Making inference from wildlife collision data: inferring predator absence from prey strikes

Wildlife collision data are ubiquitous, though challenging for making ecological inference due to typically irreducible uncertainty relating to the sampling process. We illustrate a new approach that is useful for generating inference from predator data arising from wildlife collisions. By simply conditioning on a second prey species sampled via the same collision process, and by using a biologically realistic numerical response functions, we can produce a coherent numerical response relationship between predator and prey. This relationship can then be used to make inference on the population size of the predator species, including the probability of extinction. The statistical conditioning enables us to account for unmeasured variation in factors influencing the runway strike incidence for individual airports and to enable valid comparisons. A practical application of the approach for testing hypotheses about the distribution and abundance of a predator species is illustrated using the hypothesized red fox incursion into Tasmania, Australia. We estimate that conditional on the numerical response between fox and lagomorph runway strikes on mainland Australia, the predictive probability of observing no runway strikes of foxes in Tasmania after observing 15 lagomorph strikes is 0.001. We conclude there is enough evidence to safely reject the null hypothesis that there is a widespread red fox population in Tasmania at a population density consistent with prey availability. The method is novel and has potential wider application.

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Making inference from wildlife collision data: inferring predator absence from prey strikes

10.7287/peerj.preprints.2572 ◽

2016 ◽

Author(s):

Peter Caley ◽

Geoffrey R Hosack ◽

Simon C Barry

Keyword(s):

Prey Species ◽

Red Fox ◽

Prey Availability ◽

Numerical Response ◽

Practical Application ◽

Ecological Inference ◽

Predator Species ◽

New Approach ◽

Predictive Probability ◽

Irreducible Uncertainty

Wildlife collision data are ubiquitous, though challenging for making ecological inference due to typically irreducible uncertainty relating to the sampling process. We illustrate a new approach that is useful for generating inference from predator data arising from wildlife collisions. By simply conditioning on a second prey species sampled via the same collision process, and by using a biologically realistic numerical response functions, we can produce a coherent numerical response relationship between predator and prey. This relationship can then be used to make inference on the population size of the predator species, including the probability of extinction. The statistical conditioning enables us to account for unmeasured variation in factors influencing the runway strike incidence for individual airports and to enable valid comparisons. A practical application of the approach for testing hypotheses about the distribution and abundance of a predator species is illustrated using the hypothesized red fox incursion into Tasmania, Australia. We estimate that conditional on the numerical response between fox and lagomorph runway strikes on mainland Australia, the predictive probability of observing no runway strikes of foxes in Tasmania after observing 15 lagomorph strikes is 0.001. We conclude there is enough evidence to safely reject the null hypothesis that there is a widespread red fox population in Tasmania at a population density consistent with prey availability. The method is novel and has potential wider application.

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Integrating disparate datasets to model the functional response of a marine predator: a case study of harbour porpoises in the southern North Sea

10.22541/au.162064882.28641967/v1 ◽

2021 ◽

Author(s):

Janneke Ransijn ◽

Phillip Hammond ◽

Mardik Leopold ◽

Signe Sveegaard ◽

Sophie Smout

Keyword(s):

Functional Response ◽

North Sea ◽

Prey Species ◽

Prey Availability ◽

Stomach Contents ◽

Prey Consumption ◽

Predator Species ◽

Marine Predator ◽

Southern North Sea ◽

Foraging Range

1. Quantifying consumption and prey choice for marine predator species is key to understanding their interaction with prey species, fisheries, and the ecosystem as a whole. However, parameterising a functional response for large predators can be challenging because of the difficulty in obtaining the required datasets on predator diet and the availability of multiple prey species. 2. This study modelled a Multi-Species Functional Response (MSFR) to describe the relationship between consumption by harbour porpoises (Phocoena phocoena) and the availability of multiple prey species in the southern North Sea. Bayesian methodology was employed to estimate MSFR parameters and to incorporate uncertainties in diet and prey availability estimates. Prey consumption was estimated from stomach contents data of stranded harbour porpoises. Prey availability to harbour porpoises was estimated based on the spatial overlap between prey distributions, estimated from fish survey data, and porpoise foraging range in the days prior to stranding predicted from telemetry data. 3. Results indicated a strong preference for sandeel in the study area. Prey switching behaviour (change in preference dependent on prey abundance) was confirmed by the favoured Type III functional response model. Variation in the size of the foraging range (estimated area where harbour porpoises could have foraged prior to stranding) did not alter the overall pattern of the results or conclusions. 4. Integrating datasets on prey consumption from strandings, predator foraging distribution using telemetry and prey availability from fish surveys into the modelling approach provides a methodological framework that may be appropriate for fitting MSFRs for other predators.

