j.g. pausas' blog

Una de las razones para no cortar los árboles muertos después de un incendio, es por que las condiciones semi-forestales que generan son hábitat de fauna forestal, como por ejemplo, los picos picapinos (Dendrocopos major). Aquí un picapinos en un pinar de pino carrasco (Pinus halepensis) el incendio de Bejís (2022, Castelló); video 2/2024 (de hecho, se ve uno y se oye otro). Otros beneficios de no cortar los árboles muertos se explicaron aquí y aquí.

Beneficios de no cortar los árboles después de un incendio [TheConversation | post]

Carpinteros de la madera quemada [Quercus | pdf]

In 2021 we described that some lizards can detect wildfires by smelling the smoke, and in this way they can react quickly, e.g., by moving to a safe place [1]. Specifically we performed that study with the mediterranean lizard Psammodromus algirus, from eastern Spain. In a recent paper, we suggest that some lizards are able to recognise wildfires by their sound! [2]. This study was performed with another mediterranean lizard, Sceloporus occidentalis (western fence lizard), from southern California.

References

[1] Álvarez-Ruiz L, Belliure J, Pausas JG. 2021. Fire-driven behavioral response to smoke in a Mediterranean lizard. Behavioral Ecology 32: 662–667. [doi | oup | data:dryad | pdf] – blog

[2] Álvarez-Ruiz L, Pausas JG, Blumstein DT, Putmanb BJ. 2023. Lizards’ response to the sound of fire is modified by fire history. Animal Behaviour 196: 91–102. [doi | sciencedirect | pdf]

More on: fire & lizards  and  fire & fauna

There is still little information on the response of many animals to fire [1, 2], and this limited knowledge is even more important for large predators (e.g. raptors) as their behavior in relation to fire are not easy to observe. We studied the fire response to a Bonelli’s eagle (Aquila fasciata) thanks to a serendipity event: a wildfire (Artana fire; eastern Spain) occurred in an area where friends of mine had an eagle being tracked by a GPS/GMS [3]. This allowed us to follow their behavior during the fire, compare it with both before and after the fire (during two years), and with other neighbor eagles that were also being tracked [3].

The results suggest that despite the fire affected most of the eagle’s core home-range, including the nest site, its activity was hardly affected by the fire. During the fire, the eagle moved away from the fire but did not leave its home-range; she was back to the center of the home-range when the fire was still burning (at low intensity). The minor movements during the fire were probably due to the smoke or/and to the firefighters activity (which include planes). And during the two following years, the behavior of the eagle was similar the behavior when the landscape was not burned. This suggest that the eagles prey (rabbits, pigeons, small mammals) were also little affected by the fire.

An animations of the movements of the eagle in relation to the home-range and the burned area is available here.  

References

[1] Pausas J.G., Parr C.L. 2018. Towards an understanding of the evolutionary role of fire in animals. Evol. Ecol. 32: 113–125. [doi | pdf]

[2] Pausas J.G. 2019. Generalized fire response strategies in plants and animals. Oikos 128: 147-153 [doi | pdf | blog1 blog2 blog3 | cover image]

[3] Morollón S. Pausas J.G., Urios V., López-López P. 2022. Wildfire response of GPS-tracked Bonelli’s eagles in eastern Spain. Int. J. Wildland Fire 31: 901-908 [ doi | ijwf | pdf | animation]

Early humans and native cultures have used fire for clearing the ground from parasites and diseases, and some agricultural societies use fire to reduce livestock diseases [1,2]. In such cases, fire provide an ecosystem service to humans [2]. We recently asked to what extent this ‘cleaning effect‘ of fire is also observed in the wild, that is, whether wildfires may remove parasites and thus provide some benefits to wildlife [3]. To answer this question, we compared the presence of ecotoparasites (mites,Ophionyssus) in lizard populations of Psammodromus algirus living in recently burned areas with those in adjacent unburned areas, in eastern Spain. Our results suggest that many individuals of P. algirus survive fire (the smoke of the fire acts as a cue for quickly moving to safe microsites [4], e.g., crevices, under rocks, among roots; refugia [5]); and those that survived (and live in the postfire environment) have less ecotparasites (mites) than those living in unburned conditions. That is wildfires produce a ‘cleaning effect’ by reducing lizard ectoparasites in the postfire conditions. Fire, by disrupting the host-parasite interaction, provides a window of opportunity for lizards to avoid the negative effects of ectoparasites. We propose that wildfires likely fulfill a role in controlling vector-borne diseases and pathogens for other species, but this ecological effects have been largely overlooked.

