The Wilson Journal of Ornithology 123(4):761—765, 2011 
NESTING RECORD AND POPULATION PHENOLOGY OF THE 
FLAMMULATED FLYCATCHER (DELTARHYNCHUS FLAMMULATUS) 
JORGE H. VEGA RIVERA, 13 FELIPE CAMPOS-CERDA, 1 AND MANFRED MEINERS 2 
ABSTRACT—We used misi netting in the Chamela-Cuixmala Biosphere Reserve to assess the population phenology of 
the Flammulated Flycatcher (Deltarhynchus flanimulatus). a poorly-known dry forest endemic of the Mexican Pacific 
Slope. We captured 135 birds (first records onlyi during 23,515 net hrs over a period of several years which suggests this 
flycatcher is common at the reserve. Monthly averages of captures (including monthly recaptures) differed between seasons 
with a peak (71%) during May to August tend of dry season to middle of wet season) and fewer (29%) captures during the 
rest of the vear. Flammulated’ Flycatchers in breeding condition (« = 38) were captured in June and July. Hatching year 
birds (n = 8) were captured from 10 July through 11 December. We found an active nest in a cavity on 29 June 2010. W e 
observed pieces of snake skin lining the nest, which may indicate a closer relationship with Myiarchus. Additional 
knowledge on the ecology and breeding biology of the Flammulated Flycatcher is urgently needed for de\e opment o 
effective conservation plans. Received 25 January 2011. Accepted 22 May 2011. 
The Flammulated Flycatcher (Deltarhynchus 
Jhmmulatus) is a little known, monotypic species 
endemic to the Mexican Pacific Region. Its 
habitat has been described as open thorn wood¬ 
land dominated by mesquite (Prosopis spp.) and 
acacia (Acacia spp.) (Lanyon 1982), semiarid 
thorn forest, and scrubby woodland (Howell and 
Webb 1995), or dry woods, scrub, and semi-arid 
country (Peterson and Chalif 1989). The current 
known distribution of this species includes the 
Pacific lowlands of Mexico from Sinaloa south to 
western Chiapas between sea level and 2.000 m 
elevation (Miller et al. 1957:82, AOU 1998:407). 
The Flammulated Flycatcher is generally depicted 
as an uncommon species within its range. 
Schaldach (1963:60) reported only two records 
in his bird surveys for Colima and Jalisco. Bintord 
(1989:185) described it as a "very uncommon 
pennanent resident in tropical deciduous forest in 
lower portions of the Pacific Region ', Alvarez 
del Toro (1980) described it as rare in Chiapas, 
and Ornelas et al. (1993) observed this species 
only twice during 2 years of bird surveys in the 
region of Chamela, Jalisco. This species is listed 
under the "special protection' category by the 
Mexican government due to habitat destruction 
tSEMARNAT 2010). 
There are also taxonomic reasons for attempt¬ 
ing to obtain more extensive information on the 
species. There has been discussion concerning 
1 Estaci6n de Biologia Chamela, Institute de Biologia. 
L'NAM, Km. 59. Carrctcra Fed 200. La Huerta. Jalisco 
48980, Mexico. 
: Biodiverso. A.C., Guadalajara. Jalisco, Mdxico. 
’Corresponding author: e-mail: 
jhvega@ibiologia.unam.mx 
whether this species should be included in 
Myiarchus , or continue to be treated as a 
monotypic species of Deltarhynchus. The struc¬ 
ture of the nest is considered to be critical 
(Traylor 1977, Lanyon 1982) regarding this 
controversy. We provide data relevant to the 
bird’s ecology, life history, conservation, and 
taxonomic status in western Mexico. 
METHODS 
Study Area .—This study was conducted at the 
Chamela Biological Station (3.300 ha), which is 
part of the Chamela-Cuixmala Biosphere Reserve. 
Jalisco, Mexico (19 22'-35' N, 104 56' to 105 
03' W). The weather is strongly seasonal with 
well-marked rainy (late Jun to Oct) and dry 
seasons (Bullock 1986). The Reserve (13,142 ha) 
is covered predominantly by undisturbed decidu¬ 
ous forest on dry hillsides with patches of semi- 
deciduous forest extending along arroyo flood- 
plains (Lott et al, 1987). There are records of 24 
endemic Mexican bird species in the Reserve, 20 
of which are restricted to western Mexico 
(Arizinendi et al. 1990). 
Field Procedures—We conducted mist netting 
along three trails dominated by deciduous (n = 2) 
and semi-deciduous (// = I) forests characteristic 
of mature forest of the Chamela-Cuixmala 
Biosphere Reserve and of the region in general. 
Mist nets were operated monthly from March 
1999 to August 2000 (13.135 net hrs) and at least 
once a year (mainly but not restricted to the 
breeding season) in 2001 and from 2005 to 2010 
(10.380 net hrs). We placed 8-12 mist nets (12 X 
2.5 m. 36 mm mesh size) in a line along each trail. 
separated from each other by 100 m. 
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