|Listed||November 25, 1994|
|Description||An evergreen tropical tree.|
|Habitat||Moist tropical forest.|
|Threats||Forestry practices and other disturbances, as well as the inherent risks of a very small population.|
Chupacallos (Pleodendron macranthum ) is an evergreen tree reaching 33 ft (10 m) in height, with leathery, alternate, simple leaves about 3.3-4.9 in (8.5-12.5 cm) long and 1.7-1.9 in (4.5 to 5.0 cm) wide. The blades are elliptic with the upper surface dark shiny green and the midvein sunken. The lower surface is pale green with a prominent mid-vein and with fine, parallel side veins. The leaf stalks are about 0.3 in (7 mm) long. The whitish bisexual flowers are solitary and axillary, 0.7 in (2 cm) wide and with a 1 in-long (2.5-cm-long) flower stalk. The cup-shaped calyx is persistent in the fruit and the corolla contains 12 petals. The aromatic purplish black fruit measures 0.7 in (2 cm) in diameter and contains many seeds.
Three of the chupacallos' known sites occur within the Caribbean National Forest, managed by the U. S. Forest Service. Humidity ranges from 90-100% on cloudy days. Precipitation varies from 118 to 177 in (300-450 cm) annually, with a relatively dry season occurring from February to April. The Luquillo Mountains are of volcanic origin, and igneous rocks, mostly and esitic in nature, cover the area. Basalt is the parent rock throughout these mountains. The palo colorado forest, one of four forest types, is found at elevations greater than 2,132 ft (650 m). The floor of the palo colorado forest is covered by a thick organic surface layer. It is an evergreen forest with two strata which are not sharply defined. Tree height is generally less than 49 ft (15 m), crowns are low, and trees branch profusely. Palo colorado (Cyrilla racemiflora ) is the most prominent species in this type of forest. Three tree strata are obvious—a discontinuous upper strata, a second continuous strata at 65 ft (20 m) and under-story. The forest floor is only sparsely vegetated. Bromeliads, lianas, vines, and arborescent ferns are frequently observed. Leaves are mesophyllous, and shade leaves tend to be covered with epiphytic growth. Another dominant tree, motillo, bears characteristic buttress roots.
The Río Abajo Commonwealth Forest is the other site where chupacallos can be found. This forest is found in the limestone hill region of northern Puerto Rico in the municipalities of Utuado and Arecibo. Here chupacallos grows in the semi-evergreen or evergreen seasonal forest of the subtropical moist forest life zone on limestone hills at elevations from 492 to 1,148 ft (150 to 350 m). Soils in these hills are shallow, well-drained, alkaline, and interspersed between outcrops of hard limestone. Mean annual precipitation varies from 4.9 to 6.5 ft (150 to 200 cm). Two strata are present in this type of forest. The upper strata is composed of a continuous layer which extends up to 66 ft (20 m) in height with a few emergent trees reaching 82 ft (25 m). One-third to two-thirds of the species are deciduous. The second strata reaches 32.8 ft (10 m) in height and the number of deciduous species is low. Most species are evergreen, with simple, microphyllous leaves.
Chupacallos was discovered in 1822 or 1823 and was first described in 1889. No observation or collection of the species was made for more than 40 years. The species was rediscovered, and is at present known from fewer than 50 individuals in seven localities of the subtropical wet and the subtropical montane wet forests of northern and eastern Puerto Rico. Three localities are within the Caribbean National Forest and four are within the Río Abajo Commonwealth Forest.
Forest management practices such as the establishment and maintenance of plantations, selective cutting, trail and road construction and maintenance, and shelter construction may affect the species. In addition, the extreme rarity of the species makes it vulnerable to natural catastrophes, such as the passage of Hurricane Hugo in 1989. All localities where the species occurs in the Caribbean National Forest were affected by the hurricane.
Conservation and Recovery
The critical habitat of the chupacallos occurs within the Caribbean National Forest and the Rio Abajo Commonwealth Forest. The chupacallos and its habitat should be strictly protected against any threatening activities associated with forestry, road-building, or other disturbances. This can be done by incorporating prohibitions into management plans for the Caribbean National Forest and the Rio Abajo Commonwealth Forest. One goal is to propagate the chupacallos in captivity, to provide stock for out-planting into suitable wild habitats.
U. S. Fish and Wildlife Service
Regional Office, Division of Endangered Species
1875 Century Blvd., Suite 200
Atlanta, Georgia 30345
U. S. Fish and Wildlife Service
Boquerón Ecological Services Field Office
Post Office Box 491
Boquerón, Puerto Rico 00622-0491
Telephone: (787) 851-7297
Fax: (787) 851-7440
U. S. Fish and Wildlife Service. 1994. "Determination of endangered status for two Puerto Rican trees." Federal Register 59(226):60565-60568.