Literature DB >> 35482714

Short duration overnight cattle kraaling in natural rangelands: Does time after kraal use affect their utilization by wildlife and above ground grass parameters?

Rangarirai Huruba1,2,3, Servious Nemera1, Faith Ngute1,2, Meshack Sahomba2, Peter J Mundy1, Allan Sebata1, Duncan N MacFadyen3.   

Abstract

In east and southern Africa some private ranch owners are corralling (hereafter kraaling) cattle overnight for short periods (for example, seven days) in natural rangelands to create nutrient enriched hotspots which are attractive to large herbivores. However, the effect of season and time after kraal use (alt. age of nutrient enriched hotspots) on large herbivore use of these sites has not been examined. We collated the number of large herbivore sightings per day from camera traps during wet, early and late dry season in nutrient enriched hotspots of varying ages (1, 2, 3 and 4 years) and surrounding vegetation. In addition, above ground grass biomass and height in nutrient enriched hotspots was compared to that of the surrounding vegetation. Furthermore, we tested if repeated grazing in nutrient enriched hotspots stimulated grass compensatory growth. Large herbivore use of nutrient enriched hotspots was similar during wet, early and late dry season. Time after kraal use had a significant effect on mixed feeders (impala and African savanna elephant) utilization of nutrient enriched hotspots but not grazers (zebra and warthog) and browsers (giraffe and greater kudu). Both impala and African savanna elephants mostly used nutrient enriched hotspots one year after kraal use. Aboveground grass biomass and height were higher in surrounding vegetation than in nutrient enriched hotspots. Repeated clipping (proxy for grazing) resulted in compensatory aboveground grass biomass in nutrient enriched hotspots, which declined with time after kraal use. We concluded that nutrient enriched hotspots created through short duration overnight kraaling were important foraging sites for large herbivores.

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Year:  2022        PMID: 35482714      PMCID: PMC9049567          DOI: 10.1371/journal.pone.0248795

Source DB:  PubMed          Journal:  PLoS One        ISSN: 1932-6203            Impact factor:   3.752


