conservation.arizona.edu - Human Wildlife Conflict

Exotic Pet Trade as a Cause of Biological Invasions: The Case of Tree Squirrels of the Genus Callosciurus

aburnett93 — Fri, 22 Oct 2021 21:53:17 +0000

Authors

Maria Vittoria Mazzamuto

Lucas Wauters

John Koprowski

The pet industry is a growing global multibillion dollar market. The increase of exotic and non-domesticated animal ownership has led to an increase in the number of non-native pets released that create invasive alien species (IAS) populations in the wild. IAS negatively impact the biodiversity, human health and countries’ economies. We use tree squirrels of the genus Callosciurus as a well-documented case study of pets that become IAS. We review the pathways and range of introduction and the challenge and legal importance of species identification. Next, we document how they negatively affect native plants and animals, their parasitic infections that can threat native wildlife and human health and their impact on human activities and productive systems. We discuss the diverse biological, social, political and economic reasons that make control/eradication of these charismatic species difficult in most countries. However, we also highlight the successful management of the IAS in two countries where the early detection and engagement of stakeholders were key to successful eradication. We conclude that efforts to educate and involve the broader public by actively engaging a diversity of stakeholders are more likely to build a consensus toward IAS management and should be a priority for each country.

Additional Information

Biology

Date of publication:

2021

Topics

small mammal

Research Categories

Human Wildlife Conflict Invasive Species

Seasonal flow dynamics exacerbate overlap between artisanal fisheries and imperiled Ganges River dolphins

mmerrick — Mon, 09 Nov 2020 22:51:05 +0000

Authors

Shambhu Paudel

John L. Koprowski

Michael V. Cove

Here we quantify the effects of artisanal fisheries on the ecology of a small cetacean, the Ganges River dolphin (Platanista gangetica gangetica, GRD), in a large river system of Nepal. We examine the size-classes of fisheries’ catches, behavioural changes in GRD in response to fishing activities, and diel overlap between GRD and fishing activity. We observed high human exploitation rates (> 60% of the total catch per effort) of GRD-preferred prey sizes, indicating risks of high resource competition and dietary overlap, especially during the low water season when resource availability is reduced. Competitive interactions in the feeding niches during the low water season, plus temporal overlap between the peak exploitation and critical life-history events (e.g., reproduction), likely have ecological consequences. Furthermore, we detected 48% (95% CI 43–52%) increase in the chance of behavioural changes among dolphins exposed to anthropopressure (fishing activity), risking social behaviour impairment in exposed dolphins. The higher diel overlap and increased diel coefficient as the surveys progressed towards the monsoon season suggest temporal shifts in GRD socio-behavioural states and seasonal effects on resource partitioning, respectively. This work identifies drivers of small cetaceans-fisheries interactions and their consequences, and can be used to help reduce biologically significant fishing impacts on small cetaceans. Mitigation strategies, together with river sanctuary and distanced-based approaches, should be urgently included in a framework of ecosystem-based management.

Additional Information

Scientific Reports

Date of publication:

2020

Topics

Freshwater ecology

Conservation biology

biodiversity

Research Categories

Behavioral Ecology Disturbance Ecology Human Wildlife Conflict Threatened and Endangered Species

Black-tailed prairie dog (Cynomys ludovicianus) reintroduction can limit woody plant proliferation in grasslands

mmerrick — Fri, 17 Jul 2020 20:43:34 +0000

Authors

Sarah L. Hale

John L. Koprowski

Steven R. Archer

Tree and shrub proliferation has been widespread in grasslands worldwide, and has altered ecosystem function and wildlife habitat. Several causes have been proposed for the woody plant encroachment phenomenon. The widespread eradication of a native keystone herbivore in North American grasslands, the prairie dog (Cynomys spp.), is one potential contributing factor that has received relatively little attention. We hypothesized prairie dogs would have historically suppressed woody plants by creating “browse traps” through their systematic clipping of vegetation. We tested this hypothesis by conducting surveys and experimentally manipulating shrub accessibility via exclosures and artificial saplings on and around recently reestablished black-tailed prairie dog (Cynomys ludovicianus) colonies in southeastern Arizona, United States. Shrubs were common on the nascent colonies (mean ± SE = 132 ± 32.7 plants ha–1), but at substantially reduced densities compared to off colonies (305 ± 94.9 plants ha–1). Among branches placed on colonies to simulate “saplings” 89% were damaged within 3 days of “planting,” whereas those placed off colonies were virtually untouched. This was true for both a deciduous, N2-fixing shrub (velvet mesquite, Prosopis velutina) and an evergreen non-N2-fixing shrub (creosote bush, Larrea tridentata). Prairie dogs on newly established colonies did not extirpate woody plants over the time-frame of our study, but reduced their abundance and suppressed their growth, which would ostensibly prevent them from achieving dominance. Implications for extending the longevity of widely practiced “brush management” grassland restoration treatments are discussed in the context of perceptions of prairie dogs as rangeland pests. Prairie dogs represent an enigma in keystone conservation. Whereas the reintroduction of large or charismatic keystone species [e.g., sea otters (Enhydra lutris)] are conducted to restore critical ecological function, reintroductions of other keystone species, such as gray wolves (Canis lupus) and in our case, prairie dogs, are highly controversial. Our findings suggest reintroductions of this negatively perceived small herbivore could function as a tool to locally suppress woody plant proliferation that is widely regarded as an impediment to livestock production. Accordingly, prairie dogs could promote restoration efforts to re-establish and maintain habitat for grassland endemics while promoting biological diversity and other ecosystem services.

