Overview

Distribution

Range Description

Dendroica angelae was only discovered in 1968 and is endemic to Puerto Rico (to USA) (Raffaele 1983). It was formerly considered to occur at four disjunct localities: in the east, the Sierra de Luquillo (El Yunque National Forest/Bosque Nacional del Caribe) and the Sierra de Cayey (Carite State Forest) and, in the west, the Cordillera Central (Maricao and Toro Negro Commonwealth Forests), but its existence at some of these sites has been questioned and it is now thought to be restricted to two widely separated locations: the Sierra de Luquillo and Maricao State Forest (Anadon-Irizarry 2006, Delannoy 2006). In optimal habitat it can be locally common, and although the population was previously thought to be no more than c.300 pairs (Curson et al. 1994), more accurate counts put the population at 1,830 individuals.
Creative Commons Attribution Non Commercial Share Alike 3.0 (CC BY-NC-SA 3.0)

© International Union for Conservation of Nature and Natural Resources

Source: IUCN

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

Range

Montane elfin forests of e Puerto Rico.
  • Clements, J. F., T. S. Schulenberg, M. J. Iliff, D. Roberson, T. A. Fredericks, B. L. Sullivan, and C. L. Wood. 2014. The eBird/Clements checklist of birds of the world: Version 6.9. Downloaded from http://www.birds.cornell.edu/clementschecklist/download/

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

Physical Description

Type Information

Type for Dendroica angelae Kepler & Parkes
Catalog Number: USNM 564584
Collection: Smithsonian Institution, National Museum of Natural History, Department of Vertebrate Zoology, Division of Birds
Sex/Stage: Male; Adult
Preparation: Skin: Whole; Alcoholic: Partial
Collector(s): C. Kepler
Year Collected: 1971
Locality: Sierra De Luquillo, On Ridge Between Rio Sabana and Rio Espiritu Santo Valleys, ca. 2.5 km W of Hwy 191, On El Toro Trail, Luquillo, Puerto Rico, North America
Elevation (m): 780
  • Type: Kepler & Parkes. January 1972. Auk. 89 (1): 3.
Creative Commons Attribution 3.0 (CC BY 3.0)

© Smithsonian Institution, National Museum of Natural History, Department of Vertebrate Zoology, Division of Birds

Source: National Museum of Natural History Collections

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

Ecology

Habitat

Habitat and Ecology

Habitat and Ecology
Although it inhabits elfin or montane dwarf forest on ridges and summits, montane wet forest, and sometimes ranges to lower-elevation wet forest, it reaches its highest densities in Podocarpus dominated forest (Cruz and Delannoy 1984, Raffaele et al. 1998, Delannoy 2006). Preferred areas have a dense canopy with vines, high subcanopy and sparse understorey (Curson et al. 1994, Raffaele et al. 1998). It shows a string preference for undisturbed forest, but has been recorded in secondary habitats and plantations (Cruz and Delannoy 1984). Breeding takes place in March-June, and the nest is built in aerial leaf-litter trapped in vegetation or vines, usually close to the trunk, or in a tree cavity (Curson et al. 1994, Raffaele et al. 1998, Rodriguez-Mojica 2004).

Systems
  • Terrestrial
Creative Commons Attribution Non Commercial Share Alike 3.0 (CC BY-NC-SA 3.0)

© International Union for Conservation of Nature and Natural Resources

Source: IUCN

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

Associations

Known predators

Dendroica angelae is prey of:
Buteo jamaicensis
Buteo platypterus
Accipiter striatus
Diptera
Secernentia nematodes

Based on studies in:
Puerto Rico, El Verde (Rainforest)

This list may not be complete but is based on published studies.
  • Waide RB, Reagan WB (eds) (1996) The food web of a tropical rainforest. University of Chicago Press, Chicago
Creative Commons Attribution 3.0 (CC BY 3.0)

© SPIRE project

Source: SPIRE

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

Molecular Biology and Genetics

Molecular Biology

Statistics of barcoding coverage: Dendroica angelae

Barcode of Life Data Systems (BOLDS) Stats
Public Records: 0
Specimens with Barcodes: 2
Species With Barcodes: 1
Creative Commons Attribution 3.0 (CC BY 3.0)

© Barcode of Life Data Systems

Source: Barcode of Life Data Systems (BOLD)

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

Conservation

Conservation Status

IUCN Red List Assessment


Red List Category
VU
Vulnerable

Red List Criteria
D2

Version
3.1

Year Assessed
2012

Assessor/s
BirdLife International

Reviewer/s
Butchart, S. & Symes, A.

