Amir Arnon

Mr. Amir Arnon

orcid

Research Focus & Metrics

Academic Career Length

20Years (2007-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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6 May 2011 in Israel Journal of Ecology and Evolution
Verified
Journal Article
Closed access
AAAmir Arnon
Amir Arnon
Tal SvorayTal Svoray
Tal Svoray
EUEugene David Ungar
Eugene David Ungar
Sustainable management of heterogeneous grazing systems requires better understanding of the spatial dimension of grazing ecology. We deployed animal-borne GPS devices to map the daily foraging excursions of a shepherded flock of 200 goats under traditional Bedouin management, on a study site in the semiarid region of the northern Negev, Israel. A total of 88 daily foraging excursions were mapped during the herbaceous growing seasons of 2002 and 2003, and the spatial dimension was analyzed with GIS tools. A typical foraging excursion lasted 5.5 h, during which the flock moved across the landscape at an average speed of 0.3 m/s (1.1 km/h) and traveled 5.4 km. The foraging route was highly elongated in shape and reached a distance of 1.5 km from the night corral. Flock movement speed was affected significantly by distance from the night corral, being greatest at shortest and longest distances. Speed decreased with increasing slope angle and differed between aspects. The frequency of flock presence across the study site deviated significantly from random with respect to aspect but not to slope angle and distance from the corral. The effect of aspect changed slightly between the study years. The product of daily distance traveled and flock path width yielded a rate of area coverage of 0.122 km2per day. The average amount of herbage dry matter removed on any one pass of the flock is therefore in the order of just a few grams per square meter. The use of the area available to the flock was highly non-uniform, which suggests that better planning of grazing management could mitigate negative effects of grazing.

1 December 2007 in Israel Journal of Plant Sciences
Verified
Journal Article
Closed access
AAAmir Arnon
Amir Arnon
EUEugene D. Ungar
Eugene D. Ungar
Tal SvorayTal Svoray
Tal Svoray
MSMoshe Shachak
Moshe Shachak
JBJoshua Blankman
Joshua Blankman
APAvi Perevolotsky
Avi Perevolotsky

12 May 2021 in Remote Sensing
Verified
Journal Article
Open access
PDF file
Serge Yan LandauSerge Yan Landau
Serge Yan Landau
IIIdo Isler
Ido Isler
LDLevana Dvash
Levana Dvash
BSBenny Shalmon
Benny Shalmon
AAAmir Arnon
Amir Arnon
DSDavid Saltz
David Saltz
The re-introduction paradigm is that Arabian Oryx (Oryx leucoryx) herds adjust the size of their home ranges depending on the availability of vegetation, which is directly related to rainfall. In Israel, Arabian oryx were released in two hyper-arid sites: the Arava Valley and in the Paran wilderness, belonging to the Sudanese and the Saharo–Arabian biogeographic zones, respectively. While post-release survival was similar in both, reproductive success in the Paran wilderness reintroduction site was extremely low, resulting in an acute decline of the reintroduced population over time. The hypothesis that impaired nutrition might be associated with this finding was assessed with near-infrared spectroscopy (NIRS)-aided chemistry of monthly sampled fecal pellets, used as remote sensing evidence of ingested diets, throughout a year. Fecal nitrogen (FN), used as an estimate of nutritional status, was consistently higher in the Arava. Grass was never the sole or even a major dietary component. The dietary contribution of tannin-rich browse was high and steady all year-round in the Arava and increased steadily in Paran from winter to summer, corresponding to the period of availability of Acacia raddiana pods in both regions. The oryx in Paran had a home-range that was ten-fold, compared to the Arava, suggesting less feed availability. Acacia browsing may mitigate the effects of temporal variance in primary production. Under such conditions, oryx should be preferably released in areas that support significant acacia stands.

25 June 2024 in People and Nature
Verified
Journal Article
Open access
YZYuval Zukerman
Yuval Zukerman
AAAmir Arnon
Amir Arnon
URUri Roll
Uri Roll
OBOded Berger‐Tal
Oded Berger‐Tal
People's recreational activities in nature are essential to promote wildlife conservation. The interplay between humans and the environment is complex, as the presence of humans may impact wildlife both directly and by altering species interactions. Thus, conservation management in protected areas where people frequently interact with wildlife is challenging. We investigated the combined impact of different recreational activities of varying intensity, along with environmental and temporal factors, on the activity of the endangered mountain gazelle (Gazella gazella) and its predator, the golden Jackal (Canis aureus) in Ramat Hanadiv Nature Park—a protected area in northern Israel. We placed 109 camera traps in gazelles' activity centres over 5 years. We analysed the activity patterns of both species and how these patterns were affected by visitor activity. We found that gazelles became more nocturnal in areas with higher visitor activity, which led to greater overlap in their activity periods with golden Jackals. Both species were less active when there were more visitors in the park, but jackals were more attracted to disturbed areas, while gazelles avoided them. Furthermore, we found that gazelles' activity was primarily affected by visitor activity compared to environmental factors, study year or predator activity. Policy implications. We show direct and indirect effects of visitors on a predator–prey system and highlight the importance of understanding these impacts to manage protected areas and support human–wildlife coexistence. Read the free Plain Language Summary for this article on the Journal blog.