Introduction

In African savanna ecosystems availability of nutritive forage is important for both domestic and wild herbivores. Old cattle bomas or corrals (also referred to as glades) are considered important nutrient hotspots in east and southern Africa [1-5]. Large herbivores forage in old bomas and also make use of their openness to seek refugee against predators [6]. The use of bomas to pen cattle overnight alters the ecosystem functions through redistribution of nutrients within the terrestrial ecosystem [7]. Large herbivores forage from the surrounding landscape and deposit nutrients in bomas as dung and urine overnight [8,9], resulting in translocation of nutrients. Repeated use of old bomas by large herbivores keeps them nutrient (particularly nitrogen and phosphorus) enriched and productive through dung and urine addition [10]. Nitrogen is mostly recycled as urine and phosphorus through dung deposition [11]. Some private ranch owners in east and southern Africa are now corralling (hereafter kraaling) cattle overnight for short periods (for example, seven days) in natural rangelands to create nutrient hotspots (hereafter nutrient enriched hotspots) similar to old bomas [1-4]. Although previous studies have reported preferential use of old bomas by wildlife [12-14], few studies have monitored the use of nutrient enriched hotspots by wildlife (but see [1]). Large herbivores can be classified into three feeding guilds viz. grazers, mixed feeders and browsers [15]. Within these feeding guilds large herbivores show variation in their adaptations to the quality of forage. For instance, Burchell’s zebra (Equus quagga burchelli) is a large grazer tolerant to fibrous diets, warthog (Phacochoerus africanus) is a small grazer intolerant of fibrous diets, impala (Aepyceros melampus) is a highly selective medium size mixed feeder, African savanna elephant (Loxodonta africana africana) is a less selective large mixed feeder, while giraffe (Giraffa camelopardalis giraffe) and greater kudu (Tragelaphus strepsiceros) are large obligate browsers [16,17]. Monitoring the use of nutrient enriched hotspots by large herbivores in the three feeding guilds is important in understanding the impacts of manipulating rangelands through short duration overnight cattle kraaling. The use of nutrient enriched hotspots by large herbivores in African savanna ecosystems that are characterized by distinct seasonality (wet and dry season) is expected to vary with season. Generally, grass is green and nutritious during wet season, but brown and less nutritious during dry season, influencing large herbivore foraging decisions. However, in nutrient enriched hotspots repeated grazing stimulates grass resprouting even in the dry season if there is adequate soil moisture. Thus, the differences in nutritive value of grass between wet and dry season is expected to influence use of nutrient enriched hotspots. For instance, large herbivores are expected to use nutrient enriched hotspots and surrounding landscape similarly during the wet season but to predominantly use the former during the dry season. Mayengo et al. [18] observed that grass resprouting resulted in preferential use of grazing lawns during the dry season. In southern Africa the wet season occurs between November and April, while the dry season is between May and October. Soil nutrients in nutrient enriched hotspots decline with time after kraal use [19]. For example, soil nutrients are highest within twenty-four months of kraal use and thereafter decline (Huruba unpublished data). The loss of soil nutrients with time after kraal use results in a decrease in grass quality leading to a decline in the use of nutrient enriched hotspots by grazers [1-3]. Grass nutrient quality influences the selection of foraging patches by grazers [20]. Thus, grazer use of nutrient enriched hotspots is expected to be high within two years of kraal use and thereafter decline with time. However, a positive grass-herbivore feedback loop and continued nutrient deposition through dung and urine could maintain high grass nutrient content long after kraal use. The effect of time after kraal use on the utilization of nutrient enriched hotspots by large herbivores needs to be investigated to better understand the benefits of this practice of rangeland manipulation. Above ground grass biomass and height in nutrient enriched hotspots is regulated by two factors, viz. soil nutrient content and large herbivore grazing. Grass responds to improved soil fertility through rapid growth. However, attraction of grazers to nutrient enriched hotspots, in response to availability of abundant and nutritive grass [21,22], is expected to result in intense grazing, leading to reduced aboveground grass biomass and height. The highest above ground grass biomass in nutrient enriched hotspots is recorded just after the first rains post kraaling as soil nutrients are at their peak, and thereafter decline with time after kraal use [2]. However, grazing intensity also regulates above ground grass biomass and height. In order to determine the effect of age of nutrient enriched hotspots on above ground grass biomass and height the amount of grass cropped by large herbivores needs to be measured. Impalas select short, low fiber grass which is highly digestible [22], while zebras select foraging patches with high aboveground grass biomass to achieve high digestive fill, because as hindgut fermenters they have a fast digesta passage rate [23]. However, zebra and other equids consume both short and tall grass to balance between forage quality and quantity [24]. For example, zebra have narrow muzzle considered well suited for clipping tall grasses [25]. Grass height influences herbivore habitat use [26]. Repeated grazing creates a positive herbivore-grass feedback loop that maintains high plant nutrient levels [27]. Grass resprouts are rich in nutrients and result in repeated grazing [3,28]. Nutrient enriched hotspots are subjected to repeated grazing which in the long term could result in grass failing to compensate lost biomass [29]. The ability of grass to compensate lost biomass under repeated grazing needs to be determined to better understand the effect of creating nutrient enriched hotspots in rangelands. Although repeated grazing is stimulatory to growth [30], grass responds through under-, partial- or over-compensation of lost foliar tissue [28]. Generally, most grass either under or equally- compensate the lost biomass because grazing results in loss of photosynthetic material, limiting the ability of the plants to photosynthesize [31]. Grass regrowth in nutrient enriched hotspots benefit from enhanced soil fertility due to dung and urine deposition [32,33]. In this study we investigated if repeated grazing resulted in compensatory aboveground grass biomass in nutrient enriched hotspots of different ages. The use of nutrient enriched hotspots by large herbivores can be studied using camera traps as they are cost‐effective, efficient and non‐intrusive [12-14]. Camera traps can be used to determine spatial and temporal use of foraging resources by large herbivores [16]. For example, Young et al. [32] used camera traps to study forage selection by grazers in Kruger National Park. The use of foraging resources by large herbivores can be influenced by their abundance. Hence, large herbivore abundance need to be related to the number of sightings in camera traps to calculate relative abundance indices to ascertain if the use of nutrient enriched hotspots is affected by population. The probability of sighting animals in camera traps is strongly influenced by their population [29]. We studied the use of nutrient enriched hotspots of varying ages (1, 2, 3 and 4 years after kraal use) by six large herbivores of different sizes (zebra, warthog, impala, African savanna elephants, giraffe and greater kudu) and feeding guilds (grazers–zebra and warthog; mixed feeders–impala and African savanna elephant; and browsers–giraffe and greater kudu) during different seasons (wet, early dry and late dry season). We collated the number of large herbivore sightings in nutrient enriched hotspots from camera trap photographs during the wet (January), early dry (June) and late dry (October) season. In addition, above ground grass biomass and height were measured and related to grazer sightings. Furthermore, we carried out an experiment on simulated grazing to determine the response of grass growth to repeated (three times during growth season) clipping. We tested the following hypotheses: 1) season affects use of nutrient enriched hotspots by large herbivores, 2) age of nutrient enriched hotspots affects its use by large herbivores, 3) aboveground grass biomass and height varies with time after kraal use 4) repeated grazing result in compensatory aboveground grass biomass. This study was conducted at Debshan, a mixed cattle-wildlife ranch, located in central Zimbabwe.

