{'fraction_non_alphanumeric': 0.0343213728549142, 'fraction_numerical': 0.025035287125770744, 'mean_word_length': 5.206546795758414, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
A Quantitative Method for Evaluating Contemporary Cultural Uses of Birds: A Case Study from Mexico

This study evaluates the relationship between people and birds in Mexico, a country where high cultural and biological diversity are reflected in the close associations between people and natural resources, recorded since preHispanic times. It systematically reviews 1041 records of cultural use of wild birds in Mexico published between 1996–2017 and analyzes patterns of contemporary use of avifauna. It classifies information for 252 birds by grouping uses of species and families into 11 categories and quantifies overall use with a Cultural Value Index (CVI). The data show that birds have a high cultural value as food, pets, and for medicinal uses (312, 235, and 119 records, respectively), particularly in the state of Chiapas. Large edible birds had the highest CVIs and included Plain chachalacas (Ortalis vetula; 9.72), Black-bellied whistlingducks (Dendrocygna autumnali; 6.65), Crested guams (Penelope purpurascens; 6.25), and Great currasows (Crax rubra; 6.23), with the Cracidae family recorded as favored gamebirds. Conspicuous, brightly-colored birds had high CVIs, including Keel-billed toucans (Ramphastos sulfuratus; 6.50), Red-lored amazons, (Amazona autumnalis; 6.03), and allied species, which were traded or kept as pets despite legal protection. The high CVIs of Barn owls (Tyto alba; 5.45) were related to medicinal uses, and Mourning doves (Zenaida macroura; 5.69) were mainly used as gamebirds. Wild bird populations face increasing pressure from habitat loss and overexploitation. We propose that evaluating the ethnological significance of wildlife with indices like CVIs can quantify the distinctive needs of rural communities, which when combined with information on conservation status can develop more sustainable species management plans. Received August 28, 2019 OPEN ACCESS Accepted July 18, 2020 DOI 10.14237/ebl.11.2.2020.1644 Published December 4, 2020


Research Communications
. Birds also feature in myths, rituals, art, and architecture relating to cycles of rebirth and renewal (Anderson 2017;Hull and Fergus 2017;Sault 2016).
In Latin America, birds are considered highly symbolic-especially hummingbirds and vultures, which are thought to predict life and death events (Sault 2016)-with magical powers believed to be conferred to anyone eating or possessing particular species or products (Anderson and Medina-Tzuc 2005). For centuries, indigenous Americans have made ceremonial regalia from feathers not only for their decorative qualities but also for their supposed connection to the spirit world. Those wearing feathers were thought to be able to fly, sing, and display like a bird, and could serve as sacred deities between human and other worlds (Costa-Neto et al. 2009). In pre-Hispanic Aztec culture brightly-colored iridescent feathers were highly prized, and hummingbird, quetzal, and male mallard plumage was incorporated into cloaks and shields of elite warriors, and pasted onto skin at festivals (Riedler et al. 2012). However, long-held cultural attitudes that traditionally prevented the overexploitation of natural resources are being lost, including beliefs by the Ch'orti' Maya in Guatemala about supernatural powers of birds (Hull and Fergus 2017), and traditional Maya ideology in the Yucatan that encouraged a shared responsibility for sustainably managing communally-held natural resources such as game birds (Anderson and Medina-Tzuc 2007).
Mexico is highly biodiverse with about 11% (n=1,115-1,150) of extant global bird species, including 194-212 endemic species (Navarro-Sigüenza et al. 2014). Much of its avifauna is threatened, with 26-44% of bird populations (Berlanga et al. 2017) and up to 57% of bird species (n=655) considered to be at risk (Ortiz-Pulido 2018). Avian species richness is highest in the inter-mountain habitats along the Gulf of Mexico and the Yucatan Peninsula, with endemism peaking in the western mountain ranges and Sierra Madre Oriental (Navarro-Sigüenza et al. 2014). Many bird populations are in decline owing to recent human activities (Ortiz-Pulido 2018), and endangered bird populations considered both at risk and possessing high cultural significance are considered to be especially vulnerable to over-exploitation (Tábara 2006).
This study aims to evaluate the relationship between people and birds in Mexico by analyzing patterns of contemporary cultural use of avifauna. This is achieved by quantifying the extent of cultural use of birds using a Cultural Value Index (CVI) developed for ethnobotanical studies (Turner 1988) and recently applied to ethnozoology (Ávila-Nájera et al. 2018). CVIs synthesize the detailed ethnological knowledge contained in multiple sources and generate a quantitative indicator of a species' or taxa's cultural relevance, which can indicate its risk of exploitation. CVIs can be used to incorporate cultural attitudes into conservation management of endangered wildlife populations, and for comparative studies of use and exploitation of species from different regions or following environmental or demographic changes.

Methods
We carried out a systematic search for relevant journal articles, books, theses, and online publications in Scopus, the Web of Science, and the National Consortium of Scientific and Technological Information Resources (CONRICyT). We used English and Spanish search terms relating to the cultural value or significance of, attitude towards or specific use of, wild birds in Mexico and extracted records and relevant information for the 20-year period 1996-2017. We stored records in MS Excel and corrected synonyms using Berlanga et al. (2017), and extracted species' Mexican conservation status from the NOM-059-SEMARNAT-2010 (SEMARNAT 2010).
Records were assigned to one or more of 11 categories of cultural use as used by Ávila-Nájera et al. (2018). These were: food, pets, trade, ornamental, artisanal, magic-religious (including belief in spiritual power [Anderson 2017]), medicinal purposes, killed for sport or recreation (hunted for pleasure), considered harmful or dangerous, or considered to have other benefits.
We quantified the overall cultural significance of each species using a Cultural Value Index (CVI) (Figueroa-Solano 2000, derived from the Index of Cultural Significance [Turner 1988

Research Communications
of records of all uses for all species from all sources) x 100,  Vu (Use value) = (Number of records for each species of a single use from all sources / Total number of records of a single use for all species from all sources) x 100, and  Vut (Total use value for each species) = Sum of Vu for all uses / total uses. We also calculated CVIs for bird families by substituting the data for species in the equations above with the combined data for all species in a family.

