Seasonal and individual variation in selection by feral cats for areas with widespread primary prey and localised alternative prey

2014 ◽  
Vol 41 (8) ◽  
pp. 650 ◽  
Author(s):  
Jennyffer Cruz ◽  
Chris Woolmore ◽  
M. Cecilia Latham ◽  
A. David M. Latham ◽  
Roger P. Pech ◽  
...  
Keyword(s):  
Seasonal Variation ◽  
Individual Variation ◽  
Resource Selection ◽  
Future Research ◽  
Home Ranges ◽  
Alternative Prey ◽  
Predator Control ◽  
Feral Cats ◽  
Gps Collars ◽  
Mackenzie Basin

Context Seasonal and individual variation in predator selection for primary and alternative prey can affect predator–prey dynamics, which can further influence invasive-predator impacts on rare prey. Aims We evaluated individual and seasonal variation in resource selection by feral cats (Felis silvestris catus) for areas with European rabbits (Oryctolagus cuniculus) around a breeding colony of endangered black-fronted terns (Chlidonias albostriatus) in the Upper Ohau River, within the Mackenzie Basin of New Zealand. Methods Within a feral cat population subject to localised control (within a 1-km area surrounding the tern colony), we mapped the movements of 17 individuals using GPS collars, and evaluated individual and seasonal variation in third-order resource selection (i.e. within home ranges) by using resource-selection functions with mixed effects. The year was divided into breeding and non-breeding seasons for terns. Key results Three of the eight feral cats monitored during the breeding season used the colony in proportion to availability and one selected it. These four individuals therefore pose a threat to the tern colony despite ongoing predator control. Selection by feral cats for areas with high relative rabbit abundance was not ubiquitous year-round, despite previous research showing that rabbits are their primary prey in the Mackenzie Basin. Conclusions Results suggest that rabbit control around the colony should reduce use by feral cats that select areas with high relative rabbit abundance (less than half the individuals monitored), but is unlikely to alleviate the impacts of those that select areas with low relative rabbit abundance. Hence, predator control is also required to target these individuals. Results thus support the current coupled-control of feral cats and rabbits within a 1-km buffer surrounding the tern colony. Future research should determine what scale of coupled-control yields the greatest benefits to localised prey, such as the tern colony, and whether rabbits aid hyperpredation of terns by feral cats via landscape supplementation. Implications The present study has highlighted the importance of considering seasonal and individual effects in resource selection by predators, and the role of primary prey, when designing management programs to protect rare prey.

scholarly journals Deer movement and resource selection during Hurricane Irma: implications for extreme climatic events and wildlife

2019 ◽  
Vol 286 (1916) ◽  
pp. 20192230 ◽  
Author(s):  
H. N. Abernathy ◽  
D. A. Crawford ◽  
E. P. Garrison ◽  
R. B. Chandler ◽  
M. L. Conner ◽  
...  
Keyword(s):  
Resource Selection ◽  
Global Climate ◽  
Field Studies ◽  
Mitigation Strategies ◽  
Home Ranges ◽  
Gps Collars ◽  
Behavioural Responses ◽  
Extreme Climatic Events ◽  
Demographic Effect ◽  
Hurricane Irma

Extreme climatic events (ECEs) are increasing in frequency and intensity and this necessitates understanding their influence on organisms. Animal behaviour may mitigate the effects of ECEs, but field studies are rare because ECEs are infrequent and unpredictable. Hurricane Irma made landfall in southwestern Florida where we were monitoring white-tailed deer ( Odocoileus virginianus seminolus ) with GPS collars. We report on an opportunistic case study of behavioural responses exhibited by a large mammal during an ECE, mitigation strategies for reducing the severity of the ECE effects, and the demographic effect of the ECE based on known-fate of individual animals. Deer altered resource selection by selecting higher elevation pine and hardwood forests and avoiding marshes. Most deer left their home ranges during Hurricane Irma, and the probability of leaving was inversely related to home range area. Movement rates increased the day of the storm, and no mortality was attributed to Hurricane Irma. We suggest deer mobility and refuge habitat allowed deer to behaviourally mitigate the negative effects of the storm, and ultimately, aid in survival. Our work contributes to the small but growing body of literature linking behavioural responses exhibited during ECEs to survival, which cumulatively will provide insight for predictions of a species resilience to ECEs and improve our understanding of how behavioural traits offset the negative impacts of global climate change.