Materials & method

Study site

Debshan ranch is located in central Zimbabwe (29°13′E, 19°36′S; 1230m elevation) (Fig 1). It is a mixed cattle-wildlife ranch that covers an area of 800 km2 and supports a diversity of large mammal species that include impala, Burchell’s zebra, warthog, African savanna elephant, northern giraffe and greater kudu. The study area is characterized by a catenal vegetation pattern, with most areas consisting of grassed bushland with patches of Miombo woodland [34]. The dominant woody species is Acacia karroo Hayne with the major grass species being Hyparrhenia filipendula (Hochst.) Stapf., Eragrostis curvula (Schrad.) Nees., Heteropogon contortus (L.) Roem. & Schult., Bothriochloa insculpta (Hochst. Ex A. Rich.), Digitaria milanjiana (Rendle) Stapf., and Panicum maximum Jacq. Mean annual rainfall is 612 mm, with a rainy season that runs from November to March and a dry season from April to October [34]. Mean annual temperature is 22.6°C, with October (31.4°C) the hottest month and July the coldest (8.5°C).
Fig 1

Debshan ranch location showing camera trap positions.

Creation of nutrient enriched hotspots

The short duration overnight cattle kraaling system which created the nutrient enriched hotspots (alt. previously kraaled sites) was introduced to Debshan ranch in 2012. A herd of cattle (approximately 400) is kept overnight in a kraal (70m by 100m) set up in the rangelands for seven days before being moved to a new location. The kraal is made of heavy, steel posts and thick canvas sheeting and is 1.5m high [2]. Metal poles and wire cable are used to keep the boma canvas sheeting in place. Sites for placement of kraals are randomly selected and no trees are cut. The minimum distance between any two kraals is approximately two km. The cattle are guarded by herders who sleep in portable houses adjacent to each kraal overnight to protect them from predators. During daylight hours, herders direct cattle to grazing areas and drinking points close to the kraals. The kraals are used once for a period of seven days and have water supplied in a trough.

Camera traps setting

We deployed Cuddeback Attack/Attack IR digital scouting cameras (n = 11), Cuddeback C (modular) and E model cameras (n = 25) (Cuddeback Trail Camera company, India) infrared camera traps at eighteen locations in nutrient enriched hotspots (alt. previously kraaled sites) of varying ages (1, 2, 3 and 4 years) and control sites in surrounding vegetation at Debshan ranch between January and October 2017 (Fig 1). Three kraals were randomly selected for each year treatment with each having a control marked 300m away. Each kraal replicate and control site had two cameras. The cameras were mounted on tree trunks at one meter above the ground to detect medium- to large-bodied mammals [35]. Cameras were set for pictorial (single capture/minute) data capture for diurnal and nocturnal animal at a trigger speed interval of 60 seconds and each image displayed date (dd/mm/yy), time (hh:mm) and camera number(ID). Secure Digital (SD) memory cards and non-rechargeable batteries were replaced at two week interval. The pictorial data was downloaded from the SD cards and stored in folders labeled according to kraal age. Microsoft Excel version 2016 was used to store the photographic data with the following details: camera location (kraaled or unkraaled area), camera unit identifier, date (dd/mm/yy), time (hours, minutes) and animal species. Data collection was done in January (n = 30 days), June (n = 30 days) and October (n = 30 days) 2017. The number of animal sightings of each large herbivore species during each period was recorded from the camera trap data and expressed as number of animal sightings per day. All successive photographs of a species at the same camera were treated as independent if ten minutes passed with no captures of the particular species [36]. Camera trapping is non-intrusive and effective in studying large herbivore spatial and temporal use of habitats [37].

Aerial census data

Aerial censuses are conducted annually at Debshan ranch using a helicopter during July-August. Data for the year 2017 is presented in this study and used to calculate sighting indices for the six large herbivores studied.

