scholarly journals Return of an apex predator to a suburban preserve triggers a rapid trophic cascade

2019 ◽  
Author(s):  
Kevin Leempoel ◽  
Jordana Meyer ◽  
Trevor Hebert ◽  
Nicole Nova ◽  
Elizabeth A. Hadly

ABSTRACTAbsence of apex predators simplifies food chains, leading to trophic degradation of ecosystems and diminution of the services they provide1. However, most predators do not coexist well with humans, which has resulted in a decline of carnivores and functional ecosystems worldwide2. In some instances, cryptic carnivores manage to survive amidst human settlements, finding refuge in small biological islands surrounded by urban landscapes. In such a system, we used two non-invasive data collection methods (camera trapping and fecal sampling) to investigate the multiannual relationship between predators and prey, and between competitors, through analysis of: (1) relative abundance and detection probability of species over time, (2) causal interactions via empirical dynamic modeling, (3) diet, and (4) diel activity patterns. All approaches show concordance in the results: the natural return of an apex predator, the puma (Puma concolor), triggered a trophic cascade, affecting the abundance and behavior of its main prey, subordinate predators and other prey in the studied system. Our study demonstrates that trophic recovery can occur rapidly following the return of a top predator, even in small protected areas in increasingly urbanized landscapes.

2019 ◽  
Vol 30 (5) ◽  
pp. 1324-1335 ◽  
Author(s):  
Carolyn R Shores ◽  
Justin A Dellinger ◽  
Eric S Newkirk ◽  
Shannon M Kachel ◽  
Aaron J Wirsing

Abstract Apex predators can influence ecosystems through density and behaviorally mediated effects on herbivores and mesopredators. In many parts of the world, apex predators live in, or are returning to, landscapes that have been modified by people; so, it is important to understand their ecological role in anthropogenic landscapes. We used motion-activated game cameras to compare the activity patterns of humans and 2 mesopredators, coyotes (Canis latrans) and bobcats (Lynx rufus), in areas with and without an apex predator, the gray wolf (Canis lupus), in a multiuse landscape of the northwestern United States. In areas with wolves, there was a significant increase in temporal niche overlap between the mesopredators owing to higher levels of coyote activity at all time periods of the day. Temporal overlap between mesopredators and humans also increased significantly in the presence of wolves. Coyotes exposed to wolves increased their activity during dawn, day, and dusk hours. The increase in coyote activity was greatest during the day, when wolves were least active. The direction of change in bobcat activity in areas with wolves was opposite to coyotes, suggesting a behaviorally mediated cascade between wolves, coyotes, and bobcats, although these findings would need to be confirmed with further research. Our findings suggest that mesopredators in human-dominated systems may perceive humans as less dangerous than apex predators, that humans may be more likely to encounter mesopredators in areas occupied by top predators, and that behaviorally mediated effects of apex predators on mesopredators persist in human-dominated landscapes.


2009 ◽  
Vol 78 (2) ◽  
pp. 525-536 ◽  
Author(s):  
Kelly S. Andrews ◽  
Greg D. Williams ◽  
Debbie Farrer ◽  
Nick Tolimieri ◽  
Chris J. Harvey ◽  
...  

2020 ◽  
Author(s):  
Bogdan Cristescu ◽  
L. Mark Elbroch ◽  
Justin A. Dellinger ◽  
Wesley Binder ◽  
Christopher C. Wilmers ◽  
...  

