The Pyrrhuloxia (the English name comes from a previous genus name) is a Mexican species whose range extends into the southwestern United States. Much of the range of the Pyrrhuloxia overlaps that of its close relative, the Northern Cardinal (Cardinalis cardinalis). Their habitat preferences differ slightly; Pyrrhuloxias can breed in drier areas than cardinals prefer. Where the two species breed in the same area, their territories may overlap without significant conflicts (Tweit and Thompson 1999).
Because the vocalizations of males and the plumages of females and juveniles of these two species are similar, atlasers needed to be very careful with identification. Male Pyrrhuloxias defend their breeding territories vigorously, singing from conspicuous perches, but nests are difficult to find and only 2% of the atlas records for Pyrrhuloxia are of nests.
DISTRIBUTION: Most TBBA records obtained during the 1987-1992 field work period, come from the central and eastern portions of the Trans-Pecos, the Edwards Plateau, South Texas Brush Country and Coastal Sand Plains regions. Additional records come from the southern High and Rolling plains.
Three subspecies of Pyrrhuloxia have been described. The east Mexican population,
associated with the Chihuahuan Desert, is the one found in Texas and New Mexico. The other two are resident in west Mexico and Arizona, and in Baja California Sur (Tweit and Thompson 1999)
SEASONAL OCCURRENCE: Nest Record Cards show that most nesting occurs in May, June and July. About one-quarter of the records are from each of these months. A few nests were found as early as March while about one-eighth were found as late as August. Pyrrhuloxias apparently re-nest rapidly after nest failure, but few pairs have been followed through the whole breeding season and no data are available on second successful nests (Tweit and Thompson 1999).
Although the species is not migratory and defend territories only at breeding time, seasonal movements occur. In the fall some birds form winter feeding and roosting flocks, perhaps more common in Texas, and move into areas of denser vegetation. These flocks are sometimes as large as 1000 birds (Oberholser 1974, Tweit and Thompson 1999).
BREEDING HABITAT: The most common nest site for Pyrrhuloxia in Texas is a mesquite tree, either in a grove or in grassland. In dense mesquite woodland, territories are as small as 0.25 ha (0.6 acre) and closely spaced. In more open areas, territories are as large as 2 ha (5 acres). In mesic areas with dense trees and undergrowth, habitat preferred by cardinals, Pyrrhuloxia territories are also large (Lemon and Herzog 1969).
A Pyrrhuloxia nest is usually found in a fork in the upper third of a mesquite, at an average height of 3.4 m (11 ft) above ground. The nest is placed on the north, northeast or south sides of a mesquite, not on the west side. It is not attached to the branch. The nest is a neat, compact oval cup, 10.7 x 8.8 cm (4.3 x 3.5 in) across and 5.9 cm (2.2 in) high. Nests are usually constructed of thorny twigs, strips of bark, and coarse grass, lined with rootlets, spider webs and feathers. A Pyrrhuloxia nest is smaller and more compact than that of a cardinal (Harrison 1979, Wilke 1995).
The average clutch is 3.4 eggs with a range of 3-5. The eggs usually hatch 14 days after the last egg is laid, and young birds leave the nest at 10-13 days after hatching. When young Pyrrhuloxias fledge they can walk and climb around in the mesquite, but their wings and tail are not fully-grown and they cannot fly well. More data are needed on development of young birds in the nest.
Nest Record Cards indicate cowbirds attempt to parasitize some Pyrrhuloxia nests; 13% of nests had cowbird eggs or young and another 9% had pecked Pyrrhuloxia eggs, often an indication of the presence of cowbirds at the nest (Tweit and Thompson 1999).
STATUS: Lockwood and Freeman (2004) indicate Pyrrhuloxia is a common to uncommon resident in the southwestern portion of the state and east to the western Edwards Plateau, south to the lower Rio Grande valley and north to the southern High and Rolling plains.
Breeding Bird Survey (BBS) data indicate the maximum densities of Pyrrhuloxia in the United States occur in Texas, in Jim Hogg and Brooks counties. One 40 km (25 mi) BBS route there had an incredible average of 3.6 Pyrrhuloxias at each of the 50 stops, a figure even higher than the high United States total for Northern Cardinal, also from the same BBS route (Price et al. 1995). In winter, feeding flocks are sometimes quite large (Oberholser 1974).
The range of the Pyrrhuloxia has expanded northward into the Panhandle as mesquite trees have invaded the grassland. In other parts of Texas widespread clearing of mesquite and shrubs has eliminated breeding habitat of Pyrrhuloxias (Oberholser 1974).
BBS data show a statistically significant population change of -2.1% per year for the period 1966-2004. Although this rate of decline is not as worrisome as those for some other species, it does cause long-term concern since Texas has the bulk of the United States population of this species with 75 of the 99 BBS routes on which Pyrrhuloxias were detected (Sauer et al. 2005). While Texas birdwatchers may continue to enjoy sights and sounds of this species for some years, its future is less certain than its relative, the Northern Cardinal which adapts better to the presence of people. Text by Robert C. Tweit (2005)
Harrison, H. H. 1979. A field guide to western birds’ nests. Houghton Mifflin, Boston.
Lemon, R. E. and A. Herzog. 1969. The vocal behavior of cardinals and Pyrrhuloxias.Condor71: 1-15.
Lockwood, M. W. and B. Freeman. 2004. The TOS handbook of Texas birds. Texas A&M University Press, College Station.
Oberholser, H. C. 1974. The bird life of Texas. University of Texas Press, Austin.
Sauer, J. R., J. E. Hines, and J. Fallon. 2005. The North American Breeding Bird Survey, results and analysis 1966-2004. Version 2005.1. USGS Patuxent Wildlife Research Center, Laurel MD (Web site, http://www.mbr-pwrc.usgs.gov/bbs).
Tweit, R. C., and C. W. Thompson 1999 Pyrrhuloxia (Cardinalis sinuatus). In The birds of North America, No. 391 (A. Poole and F. Gill, eds.).The Birds of North America, Inc., Philadelphia, PA
Wilke, R. R. 1995. The territorial behavior of Pyrrhuloxia (Cardinalis sinuatus) in west-central Texas with observations of breeding biology. Masters thesis. Angelo State College, San Angelo, TX.