Justification of Red List Category
This species is listed as Vulnerable because of evidence for rapid population declines, presumably as a result of the conversion and degradation of its piñon-juniper woodland habitat.
Partners in Flight (2019) place the population size at 770,000 mature individuals, although Johnson et al. (2020) suggest this figure may be an overestimate due to estimates being outdated and based on the scant, available survey data, particularly in New Mexico where 29% of the global population is thought to reside. The number of mature individuals is therefore placed in the band 500,000-999,999 mature individuals to accommodate such uncertainty.
This species has undergone a large and statistically significant decrease in North America over the past 50 years, with a 84% total population loss currently estimated (Rosenberg et al. 2016, Johnson et al. 2020). Data from Breeding Bird Survey suggest that between 2003-2013 the species underwent a decline of c.-3.6% per year (Sauer et al. 2014). Its 'half-life' is estimated at 19 years (Rosenberg et al. 2016). Partners in Flight (2019) currently estimate the species to be declining at a rate of ~3.4% per annum, which equates to a ~38% decline over three generations (~14 years). The Breeding Bird Survey estimated the species to be declining at ~2.7% per annum, which equates to a decline of ~32% over three generations (Sauer et al. 2017). As such, the rate of decline is placed in the range of 30-49% across three generations.
Gymnorhinus cyanocephalus is a permanent resident of the foothills and lower mountain slopes of the western and south-western U.S.A. and northern Baja California, Mexico. In the U.S.A., it is found from central Oregon east to western South Dakota and south to central New Mexico and extreme western Oklahoma. Recent records also place the species at Sonora (Russell and Monson 1998), Gómez Farías (Chávez et al. 2018) and near Sierra San Luis, Chihuahua, Mexico (Moreno-Contreras et al. 2016). In years when pine crops fail it becomes irruptive, with individuals often dispersing far outside their normal range (Madge and Burn 1993, Balda 2002). Thought to be owing mainly to habitat degradation/and loss, this species is estimated to have suffered a significant population decline.
This species is a highly social cooperatively-breeding bird, forming permanent flocks of 250 individuals (Madge and Burn 1993), sometimes reaching over 500 (Balda 2002), although wintering flocks of over 1000 are becoming increasingly rare (Johnson et al. 2020). Many birds spend their entire lives in their natal flocks, and individuals that do disperse (mostly young females) generally travel short distances. Dispersal habits are affected by changes in local habitat, and by fluctuating operational sex ratios within and among flocks (R. Benford in litt. 2012). Although omnivorous, it has a mutualist relationship with the pinyon pine complex of western North America, dispersing the large wingless seeds long distances and reaping the reward of an energy and nutrient rich food source (Johnson et al. 2016). Individuals have excellent spatial memories, giving them uncanny recovery accuracy when digging up food stores months after caching, even through snow. It is one of the earliest nesting passerines in the U.S.A., commencing breeding in the winter in areas where the pine-seed crop was abundant the previous autumn. One population in New Mexico breeds in autumn when pinyon pine cone crops are available (Balda 2002).
The major threat to this species may have been the destruction of its major habitat type, piñon-juniper woodland; ongoing forest loss within the species's range is currently estimated at ~5.6% per three generations (Tracewski et al. 2016). Land managers have followed a policy to eradicate this woodland, with the U.S. Forest Service classifying it as "non-commercial" and placing it in a "no-value" category. During the 1940s-1960s, major programmes to eradicate the entire habitat were carried out, during which possibly millions of G. cyanocephalus died owing to habitat destruction. Piñon-juniper woodland is also often removed to create or promote shrublands for the benefit of sage-grouse, a species targeted for conservation efforts, despite its rates of decline being slower than those of G. cyanocephalus, which declines as a result (Boone et al. 2018). Currently herbicides, mechanical ploughing and fire are used to turn piñon-juniper woodland into pasture land for cattle. Fire-suppression policies in south-west U.S.A. have led to huge, uncontrolled wildfires that consumed large areas of suitable habitat in the late 1990s (Balda 2002). Additional management actions also pose a potential threat to Pinyon Jays, particularly heavy woodland thinning (Johnson et al. 2018, Magee et al. 2019, Johnson et al. 2020). A "catastrophic" drought in the early 2000s also caused considerable mortality (Benford 2008). Drought events can lead to water stress and increase susceptibility to pinyon engraver beetles (Wiggins 2005). The decline of pinyon pine and associated encroachment of juniper associated with global warming are primary factors restricting habitat and limiting reproductive success (R. Benford in litt. 2012). However, there has also been the suggestion that it may be a decline in the woodland/shrubland transitional areas and habitat quality which may have been even more important in the continued decline of this species (E. Ammon and J. Boone in litt. 2016). Further threats include noise and habitat fragmentation from oil and gas activities (Kleist et al. 2018, Johnson et al. 2020).
Conservation Actions Underway
No new policies are in place, whilst old ones are no longer implemented (Balda 2002). A series of conservation recommendations and goals were recently published in the New Mexico Bird Conservation Plan, written by the New Mexico Avian Conservation Partners (NMACP), in order to mitigate the species ongoing decline; such recommendations focus predominantly on the preservation and management of piñon-juniper woodlands (Johnson et al. 2020).
25.5 cm. Short-tailed, uniform-coloured blue jay with a long, straight bill reflecting its specialised diet. Similar spp. Only remotely similar species is the Mexican Jay Aphelocoma ultramarina but this species has a much longer tail and is distinctly two-toned. Voice Variety of soft, nasal calls.
Text account compilers
Ammon, E., Benford, R., Benstead, P., Bird, J., Boone, J., Harding, M., Hucks, K., Inigo, E., Khwaja, N., Rosenberg, K., Sharpe, C.J., Symes, A., Taylor, J., Wells, J., Westrip, J.R.S. & Wiggins, D.
BirdLife International (2022) Species factsheet: Gymnorhinus cyanocephalus. Downloaded from http://www.birdlife.org on 05/12/2022. Recommended citation for factsheets for more than one species: BirdLife International (2022) IUCN Red List for birds. Downloaded from http://www.birdlife.org on 05/12/2022.