Sighting indices

Sighting indices were calculated using the formula:

Estimates of aboveground grass biomass cropped by grazers

We set up four chicken wire mesh (2 cm diameter holes) herbivore exclusion movable cages (1m × 1m × 1 m) in each nutrient enriched hotspot (alt. previously kraaled site) and surrounding vegetation to estimate aboveground grass biomass cropped by grazing herbivores. The cages were kept in the same position during the growth season (October 2016 to May 2017). The difference in aboveground grass biomass inside and outside the movable cages was assumed to represent grass cropped by the grazing herbivores [38]. Aboveground grass biomass both inside and outside the movable cages was clipped using a clipper, air dried, before oven drying at 60°C for 48 hours and then weighed. All the aboveground grass inside the movable cage was clipped to ground level. Cropped aboveground grass biomass was then calculated as the difference between aboveground grass biomass inside and outside the mobile cages. Grass height was also measured in each sampling site using a tape measure to the nearest mm. To test if repeated grazing results in compensatory aboveground grass biomass we clipped grass inside movable cages three times during the growth season and compared with aboveground grass biomass in a single clipping at the end of the growth season. Grass was clipped to ground level on each occasion. Aboveground grass biomass inside movable cages located in nutrient enriched hotspots (alt. previously kraaled sites) of different ages (1, 2, 3 and 4 years after kraal use) were clipped three times at twenty-eight day intervals from the beginning of the growth season (28/01/2017) (1st clipping), peak of the growth season (25/02/2017) (2nd clipping) and at the end of the growth season (25/03/2017) (3rd clipping). The aboveground grass biomass removed at each of the three clippings was recorded and the sum for all the clipping calculated. Compensatory aboveground grass biomass (gm-2) was calculated using the formula: total aboveground grass biomass for all three clippings–aboveground grass biomass clipped once at the end of growth season.

Statistical analysis

A total of 2833 camera images captured during the study period (90 days) were used for analysis of number of wildlife sightings [wet (January): n = 324; early dry (June): n = 874; late dry season (October): n = 1635]. The wildlife sightings were expressed as number of sightings per day to allow comparison of data for the three periods (wet, early dry and late dry season) as the number of camera trap images varied with season. All data were tested for homogeneity of variance and normality using Levene statistics and Shapiro-Wilk test, respectively prior to statistical analyses. The effect of season (wet, early dry and late dry) and age of kraal (no kraaling, one, two, three and four years after kraaling) on number of wildlife sightings per day (proxy for use of nutrient enriched hotspots) were tested using one way analysis of variance. Above ground grass biomass, cropped grass biomass, clipped grass biomass and compensatory grass growth among the different aged kraal sites (no kraaling, one, two, three and four years after kraaling) were also compared using one way analysis of variance. The sighting index for the six wildlife species (zebra, warthog, impala, African savanna elephants, giraffe and greater kudu) were compared using one way analysis of variance. Where differences among treatments were significant Tukey’s HSD was used for pair-wise post hoc comparisons. Burchell’s zebra and warthog (grazers) number of sightings per day were related to aboveground grass biomass and height using Pearson square correlation. Sighting index was also related to wildlife population using Pearson square correlation. All data analysis was carried out using IBM SPSS 16.

Results

Zebra, warthog, impala, African savanna elephants, giraffe and greater kudu had large number of sightings per day in the camera traps to be used as representative species for the three feeding guilds (grazers, mixed feeders and browsers). Zebra and warthog are grazers, impala and elephants mixed feeders and giraffe and greater kudu obligate browsers. Other wildlife species with low numbers sighted in the camera traps were hare (Lepus capensis), common duiker (Sylvicapra grimmia), and steenbuck (Raphicerus campestris). For each of the six species, there were no significant differences in sightings across the three seasons (early, early dry and late dry) (Burchell’s zebra: F2,9 = 1.45, p = 0.285; warthog: F2,9 = 2.40, p = 0.146; impala: F2,9 = 0.72, p = 0.511; African savanna elephant: F2,9 = 0.02, p = 0.899; giraffe: F2,9 = 0.08, p = 0.926; greater kudu: F2,9 = 0.24, p = 0.795) (Fig 2). Impala (F4,10 = 11.06, p = 0.001) and African savanna elephant (F4,10 = 153.45, p < 0.001) sightings per day significantly varied with time after kraal use (alt. age of nutrient enriched hotspots), while there were no significant differences for Burchell’s zebra (F4,10 = 2.80, p = 0.09), warthog (F4,10 = 1.66, p = 0.24), giraffe (F4,10 = 2.11, p = 0.15) and greater kudu (F4,10 = 2.39, p = 0.12) (Fig 3). Impala mostly used nutrient enriched hotspots one and four years after use, while African savanna elephant mostly preferred to use nutrient enriched hotspots one year after kraaling.
Fig 2

Mean (±SE) number of wildlife sightings per day during three periods (wet, early dry and late dry season) in nutrient enriched hotspots.

Similar letters show that there were no significant differences among the treatments.

Fig 3

Mean (±SE) number of wildlife sightings per day in nutrient enriched hotspots of varying ages.

Similar letters show that there were no significant differences among the treatments.

Mean (±SE) number of wildlife sightings per day during three periods (wet, early dry and late dry season) in nutrient enriched hotspots.

Similar letters show that there were no significant differences among the treatments.