Additional Information

Frontiers in Ecology and Evolution

Date of publication:

2020

Topics

keystone species

browse trap

grasslands

restoration ecology

Research Categories

Behavioral Ecology Human Wildlife Conflict Natural History Threatened and Endangered Species

Can we use body size and road characteristics to anticipate barrier effects of roads in mammals? A meta-analysis

mmerrick — Thu, 16 Apr 2020 20:43:51 +0000

Authors

Chen, Hsiang Ling

Koprowski, John L.

Habitat fragmentation and loss caused by road development are recognized as major threats to biodiversity and challenges to reconcile the pursuit of economic growth with the protection of wildlife habitats. Assessment of potential environmental impacts is essential in planning and design of road projects. Behavioral responses such as road avoidance that causes barrier effects are critical in assessment of effects of roads on species persistence. In this study, we synthesized literature of barrier effects on mammals to identify road characteristics and species traits that might serve as management indicators to anticipate barrier effects. We conducted a meta-analysis with 118 statistics of road crossings by 45 species from 36 studies. We used logit-transformed proportion of individuals not crossing roads as the effect size of barrier effect. Overall, all types of roads, from major highways to narrow forest roads, can impede movements for certain species of mammals. For data collected by observational methods, body mass, road width, road surface and data collection methods explained 53% of variation among data. Barrier effect decreased as body mass increased, and was increased by greater road width. Paved roads posed stronger barriers compared to gravel dirt roads. Capture-recapture methods tended to detect a weaker barrier effect compared to methods that tracked individual movements. For data collected by experimental translocation, the probability of crossing following translocation was not affected by road width and body mass. We showed that interspecific variation of mammals in barrier effects can be explained by road characteristics and body size under natural condition, and can be useful to anticipate the species-specific magnitude of barrier effects of roads and aid in planning and design of road projects, as well as reassessment of existing roads.

Additional Information

Hystrix, the Italian Journal of Mammalogy

Date of publication:

2019

Topics

road ecology

fragmentation

animal movement

anthropogenically disturbed land

Research Categories

Behavioral Ecology Disturbance Ecology Human Wildlife Conflict Spatial Ecology

El Oso Andino en el Macizo de Chingaza

thackerk1 — Thu, 27 Jun 2019 22:53:45 +0000

Authors

José F. González-Maya

Robinson Galindo-Tarazona

Marcos Manuel Urquijo Collazos

Maritza Zárate Vanegas

Angela Parra-Romero

Additional Information

El Oso Andino en el macizo de chingazaBogotá: Empresa de Acueducto, Alcantarillado y Aseo de Bogotá D. C.. EAB-ESP, Corporación

Date of publication:

2017

Research Categories

Human Wildlife Conflict Natural History Threatened and Endangered Species

Native lagomorphs suppress grass establishment in a shrub-encroached, semiarid grassland

mmerrick — Wed, 05 Jun 2019 18:23:28 +0000

Authors

Abercrombie, S. T.

Koprowski, J. L.

Nichols, M. H.

Femhi, J. S.

Shrub encroachment into arid grasslands has been associated with reduced grass abundance, increased soil erosion, and local declines in biodiversity. Livestock over‐ grazing and the associated reduction of fine fuels has been a primary driver of shrub encroachment in the southwestern United States, but shrublands continue to persist despite livestock removal and grassland restoration efforts. We hypothesized that an herbivory feedback from native mammals may contribute to continued suppression of grasses after the removal of livestock. Our herbivore exclusion experiment in southeastern Arizona included five treatment levels and allowed access to native mammals based on their relative body size, separating the effects of rodents, lago‐morphs, and mule deer. We included two control treatments and replicated each treatment 10 times (n = 50). We introduced uniform divisions of lawn sod (Cynodon dactylon) into each exclosure for 24‐hr periods prior to (n = 2) and following (n = 2) the monsoon rains and used motion‐activated cameras to document herbivore visita‐ tions. In the pre‐monsoon trials, treatments that allowed lagomorph access had less sod biomass relative to other treatments (p < 0.001), averaging 44% (SD 36%) and 29% (SD 45%) remaining biomass after the 24‐hr trial periods. Following the onset of monsoons, differences in remaining biomass among treatments disappeared. Desert cottontails (Sylvilagus audubonii) were detected more frequently than any of the other 11 herbivore species present at the site, accounting for 83% of detections dur‐ ing the pre‐monsoon trials. Significantly more (p < 0.001) desert cottontails were de‐ tected during the pre‐monsoon trials (2,077) compared to the post‐monsoon trials (174), which coincided with biomass removal from lagomorph accessible treatments. We conclude that desert cottontails are significant consumers of herbaceous vegeta‐ tion in shrub‐encroached arid grasslands and they, along with other native herbi‐ vores, may act as a biotic feedback contributing to the competitive advantage and persistence of shrubs.

Additional Information

Ecology and Evolution

Date of publication:

2018

Topics

Community ecology

grasslands

native species

lagomorph

shrub encroachment

Research Categories

Disturbance Ecology Human Wildlife Conflict Population Ecology