Fires can cause great harm to animals living in the wild. Understanding the ways these animals are harmed puts us in a much better position to help them, as well as encouraging action and further research on the subject. We are pleased to announce that Animal Ethics will be funding a research project studying the effects of fires on animals living in the wild. This project will be carried out at the Autonomous University of Madrid by Jara Gutiérrez, who is a biologist who has done her PhD in animal welfare science. Her background makes her well suited for a research project like this which is at the intersection of biology and animal welfare science.
We believe this project is important for several reasons:
We want to thank all the people who support Animal Ethics’s work for making it possible for us to fund projects such as this. Your donations and assistance are extremely valuable, as they are the only way we can fund more high quality research projects with significant potential for impact. If you would like to see more work of this kind, please consider supporting our work.
Below you can see a more detailed explanation of the research project that will be carried out by Jara Gutiérrez at the Autonomous University of Madrid.
Natural disasters are harmful for wild animals, who are often unprotected in such disadvantaged situations. Between 60,000 and 80,000 wildfires are estimated to occur each year, which can affect animals living in areas ranging from 3 to 10 million hectares. While a considerable amount of research has been done about the consequences of fires, their impact on the animals’ wellbeing has rarely been studied. Moreover, when it has been studied, the focus has been on domesticated animals.
Wildfires can be of different size and intensity, and these factors affect the level of suffering experienced by animals. It appears that small intensity fires do not cause serious harm to many large or medium sized animals,1 as has been reported in the case of pampas deers and giant anteaters. Many fires, however, do have a great impact on them.
In general terms, fires produce both direct (e.g. injuries, heat, combustion gases, and destruction of organic matter) and indirect (e.g. loss and change of habitat) negative consequences on animals. Direct injuries, which can be caused by asphyxiation, excessive heat from the flames or toxic gases/smoke inhalation, can lead to immediate or lingering death.2 Indirect harms such as hunger, dehydration, wounds and disease are also very significant.3 In the long term, these can also lead to death.
Animals who are less capable of moving will be more strongly negatively affected by fires, because it is more difficult for them to escape from the flames. Nonetheless, some small-size animals such as invertebrates, reptiles, and small mammals may be able to hide underground and survive the fire; animals who live in trees can move to treetops and escape low-to-moderate intensity fires; and animals living above ground will be more affected by fire than animals in moist habitats.4
Usually, birds are least impacted by fire as they can fly away, although chicks can be impacted depending on the season in which the fire occurs.5 However, smaller birds who fly at lower altitudes can die from smoke inhalation or exhaustion during a fire.6
In the case of fish, the most immediate consequences seem to be related to hydrological changes.7 After a fire, a large abnormal increase in suspended sediment loads in streams from runoff8 can induce physiological stress, reduce growth, and cause direct mortality in fish.9 Beyond that, when simulations of ammonium-based fire retardants used for managing fires in the 1980s in wild areas were dispersed in streams, fish mortality was shown to occur from zero to more than 10,000 meters below the point of chemical entry, depending on application parameters and stream characteristics.10
Concerning mammals, old studies have not reported a very high number of deaths for small mammals in small controlled fires, in which the flames move less quickly and with less heat.11 However, to our knowledge, these conclusions have not been checked for small fires in recent years. Apparently, some small mammals tend to run away, while a few species seem to be very well-adapted to fire. The latter is the case of the Kangaroo rats, which take mud baths in order to avoid burns and resist high temperatures.12 However, others like porcupines can decide to climb trees during the fire, which normally is not a helpful behaviour for them in this situation; and animals in burrows can die if they do not dig deep enough.13 Small mammals do not seem to escape from the flames randomly, but have been seen more abundantly in groups along roads and trails, in small clearings and in depressions, road cuts and hiking trails,14 which seems to indicate a specific flight pattern with preference for the clear paths.
Regarding larger mammals, many of them do not flee from the flames, as was the case with bison, elks, and other ungulates seen grazing and even resting less than 100 meters from the flames in the 1988 Greater Yellowstone fires.15 As this fire was the largest forest fire recorded in the history of the Yellowstone National Park in the United States, a large number of studies were carried out, and the quantification of casualties was done for many animals. For example, reported approximate numbers of deaths mammals were reported (e.g. bison, elks, mice, and cows),16 and fishes who died in streams were observed.17 However, the extent and causes of mortality were not reported.18 Other studies have observed the impact of wildfires on mammals under human control. For example, the most frequent wounds between the surviving free ranging cows were burned feet, udders, and eyes, as well as severely singed hair.19 The results may also hold true of other species of large wild mammals.