At home in a new range: wild red deer in south-eastern Queensland

2014 ◽  
Vol 41 (3) ◽  
pp. 258 ◽  
Author(s):  
Matt Amos ◽  
Greg Baxter ◽  
Neal Finch ◽  
Peter Murray
Keyword(s):  
Home Range ◽  
Red Deer ◽  
Management Strategies ◽  
Future Research ◽  
Home Ranges ◽  
Gps Collars ◽  
Deer Density ◽  
Review Management ◽  
Movement Parameters ◽  
Local Convex

Context Wild deer are increasing worldwide and, in Australia, prompting land managers to review management strategies. Management activities may be ineffective without a sound understanding of the ecology of the species. No peer-reviewed research has been published for wild red deer in Australia, where they have been introduced. Aims To help land managers gain an understanding of some movement parameters of introduced wild red deer out of their natural range. Methods GPS collars were used to obtain movement rates (m h–1), annual home range using three estimators and seasonal home range using the Local Convex Hull estimator. Key findings Deer at our study site displayed typical crepuscular movements. However, the lack of elevated activity for stags in summer varies greatly to reports from overseas. The annual home range of hinds was much smaller than that of stags. Large differences for seasonal home ranges from the same deer for two winters suggest that seasonal conditions may exert a large influence on the size of home ranges. The home ranges of deer at our study site were comparable with the largest reported in European studies, but the relationship between deer density and home-range area was markedly different. Conclusions It appears that Australian wild red deer behave differently from their European conspecifics for several important movement parameters. Wild stags did not display the high levels of movement activity in summer, like those in Europe, and the home-range areas of our deer were very large for the high densities we encountered compared with overseas reports. Implications Targeted management of hinds may prove beneficial as hinds had a much smaller and continuous home range than stags. If managers want to target stags, there is only a short rut period when they continually associate with hinds and that may be the most efficacious time for control. Additionally, future research may need to explore the link between home range and deer density, and the effect of variation in rainfall on home range and movement of wild red deer which may influence management activities more than do the regular seasonal patterns found in Europe.

A Novel Approach to the Assessment of Variations in the Human Platelet Count

2000 ◽  
Vol 83 (03) ◽  
pp. 480-484 ◽  
Author(s):  
John James ◽  
Dianne Brown ◽  
Gordon Whyte ◽  
Mark Dean ◽  
Colin Chesterman ◽  
...  
Keyword(s):  
Platelet Count ◽  
Seasonal Variation ◽  
Individual Variation ◽  
Human Platelet ◽  
First Report ◽  
Platelet Counts ◽  
Novel Approach ◽  
Platelet Number ◽  
Genetically Determined

SummaryThis is the first report of a method to assess the significance of numerical changes in the platelet count based upon a result exceeding the normal intra-individual variation in platelet numbers. Serial platelet counts from 3,789 subjects were analysed to determine the intra-individual variation in platelet numbers. A platelet count difference of 98 × 109/L in males was found to represent a change that would occur by chance in less than 1 in 1,000 platelet count determinations. Tables to determine the significance of platelet number variations, given N previous observations, are provided at two probability levels. The repeatability of the platelet count was calculated as 0.871 (males) and 0.849 (females) indicating that the heritability of platelet count is high and that the platelet count is predominantly genetically determined. A seasonal variation in platelet count was found with a ‘winter’ versus ‘summer’ difference of 5.10 × 109/L (males) and 5.82 × 109/L (females).

Movement patterns of feral predators in an arid environment – implications for control through poison baiting

2009 ◽  
Vol 36 (5) ◽  
pp. 422 ◽  
Author(s):  
K. E. Moseby ◽  
J. Stott ◽  
H. Crisp
Keyword(s):  
Home Range ◽  
Sand Dunes ◽  
Activity Patterns ◽  
Movement Patterns ◽  
Home Range Size ◽  
Range Size ◽  
Home Ranges ◽  
Feral Cats ◽  
Poison Baiting ◽  
Specific Variation

