ABCDEFG
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Group of animals
Number impacted globallyMethodologyNumber impacted in the USMethodology
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Companion1530MEstimate includes cats and dogs only, making it a highly conservative estimate:
• World Population Review estimates 350M homed and 480M stray cats in 2025
• The global dog population is estimated at between 700-900M by M. E. Gompper in "Free-Ranging Dogs and Wildlife Conservation" (2014), which is cited by a number of other papers (e.g.). 700M seems a conservative lower bound, given World Population Review's data for just 37 countries totals 350M.		193M• Averaged two estimates of the population of cats and dogs from the American Vetrinary Medical Association (2024) and IbisWorld (2024)
• Added a conservative estimate of other pets that comes from the American Vetrinary Medical Association (2024)'s estimate of number of households with different type of pets
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Farmed208B mammals, birds and finfish

Trillions of invertebrates, including 440B shrimp and >5T bees		• 84B mammals and birds, based on Our World in Data (2023) using 2022 data
• 124B finfish based on Mood et al. (2023) using 2019 data (taking the middle of the 78-171B estimated range)
• Shrimp from Rethink Priorities (2023) using 2020 data
• Bees from FAO estimate of number of bee colonies using 2021 data, multiplied by a very rough 50,000 bees per hive
• Note that estimates for mammals and birds are quite accurate due to government agricultural censuses, while estimates for acquatic animals and invertibrates are quite uncertain as production is measured in tonnes rather than individuals 		10B mammals, birds and finfish

Hundreds of billion of invertebrates, including 1.6B shrimp and >135B bees		• 10B mammals and birds, based on Our World in Data (2023) using 2022 data
• 0.46B finfish and 1.63B shrimp, estimated by taking the global estimates for these species and mutiplying by the US's 0.37% of global seafood production by volume, according to a 2024 FAO report (US produces 0.48T vs. 130.9T globally)
• >135B bees from USDA 2024 estimate of 2.71 million colonies (only counting from operations with 5+ colonies each), multiplied by a very rough 50,000 bees per hive
• Note that we've estimated the number of animals farmed in the US, which is different to the number of animals impacted by the US's consumption of animal products, given many products are imported and exported. This makes this a conservative estimate, because the US is a net-importer of the products that impact the most animals, like fish and honey.
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Lab192M• Estimate for 2015 from Taylor & Alvarez (2019), who stress that poor reporting means there are wide error bars on these estimates112M• Estimates are uncertain as data is only centrally collected for species protected by the Animal Welfare Act (780k animals in 2017), while the majority of animals tested on are rats and mice
• Carbone (2021)'s estimate is used
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WildTrillionsHuman impacts on wild animals are so broad, diverse and under-quantified that it's very hard to estimate. However we can safely say it's in the trillions based on a few data points:
• US commercial fisherman land 0.97–2.7 trillion fish annually (Mood & Brooke, 2019)
• The WWF's Living Planet Report (2024) highlights a 73% decline in monitored wildlife populations between 1970 and 2020. This decline is largely attributed to human activities such as deforestation, agriculture, and urbanization, which lead to significant habitat loss and degradation. There are no good estimated for the number of wild animals that existed in 1970, but there were an 50 billion birds alone in 2021
• This is before considering aimals that are hunted, poached, or have their population controlled through pest control programs
BillionsHuman impacts on wild animals are so broad, diverse and under-quantified that it's very hard to estimate. However we can reach a rough lower bound by considering a few key groups:
• US commercial fisherman landed 9.3 billion pounds in 2019. While fishes vary greatly in size, taking a rough weight of 1kg per fish, this equates to >4 billion individual fish
• 14.3 million hunters are active in the US, with In Defense of Animals estimating >200 million animals impacted, with many small animals like birds, rabbits and squirrels hunted per hunter
• 2.6 million acres of grassland are plowed to convert to crop production each year, likely impacting many millions of animals
• US Wildlife Services culled ~1.75 million animals in 2021, of which hundreds of thousands were native
• US Census found ~14.8 million households reported seeing rodents in the last 12 months. We can conservatively assume that this results in each household culling 1 rodent each (not all households will use pest control, but each household that does will cull >1 animal on average). Factoring in pest control in commercial and public spaces, we can safely double this estimate to ~30 million animals. This is consistent with Rethink Priorities estimate of 31 million animals exposed to rodenticide alone in the U.S.
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