Figure 2. Elk (left) grazing in a burned forest. Elk (center) and bison (right) carcasses found after the fire.20
As for reptiles, the negative impact of fire can vary according to the species and the diverse changes in ecosystem after fire. In the Iberian Peninsula, for example, some reptiles can be abundant shortly after fires (e.g. common geckos – Tarentola mauritanica – or Iberian wall lizards – Podarcis hispanica), while other suffer immediate high mortality after a fire (e.g. Hermann’s tortoise – Testudo hermanni). Regarding amphibians, those whose skin is camouflaged to look like bark or leaves are suddenly exposed after a fire, and so become vulnerable to predation.21
Finally, due to their small size, studies on the quantification of invertebrate animal deaths after a fire are difficult to carry out. In general terms, high mortality has also been reported for invertebrate animals such as terrestrial gastropods (mainly snails) and different spider species, while the number of beetles of various species has been seen to increase after a fire.
Animals can sometimes flee to “unburnt islands” within a burn area.22 Animals are exposed to possible extra harm during their escape, as well as once they arrive in the new territory. When a fire involves the movement of animals from one place to another, not only may the fleeing animals be negatively affected, but also those animals already present in the receiving area. These presumably fast changes in habitat, trophic relationships and distribution of nutrients may negatively impact animal welfare.
In addition, during their escape, animals can suffer from states of “bad stress”, which includes both distress and overstress. “Bad stress” occurs when both physiological and psychological demands on the body exceed its capacity to maintain homeostasis.23 Both overstress and distress refer to adaptive responses that require a large amount of energy and is harmful for relevant biological functions (like growth). More important, such adaptations can be major causes of animal suffering.
Another usual consequence for surviving animals in wildfires is that they may be forced to move close to roads, forest tracks, and even to urban areas. In these places, they can be exposed to new dangers such as being run over by vehicles. For example, in one case, a large number of rodents fled the flames of a forest fire and ended up running in groups by the road, with some of them hiding behind the wheels of fire vehicles that were parked near the flames. Many of these disorientated animals were subsequently run over.24 We should not overlook animal suffering as a result of other types of catastrophes, as sometimes the effects could be similar for wildfires.
Finally, negative consequences of wildfires on sentient beings can be large-scale and long-term. For instance, a positive association between wildfire smoke and human respiratory morbidity and mortality has been found. This may entail issues with asthma, chronic obstructive pulmonary disease, bronchitis and pneumonia.25 These issues could also affect animals in nearby environments. Fire could also negatively affect marine animals. For example, heavy rains that took place after wildfires in forests near the coast caused the ashes to quickly reach the water. This increased the mortality of aquatic species of vertebrates and invertebrates, e.g. shellfish, waders (birds such as storks and herons) that feed on insects in lagoons and seas, and some endangered species, such as river mussels – Margaritifera margaritifera – and Kentish plover – Charadrius Alexandrinus, among others.
In order to know how to best help animals when wildfires occur, it is necessary to have a good understanding of the specific ways in which different animals are harmed in these situations. This research project aims at evaluating individual animal challenges during and after a fire. The overall physiological, psychological, and ethological difficulties that wildfires cause in animals will be thoroughly evaluated. Hence, this project will thoroughly examine different aspects related to psychological, social, and physiological stress; states of disorientation, desperation, fear; vulnerability to being preyed upon while escaping, lack of resources such as water and food; and danger from moving towards urban areas in search of resources.
The study of how wildfires affect animals – directly and indirectly; in the short and long term – can be complex due to the variety of animals, habitats, and fires. As explained above, different animals will be harmed in different ways by wildfires. This study aims to make a sufficiently complete review of the main harms that animals experience during and after a wildfire, based on previous research and studies.
This research project will also evaluate the quantitative dimension of the harms suffered by animals in wildfires. There are currently no accurate estimates of the number of animals that die each year in fires. A detailed and effective quantification of casualties after fires will help us to better understand the difficulties faced by the surviving animals, and to improve interventions aiming at helping them.
Finally, this project will provide an example of how to use the knowledge gathered in ecology studies to examine the welfare of animals in the wild. As the case of wildfires shows, the life of wild animals is not continuously idyllic. There are important causes, like wildfires, of animal suffering in nature. For this reason, more research on welfare biology is crucial in order to better understand the reality of wild animals, and to help others to recognize the importance of the harms they suffer.
This research project will consist of a literature review of the available research on this issue. The problem of animals in wildfires has been assessed in the existing literature from different approaches, e.g. according to the affected animal group or according to the type and intensity of the fire. The review will proceed by joining the fragmented knowledge in a coherent way. The review will also consider separately concrete examples of challenges for different animal species.
This research project will provide a synthesis of the most relevant aspects of the available research on this issue.
It also aims to clearly identify the main problems reported in the literature to date faced by animals who are exposed in to wildfires.
In addition, it will identify promising future lines of research related to the topic.