Control of introduced predators is critical to both protection and successful reintroduction of threatened prey species. Efficiency of control is improved if it takes into account habitat use, home range and the activity patterns of the predator. These characteristics were studied in feral cats (Felis catus) and red foxes (Vulpes vulpes) in arid South Australia, and results are used to suggest improvements in control methods. In addition, mortality and movement patterns of cats before and after a poison-baiting event were compared. Thirteen cats and four foxes were successfully fitted with GPS data-logger radio-collars and tracked 4-hourly for several months. High intra-specific variation in cat home-range size was recorded, with 95% minimum convex polygon (MCP) home ranges varying from 0.5 km2 to 132 km2. Cat home-range size was not significantly different from that of foxes, nor was there a significant difference related to sex or age. Cats preferred habitat types that support thicker vegetation cover, including creeklines and sand dunes, whereas foxes preferred sand dunes. Cats used temporary focal points (areas used intensively over short time periods and then vacated) for periods of up to 2 weeks and continually moved throughout their home range. Aerial baiting at a density of 10 baits per km2 was ineffective for cats because similar high mortality rates were recorded for cats in both baited and unbaited areas. Mortality was highest in young male cats. Long-range movements of up to 45 km in 2 days were recorded in male feral cats and movement into the baited zone occurred within 2 days of baiting. Movement patterns of radio-collared animals and inferred bait detection distances were used to suggest optimum baiting densities of ~30 baits per km2 for feral cats and 5 per km2 for foxes. Feral cats exhibited much higher intra-specific variation in activity patterns and home-range size than did foxes, rendering them a potentially difficult species to control by a single method. Control of cats and foxes in arid Australia should target habitats with thick vegetation cover and aerial baiting should ideally occur over areas of several thousand square kilometres because of large home ranges and long-range movements increasing the chance of fast reinvasion. The use of temporary focal points suggested that it may take several days or even weeks for a cat to encounter a fixed trap site within their home range, whereas foxes should encounter them more quickly as they move further each day although they have a similar home-range size. Because of high intra-specific variability in activity patterns and home-range size, control of feral cats in inland Australia may be best achieved through a combination of control techniques.

scholarly journals Repeatability of glucocorticoid hormones in vertebrates: A meta-analysis

2017 ◽  
Author(s):  
Kelsey L Schoenemann ◽  
Frances Bonier
Keyword(s):  
Individual Variation ◽  
Meta Analysis ◽  
Adaptive Plasticity ◽  
Future Research ◽  
Life History Stages ◽  
Selective Pressures ◽  
Baseline Levels ◽  
Intensive Search ◽  
Sampling Season ◽  
Commercial Kit

We often expect that investigations of the patterns, causes, and consequences of among-individual variation in a trait of interest will reveal how selective pressures or ecological conditions influence that trait. However, many endocrine traits, such as concentrations of glucocorticoid (GC) hormones, exhibit adaptive plasticity and, therefore, do not necessarily respond to these pressures as predicted by among-individual phenotypic correlations. To improve our interpretations of among-individual variation in GC concentrations, we need more information about the repeatability of these traits within individuals. Many studies have already estimated the repeatability of baseline, stress-induced, and integrated GC measures, which provides an opportunity to use meta-analytic techniques to investigate 1) whether GC titers are generally repeatable across taxa, and 2) which biological or methodological factors may impact these estimates. From an intensive search of the literature, we collected 91 GC repeatability estimates from 47 studies. Overall, we found evidence that GC levels are repeatable, with mean repeatability estimates across studies ranging from 0.230 for baseline levels to 0.386 for stress-induced levels. We also noted several factors that predicted the magnitude of these estimates, including taxon, sampling season, and lab technique. Amphibians had significantly higher repeatability in baseline and stress-induced GCs than birds, mammals, reptiles, or bony fish. The repeatability of stress-induced GCs was higher when measured within, rather than across, life history stages. Finally, estimates of repeatability in stress-induced and integrated GC measures tended to be lower when GC concentrations were quantified using commercial kit assays rather than in-house assays. The extent to which among-individual variation in GCs may explain variation in organismal performance or fitness (and thereby inform our understanding of the ecological and evolutionary processes driving that variation) depends on whether measures of GC titers accurately reflect how individuals differ overall. Our findings suggest that while GC titers can reflect some degree of consistent differences among individuals, they frequently may not. We discuss how our findings contribute to interpretations of variation in GCs, and suggest routes for the design and analysis of future research.

scholarly journals Seasonal dynamics of a generalist and a specialist predator on a single prey

