Applying the Conservation Evidence Database to Wild Animal Welfare

Jane Capozzelli

PDF of this review

Introduction

One of Wild Animal Initiative’s foundational questions is: “what can we do to improve the welfare of wild animals?” (Wild Animal Initiative 2019). Currently, we are reviewing and summarizing relevant literature from restoration and conservation ecology, as these fields often evaluate the impacts and effectiveness of wildlife interventions. Even if conservation ecologists are not necessarily value-aligned with animal welfare advocates (e.g. diversity is good - Soulé 1985, Driscoll and Watson 2019; but see Dubois and Fraser 2013 and Beausoleil et al. 2018), impact assessments from conservation are still useful to wild animal welfare (Rowe 2019). Reviews of conservation evidence increase our understanding of the outcomes of interventions in nature and enables us to apply these interventions to welfare causes.

One such conservation database is the Conservation Evidence Project, which has evaluated over 5,400 conservation interventions and compiled synopses on what works and what doesn’t to achieve certain conservation goals. The synopses summarize scientific evidence relevant to conservation objectives and assess the effectiveness of interventions based on the available evidence, including if no evidence has been found. The Conservation Evidence Project also publishes an annual summary, What Works in Conservation (Sutherland et al. 2018).

These synopses combine the results of research projects that carried out the intervention as part of the study design and quantitatively monitored the effects of the intervention. Reviews and meta-analyses are also included. However, predictive modelling or correlative studies (e.g. surveys of species distributions in areas with long-standing management histories) are not. The advantage to this approach is that the synopses are based on direct, causal relationships between the intervention and the observed conservation outcomes (Sutherland et al. 2018). The disadvantage is that a large body of possible evidence is excluded, since observational studies provide reliable data that confirm ecological phenomenon in real-world settings and complement causative experiments (Sagarin and Pauchard 2010). The Conservation Evidence Project acknowledges that their database is just one tool in the decision-making process, and encourages researchers to consult more comprehensive systematic reviews, such as those compiled by the Centre for Evidence-Based Conservation and the Collaboration for Environmental Evidence (Sutherland et al. 2018).

To integrate the Conservation Evidence database with wild animal welfare, we highlight the interventions which overtly change the lives of animals, such as those which alter movement, feeding, or reproductive behavior or control competition and predation. Most of the summarized research measures the effects on species diversity, abundance, or population size. Reproductive success, body condition, or behavior are evaluated less frequently, which appears to reflect a limitation within the conservation and restoration literature (Cooke and Suski 2008, Cooke et al. 2013). Research on wild animal welfare can address this knowledge gap by targeting interventions to these understudied areas (Dawkins 2008, Beausoleil et al. 2018).

We also re-evaluate the interventions from the Conservation Evidence database from a welfare-oriented perspective to illustrate how conservation evidence can inform predictions of the primary and non-target effects on welfare. Target effects are the direct effect on the welfare of the focal species or individuals and non-target effects refer to the welfare impacts on other animals in the ecosystem. The outcomes on conservation targets are given in the online synopses, which are linked to when available.  We also incorporate the conservation evidence into Wild Animal Initiative’s interventions classification system (forthcoming in 2019) to further build our capacity to conduct welfare interventions in the future. Overall, we find that conservationists and welfare advocates may emphasize different potential effects and trade-offs when evaluating environmental problems, yet the different approaches may or may not, in practice, change the intervention actions.

Highlighted Interventions

Amphibian Conservation

Conservation target: reduce predation by other species

Welfare target

Improve amphibian welfare by reducing predation by other species

Welfare mechanism

remove threats/risks

Conservation intervention

Potential target effects

Potential non-target effects

Remove or control fish by drying out ponds (synopsis)

  • avoids amphibian deaths
  • may increase deaths of amphibian eggs and larvae
  • long, painful death for fish predators
  • deaths of other aquatic animals
  • alters food web by removing aquatic top predator

Remove or control fish by catching (synopsis)

  • avoids amphibian deaths
  • short, painful death for fish
  • alters food web by removing aquatic top predator

Remove or control invasive bullfrogs (synopsis)

  • avoids amphibian deaths
  • increases deaths/ risks to one amphibian species
  • increases amphibian deaths without assessing control method
  • releases resources by removing highly competitive species
  • alters food web by removing aquatic predator

Remove or control invasive snakes (synopsis)

  • avoids amphibian deaths
  • increases snake deaths without assessing control method
  • alters food web by removing terrestrial mesopredators

Remove or control mammals (synopsis)

  • avoids amphibian deaths
  • increases mammal deaths without assessing control method
  • alters food web by removing terrestrial mesopredators

Remove or control fish using Rotenone (synopsis)

