The question of how many animals are killed each second seeks a massive statistic that is impossible to answer with a single, precise figure. There is no central global registry tracking every death, meaning any total is an estimate compiled from various national and industry data sets. The true rate is derived from annual figures across multiple categories of human activity, converting vast yearly totals into an average “per second” flow. This article breaks down the estimated mortality rates across the primary activities that drive these staggering numbers.
The Primary Driver: Animals Killed for Food
The overwhelming majority of human-caused animal deaths are related to the global food system, particularly the demand for meat and seafood. Based on data from the Food and Agriculture Organization of the United Nations (FAO), chickens account for the highest volume of land animal slaughter by a massive margin. Approximately 2,400 chickens are killed globally every second for meat production alone.
The slaughter rate for other commonly farmed land animals is smaller but still represents immense numbers. An estimated 47 pigs and 10 cows are killed every second to supply the meat market. Considering other species like turkeys, ducks, and sheep, the sheer scale of farmed animal mortality on land is immense.
The mortality rate in marine ecosystems is even more difficult to quantify precisely, but the numbers are staggering due to the massive scale of industrial fishing. Estimates suggest that wild-caught fish are killed at a rate exceeding 167,000 individuals per second. Commercial aquaculture, or farmed fish, contributes an additional 6,500 animals killed every second.
Beyond the commercially harvested species, industrial fishing practices result in high rates of bycatch. This mortality includes an estimated 650,000 marine mammals, such as dolphins and seals, killed annually worldwide. Furthermore, an estimated 76 to 80 million sharks are killed each year through fishing activities, including both intentional harvest and bycatch.
Indirect Human-Caused Mortality Rates
A distinct category of mortality stems from the indirect consequences of human infrastructure and activity. Roadkill constitutes one of the largest forms of indirect mortality, with global extrapolations suggesting over 2 billion vertebrates are killed by vehicles annually. This translates to approximately 5.5 million animals dying on roads every single day.
Collisions with human-built structures also cause a massive death toll, particularly for avian species. In the United States alone, estimates suggest that well over one billion birds die annually from striking buildings and windows. Recent studies indicate that previous estimates were too low because they failed to account for the high mortality rate of birds that fly away injured but later die from internal trauma.
The broader impact of human land use and chemical application also contributes significantly to this indirect rate. Large-scale wildlife deaths result from habitat fragmentation and the widespread use of pesticides, which poison animals at various levels of the food chain. While these deaths are difficult to track and convert into a reliable “per second” rate, they represent billions of additional, uncounted lives lost due to human expansion.
Mortality in Scientific Research and Testing
The use of animals in laboratories for medical testing, education, and cosmetic trials contributes to the overall mortality rate. Global estimates suggest that approximately 115 to 192 million animals are used and subsequently killed in laboratory settings each year. This annual number includes mice, rats, fish, and birds, which often fall outside the protection of national animal welfare laws.
Converting the high-end global estimate of around 192 million laboratory animals annually into a continuous flow yields a rate of approximately six individuals killed every second. While ethically significant, this rate is a tiny fraction of the total animal mortality driven by human activity. In the United States, one estimate suggests over 110 million animals are killed in laboratories annually.
Calculating the Rate and Its Limitations
The process of converting a massive annual number into a “per second” rate uses a straightforward mathematical conversion. The total number of deaths for a given category in a year is divided by the number of seconds in a year, which is 31,536,000. This calculation provides an average flow rate that is easy to comprehend but masks the complex reality of when these deaths occur.
The inherent limitation of this “per second” average is that it smooths out real-world fluctuations, such as seasonal slaughter cycles or migratory periods for birds. The accuracy of the overall rate is also constrained by data integrity, as most statistics rely on self-reported industry data or government estimates.
Many forms of mortality, such as poaching or the full extent of habitat loss, are not systematically tracked or are based on incomplete surveys. This leads to a likely underestimation of the true total. The final “per second” figure is not a precise count of animals dying at any given instant but rather an average metric used to grasp the scale of human impact.