Material use to build the figures presented in the manuscript: The importance of livestock in the diet of Mexican wolf (Canis lupus baileyi) in Northwestern Mexico

The reintroduction of the Mexican wolf in the wilds of Northwestern Mexico
has allowed us to address its trophic ecology and elucidate conflicts with
livestock producers: their main mortality factor. Our objective was to
determine the feeding habits of wolves in Mexico, as well as the quantity
and frequency of livestock predation in relation to seasonal and
individual variables, through the analysis of genetically identified
scats. During 2012-2022 we collected 1,171 Mexican wolf scats. We
extracted and sequenced DNAm and identified individuals and their sex
using microsatellite analysis. We washed the scat and separated the
undigested components for taxonomic identification. We estimated the
frequency of prey items, the biomass it contributed to the diet, and
compared prey consumption between sexes and between the birth and
dispersal seasons. We constructed generalized linear models to identify
the relationship between livestock presence in the diet and dietary prey
richness with respect to environmental and individual variables. We
identified 68 wolves that had consumed 30 species of vertebrates. Of
these, white-tailed deer (36.12%), diversionary feeding (22.79%), and
cattle (25.56%), had the highest contribution to biomass. The ingest of
items was independent of the sex of the wolves but is dependent on the
season. The presence of deer and diversionary feeding decreased the
likelihood cattle were ingested but also decreases the richness of wild
items species in the wolf diet. Wolves in Northwestern Mexico fed on
mainly on large prey available in the reintroduction area including
livestock. As wolves consume livestock, it increases the risk of
retaliatory actions from ranchers. Our results serve as a basis for the
implementation of strategies to reduce human-wolf conflicts and set a
baseline for coexistence in Northwest Mexico.

墨西哥狼在墨西哥西北部野外的重新引入，使我们得以研究其营养生态学（trophic ecology）并阐明其与畜牧生产者（livestock producers）之间的冲突——这是狼的主要死亡因素。本研究旨在通过分析基因鉴定的粪便（scats），确定墨西哥狼的食性，以及与季节和个体变量相关的牲畜捕食量和频率。2012-2022年间，我们共收集了1171份墨西哥狼粪便样本。我们提取并测序了甲基化DNA（DNAm），并通过微卫星分析（microsatellite analysis）鉴定个体及其性别。我们清洗粪便并分离未消化成分，以进行分类学鉴定。我们估算了猎物的出现频率及其在饮食中的生物量占比，并比较了不同性别狼以及繁殖季与扩散季之间的猎物消费差异。我们构建了广义线性模型（generalized linear models），以确定饮食中牲畜的存在与否、猎物丰富度与环境及个体变量之间的关系。我们鉴定出68只狼，它们共捕食了30种脊椎动物。其中，白尾鹿（36.12%）、转向投喂（diversionary feeding，22.79%）和牛（25.56%）对生物量的贡献最高。猎物的摄入与狼的性别无关，但受季节影响。鹿和转向投喂的存在降低了狼捕食牛的可能性，但也减少了其饮食中野生猎物的物种丰富度。墨西哥西北部的狼主要以重新引入区域内可得的大型猎物为食，包括牲畜。狼对牲畜的捕食会增加牧场主报复行为的风险。我们的研究结果为制定减少人狼冲突的策略提供了依据，并为墨西哥西北部的人狼共存奠定了基础。