2021 ◽  
pp. 1-20
Author(s):  
Noah Bolohan ◽  
Victor LeBlanc ◽  
Frithjof Lutscher
Keyword(s):  
Seasonal Variation ◽  
Community Dynamics ◽  
Alternative Prey ◽  
Ecological Communities ◽  
Season Length ◽  
Simplified Models ◽  
Hunting Behaviour ◽  
Temporal Averaging ◽  
Invasion Analysis ◽  
Insight Into

In ecological communities, the behaviour of individuals and the interaction between species may change between seasons, yet this seasonal variation is often not represented explicitly in mathematical models. As global change is predicted to alter season length and other climatic aspects, such seasonal variation needs to be included in models in order to make reasonable predictions for community dynamics. The resulting mathematical descriptions are nonautonomous models with a large number of parameters, and are therefore challenging to analyze. We present a model for two predators and one prey, whereby one predator switches hunting behaviour to seasonally include alternative prey when available. We use a combination of temporal averaging and invasion analysis to derive simplified models and determine the behaviour of the system, in particular to gain insight into conditions under which the two predators can coexist in a changing climate. We compare our results with numerical simulations of the temporally varying model.

scholarly journals Tuberculosis Epidemiology and Badger (Meles meles) Spatial Ecology in a Hot-Spot Area in Atlantic Spain

Pathogens ◽  
2019 ◽  
Vol 8 (4) ◽  
pp. 292 ◽  
Author(s):  
Pelayo Acevedo ◽  
Miguel Prieto ◽  
Pablo Quirós ◽  
Isabel Merediz ◽  
Lucía de Juan ◽  
...  
Keyword(s):  
Spatial Ecology ◽  
Management Practices ◽  
Hot Spot ◽  
Tuberculin Test ◽  
Meles Meles ◽  
Home Ranges ◽  
Gps Collars ◽  
Spot Area ◽  
Preferred Habitat ◽  
Cattle Herds

We provide a temporal overview (from 2012 to 2018) of the outcomes of tuberculosis (TB) in the cattle and badger populations in a hot-spot in Asturias (Atlantic Spain). We also study the badger’s spatial ecology from an epidemiological perspective in order to describe hazardous behavior in relation to TB transmission between cattle and badgers. Culture and single intradermal tuberculin test (SITT) were available for cattle as part of the National Program for the Eradication of TB. A field survey was also carried out in order to determine the paddocks and buildings used by each farm, and the information obtained was stored by using geographic information systems. Moreover, eighty-three badgers were submitted for necropsy and subsequent bacteriological studies. Ten badgers were also tracked, using global positioning system (GPS) collars. The prevalence of TB in cattle herds in the hot-spot increased from 2.2% in 2012 to 20% in 2016; it then declined to 0.0% in 2018. In contrast, the TB prevalence in badgers increased notably (from 5.55% in 2012–2015 to 10.64% in 2016–2018). Both cattle and badgers shared the same strain of Mycobacterium bovis. The collared badgers preferred paddocks used by TB-positive herds in spring and summer (when they were more active). The males occupied larger home ranges than the females (Khr95: males 149.78 ± 25.84 ha and females 73.37 ± 22.91 ha; Kcr50: males 29.83 ± 5.69 ha and females 13.59 ± 5.00 ha), and the home ranges were smaller in autumn and winter than in summer. The averages of the index of daily and maximum distances traveled by badgers were 1.88 ± (SD) 1.20 km and 1.99 ± 0.71 km, respectively. One of them presented a dispersive behavior with a maximum range of 18.3 km. The most preferred habitat was apple orchards in all seasons, with the exception of winter, in which they preferred pastures. Land uses and landscape structure, which have been linked with certain livestock-management practices, provide a scenario of great potential for badger–cattle interactions, thus enhancing the importance of the badgers’ ecology, which could potentially transmit TB back to cattle in the future.

scholarly journals Beyond the Core: Who Has Larger Social Networks?