  • avoids amphibian deaths
  • may increase deaths of amphibian eggs and larvae
  • long, painful death to fish
  • deaths of other aquatic animals
  • alters food web by removing aquatic meso- and top predators

Exclude fish with barriers (synopsis)

  • avoids amphibian deaths
  • alters food web by partially removing aquatic meso- and top predators

Encourage aquatic plant growth as refuge against fish predation

  • avoids amphibian deaths
  • decreases food availability for fish
  • creates habitat for species that prefer dense vegetation while removing habitat for species that prefer less vegetation

Remove or control non-native crayfish

  • avoids amphibian deaths
  • increases crustacean deaths without assessing control method
  • releases resources by removing highly competitive species

Amphibian Conservation

Conservation target: reduce competition with other species

Welfare target

Improve amphibian welfare by reducing competition with other species

Welfare mechanism

remove threats/risks

Conservation intervention

Potential target effects

Potential non-target effects

Reduce competition from native amphibians (synopsis)

  • avoids amphibian deaths
  • increase amphibian body condition
  • increases deaths/risks to other amphibian species
  • releases resources by removing highly competitive species

Remove or control invasive Cuban tree frogs (synopsis)

  • avoids amphibian deaths
  • increase amphibian body condition
  • increases deaths/risks to one amphibian species
  • releases resources by removing highly competitive species

Remove or control invasive cane toads

  • avoids amphibian deaths
  • increases deaths/risks to one amphibian species
  • releases resources by removing highly competitive species
  • reduces deaths to predators which eat cane toads

Bat Conservation

Conservation target: reduce interactions with exotic plants, animals, and pathogens

Welfare target

Improve bat welfare by reducing interactions with exotic organisms

Welfare mechanism

remove threats/risks

Conservation intervention

Potential target effects

Potential non-target effects

Remove invasive plants (synopsis)

  • avoids bat deaths
  • increases bat body condition
  • increases aerial insect abundances
  • increases predation of aerial insects by bats

Translocate to predator-free or disease-free areas (synopsis)

  • avoids bat deaths
  • increase risks to translocated bats
  • alters food web by adding a new predator to the community
  • interferes with bats’ normal behaviors
  • alters disease dynamics by adding a new host for pathogens to a community

Control invasive predators

  • avoids bat deaths
  • increases deaths of predators without assessing control method
  • alters food web by removing predators

Bat Conservation

Conservation target: increase habitat suitability

Welfare target

Improve bat welfare by increasing habitat suitability

Welfare mechanism

providing resources (e.g. food and shelter)

Conservation intervention

Potential target effects

Potential non-target effects

Leave bat roosts, roost entrances, and commuting routes unlit (synopsis)

  • avoids bat deaths
  • increases ability for bats to perform normal behaviors
  • increases normal behavior of other light-sensitive animals
  • alters amount of predation of flying insects by bats

Use low intensity lighting (synopsis)

  • increases ability for bats to perform normal behaviors

  • increases normal behavior of other light-sensitive animals
  • alters amount of predation of flying insects by bats

Provide artificial roost structures for bats (synopsis)

  • increases ability for bats to perform normal behaviors

  • alters food web by adding or increasing the number of bat predators in the community

Restrict timing of lighting

  • increases ability for bats to perform normal behaviors
  • alters amount of predation of flying insects by bats
  • increases normal behavior of other light-sensitive animals

Use low pressure sodium lamps or UV filters

  • increases ability for bats to perform normal behaviors

  • alters amount of predation of flying insects by bats
  • increases normal behavior of other light-sensitive animals

Impose noise limits in proximity to roosts and bat habitats

  • increases ability for bats to perform normal behaviors

  • alters amount of predation of flying insects by bats
  • increases normal behavior of other light-sensitive animals

Bird Conservation

Conservation target: reduce predation by other species

Welfare target

Improve bird welfare by reducing predation by other species

Welfare mechanism

remove risks/threats

Conservation intervention

Potential target effects

Potential non-target effects

Remove or control mammalian predators on islands (synopsis)

  • avoids bird deaths
  • increases mammalian deaths without assessing control method

Reduce predation by translocating predators (synopsis)

  • avoids bird deaths
  • alters food webs by adding new predators or increasing the number of predators in communities

Control predators not on islands (synopsis)

  • avoids bird deaths
  • increases deaths/risks to raptor and corvid predators
  • increases predator deaths without assessing control method
  • alters food webs by decreasing predator abundances in communities

Bird Conservation

Conservation target: reduce incidental bird mortality during predator eradication or control

Welfare target

Improve bird welfare by reducing incidental bird mortality during predator eradication or control

Welfare mechanism

remove risks/threats

Conservation intervention

Potential target effects

Potential non-target effects

Distribute bait using dispensers (synopsis)

