Sunday, February 19, 2012

[Herpetology • 1995] 6 new Brookesia | B. ambreensis, B. antakarana, B. lineata, B. lolontany, et. al. • Systematics, speciation and biogeography of the dwarf chameleons (Brookesia; Reptilia, Squamata, Chamaeleontidae) of northern Madagascar


Brookesia ambreensis 

Brookesia dwarf chameleons, endemic to Madagascar, were surveyed at  the following localities in  northern  Madagascar (north of 16”s): Montagne  d’Ambre, Ankarana, Manongarivo, Tsaratanana, Marojejy and Masoala. A total of 15 species occur in this region. Six new species are  described  and five new synonyms are identified. The genus Brookesia, the most speciose chamaeleontid genus in Madagascar, contains 23 species. 
Almost all the northern Brookesia species are restricted to rainforest and occupy a relatively narrow elevational range. Although the northern rainforests represent just one-third of the total rainforest and  about 5 %  of the total island  area,  65%  of the Brookesia species occur in this region, and 52% are endemic t o  the northern rainforest. Five new biogeographic regions of the northern rainforest are identified based on centres of Brookesia endemicity: Montagne d’Ambre, Northwest, Tsaratanana, Northeast and East. Speciation is thought to have been facilitated in the  north  through geographic isolation, with  the  Tsaratanana mountain range and the dry forests south of Montagne d’Ambre forming barriers  to dispersal,  and the Tsaratanana mountains acting as a centre of isolation. The fragmented distribution of several Brookesia species of low altitude rainforest suggests a period in Madagascar’s history when the climate was wetter and low altitude rainforest much more widespread. 


Brookesia ambreensis sp. nov. 
Holotype- UMMZ  203635,  mature  male,  collected  8  January  1992,  Antomboka  River, Montagne D’Ambre National  Park,  12’29’5  49” lO’E,  670 m  altitude,  Antsiranana Fivondronana, Antsiranana (Diego Suarez) Province, Madagascar,  by J.B. Ramanamanjato,  A. Raselimanana and C.J. Raxworthy.

Etymology- The  specific name refers to the type locality Montagne d’Ambre
Habitat and  distribution.- All  specimens collected  in  primary rainforest. All known specimens were collected between 650 and 1150m altitude a t  Montagne  d’Ambre, within the National Park and Parcel 2 of the Special Reserve. This species is probably endemic to  Montagne d’Ambre.


Brookesia antakarana sp. nov. 
Holotype- UMMZ  200071,  mature male, collected  6  December  1991, Antomboka  River, Montagne d’Ambre National Park,  12’32’S, 49’10’E,  1050 m altitude, Antsiranana Fivondronana, Antsiranana  (Diego Suarez) Province, Madagascar, by J.B. Ramanamanjato, A. Raselimanana and C.J. Raxworthy.

Etymology- The specific name refers to the Antakarana people and region of northern Madagascar, where this species appears to be restricted. 
Habitat  and  distribution- All  known specimens were collected in rainforest between  50-1200 m altitude  at Montagne d'Ambre, within the National Park and from Parcel 2 of the Special Reserve. This species is probably endemic to Montagne d'Ambre. 


Brookesia bekolosy sp. nov. 
Holotype- UMMZ  200078, mature male, collected 8 March  1992, Bekolosy, Manongarivo Special Reserve, 14"03'S, 48" 1 S'E,  1200 m altitude, Ambanja Fivondronana, Antsiranana (Dikgo Suarez) Province, Madagascar, by C.J. Raxworthy.

Etymology- The specific name refers to the type locality, the Bekolosy Plateau at  Manongarivo. 
Habitat and distribution- The  holotype was collected at 22:00 h, roosting on a thin branch at 1 m height, in primary rainforest at 1200m altitude on a ridge. No other locality is presently known  for  this species. The rainforest  a t  Berkolosy is  high altitude, with the forest  canopy typically between  5-10m in height,  and  tree branches  heavily  draped  with lichens. A more intensive survey was made by us at lower elevation forests in the Manongarivo Reserve (between 50-800m).  The absence of this species a t  these lower altitudes makes us think it is restricted to higher  elevation forest,  probably  in  excess  of  1000m. This species is  probably  restricted  to rainforest in the Northwest biogeographic region (see below). 