Finally, the research project will provide the basis to design protocols and management plans that can prevent or minimize the harms animals suffer due to fires, including animal rescues.
The results of this research will be presented in a peer-reviewed journal article, as well as in an online open access report.
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1 Silveira, L.; Henrique, F.; Rodrigues, G.; de Almeida Jácomo, A. T. & Diniz Filho, J. A. F. (1999) “Impact of wildfires on the megafauna of Emas National Park, central Brazil”, Oryx, 33, pp. 108-114 [accessed on 4 November 2019].
2 Quinn, R. D. (1979) “Effects of fire on small mammals in the chaparral”, Cal-Neva Wildlife, pp. 125-133.
3 Silveira, L.; Henrique, F.; Rodrigues, G.; de Almeida Jácomo, A. T. & Diniz Filho, J. A. F. (1999) “Impact of wildfires on the megafauna of Emas National Park, central Brazil”, op. cit.
5 Palmisiano, J. (2014) “Logging in national parks and forests: A contentious debate”, Law Street Media, October 3 [accessed on 2 December 2019]. Tomasik, B. (2013-2016) “How forest fires affect wild-animal suffering”, Essays on Reducing Suffering [accessed on 4 November 2019].
6 Campbell, M. (2016) “What will the Fort McMurray fires mean for wildlife?”, Maclean’s, May 9 [accessed on 28 October 2019].
7 Bozek, M. A. & Young, M. K. (1994) “Fish mortality resulting from delayed effects of fire in the Greater Yellowstone Ecosystem”, The Great Basin Naturalist, 54, pp. 91-95 [accessed on 17 November 2019].
8 Minshall, G. W. & Brock, J. T. (1991) “Observed and anticipated effects of forest fire on Yellowstone stream ecosystems”, in Keiter, R. B. & Boyce, M. S. (eds.) The Greater Yellowstone Ecosystem: Redefining America’s wilderness heritage, New Haven: Yale University Press, pp. 123-135.
9 Newcombe, C. P. & Macdonald, D. D. (1991) “Effects of suspended sediments on aquatic ecosystems”, North American Journal of Fisheries Management, 11, pp. 72-82.
10 Norris, L. A. & Webb, W. L. (1989) “Effects of fire retardant on water quality”, in Berg, N. H. (coord.) Proceedings of the Symposium on Fire and Watershed Management: October 26-28, 1988, Sacramento, California, Berkeley: Pacific Southwest Forest and Range Experiment Station [accessed on 13 November 2019].
11 Howard, W. E.; Fenner, R. L. & Childs, H. E., Jr. (1959) “Wildlife survival in brush burns”, Journal of Range Management, 12, pp. 230-234. Lawrence, G. E. (1966) “Ecology of vertebrate animals in relation to chaparral fire in the Sierra Nevada foothills”, Ecology, 47, pp. 278-291.
12 Quinn, R. D. (1979) “Effects of fire on small mammals in the chaparral”, op. cit.
13 Campbell, M. (2016) “What will the Fort McMurray fires mean for wildlife?”, op. cit. Quinn, R. D. (1979) “Effects of fire on small mammals in the chaparral”, op. cit.
14 Quinn, R. D. (1979) “Effects of fire on small mammals in the chaparral”, op. cit.
15 Barkley, Y. (2019) “Wildfire and wildlife habitat”, op. cit., figure 2.
16 Singer, F. J.; Schreier, W.; Oppenheim, J. & Garton, E. O. (1989) “Drought, fires, and large mammals”, BioScience, 39, pp. 716-722.
17 Minshall, G. W.; Brock, J. T. & Varley, J. D. (1989) “Wildfires and Yellowstone’s stream ecosystems”, BioScience, 39, pp. 707-715.
18 Bozek, M. A., & Young, M. K. (1994) “Fish mortality resulting from delayed effects of fire in the Greater Yellowstone Ecosystem”, op. cit.
19 Rethorst, D. N.; Spare, R. K. & Kellenberger, J. L. (2018) “Wildfire response in range cattle”, Veterinary Clinics: Food Animal Practice, 34, pp. 281-288.
20 Singer, F. J.; Schreier, W.; Oppenheim, J. & Garton, E. O. (1989) “Drought, fires, and large mammals”, op. cit.
22 Quinn, R. D. (1979) “Effects of fire on small mammals in the chaparral”, op. cit.
23 Selye, H. (1974) Stress without distress, Philadelphia: Lippincott.
24 Quinn, R. D. (1979) “Effects of fire on small mammals in the chaparral”, op. cit.
25 Pan, A.; Solongo, T. & Xu, H. (2019) “The effect of wildfires on air quality and public health”, Ithaca: Cornell University [accessed on 4 November 2019]..