coastal port of Tanga. The joint Universities’ Mission to Central Africa (UMCA) established a base at Magila in the Tanga hinterland in 1868 ( Temu 1980:88) or 1875 ( Sayers 1930; Small 1980), on the southern edge of the isolated Mlinga range. This north–south ridge, drained by the Mkurumuzi river, rises in altitude from 600 m close to Magila, to over 1000 m some 15–18 km away at its northern end, and forms an eastern outlier of the East Usambara Mountains.

Kielland (1987: 120) gave the type locality as ‘‘Magila … Tanga Region, at the foot of the East Usambara Mts’’, corresponding to the UMCA mission station. However, three years later he apparently accepted the now seemingly better-known northern village as the type locality, as he wrote ‘‘Magila, W. Usambaras’’ ( Kielland 1990: 40). The site near Tanga is undoubtedly the correct source. The labels ‘‘Farler, Magila’’ on the type specimens refer to the Rev. John P. Farler, a Cambridge graduate and priest who spent most of his 14 years of service for UMCA based at Magila ( Bellville 1876; Farler 1879, 1889; Small 1980). Figure 5 reproduces Farler’s (1879) map of Magila and the surrounding area.

Kielland (1990: 40) states that P. h. hornimani occurs in ‘‘rather heavy forest from 400 to 2200 m’’, but described subspecies P. h. mwanihanae from a locality at 300 m. The mission station at Magila was situated about 240 m above sea level ( Farler 1879), perhaps just too low for the butterfly (but see below). Mt Manga, immediately to the north of Magila, rises to 600 m. Farler (1879) indicates that the peaks behind the Magila mission were then referred to as the Magila Mountains, and he describes how he travelled quite widely through the thick forests. Although Johnston (1879:553) considered that the trees of this range were relatively small in comparison to the ‘‘great forest’’ of the main Usambaras to the west, Bellville (1876: 76) describes how the Magila mission was ‘‘under the shadow of a lofty wooded mountain’’ and that ‘‘we [presumably including Farler] … ascended the nearest peak to the station’’. Thus there is no reason to doubt the authenticity of the stated provenance, which was clearly the southern end of the Mlinga range, in the vicinity of the Magila mission station.

The original specimens must have been collected by or for Farler sometime between July 1875 and October 1878. Farler arrived at Magila with Bellville and others on 9 July 1875, this apparently being his first visit. Having joined the mission in 1875, he eventually withdrew in 1889 (at a time when he clearly viewed the advancing German colonization of East Africa with great alarm: Farler 1889), and died on Pemba in 1908 ( Small 1980). Farler was evidently in England in November 1878 ( Farler 1879), at about the time when Distant’s description of the butterfly must have been prepared.

According to Norbert Cordeiro (in litt.), Papilio hornimani still exists in and around the Mlinga Forest Reserve (see below), mainly in the remaining tracts of upland forest, up to about 1000 m, the lower parts having largely been cleared. It also occurs in the Sigi river area, south and east of Amani, in these lower areas being restricted to gallery forests, where it sometimes occurs as low as 250 m. Amani lies about 12–14 km to the west of Magila, across the wide Kihuwi valley, on the southern edge of the main East Usambaras block. Starting at about 750 m and rising to a central elevation of about 850–900 m, Amani has long been a well-known locality for the insect ( Carcasson 1975: 13). The Mlinga area is connected, via the Longuza and Sigi forests, to Amani, and it is possible that individual Papilio hornimani can move throughout the whole region (Theron Morgan-Brown pers. comm.). Whether they really do so would provide valuable information regarding the population structure of this species, and its conservation needs.

Forest conservation in the East Usambaras

As noted above, Norbert Cordeiro confirms the continuing existence of Papilio hornimani hornimani in the Mlinga Forest, 125 years after it was first encountered at Magila by the Rev. John Farler. Whatever understanding we may gain about the autecology of this insect, more generally the butterfly’s survival will surely depend, first and foremost, on the fate of the Usambara forests.

Much of the region between the East Usambaras and the coast, according to Kielland (1990: 15), has already been deforested. The descriptions of Bellville (1876) and Farler (1879) suggest that a wide stretch of this lowland ‘‘wilderness’’ had long been dry coastal savannah rather than forest, perhaps made so by fires for hunting. However, Norbert Cordeiro (in litt. August 2002) confirms that much deforestation of the East Usambara lowlands has been recent, and this includes some coastal forest as well as interior woodlands. He points out that, unlike the forest and woodland areas cleared for sisal plantations during the British and German colonial period (see references in Hamilton and Bensted-Smith 1989), the more recent degradation has been caused by fires, subsistence agriculture and charcoal burning ( Burgess and Clarke 2000; Cordeiro and Githiru 2000).

According to Johansson et al. (1998), fragmentation is probably the major threat to the biodiversity of the East Usambaras. Fourteen separate forest reserves are now designated in the area, including the Amani Nature Reserve as well as the much smaller Mlinga Forest Reserve ( Johansson et al. 1998: fig. 1), possibly critical for survival of the population from which the original material of P. hornimani was obtained. According to Hall et al. (2002 – who did not encounter P. hornimani during their Frontier Tanzania survey), the reserve is very rocky, covers 890 ha, and has an altitudinal range of 220 m, ascending to a maximum of 1069 m asl.

Established by a Declaration Order dated May 1997, the main Amani Nature Reserve will exceed 8300 ha, including 1065 ha of forest managed by the collective East Usambara Tea Company. The ANR also includes the famous Amani Botanical Garden (no longer maintained, according to Cordeiro pers. comm.), historically part of the Biologisch-Landwirtschaftliches Institut , opened in June 1904. Frontier Tanzania, together with the East Usambara Catchment Forestry Project ( EUCFP), and working in collaboration with a number of other organizations including the University of Dar es Salaam, are carrying out biodiversity surveys in the East Usambaras ( Johansson et al. 1998) .

In this context, the recent founding of the Amani Butterfly Project may be significant. According the project’s website (http://www.amanibutterflyproject.org/), this is a non-profit organization to market butterfly pupae on behalf of East Usambara butterfly farmers. The aim is to provide communities near the protected areas with a sustainable income that is dependent on the health and integrity of the forests. The project has been backed by the Wildlife Department of Tanzania, Amani Nature Reserve, Longuza Forest Reserve, East Usambara Mountains Conservation Area Management Program, and Muheza District Council. If successful, this enterprise could also give the opportunity to describe the early stages and understand more of the ecology of Papilio hornimani hornimani , a striking butterfly endemic to several of the highly threatened Eastern Arc mountains ( Burgess et al. 2007; Cordeiro et al. 2007).

Figures

Figure 5. Map of Tanga district and southeastern Usambaras, locating Magila, type locality of Papilio hornimani Distant, reproduced from Farler (1879). The detail is enlarged to show Magila (arrow).