Habitat mediates coevolved but not novel species interactions

Ongoing recovery of native predators has the potential to alter species interactions, with community and ecosystem wide implications. We estimated the co-occurrence of three species of conservation and management interest from a multi-species citizen science camera trap survey. We demonstrate fundamental differences in novel and coevolved predator–prey interactions that are mediated by habitat. Specifically, we demonstrate that anthropogenic habitat modification had no influence on the expansion of the recovering native pine marten in Ireland, nor does it affect the predator's suppressive influence on an invasive prey species, the grey squirrel. By contrast, the direction of the interaction between the pine marten and a native prey species, the red squirrel, is dependent on habitat. Pine martens had a positive influence on red squirrel occurrence at a landscape scale, especially in native broadleaf woodlands. However, in areas dominated by non-native conifer plantations, the pine marten reduced red squirrel occurrence. These findings suggest that following the recovery of a native predator, the benefits of competitive release are spatially structured and habitat-specific. The potential for past and future landscape modification to alter established interactions between predators and prey has global implications in the context of the ongoing recovery of predator populations in human-modified landscapes.

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Native and invasive squirrels show different behavioural responses to scent of a shared native predator

Royal Society Open Science ◽

10.1098/rsos.191841 ◽

2020 ◽

Vol 7 (2) ◽

pp. 191841 ◽

Cited By ~ 3

Author(s):

Joshua P. Twining ◽

W. Ian Montgomery ◽

Lily Price ◽

Hansjoerg P. Kunc ◽

David G. Tosh

Keyword(s):

Species Interactions ◽

Native Species ◽

Prey Species ◽

Red Squirrel ◽

Pine Marten ◽

Grey Squirrel ◽

Red Squirrels ◽

Behavioural Responses ◽

Grey Squirrels ◽

Native Predator

Invasive species pose a serious threat to native species. In Europe, invasive grey squirrels ( Sciurus carolinensis ) have replaced native red squirrels ( Sciurus vulgaris ) in locations across Britain, Ireland and Italy. The European pine marten ( Martes martes ) can reverse the replacement of red squirrels by grey squirrels, but the underlying mechanism of how pine martens suppress grey squirrels is little understood. Research suggests the reversal process is driven by direct predation, but why the native red squirrel may be less susceptible than the invasive grey squirrel to predation by a commonly shared native predator, is unknown. A behavioural difference may exist with the native sciurid being more effective at avoiding predation by the pine marten with which they have a shared evolutionary history. In mammals, olfactory cues are used by prey species to avoid predators. To test whether anti-predator responses differ between the native red squirrel and the invasive grey squirrel, we exposed both species to scent cues of a shared native predator and quantified the responses of the two squirrel species. Red squirrels responded to pine marten scent by avoiding the feeder, increasing their vigilance and decreasing their feeding activity. By contrast, grey squirrels did not show any anti-predator behaviours in response to the scent of pine marten. Thus, differences in behavioural responses to a shared native predator may assist in explaining differing outcomes of species interactions between native and invasive prey species depending on the presence, abundance and exposure to native predators.

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Emergence of a novel interaction between brown bear and cicada due to anthropogenic habitat modification

10.1101/2020.02.22.960583 ◽

2020 ◽

Author(s):

Kanji Tomita ◽

Tsutom Hiura

Keyword(s):

Species Interactions ◽

Ursus Arctos ◽

Novel Species ◽

Brown Bear ◽

Habitat Modification ◽

Natural Forests ◽

Predator Prey ◽

Anthropogenic Habitat ◽

Typical Type ◽

Prey Interaction

AbstractNovel species interactions have generally emerged in ecosystems that are highly modified by human activities. Anthropogenic habitat modification, such as afforestation, is one possible driver of novel species interactions; however, empirical evidence remains scarce. In this study, we show that a novel predator-prey interaction between the brown bear (Ursus arctos) and nymphs of a cicada species (Lyristes bihamatus) is generated by anthropogenic habitat modification. We evaluated the frequency of brown bear predation on cicada nymphs and the density of cicada nymphs between natural forests and plantations, which are a typical type of human-modified habitat. We found that brown bear predation on cicada nymphs occurred only in the plantations. The density of cicada nymphs in the plantations was significantly higher than in the natural forest. Our results indicate that the plantation leads to the emergence of the bear-cicada interaction due to increasing the density of cicada nymphs. The study draws attention to the overlooked effects of anthropogenic habitat modification on species interactions.