Mean (±SE) number of wildlife sightings per day in nutrient enriched hotspots of varying ages.

Similar letters show that there were no significant differences among the treatments. Aboveground grass biomass was highest in surrounding vegetation (unkraaled sites) (F4,20 = 1167, p < 0.001), with most aboveground grass biomass cropping occurring in the three year old nutrient enriched hotspots (F4,20 = 112.98, p < 0.001) (Fig 4). Grass was tallest in surrounding vegetation (unkraaled sites) (F4,20 = 407.13, p < 0.001; Fig 5). Zebra and warthog sightings were not significantly correlated to aboveground grass biomass (zebra: r = 0.54, p = 0.34, n = 5; warthog: r = - 0.68, p = 0.21, n = 5) and grass height (zebra: r = 0.57, p = 0.31, n = 5; warthog: r = - 0.76, p = 0.14, n = 5). Aerial census counts at Debshan ranch in 2017 showed that impala and giraffe were the most and least abundant wildlife species respectively (Fig 6). Giraffe had the highest sighting index (F5,18 = 7.02, p = 0.001; Fig 7). Sighting index was not significantly correlated to wildlife population (r = 0.10, p = 0.85, n = 6). Repeated grass clipping (proxy for grazing) resulted in compensatory above ground grass biomass, with the highest in the one year after kraal use sites (Table 1).
Fig 4

Mean (±SE) aboveground and cropped grass biomass at nutrient enriched hotspots of different ages.

Different letters (a, b, c and d—for aboveground grass biomass; and A, B, C, D—for cropped aboveground grass biomass) show differences in the treatments.

Fig 5

Mean (±SE) grass height in nutrient enriched hotspots of different ages.

Similar letters show that there were no significant differences between the treatments.

Fig 6

Number of wildlife at Debshan ranch in 2017.

Fig 7

Mean (±SE) sighting index for six wildlife species.

Similar letters show that there were no significant differences between the treatments.

Table 1

Mean (±SE) aboveground grass biomass (gm-2) in cages clipped once and repeatedly (three times) in previously kraaled sites of different ages.

Clipped onceRepeated clippingCompensatory growth
1st clipping2nd clipping3rd clippingTotal for repeated clipping
1 year after kraal use2 years after kraal use3 years after kraal use4 years after kraal use248.40b ± 4.46252.40b ± 3.75287.40a ± 3.33255.20b ± 4.19F3,16 = 20.54,p < 0.001379.20a ± 2.85331.20b ± 15.99281.60c ± 2.20205.00d ± 1.61F3,16 = 81.55,p < 0.001133.80b ± 1.69155.40a ± 1.29131.60b ± 1.62112.00c ± 0.95F3,16 = 152.58,p < 0.00185.20a ± 1.7772.60b ± 0.9371.05b ± 2.5237.00c ± 2.10F3,16 = 116.88,p < 0.001599.20a ± 2.08535.20b ± 1.83497.40c ± 1.81353.00d ± 4.36F3,16 = 1453.00,p < 0.001351.20a ± 3.31274.20b ± 1.66209.40c ± 2.58101.00d ± 1.58F3,16 = 1964.00,p < 0.001

Mean (±SE) aboveground and cropped grass biomass at nutrient enriched hotspots of different ages.

Different letters (a, b, c and d—for aboveground grass biomass; and A, B, C, D—for cropped aboveground grass biomass) show differences in the treatments.

Mean (±SE) grass height in nutrient enriched hotspots of different ages.

Similar letters show that there were no significant differences between the treatments.

Mean (±SE) sighting index for six wildlife species.

Similar letters show that there were no significant differences between the treatments.