Contributor/s
Rodriguez, R., Anadón, V., Delannoy, C. & Colón-Merced, R.

Justification
This species is listed as Vulnerable because it has a very small range and, were data to show that it is declining in population or range, it would be uplisted to Endangered.

Creative Commons Attribution Non Commercial Share Alike 3.0 (CC BY-NC-SA 3.0)

© International Union for Conservation of Nature and Natural Resources

Source: IUCN

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

Population

Population
The population is estimated to number at least 1,800 mature individuals, based on censuses conducted using playback methods. This is roughly equivalent to at least 2,700 individuals in total.

Population Trend
Decreasing
Creative Commons Attribution Non Commercial Share Alike 3.0 (CC BY-NC-SA 3.0)

© International Union for Conservation of Nature and Natural Resources

Source: IUCN

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

Threats

Major Threats
By the late 1940s, the natural vegetation of Puerto Rico had been reduced to c.6% of the island's land surface, but rapid regeneration of forest increased this figure to 31% in the early 1980s, a change which will probably benefit this species (Cruz and Delannoy 1984). However, Podocarpus dominated forest, which may be crucial to this species survival, makes up a tiny percentage of the total remaining forest and continues to destroyed by infrastructure projects, including tourism developments in protected areas (R. Rodriguez in litt. 2007). Natural disasters will continue to be a threat while the species's population and range remain so small.
Creative Commons Attribution Non Commercial Share Alike 3.0 (CC BY-NC-SA 3.0)

© International Union for Conservation of Nature and Natural Resources

Source: IUCN

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

Management

Conservation Actions

Conservation Actions

Conservation Actions Underway
Both known areas area protected, and the species is probably secure as long as suitable habitat is maintained in these reserves (Cruz and Delannoy 1984). In July 2011 Sociedad Ornitológica Puertorriqueña (SOPI), in collaboration with BirdLife, started a project which aims to carry out surveys for the bird in the Carite Commonwealth Forest and surrounding, privately-owned, potential habitat to determine the presence of a potential third population (V. Anadon in litt. 2012).

Conservation Actions Proposed
Ensure the complete protection of the two sites where it persists. Assess the current distribution (especially by surveying away from known sites) and population. Research factors limiting range and population, and attempt to determine why it disappeared from parts of its former range. Protect private land where the species occurs through cooperative agreements with landowners (USFWS).
Creative Commons Attribution Non Commercial Share Alike 3.0 (CC BY-NC-SA 3.0)

© International Union for Conservation of Nature and Natural Resources

Source: IUCN

Trusted

Article rating from 0 people

Default rating: 2.5 of 5

Wikipedia

Elfin woods warbler

The elfin woods warbler (Setophaga angelae) is a bird endemic to the Caribbean island of Puerto Rico where it is a local and uncommon species. Discovered in 1968 and described in 1972, it is the most recently described species of New World warbler (Parulidae family). The species name, angelae, is a tribute to Angela Kepler, one of its discoverers. An insectivore, it feeds by gleaning small insects off leaves.

Due to its small populations and restricted habitats, conservation efforts were begun in 1982 to protect this species but, as of 2005, the warbler was still in need of protection. The species is not in immediate danger as the majority of its habitat is protected forest, but introduced species, such as rats and small Asian mongooses, habitat reduction, and natural disasters represent potential threats to the population.