References

[1] Pausas J.G. & Keeley J.E. 2009. A burning story: The role of fire in the history of life. BioScience 59: 593-601 [doi | OUP | pdf]

[2] Pausas J.G. & Keeley J.E. 2019. Wildfires as an ecosystem service. Front. Ecol. Environ. 17: 289-295. [doi | pdf]

[3] Álvarez-Ruiz L, Belliure J, Santos X., Pausas JG. 2021. Fire reduces parasite load in a Mediterranean lizard. Proceed. Royal Soc. B. [doi | pdf]  New!

[4] Álvarez-Ruiz L, Belliure J, Pausas JG. 2021. Fire-driven behavioral response to smoke in a Mediterranean lizard. Behav. Ecol. [doi | oup | PDF]

[5] Pausas J.G. 2019. Generalized fire response strategies in plants and animals. Oikos 128: 147-153 [doi | pdf]

The evolutionary role of fire in animals has been poorly explored [1]. We recently conducted an experiment with the mediterranean lizard Psammodromus algirus to evaluate a possible adaptive response to fire [2]. Specifically we tested whether detecting a fire by smoke is adaptive for lizards living in fire-prone ecosystems. To do so we collected lizards from habitats with contrasted fire regimes (fire-prone shrublands vs. non-fire-prone dunes) and exposed them to smoke and to a false smoke (control) in a terrarium. We video-recorded the behavioral reaction to the treatments, and determined whether each individual detected the smoke and the intensity of the reaction. We found that in populations from fire-prone habitats, more lizards reacted to smoke, and their behavioral response was more intense than in lizard populations from non-fire-prone habitats. Our results suggest that the enhanced response to smoke may have been selected as adaptive behavior in fire-prone habitats to increase survival. Smoke has been considered a very important cue for enhancing germination in plants [3]; now we show that is also a cue for fire avoidance in animals. To our knowledge, this is the first evidence of smoke detection by reptiles in wild populations. 

References

[1] Pausas JG, Parr CL 2018. Towards an understanding of the evolutionary role of fire in animals. Evol. Ecol. 32: 113–125. [doi | pdf]

[2] Álvarez-Ruiz L, Belliure J, Pausas JG. 2021. Fire-driven behavioral response to smoke in a Mediterranean lizard. Behavioral Ecol. [doi |oup | data:dryad | pdf]  [ver también: ¿Cómo sobreviven los animales a los incendios?]

[3] Keeley & Pausas 2018. Evolution of ‘smoke’ induced seed germination in pyroendemic plants. S. Afr. J. Bot. 115: 251-255. [doi | pdf];  Moreira & Pausas 2018. Shedding light through the smoke on the germination of Mediterranean Basin flora. S. Afr. J. Bot. 115: 244-250. [doi | pdf];  Tormo et al. 2014. Field evidence of smoke-stimulated seedling emergence and establishment in Mediterranean Basin flora. J. Veget. Sci. 25: 771-777. [doi| pdf];  Moreira et al. 2010. Disentangling the role of heat and smoke as germination cues in Mediterranean Basin flora. Ann. Bot. 105: 627-635. [pdf | doi]

Hummingbirds are among the most iconic birds of America, especially abundant in the tropics. They are very important pollinators (nectar feeders), thus their abundance and distribution are likely to affect hummingbird-pollinated plants, many of which are endemic or endangered. A recent review in western United States [1] suggests that most hummingbird species respond positively to wild or prescribed fire and thus, for the conservation of these emblematic birds, it is important to promote landscape mosaics, with early and mid postfire successional habitats, together with forest patches.

Here is a video by Contreras-Martínez et al. on hummingbirds and wildfires in Sierra de Manantlán Biosphere Reserve, Mexico [2]. The video is in Spanish; hummingbirds are ‘colibríes’ or ‘picaflores’

Créditos del vídeo:
Filmación y Edición: Carlos Armando Pacheco Contreras (Vidacinema)
Productor: Sarahy Contreras Martínez
Guión: Sarahy Contreras Martínez, Carlos Armando Pacheco Contreras & Oscar Cárdenas Hernández
Narración: Cesar Híjar Tejada
Investigación Científica: Sarahy Contreras Martínez (Colibríes) & Enrique Jardel Peláez (Fuego)
Música Original: Erick Ríos Vázquez
Mezcla de audio: Sognare Estudios
Also available at: https://www.facebook.com/watch/?v=869506306897201