Brookesia brygooi sp. nov .  
Holotype- MHNP 8219,  female, collected  at  Analavelona, Southwest  Madagascar by H.  Humbert.

Etymology- The  specific name honours Dr  E.  R. Brygoo, who first described specimens of this new species, and contributed to the understanding of Brookesia systematics. 
Habitat and distribution- In  addition  to the localities given for the holotype, paratype  and other specimens, Brygoo (1 978) reported specimens (without calalogue numbers) from Bemaraha (Rtserve Naturelle IntCgrale No. 11) and Antsalova, also in the Southwest, Brookesia brygooi is found  in  the arid  Southwest  and  West  of  Madagascar,  occurring between  17-23"S,  and  is probably restricted t o  native deciduous forests in these regions. Brookesia brygooi is one of the few  arid-adapted species of the genus. The other species found in arid habitats of the Western Domain are B. bonsi, B. decaryi, B. perarmata  and B. stumpfi. 


Brookesia lineata sp. nov. 
Holotype- UMMZ  200073, mature male, collected 8 March  1992, Bekolosy, Manongarivo Special Reserve, 14"03'S, 48" 18'E, 1200 m altitude, Ambanja Fivondronana, Antsiranana (Diego Suarez) Province, Madagascar, by A. Raselimanana. 

Etymology- The  specific name refers t o  the unusual dark lines on the body of this species. 
Habitat and distribution- The  holotype was collected a t  night, roosting on a leaf a t  1 m height, in primary rainforest  a t  1200 m altitude on a ridge. No other locality is presently known for this species. For additional information see comments on habitat for Brookesia bekolosy
Remarks- Brookesia lineata is unusual in that  the flanks are marked  by  bold, dark brown, longitudinal lines. Brygoo (1978) does  not  describe such  a coloration pattern for any other Brookesia species, although dark flank lines occur in male Brookesia thieli (UMMZ 196217-8). 


Brookesia lolontany sp. nov. 
Holotype- UMMZ  203629,  mature  female, collected  29  March  1993, Matsabory  Lake, Tsaratanana,  14"09/S, 48"58/E, 2050 m altitude,  Bealanana  Fivondronana,  Mahajanga Province, Madagascar, by Angeluc Razafimanantsoa. 

Etymology- The  specific name “lolontany” is  the Malagasy name of  the Tsaratanana mountain spirits that are believed to occupy the forests where the types were collected. 
Habitat  and distribution- UMMZ  203629 collected at  20:00h, roosting on a leaf at 0.7m height, in bamboo dominated primary rainforest; UMMZ  203630 collected at  20:00 h, roosting on  a branch  a t   0.05m  height, in  primary rainforest.  Both specimens were  collected  in  the Tsaratanana mountain range, which includes the highest mountain in Madagascar, Maromokotro,  at  2876m altitude. The holotype of Brookesia lolontany was collected at  a higher altitude than any other Brookesia species. This species is probably restricted to  high altitude rainforest in the Tsaratanana Mountains. 
Remarks- The only other species known to occur at a similarly high elevation is Brookesia nasus, which  has been collected up to 1650m altitude at Andringitra. The latter species is morphologically the most similar species to Brookesia lolontany


Raxworthy, C. J. & R. A. Nussbaum 1995. Systematics, speciation and biogeography of the dwarf chameleons (Brookesia; Reptilia, Squamata, Chamaeleontidae) of northern Madagascar. J. Zool., London 235: 525-558. http://deepblue.lib.umich.edu/bitstream/2027.42/75501/1/j.1469-7998.1995.tb01767.x.pdf

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