AbstractKill rates and functional responses are fundamental to the study of predator ecology and the understanding of predatory-prey dynamics. As the most widely distributed apex predator in the western hemisphere pumas (Puma concolor) have been widely studied yet a biogeographical synthesis of their kill rates is currently lacking. We reviewed the literature and compiled data on sex- and age-specific kill rate estimates of pumas on ungulates, and conducted analyses aimed at understanding ecological factors explaining the observed variation across their range. Kill rate studies on pumas, while numerous, were primarily conducted in Temperate Conifer Forests (< 10% of puma range), revealing a dearth of knowledge across much of their range, especially from tropical and subtropical habitats. Across studies, kill rates in ungulates/week were highest for adult females with kitten(s) (1.24 ± 0.41 ungulates/week) but did not vary significantly between adult males (0.84 ± 0.18) and solitary adult females (0.99 ± 0.26). Kill rates in kg/day did not differ significantly among reproductive classes. Kill rates of adult pumas increased with ungulate density. Ungulate species richness had a weak negative association with adult male kill rates. Neither scavenger richness, the proportion of non-ungulate prey in the diet, nor regional human population density had a significant effect on ungulate kill rates. Our results had a strong temperate-ecosystem bias highlighting the need for further research across the diverse biomes pumas occupy in order to make species level inferences. Data from more populations would also allow for multivariate analyses providing deeper inference into the ecological and behavioural factors driving kill rates and functional responses of pumas, and apex predators in general.


2020 ◽  
Vol 101 (5) ◽  
pp. 1279-1288
Author(s):  
Marta Prat-Guitart ◽  
David P Onorato ◽  
James E Hines ◽  
Madan K Oli

Abstract Increases in apex predator abundance can influence the behavior of sympatric species, particularly when the available habitat and/or resources are limited. We assessed the temporal and spatiotemporal interactions between Florida panthers (Puma concolor coryi) and six focal sympatric species in South Florida, where Florida panther abundance has increased by more than 6-fold since the 1990’s. Using camera trap data, we quantified species’ diel activity patterns, temporal overlap, and time-to-encounter (i.e., time between consecutive visits of a Florida panther and a focal species and vice versa). The Florida panther and bobcat (Lynx rufus) displayed a nocturnal activity pattern; the black bear (Ursus americanus), white-tailed deer (Odocoileus virginianus), wild boar (Sus scrofa), and wild turkey (Meleagris gallopavo) were mostly diurnal; and the raccoon (Procyon lotor) was cathemeral. Prey species and black bears minimized encounters with Florida panthers by being active during the day and displaying longer time-to-encounter, whereas Florida panthers visited a site after a prey species at higher probabilities than after competitor species, and were more likely to visit an elevated site or upland habitat. Our results suggest that interactions between Florida panthers and sympatric species in our study system are driven by species-specific behavioral responses. Gaining a better understanding of the crucial interactions driving species coexistence is important for a better understanding of the structure and function of ecological communities and help manage the potential expansion of the Florida panther into Central Florida.


2017 ◽  
Vol 284 (1854) ◽  
pp. 20170111 ◽  
Author(s):  
Timothy Morris ◽  
Mike Letnic

It is widely assumed that organisms at low trophic levels, particularly microbes and plants, are essential to basic services in ecosystems, such as nutrient cycling. In theory, apex predators' effects on ecosystems could extend to nutrient cycling and the soil nutrient pool by influencing the intensity and spatial organization of herbivory. Here, we take advantage of a long-term manipulation of dingo abundance across Australia's dingo-proof fence in the Strzelecki Desert to investigate the effects that removal of an apex predator has on herbivore abundance, vegetation and the soil nutrient pool. Results showed that kangaroos were more abundant where dingoes were rare, and effects of kangaroo exclusion on vegetation, and total carbon, total nitrogen and available phosphorus in the soil were marked where dingoes were rare, but negligible where dingoes were common. By showing that a trophic cascade resulting from an apex predator's lethal effects on herbivores extends to the soil nutrient pool, we demonstrate a hitherto unappreciated pathway via which predators can influence nutrient dynamics. A key implication of our study is the vast spatial scale across which apex predators' effects on herbivore populations operate and, in turn, effects on the soil nutrient pool and ecosystem productivity could become manifest.


2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Hope J. Woods ◽  
Ming Fei Li ◽  
Ujas A. Patel ◽  
B. Duncan X. Lascelles ◽  
David R. Samson ◽  
...  