Discovery and naming[edit]

The elfin woods warbler is one of many species in the genus Setophaga of the New World warbler family Parulidae. It was first observed in 1968 by Cameron and Angela Kepler while they were conducting observations on two Puerto Rican endemic birds, the Puerto Rican Amazon and the Puerto Rican tody. On May 18, 1971, a specimen was captured in El Yunque National Forest, which at the time was believed to be its only habitat. A year later Kepler and Parkes described and named the species making it the most recent Setophaga warbler discovered in the New World.[2] Also, it is the first species described in the Caribbean since 1927 and the first Puerto Rican species described in the 20th century.[3] The species name, angelae, is a tribute to Angela Kepler. Elfin-woods warbler is an alternative spelling, and Reinita de Bosque Enano is the Spanish name.

Description[edit]

The warbler's upper body is predominantly black with white areas while its underparts are white with black streaks. Other identifying characteristics are dark brown eyes, white patches on its ears and neck, an incomplete white eyering, a white eyestripe, and two white spots on its outer tail feathers.[4] Characteristic of Antillean warblers (S. adelaidae, S. delicata, S. plumbea and S. pharetra), the species features a long bill and short, round wings (53.8 mm or 2.12 in average). Among Setophaga spp., only S. adelaidae has a shorter wing length average (50 mm or 2.0 in) than the elfin woods warbler.[3] Juveniles differ from adults, retaining a greyish-green back for approximately a year and partially moulting from July to October. The warbler's average mature length is 12.5 cm (4.9 in) and its average weight is 8.4 g (0.30 oz).[5] Sexual dimorphism is not present in this species.

Identification[edit]

Black-and-white warbler, a species commonly mistaken for the elfin woods warbler

The elfin woods warbler is often confused with the black-and-white warbler (Mniotilta varia), a non-breeding species in the Caribbean occurring in Puerto Rico from mid-September to early May. The main physical distinction is in the eyes. The elfin woods warbler has an incomplete white eyering and the black-and-white warbler has a white band across the eye and a white lower half of the eyering. Another distinction is found in the crown, with the elfin woods warbler's being entirely black and the black-and-white's having a white band across. The latter species forages on larger branches compared with the elfin woods warbler's foraging in the canopy and on smaller branch tips.[6]

Voice[edit]

External audio
Bird Call
Elfin woods warbler vocals

The elfin woods warbler's song and call are difficult to hear.[7] The species has a subtle voice and its call and song resemble those of the bananaquit, the most abundant bird in Puerto Rico. The song is a series of "short, rapidly uttered, rather unmusical notes on one pitch, swelling in volume and terminating with a short series of distinct double syllables sounding slightly lower in pitch"[2] while the call has been described as "a single, short, metallic chip".[2]

Behavior[edit]

Breeding[edit]

The elfin woods warbler breeds from March to June. Both parents are involved in the construction of the nest and in feeding the chicks. Nests are built close to the tree trunk within dry aerial leaf litter, usually Cecropia leaves (a material used by no other Parulidae species), in Bulbophyllum wadsworthii trees. Nests are well-concealed and located 1.3 to 7.6 metres (4.3 to 24.9 ft) above ground level.[8] Nests are cup-shaped and made from small roots and twigs, dry leaves of Chusquea abietifolia and B. wadsworthii, and dry Panicum maximum leaves. The interior is made from fibers of C. abietifolia, dry leaves and other plant matter.[9] Females lay two or three white colored eggs with red-brown spots.[10] The chick's diet consists of insects—parents have been observed offering lepidopteran and orthopteran adults and lepidopteran larvae to hatchlings.[9]

Feeding[edit]

The elfin woods warbler is commonly found foraging the middle canopy for insects.[5] While searching for food it often flocks with other birds, such as black-and-white warblers, Puerto Rican tanagers and Lesser Antillean pewees. Three maneuvers used for catching prey—gleaning, sally-hovering and probing—have been described.[5] Gleaning is described as a hunting maneuver made by a standing or moving bird. Sally-hovering is a hunting maneuver made by a bird in flight. Probing is a maneuver in which the bird, by digging with its beak, forages the substrate looking for food in a manner similar to chickens.[5] Gleaning, especially off leaves, is the maneuver used with more frequency by the elfin woods warbler while probing is the least used.[5]

Distribution and habitat[edit]