Discussion
Overall, this study emphasizes the incredibly high diversity and ongoing cultural significance of birds in Mexico. Nearly a quarter of the bird species we evaluated were valued for at least one cultural use, and some had multiple uses. A quarter of species of notable cultural value are considered endangered in Mexico, but the conservation status of many Mexican species probably underestimates their vulnerability because we lack sufficient data to determine whether their populations are in decline (SEMARNAT 2010). Indeed, Ortiz-Pulido et al. (2016) express concern about the conflicting information that informs the conservation status of many Mexican birds, which means that many species probably lack adequate legal protection.
The high CVIs of some birds reflect extensive levels of use (total number of records) as well as a variety of cultural applications for species such as O. vetula, R. sulfuratus, and P. purpurascens, of which two species are known to be endangered in Mexico (SEMARNAT 2010). The data for the CVIs originated from 21 of the 33 Mexican states, with high levels of cultural use particularly in tropical areas that also have high biodiversity and avian endemism

Research Communications
(Navarro-Sigüenza 2014). However, the limited nature of the available literature means that our analyses do not cover all Mexican regions to the same extent, indicating the need for further ethnozoological research.
The most frequent cultural uses of birds were for food, pets, or medicines, which together far outnumber the records for other cultural uses. Documented records of wild birds as everyday foodstuffs have existed in Mexico since the Aztec codices (Valadez 2003); They continue to have high dietary significance for rural communities like those in the Yucatan, where large birds like C. rubra and M. ocellata are the most valuable and frequently-consumed game after large mammals (Anderson and Medina-Tzuc 2005). The major food species we identified are all large Cracids (O. vetula, C. rubra, and P. purpurascens), and although C. rubra is listed in the IUCN red list status as "of least concern," it is believed to be under pressure from the international pet trade and human consumption (Birdlife International 2018). This observation emphasizes how indices of conservation status depend upon the availability of reliable population data which may differ at national or regional levels. We suggest that CVIs can help identify species that appear to be widely distributed and relatively abundant across their range, but which are in need of further study and/or protection on a regional or national level.
More species were valued as pets than for food, including 19 Psittacidae (parrot) species, echoing the global popularity of parrots, parrotlets, and macaws. A. autumnalis was the most frequently mentioned pet and is another Mexican bird for which we lack accurate population data. However, overcollection for the pet-trade has resulted in severely depleted populations of rarer, higher-value Psittacids across much of their ranges (Alves et al. 2013). In Mexico, 13 of the 20 endemic Psittacid species are under threat (Pires 2012), and parrots, including species listed in Table 1, are sold in rural Mexican markets despite their protected status (Roblero-Morales 2008) and are exposed to high levels of risk during capture and transport. This suggests that CVIs can identify the species and groups most at risk of overexploitation for particular purposes, and draw attention to species whose populations are not currently considered to be endangered.
Other  extinctions of tropical birds have been reported elsewhere and are linked to the demise of at least 13 Indonesian species (Eaton et al. 2015). This suggests that the pet trade needs to be more closely monitored, particularly for species where legal protection is not being enforced (Anderson and Medina-Tzuc 2005;Roblero-Morales 2008).
High levels of medicinal use were recorded for two vultures (C. astratus and C. aura), as well as Greattailed grackles (Q. mexicanus), Barn owls (T. alba), Mourning doves (Z. macroura), and Common pigeons (C. livia). This probably stems from ancient beliefs about vultures and owls as bearers of bad omens (Anderson and Medina-Tzuc 2005;Jacobo-Salcedo 2011), and from the ubiquity and abundance of doves and pigeons, making them readily available for ritual and other purposes.
Birds are extremely popular study subjects, so we know more about their ecology and conservation status than other terrestrial vertebrate taxa, making the state of avifauna a good indicator of overall ecosystem condition (Birdlife International 2018). Local knowledge and attitudes towards natural resources are factors behind the success or failure of many conservation initiatives (Alves et al. 2018;White et al. 2011). This suggests that CVIs could be particularly useful for species where we lack population data (like many Mexican birds) because they indicate a level of demand and identify cultural uses linked to the collection or culling of wild species. CVIs are also 3 Number of species of birds (unfilled bars) and number of records for each category of use of birds (black bars) in Mexico grouped into 11 classes (food, pet, trade, ornamental, artisanal, magical religious, harmful, medicinal, sport hunting, recreational, or other beneficial use) from records published between 1996 and 2017.
Research Communications relevant to species that historically benefitted from the protection offered by communally-held lands such as traditional Mexican ejidos, where communities operated a system of access rights and tenure that prevented overuse. There is considerable concern that such practices are being lost or ignored (Anderson and Medina-Tzuc 2005). In addition to the spatial or countrywide approach used here, CVIs could be applied to make temporal comparisons among species or taxa, particularly following demographic change or habitat loss in an area. Therefore, use-value estimates can help inform decisions concerning the sustainable management of well-studied taxa whilst also benefitting the wider ecosystem and supporting local community efforts to sustainably manage natural resources (Alves and Souto 2015;Anderson and Medina-Tzuc 2005).

Declarations
Permissions: Not declared (based on secondary data extracted from publications in the public domain). Sources of funding: Dulce Maria Ávila Nájera, postdoctoral research scholarship (UAM-X-CA-24) from the Secretaria de Educación Pública, Mexico. Conflicts of Interest: None declared.