AbstractThe study of companion (pet) dogs is an area of great translational potential, as they share a risk for many conditions that afflict humans. Among these are conditions that affect sleep, including chronic pain and cognitive dysfunction. Significant advancements have occurred in the ability to study sleep in dogs, including development of non-invasive polysomnography; however, basic understanding of dog sleep patterns remains poorly characterized. The purpose of this study was to establish baseline sleep–wake cycle and activity patterns using actigraphy and functional linear modeling (FLM), for healthy, adult companion dogs. Forty-two dogs were enrolled and wore activity monitors for 14 days. FLM demonstrated a bimodal pattern of activity with significant effects of sex, body mass, and age; the effect of age was particularly evident during the times of peak activity. This study demonstrated that FLM can be used to describe normal sleep–wake cycles of healthy adult dogs and the effects of physiologic traits on these patterns of activity. This foundation makes it possible to characterize deviations from normal patterns, including those associated with chronic pain and cognitive dysfunction syndrome. This can improve detection of these conditions in dogs, benefitting them and their potential as models for human disease.


2015 ◽  
Vol 65 (3-4) ◽  
pp. 209-217 ◽  
Author(s):  
Yadong Xue ◽  
Diqiang Li ◽  
Wenfa Xiao ◽  
Fang Liu ◽  
Yuguang Zhang ◽  
...  

There are significant gaps in our knowledge of wild camel ecology; especially the activity patterns that allow them to adapt to desert environments. The wild Bactrian camel (Camelus bactrianus) is a critically endangered species that survives in the extreme desert conditions of Central Asia. We conducted camera trapping surveys at seven watering sites in the northern piedmont of the Altun Mountains from 2010 to 2012. We analyzed the frequency of photo-captures to elucidate the wild camels’ diel activity patterns, and the seasonal variation in their activity at watering sites. We found that these wild camels were predominantly diurnal at watering sites, with an increase in relative activity from sunrise, reaching a peak toward midday, and then gradually decreasing in activity until sunset. The camels visited watering sites more often in winter than in summer. These results provide a guide for water development in the conservation of ungulates in arid areas.


2018 ◽  
Vol 56 (4) ◽  
pp. 872-881 ◽  
Author(s):  
Kaitlyn M. Gaynor ◽  
Paola S. Branco ◽  
Ryan A. Long ◽  
Dominique D. Gonçalves ◽  
Petter K. Granli ◽  
...  

2008 ◽  
Vol 12 (1) ◽  
pp. 113 ◽  
Author(s):  
Christian Giovanii Estrada Hernández