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The enemy of my enemy is my friend: native pine marten recovery reverses the decline of the red squirrel by suppressing grey squirrel populations

Proceedings of The Royal Society B Biological Sciences ◽

10.1098/rspb.2017.2603 ◽

2018 ◽

Vol 285 (1874) ◽

pp. 20172603 ◽

Cited By ~ 24

Author(s):

Emma Sheehy ◽

Chris Sutherland ◽

Catherine O'Reilly ◽

Xavier Lambin

Keyword(s):

Native Species ◽

Site Occupancy ◽

Apparent Competition ◽

Red Squirrel ◽

Pine Marten ◽

Grey Squirrel ◽

Capture Recapture ◽

Contrast Exposure ◽

The Impact ◽

Grey Squirrels

Shared enemies may instigate or modify competitive interactions between species. The dis-equilibrium caused by non-native species introductions has revealed that the outcome of such indirect interactions can often be dramatic. However, studies of enemy-mediated competition mostly consider the impact of a single enemy, despite species being embedded in complex networks of interactions. Here, we demonstrate that native red and invasive grey squirrels in Britain, two terrestrial species linked by resource and disease-mediated apparent competition, are also now linked by a second enemy-mediated relationship involving a shared native predator recovering from historical persecution, the European pine marten. Through combining spatial capture–recapture techniques to estimate pine marten density, and squirrel site-occupancy data, we find that the impact of exposure to predation is highly asymmetrical, with non-native grey squirrel occupancy strongly negatively affected by exposure to pine martens. By contrast, exposure to pine marten predation has an indirect positive effect on red squirrel populations. Pine marten predation thus reverses the well-documented outcome of resource and apparent competition between red and grey squirrels.

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Frequent Consumption and Rapid Digestion of Prey by the Lake Erie Watersnake with Implications for an Invasive Prey Species

Copeia ◽

10.1643/ch-08-119 ◽

2009 ◽

Vol 2009 (3) ◽

pp. 437-445 ◽

Cited By ~ 17

Author(s):

Peter C. Jones ◽

Richard B. King ◽

Kristin M. Stanford ◽

Tyler D. Lawson ◽

Matt Thomas

Keyword(s):

Lake Erie ◽

Prey Species ◽

Frequent Consumption ◽

Invasive Prey

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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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Something different for dinner? Responses of a native Australian predator (the keelback snake) to an invasive prey species (the cane toad)

Biological Invasions ◽

10.1007/s10530-009-9521-5 ◽

2009 ◽

Vol 12 (5) ◽

pp. 1045-1051 ◽

Cited By ~ 23

Author(s):

John Llewelyn ◽

Lin Schwarzkopf ◽

Ross Alford ◽

Richard Shine

Keyword(s):

Prey Species ◽

Cane Toad ◽

Invasive Prey

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Urbanization and Population Genetic Structure of the Panama City crayfish (Procambarus econfinae)

Journal of Heredity ◽

10.1093/jhered/esz072 ◽

2019 ◽

Vol 111 (2) ◽

pp. 204-215

Author(s):

Sarah I Duncan ◽

Ellen P Robertson ◽

Robert J Fletcher ◽

James D Austin

Keyword(s):

Genetic Diversity ◽

Genetic Structure ◽

Habitat Loss ◽

Legal Protection ◽

Habitat Modification ◽

Panama City ◽

Habitat Patches ◽

Anthropogenic Habitat ◽

Habitat Loss And Fragmentation

Abstract For species with geographically restricted distributions, the impacts of habitat loss and fragmentation on long-term persistence may be particularly pronounced. We examined the genetic structure of Panama City crayfish (PCC), Procambarus econfinae, whose historical distribution is limited to an area approximately 145 km2, largely within the limits of Panama City and eastern Bay County, FL. Currently, PCC occupy approximately 28% of its historical range, with suitable habitat composed of fragmented patches in the highly urbanized western portion of the range and managed plantations in the more contiguous eastern portion of the range. We used 1640 anonymous single-nucleotide polymorphisms to evaluate the effects of anthropogenic habitat modification on the genetic diversity and population structure of 161 PCC sampled from across its known distribution. First, we examined urban habitat patches in the west compared with less-developed habitat patches in the east. Second, we used approximate Bayesian computation to model inferences on the demographic history of eastern and western populations. We found anthropogenic habitat modifications explain the genetic structure of PCC range-wide. Clustering analyses revealed significant genetic structure between and within eastern and western regions. Estimates of divergence between east and west were consistent with urban growth in the mid-20th century. PCC have low genetic diversity and high levels of inbreeding and relatedness, indicating populations are small and isolated. Our results suggest that PCC have been strongly affected by habitat loss and fragmentation and management strategies, including legal protection, translocations, or reintroductions, may be necessary to ensure long-term persistence.

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