References
[1] Alexander JD, Williams EJ, Gillespie CR, Contreras-Martínez S & Finch DM. 2020. Effects of restoration and fire on habitats and populations of western hummingbirds: A literature review. Gen. Tech. Rep. RMRS-GTR-408. Fort Collins, CO, USDA, https://www.fs.usda.gov/treesearch/pubs/59664

[2] Pausas JG 2016. Flammable Mexico. Internat. J. Wildland Fire 25: 711-713. [doi | pdf ]

[3] Other related videos: Burning for biodiversity | Fire & the Florida scrub | La huella del fuego | Fish & fire | 

[4] Other post on fire & fauna | fire & pollination | fire & Mexico |

Are the fish adapted to fire? How can fish benefit from wildfire? The answer is in this 5-minute video.

For more information on animal adaptations to wildfires see:

Pausas J.G., Parr C.L. 2018. Towards an understanding of the evolutionary role of fire in animals. Evolutionary Ecology 32: 113–125. [doi | pdf]

Pausas J.G. 2019. Generalized fire response strategies in plants and animals. Oikos 128: 147-153 [doi | pdf | blog1 blog2 blog3]

Our paper “Generalized fire response strategies in plants and animals” is the Editor’s Choice of the last Oikos issue (128:2, February 2019).

In addition, one of my pictures has been selected for the cover!

Thanks @Oikos_Journal

Description of the image: Charaxes jasius taken in the middle of a burnt area (colonizing) 10 days after the wildfire that burned with very high intensity in Òdena, Barcelona, NE Spain (August 2015). Photo: JG Pausas

• Pausas J.G. 2019. Generalized fire response strategies in plants and animals. Oikos 128: 147-153 [doi | wiley | pdf]
• Oikos blog: Towards a common fire strategy scheme for plants and animals
• jgpausas blog: Generalized fire strategies in plants and animals

Other journal covers using my pictures

Trends in Plant Science 22 (13)                                 Journal of Ecology 105 (2)

One of the unifying approaches in ecology is to search for common strategies, that is, to group species sharing mechanisms and responses to environmental factors and disturbances. Plant strategies to persist in fire-prone ecosystems (and the traits involved) are now quite well known [1]. However, less is known about fire strategies in animals, despite many fire-prone ecosystems harbor a very rich fauna [2]. This difference in knowledge is probably due to the intrinsic differences between plants (immobile) and animals (mobile) [2]. However, there is a demand for unifying plant an animals paradigms in order to better asses biodiversity in fire-prone ecosystems [3]. In a recent paper [4] I am providing an unifying framework by emphasizing the similarities between plants and animals in relation to the mechanisms for living in fire-prone ecosystems. To do so, I propose a very simple fire strategy scheme that should be valid for both plants and animals (Table 1). The advantage of having a unified framework of fire strategies include: (1) we can learn how species respond to fire from a great diversity of life forms; (2) animal and plant ecologists can benefit from shared expertise in fire responses (some common strategies in plants may be overlooked in animals, or vice-versa); (3) we could better predict changes in plant-animal interactions with fire regime changes, and (4) we could better assess and generalize the effects of fire on biodiversity. I hope this framework would facilitate finding knowledge gaps and directing future research for gaining a better understanding of the role of fire on biodiversity.

Table 1. Generalized mechanisms of species response to fire (strategy), their fire dynamics and persistence scale, and the prevalence for animals and plants in fire prone ecosystems (low, moderate, and high). The last column refers to the fire characteristics where this strategy is most likely to occur (‘high’ and ‘low’ refers to fire intensity). [4]

Fig. 1. The rhea (Rhea americana) has a cryptic coloration in postfire environments, when sitting in the ground, the neck cannot be differentiated from a burned stem. Photo: JG Pausas

Fig. 2. Charaxes jasius colonizing the middle of a burnt area 10 days after the wildfire that burned with very high intensity in NE Spain (note that only thick branches remained). Photo: JG Pausas.