RESUMEN: La Selva Maya es el bosque tropical de hoja ancha más extenso de Centroamérica, se extiende entre México, Guatemala y Belice. El jaguar y el puma, son los felinos más grandes de América. En esta zona viven simpátricamente por lo que se presupone segregación en alguno de los componentes de su nicho ecológico. En este estudio se analizaron y compararon tres de los componentes principales del nicho: dieta, uso de hábitat y patrones de actividad, con el objetivo de evaluar si existe segregación entre el jaguar y el puma. Para la obtención de los datos se colectaron excrementos de manera oportunista, y se utilizaron trampas de cámaras automáticas en cuatro áreas protegidas. Se analizo la zona de estudio, a través de sistemas de información geográfica para determinar las proporciones de distintos tipos de hábitat presentes, y se colectaron datos de abundancias de las presas. Se analizaron los patrones y en la dieta, en el hábitat utilizado y en el horario de actividad. Se determino que el jaguar tuvo una dieta diferente y mas amplia comparada con la del puma, así también que este consume en promedio, presas más pequeñas. Las presas preferidas por elpuma fueron, tres especies de venados y tepezcuintles. Para el jaguar fueron coches de monte, pizotes y armadillos. Ambas especies presentaron un patrón similar de uso de hábitat, donde el "bosque alto" fue utilizado proporcionalmente a su abundancia, y el puma evitó el "bosque bajo". En cuanto a los patrones de actividad, ambos prefirieron horas nocturnas para desplazarse, aunque el puma presento mayor variabilidad. Se observo que ambas especies no se segregan mutuamente, espacial ni temporalmente. La frecuente utilización del "bosque bajo" y su relación con las aguadas y arroyos, es un factor importante en el mantenimiento de poblaciones de grandes felinos en la Selva MayaPALABRAS CLAVE: Felidae, Panthera onca, Puma concolor, coexistencia, nicho ecológico, Selva Maya, segregación ecológica.ABSTRACT: The Mayan Forest is the largest tropical broad-leaf forest remainder in Central America which extends between Mexico, Guatemala and Belize. Jaguar and puma are the biggest American wild cats. In this area both live sympatric which suggest segregation in at least one of its ecological niche components. In this study I analyzed and compared three of the principal niche components: diet, habitat use and activity patterns, with the main objective of assess if occurs ecological segregation among jaguar and puma. To obtain the data it was collected  jaguar and puma’s scats in an opportunistic way, and was used automatic camera traps in four protected areas. I analyzed the study area by geographic information system (GIS) to determine proportions of different habitat types, and also I used  previous collected prey abundance data. I analyzed patterns in diet, in habitat use and temporal activity. I found that jaguar had a wider prey spectrum than puma; jaguar took (in average) smallest preys, consequently, diets were significantly different. Puma preferred deer, brocket deer and paca as main prey; in contrast, jaguar preferred collared pecari, coati and armadillo. Both predator species presented a similar pattern in habitat usage, in which "highland forest" was used accordingly with its availability and puma avoided "lowland forest". About activity patterns, both were more active in the night time, however, puma was more variable in this aspect. Both species did not show segregation spatially or temporally. KEYWORDS: Felidae, Panthera onca, Puma concolor, coexistence, ecologic niche, Mayan forest, ecologic segregation.


2019 ◽  
Vol 11 (4) ◽  
pp. 13432-13447 ◽  
Author(s):  
Shomita Mukherjee ◽  
Priya Singh ◽  
André Pinto Silva ◽  
Chandan Ri ◽  
Kashmira Kakati ◽  
...  

Fifteen extant species of cats inhabit India, and the northeastern region of the country is among the richest with nine species.  Among these are the “standard four”, an assemblage of Clouded Leopard Neofelis nebulosa, Asiatic Golden Cat Catopuma temminckii, Marbled Cat Pardofelis marmorata, and Leopard Cat Prionailurus bengalensis, which also occur across southeastern Asia.  Within India, despite several surveys in this region, very little information exists on the ecology of this assemblage to explain their co-occurrence.  In this paper, we put together data from several independent camera trapping studies over 10 sites across northeastern India to examine and interpret diel activity patterns of this group.  While we present results for all the four species, we focus on two species, the Marbled Cat and Leopard Cat, which are of very similar body size and are potential competitors.  We used kernel density estimates to measure diel activity patterns of all four species and overlap in activity between Marbled Cat and Leopard Cat at the regional scale as well as the point scale.  We obtained 783 captures of the standard four from >27,500 trap nights.  The Asiatic Golden Cat and Marbled Cat were strongly diurnal, Clouded Leopard largely crepuscular and nocturnal, and Leopard Cat largely nocturnal.  The degree of overlap between Marbled Cat and Leopard Cat activity was low and in consensus with other studies across southeastern Asia.  We interpret this as the differing niche spaces of the two cats due to their specific pre-existing adaptations, not restricted to the effects of competition.  The point scale analysis when both cats are captured at the same location and separately show no shift in activity pattern, supporting our hypothesis of pre-existing differences in resources, such as food, playing a major role in facilitating co-existence.  Our study, however, is preliminary and additional information with robust analysis is required to test this finding.


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