When first discovered, the elfin woods warbler was believed to exclusively occur in the high elevation, from 640 to 1,030 metres (2,100 to 3,380 ft), dwarf or elfin forests of the El Yunque National Forest in eastern Puerto Rico. The wind-clipped trees in these forests rarely exceed 5 metres (16 ft) height and are characterized by stiff, thick twigs, leathery leaves and impenetrable, dense undergrowth ideal for hiding from predators. Three more populations were later discovered in the Maricao State Forest (1972, largest known population), the Carite State Forest (1977) and the Toro Negro State Forest (late 1970s).[8] Also, studies showed that the species migrated altitudinally to lower elevations, between 370 and 600 metres (1,210 and 1,970 ft), in Tabonuco and Palo Colorado forests.[11]

Historically, the elfin woods warbler was restricted to humid mountainous forests at four distinct locales in Puerto Rico. Presently, the species is presumed extirpated from two locales, occurring only at El Yunque National Forest and the Maricao State Forest. The elfin forest at El Yunque National Forest is characterized by high rainfall and humidity, low temperatures and insolation, and constant winds. It is found at mountain summits and is primarily composed of dense shrub and small trees with moss and epiphyte growth in its plants and floor. The species richness is low when compared to other types of forests (tabonuco, palo Colorado and palma sierra forests) found in the Luquillo Mountains.[11] The elfin forest at the Maricao State Forest, located in western Puerto Rico, receives an annual average rainfall of 2,250 millimetres (89 in), a high amount considering that a rainforest, by definition, receives a minimum of 1,700 millimetres (67 in) annually. However, since its soil has low water holding capacity its vegetation is more xeric than expected.[11] The species's highest density occurs in Podocarpus forests in the Maricao State Forest. Little information is available on the elfin forests at Toro Negro and Carite.

Status and conservation[edit]

Population[edit]

Bird count of the elfin woods warbler (2001)

In September 1989, Hurricane Hugo struck the central and eastern region of Puerto Rico affecting three (the El Yunque National Forest, Toro Negro and Carite populations) of the four known populations of the elfin woods warbler. A survey conducted two years later in the Toro Negro Forest, located in the Cordillera Central, did not find any individuals.[12] Recent surveys suggest that, for reasons yet unknown, the populations at Carite and Toro Negro were likely extirpated.[8] Continued monitoring of the elfin woods warbler populations is achieved through bird counts performed every 3 to 4 years by the Puerto Rican Breeding Bird Survey (PRBBS). A survey conducted in 2001  found three individuals at the Maricao State Forest. An IUCN assessment of the elfin woods warbler, prepared in 2000, estimated a stable population of 600 mature individuals.[13] More recently the population has been estimated to comprise at least 1800 mature individuals, a figure which equates to at least 2700 individual birds.[14]

Threats[edit]

Puerto Rican sharp-shinned hawk, a natural predator of the elfin woods warbler

The survival of the elfin woods warbler faces two main threats, predation and the destruction or alteration of suitable habitat. Confirmed native predators are the pearly-eyed thrasher (Margarops fuscatus), the Puerto Rican sharp-shinned hawk (Accipiter striatus venator) and the extirpated white-necked crow (Corvus leucognaphalus) while unconfirmed native predators include two endemic snakes and several carnivores (from fossil records). Introduced species, such as cats (Felis domesticus), dogs (Canis lupus familiaris), black rats (Rattus rattus) and small Asian mongooses (Herpestes javanicus) are also potential nest predators.[9] These species have proliferated due to the presence of human-developed facilities, mainly for communication purposes, in the Maricao State Forest and El Yunque National Forest. Two factors contribute to the destruction of the elfin woods warbler's habitat, humans and nature. Human-related habitat destruction includes the construction of communication towers, acquisition of timber, and expansion of roads and trails. Nature's contribution comes from natural disasters such as forest fires and hurricanes.[2]

Protection[edit]