  • avoids bird deaths
  • no effect: do birds take bait designed for pest control? (synopsis)
  • kills fewer predators

Use colored baits to reduce accidental mortality during predator control (synopsis)

  • avoids bird deaths
  • no effect: do birds take bait designed for pest control? (synopsis)
  • kills fewer predators

Use repellents on baits (synopsis)

  • avoids bird deaths
  • no effect: do birds take bait designed for pest control? (synopsis)
  • kills fewer predators

Bird Conservation

Conservation target: reduce nest predation by excluding predators from nests or nesting areas

Welfare target

Improve juvenile bird welfare by reducing nest predation

Welfare mechanism

remove risks/threats

Conservation intervention

Potential target effects

Potential non-target effects

Physically protect nests from predators using non-electric fencing (synopsis)

  • avoids juvenile bird deaths
  • increases avian deaths: can nest protection increase nest abandonment? (synopsis); can nest protection increase predation of adults and chicks? (synopsis)
  • alters food web by shifting predation to non-bird species
  • interferes with normal behavior of predators
  • increases risks to predators

Physically protect nests with individual exclosures/barriers or provide shelters for chicks (synopses #1, #2, #3, #4)

  • avoids juvenile bird deaths
  • increases avian deaths: can nest protection increase nest abandonment? (synopsis); can nest protection increase predation of adults and chicks? (synopsis)
  • alters food web by shifting predation to non-bird species
  • interferes with normal behavior of predators
  • increases risks to predators

Protect bird nests using electric fencing (synopsis)

  • avoids juvenile bird deaths
  • increases bird deaths: can nest protection increase nest abandonment? (synopsis); can nest protection increase predation of adults and chicks? (synopsis)
  • alters food web by shifting predation to non-bird species
  • interferes with normal behavior of predators
  • increases risks to predators

Use artificial nests that discourage predation (synopsis)

  • avoids juvenile bird deaths
  • alters food web by shifting predation to non-bird species

Guard nests to prevent predation (synopsis)

  • avoids juvenile bird deaths
  • interferes with normal behavior of birds
  • increases bird deaths: can nest protection increase nest abandonment? (synopsis); can nest protection increase predation of adults and chicks? (synopsis)
  • alters food web by shifting predation to non-bird species
  • interferes with normal behavior of predators
  • increases risks to predators

Protect nests from ants (synopsis)

  • avoids juvenile bird deaths
  • increases deaths of ants and other small animals by sticky traps
  • increases risks to ants and other insects from chemical repellents

Use multiple barriers to protect nests (synopsis)

  • avoids juvenile bird deaths
  • increases bird deaths: can nest protection increase nest abandonment? (synopsis); can nest protection increase predation of adults and chicks? (synopsis)
  • alters food web by shifting predation to non-bird species
  • interferes with normal behavior of predators
  • increases risks to predators

Use naphthalene to deter mammalian predators (synopsis)

  • avoids juvenile bird deaths
  • decreases body condition
  • interferes with normal behavior of predators
  • alters food web by shifting predation to non-bird species
  • increases insect deaths

Use snakeskin to deter mammalian nest predators (synopsis)

  • avoids juvenile bird deaths
  • alters food web by shifting predation to non-bird species

Play spoken-word radio programs to deter predators

  • avoids juvenile bird deaths
  • interferes with normal behavior of birds
  • interferes with normal behavior of predators
  • alters food web by shifting predation to non-bird species

Use “cat curfews” to reduce predation

  • avoids juvenile bird deaths

  • interferes with normal behavior of outdoor cats

Use lion dung to deter domestic cats

  • avoids juvenile bird deaths

  • interferes with normal behavior of outdoor cats
  • alters food web by shifting predation to non-bird species

Use mirrors to deter nest predators

  • avoids juvenile bird deaths
  • alters food web by shifting predation to non-bird species
  • interferes with normal predator behavior

Use ultrasonic devices to deter cats

  • avoids juvenile bird deaths
  • interferes with normal behavior of outdoor cats
  • alters food web by shifting predation to non-bird species

Bird Conservation

Conservation target: reduce bird mortality by reducing hunting ability or changing predator behavior

Welfare target

Improve bird welfare by decreasing predation by reducing hunting ability or changing predator behavior

Welfare mechanism

remove risks/threats

Conservation intervention

Potential target effects

Potential non-target effects

Reduce predation by translocating nest boxes (synopsis)

  • avoids bird deaths
  • increases risks to birds by moving birds’ nests
  • alters food web by shifting predation to non-bird species

Use collar-mounted devices to reduce predation (synopsis)

  • avoids bird deaths
  • alters food web by shifting predation to non-bird species
  • interferes with normal predator behavior

Use supplementary feeding of predators to reduce predation (synopsis)

