Anthropogenic disturbance is a major cause of worldwide declines in biodiversity. Understanding the implications of this disturbance for species and populations is crucial for conservation biologists wishing to mitigate negative effects. Anthropogenic light pollution is an increasing global problem, affecting ecological interactions across a range of taxa and impacting negatively upon critical animal behaviors including foraging, reproduction, and communication (for review see). Almost all bats are nocturnal, making them ideal subjects for testing the effects of light pollution. Previous studies have shown that bat species adapted to foraging in open environments feed on insects attracted to mercury vapor lamps. Here, we use an experimental approach to provide the first evidence of a negative effect of artificial light pollution on the commuting behavior of a threatened bat species. We installed high-pressure sodium lights that mimic the intensity and light spectra of streetlights along commuting routes of lesser horseshoe bats (Rhinolophus hipposideros). Bat activity was reduced dramatically and the onset of commuting behavior was delayed in the presence of lighting, with no evidence of habituation. These results demonstrate that light pollution may have significant negative impacts upon the selection of flight routes by bats.
Establishing and maintaining protected areas (PAs) are key tools for biodiversity conservation. However, this approach is insufficient for many species, particularly those that are wide-ranging and sparse. The cheetah Acinonyx jubatus exemplifies such a species and faces extreme challenges to its survival. Here, we show that the global population is estimated at ∼7,100 individuals and confined to 9% of its historical distributional range. However, the majority of current range (77%) occurs outside of PAs, where the species faces multiple threats. Scenario modeling shows that, where growth rates are suppressed outside PAs, extinction rates increase rapidly as the proportion of population protected declines. Sensitivity analysis shows that growth rates within PAs have to be high if they are to compensate for declines outside. Susceptibility of cheetah to rapid decline is evidenced by recent rapid contraction in range, supporting an uplisting of the International Union for the Conservation of Nature (IUCN) Red List threat assessment to endangered. Our results are applicable to other protection-reliant species, which may be subject to systematic underestimation of threat when there is insufficient information outside PAs. Ultimately, conserving many of these species necessitates a paradigm shift in conservation toward a holistic approach that incentivizes protection and promotes sustainable human-wildlife coexistence across large multiple-use landscapes.population viability analysis | threat assessment | protected areas | landscape conservation | megafauna T he spread and dominance of humans across the world during the Anthropocene have precipitated a sixth global biodiversity extinction crisis (1). To maximize biodiversity retention through this period of rapid change, scarce conservation resources need to be targeted toward species and ecosystems that are most Significance Here, we compile and present the most comprehensive data available on cheetah distribution and status. Our analysis shows dramatic declines of cheetah across its distributional range. Most cheetah occur outside protected areas, where they are exposed to multiple threats, but there is little information on population status. Simulation modeling shows that, where cheetah population growth rates are suppressed outside protected areas, extinction risk increases markedly. This result can be generalized to other "protection-reliant" species, and a decision tree is provided to improve their extinction risk estimation. Ultimately, the persistence of protection-reliant species depends on their survival outside and inside protected areas and requires a holistic approach to conservation that engages rather than alienates local communities.
Artificial lighting is a key biodiversity threat and produces 1900 million tonnes of CO 2 emissions globally, more than three times that produced by aviation. The need to meet climate change targets has led to a global increase in energyefficient light sources such as high-brightness light-emitting diodes (LEDs). Despite the energetic benefits of LEDs, their ecological impacts have not been tested. Using an experimental approach, we show that LED street lights caused a reduction in activity of slow-flying bats (Rhinolophus hipposideros and Myotis spp.). Both R. hipposideros and Myotis spp. activities were significantly reduced even during low light levels of 3.6 lux. There was no effect of LED lighting on the relatively fast-flying Pipistrellus pipistrellus, Pipistrellus pygmaeus and Nyctalus/Eptesicus spp. We provide the first evidence of the effects of LED lights on bats. Despite having considerable energy-saving benefits, LED lights can potentially fragment commuting routes for bats with associated negative conservation consequences. Our results add to the growing evidence of negative impacts of lighting on a wide range of taxa. We highlight the complexities involved in simultaneously meeting targets for reduction of greenhouse gas emissions and biodiversity loss. New lighting strategies should integrate climate change targets with the cultural, social and ecological impacts of emerging lighting technologies.
Even though they are fed daily by their owners, free-ranging pet cats Felis catus may kill wild birds and, given their high densities (typically > 200 cats/km 2 ), it has been postulated that cat predation could be a significant negative factor affecting the dynamics of urban bird populations. In this study, we: (1) used questionnaire surveys in 10 sites within the city of Bristol, UK, to estimate cat density; (2) estimated the number of birds killed annually in five sites by asking cat owners to record prey animals returned home; and then (3) compared the number of birds killed with breeding density and productivity to estimate the potential impact of cat predation. In addition, we (4) compared the condition of those birds killed by cats versus those killed in collisions, e.g. window strikes. Mean (± sd) cat density was 348 ± 86 cats/km 2 ( n = 10 sites); considering the eight species most commonly taken by cats, the mean ratios of adult birds/cats and juvenile birds/cats across the five sites were 1.17 ± 0.23 and 3.07 ± 0.74, respectively. Approximately 60% of the cats studied for up to 1 year at each site never returned any prey home; despite this, the estimated number of birds killed was large relative to their breeding density and productivity in many sites. Across species, cat-killed birds were in significantly poorer condition than those killed following collisions; this is consistent with the notion that cat predation represents a compensatory rather than additive form of mortality. Interpretation of these results is, however, complicated by patterns of body mass regulation in passerines. The predation rates estimated in this study would suggest that cats were likely to have been a major cause of mortality for some species of birds. The effect of cat predation in urban landscapes therefore warrants further investigation. The potential limitations of the current study are discussed, along with suggestions for resolving them.Keywords: fluctuating asymmetry, garden birds, hyperpredation, introduced species, urban biodiversity.The accidental or deliberate introduction of species into areas beyond their natural geographical range by humans is widely recognized as one of the major processes adversely affecting global biodiversity (Atkinson 1996, Mack et al . 2000, Clavero & GarciaBerthou 2005 and predatory non-native mammals have notably caused the extinction, extirpation and decline of a wide range of vertebrate species (Fitzgerald 1988, Kinnear et al . 1988, 2002, Roy 2001, Keitt et al . 2002, Nogales et al . 2004, Davey et al . 2006, Wayne et al . 2006. Domestic cats Felis catus exhibit varying degrees of dependence on humans from truly feral animals, such as on islands, that are totally non-reliant on people for food and shelter, to semi-feral individuals that are fed to some degree by humans (Centonze & Levy 2002, Levy et al . 2003, through to companion animals (also known as house cats and inside/outside cats) that are provided with food daily and which co-habit with their owners. The size of a truly fer...
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
customersupport@researchsolutions.com
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.