Discussion

Our research highlights the importance of using short duration overnight cattle kraaling in rangelands to create nutrient enriched hotspots attractive to wildlife in an African savanna ecosystem. We used the number of animal sightings per day from camera traps as a proxy for use of nutrient enriched hotspots and surrounding vegetation. All the six large herbivores (zebra, warthog, impala, African savanna elephants, giraffe and greater kudu) used nutrient enriched hotspots throughout the year. Previous studies have reported impala, warthog, African savanna elephants and other large herbivores as using nutrient enriched hotspots [1,3,5,12]. Our findings did not support the first hypothesis as wildlife use of nutrient enriched hotspots was similar during the wet and dry season. This suggests that the nutrient enriched hotspots provided nutritive forage and / or refugee to wildlife during both wet and dry season [1,39]. Our results showed that giraffe used nutrient enriched hotspots more than the surrounding vegetation. Conversely, Veblen and Porensky [5] reported giraffes as avoiding nutrient enriched hotspots, instead foraging in the surrounding vegetation. Our short duration overnight cattle kraaling system did not cut down trees and shrubs, with plant damage only due to cattle trampling. Traditional glades in east Africa are treeless because trees are cut down for use as kraal fences [40]. Zebra, African savanna elephants and kudu had low sighting indices, implying low use of nutrient enriched hotspots. Veblen and Porensky [5] also reported zebra as not actively seeking out high quality forage in nutrient enriched hotspots, presumably, because their large size and hind-gut fermentation allowed them to consume fibrous diets. In addition, low aboveground grass biomass in nutrient enriched hotspots, presumably, made them less attractive to zebra [4]. Our results showed that only mixed feeders use of nutrient enriched hotspot varied with time after kraal use (alt. age of previously kraaled sites). For both impala and African savanna elephant nutrient enriched hotspots were mostly used one year after kraal use. This was, presumably, due to the openness of these sites which improved impala predator detection and allowed African savanna elephant easy movement. No plausible explanation could be proffered for the impala use of four year old nutrient enriched hotspots. Previous studies reported nutrient enriched hotspots as most attractive to mixed feeders [14,41,42]. Shannon et al. [42] attributed this to the ability of mixed feeders (particularly African savanna elephants) to mainly browse while also consuming grass. Huruba et al. [1] reported cattle as breaking woody plant stems and stripping them of foliage during overnight kraaling initiating resprouting, with the resprouts attractive to impala due to high foliar nitrogen and low condensed tannin concentrations. Aboveground grass biomass and height were highest in surrounding vegetation, presumably, because of low grazing intensity. This is supported by the low aboveground grass biomass cropping in the surrounding vegetation. These results show that nutrient enriched hotspots were more intensely grazed than surrounding vegetation. Huruba et al. [2] reported warthogs as intensely grazing in nutrient enriched hotspots. Interestingly, aboveground grass biomass was not significantly correlated to zebra and warthog number of sightings per day. Generally, aboveground grass biomass and height in nutrient enriched hotspots tended to decrease with time after kraal use (see Fig 4), with cropping showing an opposite trend. Aboveground grass biomass cropped was within the range of 89 to 951 gm-2 reported in the Kruger National Park by Burkepile et al. [43]. Grass in the surrounding vegetation was moribund and unattractive even to zebra that are tolerant to fibrous diets. Zebra are tolerant to fibrous low quality grass because of their fast passage rate of forage through the gastrointestinal tract [44]. Repeated clipping (proxy for grazing) resulted in compensatory aboveground grass biomass in nutrient enriched hotspots. McNaughton [27] reported grasses in the Serengeti as over-compensating lost foliage. Compensatory aboveground grass biomass declined with time after kraal use, presumably, due to a decline in soil fertility. Improved soil fertility due to dung and urine deposition, particularly one year after kraal use, could have enhanced grass compensatory growth. Venter et al. [45] reported nutrient addition (in the form of animal dung) as increasing aboveground grass biomass. The decline in aboveground grass biomass regrowth between first and third clipping (see Table 1) was, presumably, due to resource exhaustion as a result of multiple grass resprouting in response to clipping [46]. Mudongo et al. [47] also reported a decrease in aboveground grass biomass regrowth with increasing clipping frequency. In the long-term repeated grazing could negatively affect tillering leading to the loss of the grass [48]. While previous studies have shown that grazing in the preceding growth season reduces grass productivity in the next growth season [49,50], our results show that a decline in regrowth occurs in the current season. In addition, the decline in aboveground grass biomass regrowth with repeated clipping could be attributed to reduced soil moisture availability with advancing growth season which negatively affects nutrient mineralization [51]. Soil mineralization is higher early in the growth season when soil moisture is high as compared to late in the dry season [47]. The purpose of calculating sighting index was to determine if use of nutrient enriched hotspots was influenced by wildlife abundance. Thus, the fact that sighting index was not significantly correlated to wildlife population implies that use of nutrient enriched hotspots was independent of animal abundance. For example, giraffe had the lowest population and highest sighting index, implying that there were frequent users of nutrient enriched hotspots.

