NATURAL AREAS AND REGIONS 



615 



Capita maculicoronatus maculicoronatus 

 (spotted-crowned barbet), Jacamerops 

 aurea (great jaeamar), Hylomanes ino- 

 motula obscurus (Panama tody-motmot), 

 Electron platijrhynchum minor (lesser 

 broad-billed motmot), Urospatha viartii 

 semirufa (greater rufous motmot), Euto- 

 x^res aquila salvini (Salvin's sickle-bill), 

 Pittasoma michleri viichleri (Michler's 

 antpitta), Myrrneciza exsul exsul (Scla- 

 ter's antbird), Gymnocichla nudiceps 

 nudiceps (bare-crowned antbird), Praedo 

 audax (black-billed flycatcher). 



Plants : Lycopodium dichotomuni. Heli- 

 conia wagneriana, Brosimum utile, Cecro- 

 pia arachnoides (guarumo), Ficus pana- 

 mensis (Panama wild fig), Ficus piiiieri 

 (Pittier's wild fig), Inophleum armatum 

 (Maragua), Swartzia panamensis (cu- 

 taro), Sloanea megalophylla, Pachira 

 aquatica, Eschiveilera panamensis, Gus- 

 tavia nana, Gustavia parvi folia, Miconia 

 barbinervis, Sagraea petiolata. 



b. Arid Lower Tropical Zone (arid 

 deciduous forest and savanna). The 

 Arid Lower Tropical Zone extends in a 

 belt of varying w-idth, mainly at low 

 elevations, all along the southern side 

 of the Isthmus, excepting the south- 

 eastern part, from the Pacific coast line 

 to near the base of the higher mountains, 

 reaching farthest inland along the valley 

 of the Tuyra River, and at the base of 

 the Azuero Peninsula. In the vicinity 

 of the Canal Zone it crosses the conti- 

 nental divide and invades a part of the 

 valley of the Chagres River; islands off 

 the southern coast are also included in 

 its scope. 



The total rainfall is by no means 

 scanty, and in the wet season the for- 

 ested parts of this zone differ compara- 

 tively little from Humid Lower Tropical 

 areas, truly arid conditions prevailing 

 only during the dry season when much 

 of the forest, except near water, is 

 leafless and the contrast with the con- 

 tinuously humid areas is very striking. 



Two principal associational divisions 

 are recognizable within the Arid Lower 

 Tropical section of the Lower Tropical 

 Zone. These are an arid or semi-arid 

 forest association, and a savanna and 



savanna border association. The for- 

 ests are generally continuous along the 

 basal slopes of the mountains and cover 

 irregular contours to near the sea. 

 They also extend as semi-arid belts 

 along the river valleys. Open, grassy 

 plains or savannas, often of wide extent, 

 cover generally level areas along the 

 Pacific slope from near the Costa Rican 

 frontier eastward to the Bayano River. 

 Savannas also occur in the valley of the 

 Chagres River east of the Canal Zone. 

 Many mammals and birds are not 

 definitely assignable to savanna or 

 forest as they find their most congenial 

 habitat along the forest borders where 

 they seek food in the open spaces and 

 retire to the woodland for shelter. No 

 effort is made to differentiate these 

 elements in the brief lists of indicators 

 following: 



Mammals: Marmosa mexicana savan- 

 narum (savanna marmosa). Philander 

 laniger pallidus (pale woolly opossum), 

 Odocoileus chiriquensis (Chiriqui white- 

 tailed deer), Macrogeomys pansa (Bug- 

 aba pocket gopher), Liomys adspersus 

 (Peter's spiny pocket mouse), Sciurus 

 variegatoides helveolus (Canal Zone squir- 

 rel), Sylvilagus gabbi consobrinus (sa- 

 vanna rabbit). 



Birds: Rupornis ruficauda (rufous- 

 tailed hawk), Odontophorus castigatus 

 (Panama partridge), Leptotila rujinucha 

 (rufous-naped dove), Gymnocichla nu- 

 diceps erratilis (Costa Rican bare- 

 crowned antbird), Myrrneciza exsul oc- 

 cidentalis (Cherrie's antbird), Pheugo- 

 pedius fasciatoventris melanogaster 

 (black-bellied wren), Anihiis parvus 

 (Panama pipit), Basileuterus semicervi- 

 nus veraguensis (buff-rumped warbler), 

 Sturnella magna inexpectata (Central 

 American meadowlark), Leistes militaris 

 (Cayenne red-breasted blackbird), ^m- 

 modramus savannarum obscurus (Mina- 

 titlan sparrow), Sporophila minuta mi- 

 7iuta (minute seedeater). 



Plants : Sweetia panamensis, Dalbergia 

 reiusa (cocobola), Cedrela mexicana 

 (Spanish cedar), Swietenia macrocarpa 

 (mahogany), Ceiba pentandra, Cavanil- 

 lesia platanifolia (cuipo), Bromelia pin- 



