Describing and understanding behavioral responses to multiple stressors and multiple stimuli

Hale, Robin; Piggott, Jeremy J.; Swearer, Stephen E.

doi:10.1002/ece3.2609

Cited by 59 publications

(35 citation statements)

References 36 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This result may be due simply to chance although it is also possible that there is some synergism occurring between the two sensory modalities (Hale et al. ). More work is needed to explore if this is a biologically meaningful result, and if so, its underlying cause.…”

Section: Discussionmentioning

confidence: 99%

Stormwater wetlands can function as ecological traps for urban frogs

Sievers

Parris

Swearer

et al. 2018

Ecological Applications

Self Cite

View full text Add to dashboard Cite

Around cities, natural wetlands are rapidly being destroyed and replaced with wetlands constructed to treat stormwater. Although the intended purpose of these wetlands is to manage urban stormwater, they are inhabited by wildlife that might be exposed to contaminants. These effects will be exacerbated if animals are unable to differentiate between stormwater treatment wetlands of varying quality and some function as "ecological traps" (i.e., habitats that animals prefer despite fitness being lower than in other habitats). To examine if urban stormwater wetlands can be ecological traps for frogs, we tested if survival, metamorphosis-related measures, and predator avoidance behaviors of frogs differed within mesocosms that simulated stormwater wetlands with different contaminant levels, and paired this with a natural oviposition experiment to assess breeding-site preferences. We provide the first empirical evidence that these wetlands can function as ecological traps for frogs. Tadpoles had lower survival and were less responsive to predator olfactory cues when raised in more polluted stormwater wetlands, but also reached metamorphosis earlier and at a larger size. A greater size at metamorphosis was likely a result of increased per capita food availability due to higher mortality combined with eutrophication, although other compensatory effects such as selective-mortality removing smaller individuals from low-quality mesocosms may also explain these results. Breeding adults laid comparable numbers of eggs across wetlands with high and low contaminant levels, indicating no avoidance of the former. Since stormwater treatment wetlands are often the only available aquatic habitat in urban landscapes we need to better understand how they perform as habitats to guide management decisions that mitigate their potential ecological costs. This may include improving wetland quality so that fitness is no longer compromised, preventing colonization by animals, altering the cues animals use when selecting habitats, pretreating contaminated water prior to release, providing off-line wetlands nearby, or simply not constructing stormwater treatment wetlands in sensitive areas. Our study confirms the potential for urban stormwater treatment wetlands to function as ecological traps and highlights the need for greater awareness of their prevalence and impact at landscape scales.

show abstract

Section: Discussionmentioning

confidence: 99%

Stormwater wetlands can function as ecological traps for urban frogs

Sievers

Parris

Swearer

et al. 2018

Ecological Applications

Self Cite

View full text Add to dashboard Cite

show abstract

“…Although the complexity of the systems in which responses are measured may hamper generalizable explanations and prediction, differences in (1) interaction classification frameworks, which define mathematically what constitutes a synergistic and antagonistic interaction (for details see Hale, Piggott, & Swearer, 2017) and (2) the type of null models underlying such frameworks add to the variability in reported interaction types, thus limiting comparability. The selected null model should ideally be underpinned by a mechanistic understanding of single/multiple stressor effects, determined by the stressor/s mode of action and stressor-effect relationship/s (Figure 1a), although to date this has been largely overlooked due to statistical convenience.…”

Section: Introductionmentioning

confidence: 99%

Advancing understanding and prediction in multiple stressor research through a mechanistic basis for null models

Schäfer

Piggott

2018

Global Change Biology

Self Cite

159

210

View full text Add to dashboard Cite

Global environmental change is driven by multiple anthropogenic stressors. Conservation and restoration require understanding the individual and joint action of these stressors to evaluate and prioritize management measures. To date, most studies on multiple stressor effects have sought to identify potential stressor interactions, defined as deviations from null models, and related meta-analyses have focused on quantifying the relative proportion of stressor interactions across studies. These studies have provided valuable insights about the complexity of multiple stressor effects, but remain largely devoid of a theoretical framework for null model selection and prediction of effects. We suggest that multiple stressor research would benefit by (1) integrating and developing additional null models and (2) selecting null models based on their mechanistic assumptions of the stressor mode of action and organism sensitivities as well as stressor-effect relationships for individuals and populations. We present a range of null models and outline their underlying assumptions and application in multiple stressor research. Moving beyond mere description requires multiple stressor research to shift its focus from identifying statistically significant interactions to the use and development of mechanistic (null) models. Justified selection of the appropriate null model is a first step to achieve this.

show abstract

“…Multiple stressors can act: synergistically (outcome is stronger than predicted based on the sum of the individual effects); antagonistically (outcome is weaker than predicted based on the sum of the individual effects); additively (equal to the sum of the individual effects, i.e. no interaction); or even produce an 'ecological surprise', such as when two stressors exhibit no effects in isolation, but do together (Crain et al, 2008;Hale et al, 2017).…”

Section: Introductionmentioning

confidence: 99%

Contaminant mixtures interact to impair predator-avoidance behaviours and survival in a larval amphibian

Sievers

Hale

Swearer

et al. 2018

Ecotoxicology and Environmental Safety

Self Cite

View full text Add to dashboard Cite

Global declines in amphibian populations are a significant conservation concern, and environmental contamination is likely a contributing driver. Although direct toxicity may be partly responsible, contaminants are often present at sub-lethal concentrations in the wild. Behavioural end-points are becoming an increasingly useful method to estimate the impact of contaminants, particularly if the behavioural responses manifest to affect individual fitness (i.e. survival, growth, or reproduction). In the wild, most animals are affected by multiple stressors, and determining how these interact to affect behaviour is critical for understanding the ecological implications of contaminant exposure. Here, we examined the individual and interactive effect of the heavy metal copper and the insecticide imidacloprid on mortality rates and anti-predator behaviours of spotted marsh frog (Limnodynastes tasmaniensis) tadpoles. This common species frequently occupies and breeds in contaminated stormwater and agricultural wetlands, where copper and imidacloprid are often present. These contaminants may alter behaviour via physiological and neurological pathways, as well as affecting how tadpoles respond to chemical cues. Tadpoles suffered unexpectedly high mortality rates when exposed to imidacloprid concentrations well below published LC50 concentrations. Only unexposed tadpoles significantly avoided predator cues. Copper and imidacloprid reduced swimming speed and distance, and escape responses, while increasing erratic swimming. We observed an interactive effect of imidacloprid and copper on erratic swimming, but in general imidacloprid and copper did not act synergistically. Our results suggest that as contaminants enter waterbodies, tadpoles will suffer considerable direct mortality, reduced foraging capacity, and increased susceptibility to predation. Our results provide the first evidence of imidacloprid affecting amphibian behaviour, and highlight both the adverse effects of copper and imidacloprid, and the importance of exploring the effect of multiple contaminants simultaneously.

show abstract

Describing and understanding behavioral responses to multiple stressors and multiple stimuli

Cited by 59 publications

References 36 publications

Stormwater wetlands can function as ecological traps for urban frogs

Stormwater wetlands can function as ecological traps for urban frogs

Advancing understanding and prediction in multiple stressor research through a mechanistic basis for null models

Contaminant mixtures interact to impair predator-avoidance behaviours and survival in a larval amphibian

Contact Info

Product

Resources

About