Social Forces ◽  
2020 ◽  
Author(s):  
Bas Hofstra ◽  
Rense Corten ◽  
Frank van Tubergen
Keyword(s):  
Social Networks ◽  
Individual Variation ◽  
Bayesian Modeling ◽  
State Of The Art ◽  
Scale Up ◽  
Network Size ◽  
Future Research ◽  
Social Contacts ◽  
Core Networks ◽  
Social Network Size

Abstract The sociological literature on social networks overwhelmingly considers the number of core social contacts. Social networks, however, reach far beyond this small number of social ties. We know little about individual variation in the size of such extended social networks. In this study, we move beyond core networks and explain individual variation in the extended social network size among youth. We use survey data of Dutch adolescents (N = 5,921) and use two state-of-the-art measurements to compute extended network sizes: network scale-up methods through Bayesian modeling and the observed number of contacts on Facebook. Among both measurements, we find that extended networks are larger among ethnic majority members, girls, and those who often engage in social foci. This highlights a crucial role for preferences and opportunity in the genesis of extended networks. Additionally, we find that differences between both network sizes (scale-up and Facebook) are smaller for girls and higher educated. We discuss the implications of these findings and suggest directions for future research.

scholarly journals Seasonal and spatial shifts in feral cat predation on native seabirds vs. non-native rats on Mikura Island, Japan

2020 ◽  
Author(s):  
Sarara Azumi ◽  
Yuya Watari ◽  
Nariko Oka ◽  
Tadashi Miyashita
Keyword(s):  
Native Species ◽  
Control Strategies ◽  
Interspecific Interactions ◽  
Rattus Rattus ◽  
Large Body ◽  
Effective Control ◽  
Alternative Prey ◽  
Feral Cat ◽  
Feral Cats ◽  
Invasive Predators

Abstract Understanding how invasive predators impact native species is essential for the development of effective control strategies, especially in insular environments where alternative non-native prey species exist. We examined seasonal and spatial shifts in diet of feral cat Felis silvestris catus focusing on the predation on native streaked shearwaters, Calonectris leucomelas, and introduced rats, Rattus rattus and R. norvegicus, which are alternative prey to shearwaters, on Mikura Island, Japan. Streaked shearwaters breed at low elevations on the island from spring to autumn, whereas rats inhabit the island throughout the year, which makes them an alternative prey when native shearwaters are absent. Fecal analysis revealed that feral cats dramatically shifted their diets from introduced rats in winter to streaked shearwaters in seabird-season in low elevation areas of the island, while cats preyed on rats throughout the year at high altitudes on the island. This finding suggests that feral cats selectively prey on shearwaters. This is probably because of their large body size and less cautious behavior, and because introduced rats sustain the cat population when shearwaters are absent. The number of streaked shearwaters killed was estimated to be 313 individuals per cat per year, which represents an indication of top-down effects of feral cats on streaked shearwaters. Further studies on the demographic parameters and interspecific interactions of the three species are required to enable effective cat management for the conservation of streaked shearwaters on this island.

scholarly journals Blakiston’s Fish-owl Bubo blakistoni and logging: Applying resource selection information to endangered species conservation in Russia

2015 ◽  
Vol 26 (2) ◽  
pp. 214-224 ◽  
Author(s):  
JONATHAN C. SLAGHT ◽  
SERGEI G. SURMACH
Keyword(s):  
Protected Area ◽  
Resource Selection ◽  
Agricultural Development ◽  
Species Conservation ◽  
Biosphere Reserve ◽  
Road Construction ◽  
Home Ranges ◽  
Area Network ◽  
Protected Area Network ◽  
North East

SummaryBlakiston's Fish-owl Bubo blakistoni is classified as ‘Endangered’ by IUCN; this species is associated with riparian old-growth forests in north-east Asia, a landscape threatened by a variety of impacts (e.g. logging, agricultural development, human settlement). We examined a 20,213 km2 study area in Primorye, Russia, and assessed the ability of the protected area network to conserve Blakiston's Fish-owls by analysing resource selection of radio-marked individuals. Based on resource selection functions, we predicted that 60–65 Blakiston's fish-owl home ranges could occur within the study area. We found that the protected area network within our study area contained only 19% of optimal Blakiston's fish-owl habitat and contained only eight potential home ranges (five of these within a single protected area—Sikhote-Alin Biosphere Reserve). We also found that 43% of optimal Blakiston's Fish-owl habitat was within current logging leases; lands capable of supporting habitat equivalent to 24 home ranges. The remaining optimal habitat (38%) was on federal land and potentially contained 28–33 Blakiston's Fish-owl home ranges. The current protected area network, by itself, is not sufficient to conserve the species because relatively few home ranges are actually protected. Therefore, outside of protected areas, we recommend protecting specific locations within potential home ranges that likely contain suitable nest and foraging sites, maintaining integrity of riparian areas, modifying road construction methods, and closing old and unused logging roads to reduce anthropogenic disturbance to the owls and the landscape.

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