The elfin woods warbler was placed on the United States federal candidate list for Endangered Species Act in 1999 and the announcement was published on the Federal Register of 10/25/1999, Volume 64, No. 205, pages 57535-57547. The USFWS started to considered the need to protect the elfin woods warbler in 1982.[15] &nbsp In 2005, a group of scientists, scholars, artists and environmentalists petitioned the Bush administration to admit 225 species, among these the elfin woods warbler, to the Endangered Species Act. Of these 225 species, more than one third have been on the candidate list for 20 or more years and half for 10 or more years. Recent studies also show that since the creation of the Endangered Species Act in 1973, 114 United States species have become extinct, many because of lack of habitat protection by the federal government.[16]

The IUCN first evaluated the status of the elfin woods warbler in 1988. At the time it was given a classification of lower Risk/least concern. In 1994, its status was changed to Lower Risk/near threatened and in 2000, its status was changed to vulnerable, where it remains.[1] The justification for maintaining the species' status as vulnerable is that "There are no direct or immediate threats, but the combination of a very small range and population may have important implications for its chances of long-term survival, and this species consequently qualifies as Vulnerable".[13]

See also[edit]

References[edit]

Cited references[edit]

  1. ^ a b BirdLife International (2012). "Dendroica angelae". IUCN Red List of Threatened Species. Version 2013.2. International Union for Conservation of Nature. Retrieved 26 November 2013. 
  2. ^ a b c d Cuevas, Victor, M. (January 2002). "Wildlife Facts – January 2002 – Elfin-woods Warbler". USDA Forest Service. Retrieved 19 March 2006. 
  3. ^ a b Kepler, C. B.; Parkes, K. (January 1972). "A New Species of Warbler (Parulidae) from Puerto Rico". The Auk 89 (1): 1–18. doi:10.2307/4084056. 
  4. ^ Curson, Jon; Quinn, David; Beadle, David (1994). New World Warblers. London: Christopher Helm. pp. 155–56. ISBN 0-7136-3932-6. 
  5. ^ a b c d e Cruz, Alexander; Delannoy, Carlos A. (1984). "Ecology of the Elfin-woods Warbler (Dendroica Angelae) II". Carib. J. Sci. 20 (3–4): 153–62. 
  6. ^ Wauer, Roland H. (1996). A Birder's West Indies: An Island-by-Island Tour. University of Texas Press. p. 69. ISBN 0292791011. 
  7. ^ To listen to the sound of this species click here [1].
  8. ^ a b c Anadón Irrizary, Verónica (2006). Distribution, habitat occupancy and population density of the Elfin-woods Warbler. MS Thesis. University of Puerto Rico at Mayagüez.
  9. ^ a b c Arroyo Vázquez, Bryan (June 1992). "Observations of the breeding biology of the Elfin Woods Warbler". The Wilson Bulletin 104 (2): 362–65. 
  10. ^ "Elfin-woods Warbler". Oiuseax.net. Retrieved March 19, 2006. 
  11. ^ a b c "Candidate and Listing Priority Assignment Form – Elfin woods Warbler". 2001. Archived from the original on 24 July 2006. Retrieved 19 March 2006. 
  12. ^ Arroyo Vázquez, B. (2001). Comparative study of foraging behavior and habitat selection of resident wood warblers (Dendroica) in southwestern Puerto Rico. 
  13. ^ a b "Species factsheet: Dendroica angelae". BirdLife International. 2005. Retrieved 19 March 2006. 
  14. ^ "Elfin Woods Warbler Dendroica angelae". Species factsheet. BirdLife International. 2012. Retrieved 2012-11-02. 
  15. ^ All Federal Register Documents for the Elfin Woods Warbler
  16. ^ Lucas, Tim (5 April 2004). "A Coalition for Conservation". Archived from the original on 7 November 2005. Retrieved 19 March 2006. 

General references[edit]

Creative Commons Attribution Share Alike 3.0 (CC BY-SA 3.0)

Source: Wikipedia

Unreviewed

Article rating from 0 people

Default rating: 2.5 of 5

Disclaimer

EOL content is automatically assembled from many different content providers. As a result, from time to time you may find pages on EOL that are confusing.

To request an improvement, please leave a comment on the page. Thank you!