  • avoids bird deaths
  • increases bird deaths by attracting predators
  • alters the food web by increasing/decreasing predation pressure on other species

Use aversive conditioning to reduce nest predation (synopses #1, #2)

  • avoids bird deaths
  • alters food web by shifting predation to non-bird species
  • interferes with normal predator behavior

Bird Conservation

Conservation target: reduce competition with other species for food and nest sites

Welfare target

Improve juvenile bird welfare by reducing competition with other species for food and nest sites

Welfare mechanism

remove risks/threats

Conservation intervention

Potential target effects

Potential non-target effects

Reduce inter-specific competition for food by removing or controlling competitor species (synopsis)

  • avoids bird deaths
  • increases bird body condition
  • increases risks to the bird competitor species
  • increases deaths of competitive species without assessing control method
  • releases resources by removing highly competitive species

Protect nest sites from competitors (synopsis)

  • avoids bird deaths
  • increases risks to the bird competitor species
  • interferes with normal behavior of competitive species

Reduce competition between species by providing nest boxes (synopsis)

  • avoids bird deaths
  • alters the food web by increasing the number of birds in the community

Reduce inter-specific competition for nest sites by modifying habitats to exclude competitor species (synopses #1, #2, #3, #4)

  • avoids juvenile bird deaths
  • increases risks to the bird competitor species
  • releases resources by removing highly competitive species
  • interferes with normal behavior of competitive species

Bird Conservation

Conservation target: increase habitat suitability

Welfare target

Improve bird welfare by increasing habitat suitability

Welfare mechanism

providing resources (e.g. food and shelter)

Conservation intervention

Potential target effects

Potential non-target effects

Plant wild bird seed or cover mixture (synopsis)

  • increases ability for birds to perform normal behaviors
  • alters the food web by increasing the number of birds in the community

Relocate nests at harvest time to reduce nestling mortality (synopsis)

  • avoids juvenile bird behavior
  • increases risks by moving birds’ nests
  • alters the food web by increasing the number of birds in the community

Rehabilitate injured birds (synopsis)

  • avoids bird deaths
  • interferes with birds’ normal behaviors
  • increases humans’ connection to nature by rescuing birds

Remove eggs from wild nests to increase reproductive output (synopsis)

  • avoids bird deaths if sibling competition is avoided
  • alters the food web by increasing the number of birds in the community

Use artificial visual and auditory stimuli to induce breeding in wild populations (synopsis)

  • increases ability for birds to perform normal behaviors
  • alters the food web by increasing the number of birds in the community

Literature Cited

Beausoleil, N. J., D. J. Mellor, L. Baker, S. E. Baker, M. Bellio, A. S. Clarke, A. Dale, S. Garlick, B. Jones, A. Harvey, B. J. Pitcher, S. Sherwen, K. A. Stockin, and S. Zito. 2018. “Feelings and fitness” not “feelings or fitness” – the raison d’être of conservation welfare, which aligns conservation and animal welfare objectives. Frontiers in Veterinary Science 5:1–14.

Cooke, S. J., L. Sack, C. E. Franklin, A. P. Farrell, J. Beardall, M. Wikelski, and S. L. Chown. 2013. What is conservation physiology? Perspectives on an increasingly integrated and essential science. Conservation Physiology 1:1–23.

Cooke, S. J., and C. D. Suski. 2008. Ecological restoration and physiology: an overdue integration. BioScience 58:957–968.

Dawkins, M. S. 2008. The science of animal suffering. Ethology 114:937–945.

Driscoll, D. A., and M. J. Watson. 2019. Science denialism and compassionate conservation: response to Wallach et al. 2018. Conservation Biology 0(0):1-4.

Dubois, S., and D. Fraser. 2013. Rating harms to wildlife: a survey showing convergence between conservation and animal welfare views. Animal Welfare 22:49–55.

Rowe, A. 2019, June. Beausoleil et al. show the value of collaboration between wild animal welfare advocates and conservationists. Wild Animal Initiative. https://www.wildanimalinitiative.org/blog/beausoleil-et-al [Accessed June 2019]

Sagarin, R., and A. Pauchard. 2010. Observational approaches in ecology open new ground in a changing world. Frontiers in Ecology and the Environment 8:379–386.

Soule, M. E. 1985. What is conservation? BioScience 35:727–734.

Sutherland, W. J., L. V. Dicks, N. Ockendon, S. O. Petrovan, and R. K. Smith. 2018. What Works in Conservation. Page Oryx. Open Book Publishers, Cambridge, UK.

Wild Animal Initiative. 2019. Research Agenda — 2019. New York, New York. https://www.wildanimalinitiative.org/strategy [Accessed June 2019]

Wild Animal Initiative