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Biological reference points for fish stocks in a multispecies context

Canadian Journal of Fisheries and Aquatic Sciences ◽

10.1139/f01-158 ◽

2001 ◽

Vol 58 (11) ◽

pp. 2167-2176 ◽

Cited By ~ 79

Author(s):

Jeremy S Collie ◽

Henrik Gislason

Keyword(s):

Life History ◽

Growth Rates ◽

Prey Species ◽

Prey Availability ◽

Mortality Rates ◽

Reference Points ◽

Natural Mortality ◽

Fishing Mortality ◽

Predator Species ◽

Life History Parameters

Biological reference points (BRPs) are widely used to define safe levels of harvesting for marine fish populations. Most BRPs are either minimum acceptable biomass levels or maximum fishing mortality rates. The values of BRPs are determined from historical abundance data and the life-history parameters of the fish species. However, when the life-history parameters change over time, the BRPs become moving targets. In particular, the natural mortality rate of prey species depends on predator levels; conversely, predator growth rates depend on prey availability. We tested a suite of BRPs for their robustness to observed changes in natural mortality and growth rates. We used the relatively simple Baltic Sea fish community for this sensitivity test, with cod as predator and sprat and herring as prey. In general, the BRPs were much more sensitive to the changes in natural mortality rates than to growth variation. For a prey species like sprat, fishing mortality reference levels should be conditioned on the level of predation mortality. For a predator species, a conservative level of fishing mortality can be identified that will prevent growth overfishing and ensure stock replacement. These first-order multispecies interactions should be considered when defining BRPs for medium-term (510 year) management decisions.

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Sensory-based niche partitioning in a multiple predator–multiple prey community

Proceedings of The Royal Society B Biological Sciences ◽

10.1098/rspb.2015.0520 ◽

2015 ◽

Vol 282 (1808) ◽

pp. 20150520 ◽

Cited By ~ 23

Author(s):

Jay J. Falk ◽

Hannah M. ter Hofstede ◽

Patricia L. Jones ◽

Marjorie M. Dixon ◽

Paul A. Faure ◽

...

Keyword(s):

Species Interactions ◽

Prey Species ◽

Niche Partitioning ◽

Signal Evolution ◽

Signal Design ◽

Predator Species ◽

Mate Attraction ◽

Communication Signals ◽

Signal Features ◽

The Impact

Many predators and parasites eavesdrop on the communication signals of their prey. Eavesdropping is typically studied as dyadic predator–prey species interactions; yet in nature, most predators target multiple prey species and most prey must evade multiple predator species. The impact of predator communities on prey signal evolution is not well understood. Predators could converge in their preferences for conspicuous signal properties, generating competition among predators and natural selection on particular prey signal features. Alternatively, predator species could vary in their preferences for prey signal properties, resulting in sensory-based niche partitioning of prey resources. In the Neotropics, many substrate-gleaning bats use the mate-attraction songs of male katydids to locate them as prey. We studied mechanisms of niche partitioning in four substrate-gleaning bat species and found they are similar in morphology, echolocation signal design and prey-handling ability, but each species preferred different acoustic features of male song in 12 sympatric katydid species. This divergence in predator preference probably contributes to the coexistence of many substrate-gleaning bat species in the Neotropics, and the substantial diversity in the mate-attraction signals of katydids. Our results provide insight into how multiple eavesdropping predator species might influence prey signal evolution through sensory-based niche partitioning.