References

[1] Keeley J.E., Bond W.J., Bradstock R.A., Pausas J.G. & Rundel P.W. 2012. Fire in Mediterranean Ecosystems: Ecology, Evolution and Management. Cambridge University Press. [the book]  

[2] Pausas J.G., Parr C.L. 2018. Towards an understanding of the evolutionary role of fire in animals. Evolutionary Ecology 32: 113–125. [doi | pdf]  

[3] Kelly L.T., Brotons L, Giljohann K.M., McCarthy M.A., Pausas J.G., Smith A.L. 2018. Bridging the divide: integrating animal and plant paradigms to secure the future of biodiversity in fire-prone ecosystems. Fire 1(2): 29. [doi | mdpi | pdf]  

[4] Pausas J.G. 2019. Generalized fire response strategies in plants and animals. Oikos 128:147-153 [doi | wiley | pdf | oikosblog]

For two years we sampled invertebrates after two large wildfires in eastern Spain and demonstrate that two flower beetle species, Protaetia morio and P. oblonga (Cetoniidae; Fig. 1 & 2 below), show a pyrophilous behaviour [1]. These beetles were much more numerous after the fires than in unburnt plots around the fire perimeter; in addition, these species tended to increase in number with the distance from the fire perimeter and with fire recurrence (Fig. 3 below). These results suggest that local populations survived the fire as eggs or larvae protected in the soil, and then they were favoured postfire (i.e., population size increased, compared with unburnt zones). We propose that this could be driven by the reduction of their predator populations, as vertebrates that feed on these beetles are disfavored by fire. That is, the results suggest that these flower beetle species benefit from fire because fire disrupts antagonistic interactions with their predators (predation release hypothesis).

Fig. 1. Protaetia morio: eggs, larva, pupal, and adult (photos: S. Montagud); pitfall trap full of Protaetia beetles (bottom left).

Fig. 2: Protaetia morio (male and famale) and Protaetia oblonga (male and female)

Fig. 3: Abundance (number of individuals) of Protaetia morio one and two years after fire (from two fires that occurred in 2012). Green: Unburnt; Yellow: Burnt edge (< 700 m from the fire perimeter); Orange: Burnt center (> 1.3 km from the fire perimeter). P. oblonga showed a similar pattern. For details, see [1].

Reference 

[1] Pausas, J.G., Belliure, J., Mínguez, E. & Montagud, S. (2018) Fire benefits flower beetles in a mediterranean ecosystem. PLoS ONE, 13: e0198951. [doi | plos | pdf]

Plants show a plethora of adaptive traits for persisting under recurrent fires [1]. However, fire-prone ecosystems also harbor a rich fauna, and little is know about their adaptive traits for fire survival. In a recent paper [2] we review this issue and suggest that many animals are adapted to the open habitats generated by fire; yet although they require fires for survival (fire-dependent animals), they do not necessarily show any specific morphological adaptation to fire. However, these species would become very rare or even extinct in the absence of fires generating their habitat. In addition, in some cases, animals from these fire-prone ecosystems show specific fire adaptation (fire-adapted animals). Currently, there are few examples of morphological adaptations to fire in the animal kingdom (reviewed in [2]). In part this may simply reflect the low number of studies that have attempted to look for fire adaptations. We propose that there remains significant scope for research on fire adaptations in animals, and especially in relation to the rich behavioral traits that allow persistence in fire-prone ecosystems. This is because, in contrast to plants, most animals are unitary organisms with reduced survival when directly burnt by fire, but are mobile and can move away from the fire. That is, behavioral traits are poorly explored under the framework of the evolutionary fire ecology and may provide a rich source for fire adaptations. Developing this understanding is critical to better understand the role of fire in determining the biodiversity of our landscapes.

Photo 1: An owl hunting in the fire front (fire-foraging) at Aransas National Wildlife Refuge in Texas (Photo: Jeffrey Adams/USFWS; from www.fws.gov).

Photo 2: The rhea (Rhea americana) is a flightless bird living in Brazilian savannas; it has a cryptic colors in postfire environments, when it sits in the ground in cannot be differentiated from burn stems (Photo: JG Pausas, 2009).

References

[1] Keeley J.E., Bond W.J., Bradstock R.A., Pausas J.G. & Rundel P.W. 2012. Fire in Mediterranean Ecosystems: Ecology, Evolution and Management. Cambridge University Press. [the book]

[2] Pausas J.G., Parr C.L. 2018. Towards an understanding of the evolutionary role of fire in animals. Evolutionary Ecology. [doi | pdf]  

More on fire and evolution

The 27th of July a fire in Òdena (Anoia, central Catalonia, NE Spain) burned ca. 1200 ha, mainly of Pinus halepensis. It was a crown fire of relatively high intensity. Twelve days after the fire, everything was still black, there were not yet signs of any plant resprouting; however, there were already few visitors. Here a couple of examples.

Charaxes jasius (left) and Parasteropleurus (Steropleurus) perezii (right) on recently burned trees (Photos by A. Mazcuñan and P. Mazcuñan, respectively).