24 October 2021 in Remote Sensing
Verified
Journal Article
Open access
PDF file
AAAmir Arnon
Amir Arnon
Serge Yan LandauSerge Yan Landau
Serge Yan Landau
Ido IzhakiIdo Izhaki
Ido Izhaki
DMDan Malkinson
Dan Malkinson
YLYaniv Levy-Paz
Yaniv Levy-Paz
GDGuy Dovrat
Guy Dovrat
The populations of the endangered mountain gazelle (Gazella gazella), which inhabit large parts of Israel, across various ecosystems and climatic conditions, shrunk drastically over the last decades. To date, data on gazelle nutrition, how these relate with individual characteristics and respond to seasonal and environmental changes, have not been available. We analyzed 110 samples from gazelle rumen contents collected throughout the country from occasional fatalities, mainly roadkills, and tested the feasibility of using them for near-infrared spectrometry (NIRS) calibrations. Although NIR calibrations for crude protein, in vitro dry matter digestibility, and ash were reasonable, we found that using calibrations based on local forage and feed plant species performed better, and used these to estimate several nutritional constituents in gazelle rumens, using NIRS. We tested how constituents relate to the sex, age-class, and weight of the individual gazelle, and to season and ecosystem type, and found that season plays a major role in gazelle nutrition. Winter is the most propitious season, when crude protein, ash and digestibility are highest, and acid detergent fiber (ADF), neutral detergent fiber (NDF), and the carbon to nitrogen (C:N) ratio are lowest. Autumn, being the harshest season, mirrors winter conditions, and summer and spring show intermediate levels. Yet the relative changes between seasons were mild: about 30%, for crude protein, digestibility, and ash, and 14–22% for ADF, NDF, and C:N ratio. Ecosystem type affected several constituents, and nutrition was slightly better in Mediterranean than in dry ecosystems. Gazelle sex, weight, and age-class had minor effects on nutrition. Overall, it seems that the adaptation of gazelles to their environment is germane to keeping relatively steady nutrition throughout the year. Our results, which do not show a dramatic decline in the quality of gazelle nutrition during any season or among the climatic regions that were studied, suggest that nutrition is not a major driver of the survival of gazelles in the populations surveyed.

30 January 2025 in Animal Conservation
Verified
Journal Article
Open access
AAAmir Arnon
Amir Arnon
TWTorsten Wronski
Torsten Wronski
DMDan Malkinson
Dan Malkinson
IIIdo Izhaki
Ido Izhaki
MDMiranda Davis
Miranda Davis
A major side effect of urbanization is the increased availability of food for wildlife in peri‐urban areas. Most research has focused on highly adaptive exploiter species that thrive under such conditions, overlooking avoider species, which are often predated upon by exploiters. Moreover, peri‐urban areas are often grazed by livestock, mainly to reduce the frequency and intensity of fires, a practice that can also adversely affect vulnerable wildlife species. We examined the long‐term effects of excess food provided to discourage exploiter species, namely golden jackal ( Canis aureus ) and wild boar ( Sus scrofa ), from foraging on farmland and in human residencies. Both species prey on endangered mountain gazelles ( Gazella gazella ) in our peri‐urban study area, which is nested within a mosaic of settlements and agricultural lands in Mediterranean Israel. Because the park is routinely subjected to seasonal cattle ranching, we included cattle stocking rate (mean ± SD: 51.77 ± 18.21 cow grazing days/ha) as an alternative factor, into our analysis. We used Generalized Linear Mixed Models to analyze an extensive dataset, comprising 724 surveys conducted over 17 years, and modeled gazelle encounter rates in response to excess food and cattle ranching, while controlling for environmental factors. Our results suggest that anthropogenic excess food through diversionary feeding led to decreasing gazelle densities, probably through increased predation by exploiter species. When diversionary feeding ceased after 12 years, gazelle encounter rates increased. We argue that this increase corresponds to population recovery, although it could be consistent with alternative mechanisms such as altered space‐use and movement patterns. To conserve vulnerable and endangered wildlife species in urban and peri‐urban areas, managers should reduce the availability of anthropogenic food for predators and scavengers. Furthermore, moderate cattle ranching (i.e., seasonal with low stocking rates) could mitigate potential adverse impacts of cattle ranching on mountain gazelle populations.