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Gut content analysis of cattle egrets (Bubulcus ibis) in Asam Kumbang Crocodile Park, North Sumatra

IOP Conference Series Earth and Environmental Science ◽

10.1088/1755-1315/912/1/012105 ◽

2021 ◽

Vol 912 (1) ◽

pp. 012105

Author(s):

E Jumilawaty ◽

N Namira ◽

A Anggelicha ◽

A Hartanto

Keyword(s):

Content Analysis ◽

Prey Species ◽

Prey Availability ◽

Biological Control Agent ◽

Food Resource ◽

Control Agent ◽

Gut Content Analysis ◽

Gut Content ◽

Dominant Group ◽

Bubulcus Ibis

Abstract Cattle egret (Bubulcus ibis) is a widespread avian species inhabiting a variety of natural and artificial sites. Asam Kumbang Crocodile Park is one of establishments that occupied some portions of B. ibis habitat with no recent information on the food resource and prey availability for the viability of B. ibis. To this aim, we collected 10 random individuals of B. ibis to be sacrificed for gut content analysis of prey species. A total of 19 taxa was found as prey items in the gut of B. ibis with the dominant group from insects (Orthoptera, Scolopendromorpha). The diversity of prey species was categorized as moderate with intraspecific diet variation which formed four guilds that fed on specific taxa namely Group 1 (Haplotaxida, Lepidoptera, Anurans), Group 2 (Blattodea, Coleoptera, Araneae), Group 3 (Orthoptera, Scolopendromorpha); and Group 4 (Dermaptera, Squamata). Oxya chinensis and Oxya velox are important rice grasshopper pests that were also found in the gut of B. ibis reflecting their potential function as biological control agent.

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Ecology of gyrfalcons, Falco rusticolus, in the central Canadian Arctic: diet and feeding behaviour

Canadian Journal of Zoology ◽

10.1139/z88-050 ◽

1988 ◽

Vol 66 (2) ◽

pp. 334-344 ◽

Cited By ~ 23

Author(s):

K. G. Poole ◽

D. A. Boag

Keyword(s):

Feeding Behaviour ◽

Prey Species ◽

Prey Availability ◽

Optimal Foraging Theory ◽

Ground Squirrels ◽

Spermophilus Parryii ◽

Falco Rusticolus ◽

Lagopus Mutus ◽

Spring Arrival ◽

Average Size

Diet and aspects of feeding behaviour in a population of gyrfalcons (Falco rusticolus) in the Northwest Territories were examined between 1984 and 1986. Three prey species, rock ptarmigan (Lagopus mutus), arctic ground squirrel (Spermophilus parryii), and arctic hare (Lepus arcticus), composed 96.5% of total prey biomass identified. Ptarmigan and hares were taken in May and June of all years (98.2% of biomass). Juvenile squirrels were used extensively in July and August of 1984 and 1985 but not in 1986, when squirrel production fell to almost zero; ptarmigan continued to be the dominant prey species throughout that summer. Because densities of breeding ptarmigan remained relatively constant during the study, but those of juvenile ground squirrels did not, it appeared that gyrfalcons responded functionally to varying availability of prey. Mean weight (250 g) of prey taken by male gyrfalcons was significantly less than the weight (330 g) of prey taken by females. As predicted by optimal foraging theory, average size of prey brought to the nest increased as time away from the nest increased. Conditions of food abundance were observed at most nests, suggesting that the amount of food available during the nestling period was not limiting production. We suggest that annual production is a function of spacing of pairs, which is set during courtship and prelaying, when prey availability is at its yearly low and when males must forage for both members of the pair. The fact that most gyrfalcon pairs initiated laying only after the spring arrival of migrating ptarmigan is consistent with this conclusion.