Conclusion

Our findings showed that nutrient enriched hotspots created through short duration overnight cattle kraaling in natural rangelands were attractive to large herbivores. Large herbivore use of nutrient enriched hotspots was similar during wet and dry season. Time after kraal use (alt. age of previously kraaled sites) had an effect on mixed feeders (impala and African savanna elephants) use of nutrient enriched hotspots but not grazers (zebra and warthog) and browsers (giraffe and greater kudu). Aboveground grass biomass and height in nutrient enriched hotspots was lower than in surrounding vegetation due to more intense grazing by large herbivores. Repeated grazing resulted in compensatory grass growth that declined with age of nutrient enriched hotspots. The creation of nutrient enriched hotspots in rangelands improves the availability of foraging resources to large herbivores in both wet and dry season. 26 Apr 2021 PONE-D-21-06800 Short duration overnight cattle kraaling in natural rangelands: does time after kraal use affect their utilization by wildlife and above ground grass parameters? PLOS ONE Dear Dr. Huruba, Thank you for submitting your manuscript to PLOS ONE. After careful consideration, we feel that it has merit but does not fully meet PLOS ONE’s publication criteria as it currently stands. Therefore, we invite you to submit a revised version of the manuscript that addresses the points raised during the review process. The reviewers provide important feedback on this study, in particular, on clarifying the framing of the study, the details of the methodology used, and interpretation of results. 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Is the manuscript technically sound, and do the data support the conclusions? The manuscript must describe a technically sound piece of scientific research with data that supports the conclusions. Experiments must have been conducted rigorously, with appropriate controls, replication, and sample sizes. The conclusions must be drawn appropriately based on the data presented. Reviewer #1: Partly Reviewer #2: Partly ********** 2. Has the statistical analysis been performed appropriately and rigorously? Reviewer #1: Yes Reviewer #2: Yes ********** 3. Have the authors made all data underlying the findings in their manuscript fully available? The PLOS Data policy requires authors to make all data underlying the findings described in their manuscript fully available without restriction, with rare exception (please refer to the Data Availability Statement in the manuscript PDF file). The data should be provided as part of the manuscript or its supporting information, or deposited to a public repository. For example, in addition to summary statistics, the data points behind means, medians and variance measures should be available. If there are restrictions on publicly sharing data—e.g. participant privacy or use of data from a third party—those must be specified. Reviewer #1: No Reviewer #2: Yes ********** 4. Is the manuscript presented in an intelligible fashion and written in standard English? PLOS ONE does not copyedit accepted manuscripts, so the language in submitted articles must be clear, correct, and unambiguous. Any typographical or grammatical errors should be corrected at revision, so please note any specific errors here. Reviewer #1: Yes Reviewer #2: Yes ********** 5. Review Comments to the Author Please use the space provided to explain your answers to the questions above. You may also include additional comments for the author, including concerns about dual publication, research ethics, or publication ethics. (Please upload your review as an attachment if it exceeds 20,000 characters) Reviewer #1: I appreciate the opportunity to review this manuscript. The work examines wildlife visitation of abandoned cattle Kralls spanning from one- to four-year-old and also reports on above grass biomass accumulation in these heavily grazed sites. This work is of interest to a broad audience and underpins some of the benefits associated with both current and legacy effects of livestock wildlife integration in rangelands. The manuscript is fairly well written but may require some major revision before it gets to a level that is acceptable for publication. Particularly, I found the introduction not quite well done, and there are also some fundamental concerns on the design of the study. I have itemized some of these concerns below; General Comments First, the introduction section lacks of coherent flow between paragraphs. For example, I found it quite distracting switching from paragraph one (which talks about nutrient hotspots created by old cattle bomas) to paragraph 2 (which talks about effectiveness of camera trapping…. something that I actually don’t think should be presented here) to paragraph 3 (which revisits the same issues in paragraph 1) and later in paragraph 7 camera traps are revisited. Additionally, there is a lot of repetition and contradicting statements from one paragraph to another. I have pointed out some of these under specific comments below. Suffices to say, it is hard to read and follow though the introduction section as presented. Secondly and most critical, there is little or no information relating to how the cattle bomas were set up. The authors present information about the age of the various bomas; which in real sense doesn’t tell much. For example, we know the trajectory of an abandoned boma depends on many factors including; i) the amount of time it was occupied, ii) what livestock species occupied it, iii) how many individual animals were present, iv) the prevailing conditions during occupation (e.g. was is rainy or dry season), v) prevailing conditions after abandonment—which affects dung decomposition and recolonization dynamics, vi) soil type. All, the factors will affect how utilization patterns of an abandoned boma will unfold. Additionally, only get to learn under the discussion session, that creation of bomas that were used for this study did not involve cutting of trees. This is a novel aspect of this work, since most of abandoned bomas elsewhere are devoid of trees; which affects perceived predation risk. Thirdly, it is misleading to state that “few studies have monitored the use of nutrient hotspots created through kraaling cattle in temporary mobile overnight kraals by wildlife”. Indeed, a lot of work has been done on this this subject, e.g see the citations below. Instead, the authors should clarify the novel aspects of their work. Augustine, David J., Veblen, Kari E., Goheen, Jacob R., Riginos, Corinna, and Young, Truman P. 2011. "Pathways for Positive Cattle–Wildlife Interactions in Semiarid Rangelands." Smithsonian Contributions to Zoology. 