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Emergent Facilitation among Predators on Size-Structured Prey

Population and Community Ecology of Ontogenetic Development ◽

10.23943/princeton/9780691137575.003.0005 ◽

2013 ◽

Author(s):

André M. de Roos ◽

Lennart Persson

Keyword(s):

Life History ◽

Prey Species ◽

The Other ◽

Positive Interactions ◽

Predator Species ◽

Life History Stages ◽

Specific Predator ◽

Specialist Predators

This chapter discusses a variety of positive interactions between predators foraging on different stages of the same prey species, which all emerge owing to the biomass overcompensation that may occur in prey life history stages in response to increased mortality. These interactions include emergent facilitation of specialist predators by generalists that forage on the same prey individuals as the specialists, but in addition forage on smaller or larger prey individuals as well. Furthermore, the chapter shows that two predators that specialize on different life-history stages of prey can facilitate each other to the extent that one predator relies on the presence of the other for its persistence. A stage-specific predator may act as a catalyst species, which promotes and in fact is necessary for the invasion of another predator species, but is subsequently outcompeted by the latter.

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A PREY-PREDATOR MODEL WITH DIFFUSION AND A SUPPLEMENTARY RESOURCE FOR THE PREY IN A TWO‐PATCH ENVIRONMENT

Mathematical Modelling and Analysis ◽

10.3846/13926292.2004.9637238 ◽

2005 ◽

Vol 9 (1) ◽

pp. 9-24 ◽

Cited By ~ 9

Author(s):

J. Dhar

Keyword(s):

Steady State ◽

Asymptotic Stability ◽

Prey Species ◽

Steady State Solution ◽

State Solution ◽

Prey Population ◽

Predator Species ◽

Additional Resource ◽

Linear And Nonlinear ◽

Predator Model

In this paper, a prey‐predator dynamics, where the predator species partially depends upon the prey species, in a two patch habitat with diffusion and there is a non‐diffusing additional resource for the prey population, is modeled and analyzed. It is shown, that there exists a positive, monotonic, continuous steady state solution with continuous matching at the interface for both the species separately. Further, we obtain conditions for asymptotic stability for both linear and nonlinear cases. Šiame straipsnyje modeliuojama ir analizuojama plešr‐unu ir auku dinamika, laikant, kad plešr-unu populiacija dalinai priklauso nuo auku skačiaus. Areala sudaro dvi sritys, kuriose vyksta populiaciju individu difuzija, be to, aukoms yra išskirtas nedifunduojantis resursas. Irodyta, kad egzistuoja teigiamas, monotoniškas, tolydus stacionarusis sprendinys, tenkinantis tolydumo salyga abiems populiacijoms atskirai. Gautos asimptotinio stabilumo salygos tiesiniu ir netiesiniu atvejais.

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Knowing the Enemy: Inducible Defences in Freshwater Zooplankton

Diversity ◽

10.3390/d12040147 ◽

2020 ◽

Vol 12 (4) ◽

pp. 147 ◽

Cited By ~ 3

Author(s):

Patricia Diel ◽

Marvin Kiene ◽

Dominik Martin-Creuzburg ◽

Christian Laforsch

Keyword(s):

Life History ◽

Chemical Cues ◽

Prey Species ◽

Inducible Defences ◽

Animal Kingdom ◽

Predator Species ◽

Freshwater Zooplankton ◽

Taxonomic Range ◽

Set Up ◽

Made In

Phenotypic plasticity in defensive traits is an appropriate mechanism to cope with the variable hazard of a frequently changing predator spectrum. In the animal kingdom these so-called inducible defences cover the entire taxonomic range from protozoans to vertebrates. The inducible defensive traits range from behaviour, morphology, and life-history adaptations to the activation of specific immune systems in vertebrates. Inducible defences in prey species play important roles in the dynamics and functioning of food webs. Freshwater zooplankton show the most prominent examples of inducible defences triggered by chemical cues, so-called kairomones, released by predatory invertebrates and fish. The objective of this review is to highlight recent progress in research on inducible defences in freshwater zooplankton concerning behaviour, morphology, and life-history, as well as difficulties of studies conducted in a multipredator set up. Furthermore, we outline costs associated with the defences and discuss difficulties as well as the progress made in characterizing defence-inducing cues. Finally, we aim to indicate further possible routes in this field of research and provide a comprehensive table of inducible defences with respect to both prey and predator species.

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