55–71. https://doi.org/10.5479/si.00810282.632.55 Veblen, K. (2012). Savanna glade hotspots: Plant community development and synergy with large herbivores. Journal of Arid Environments, 78, 119–127. Donihue, C. M., Porensky, L. M., Foufopoulos, J., Riginos, C., & Pringle, R. M. (2013). Glade cascades: Indirect legacy effects of pastoralism enhance the abundance and spatial structuring of arboreal fauna. Ecology, 94(4), 827–837. Fourthly, it is not clear how successive photographs of an individual animal or a group of animals were treated. With camera traps, you often get cases of some animals hanging out on front of a camera trap, consequently triggering the camera multiple times. Where these analyzed as independent detections. If so, how about individuals that could possibly have been in the glade, but not immediately in front of a camera trap, hence fewer photographs of them taken. I know this is a thorny issue, but there are number of recommendations about deciding which of the triggers are independent detections. Some studies have set a threshold of 20min, others 30min, and even 1hr. Whatever threshold is used, it is important to be explicit about it Lastly, in addition to documenting above grass biomass accumulation and compensatory growth, the authors should also have looked at species composition. Growth strategies and response to grazing vary remarkably across different species and we also know that nutrient hotspots like these promote dominance of distinct herbaceous communities, which may actually change over time. Specific suggestions: Ln 16: delete “natural” Ln 18 (and multiple other places): “determine” has a connotation of causality inference. Replace with something like “examine) Ln 27: delete “to ascertain their use of these nutrient hotspots” Ln 35-35: would have been more interesting if this compensatory growth in the hotspots was compared with the matrix Ln 35: “Impala benefited the most….”: The fact that they used the hotspots more frequently doesn’t imply the benefited more. Why not just say: “Impala were attracted to …..” Ln 38 (and elsewhere): the conclusion about nutrients hotspots increasing rangeland heterogeneity is not supported by the data presented here. How was rangeland heterogeneity measured? Ln 49: congregate -> are attracted Ln 53: "lawns, old”: insert coma Ln 74-74: sentence not clear Lin 79: there are many studies that report attraction of herbivores to glades. Consider citing some of them here Ln 96-97: not clear what the ‘feedback loop’ is here Ln 88-104: sounds repetitive Ln 124-126: contradicts earlier statement? Ln 137: “restricts grass height” -> “maintains grass short” Ln 174-175: This study was conducted in Debshan ranch, located….. Ln 204-207: hard to understand this sentence Ln 207-208: What date was recoded here? Ln 277-278: there is no mention of there this wildlife abundance data is coming from Ln 330: the explanation as to why impala were attracted to 4yr old glades is not quite convincing: what would occasion the changes in grass and browse? Reviewer #2: Short duration overnight cattle kraaling in natural rangelands: does time after kraal use affect their utilization by wildlife and above ground grass parameters? 1. The study presents the results of original research The study investigated the use of previously kraaled sites (aged 1,2,3 and 4 years) by Burchell’s zebra and warthogs (grazers), impala and African savanna elephants (mixed feeders) and northern giraffe and kudu (browsers) during the wet season (January), early dry season (June) and late dry season (October). Camera traps were used to record large herbivore sightings in previously kraaled sites. In addition, an experiment to simulate grazing was carried out to determine the response of grass growth to repeated removal of grass biomass during the 3 stated seasons. The study was carried out at Debshan ranch, a mixed cattle-wildlife ranch in central Zimbabwe. The study presents results of original work. 2. Results reported have not been published elsewhere To the best of my efforts and checking, I confirm that the results reported in this manuscript have not been published in the peer-reviewed literature. However, it is noted that this manuscript has been deposited in the preprint server bioRxiv. PLOS accepts and supports this practice as per PLOS ONE criteria for publication #2. 3. Experiments, statistics, and other analyses are performed to a high technical standard and are described in sufficient detail. The study was conducted following the scientific method or process. The data collection methods were described and data analyzed. However, the following needs attention: - Abstract Lines 30-32: Please clarify what ‘similarly’ stand for or mean. Results showed that the 8 mammals did not use the previously kraaled sites in the same way. So, what does “similarly; mean? Introduction • Lines 68-72 This paragraph is too short and is like a hanging paragraph. Please cite more studies that have used camera traps on nutrient hotspot by wildlife. In addition, state some limitations of using camera traps and how you addressed these in your study. Include, if any, how the results of your studies were or were not affected by the use of camera traps • Line 16, 90, 91, while it may be obvious, the use of “Short duration overnight” must be clearly defined or elaborated in the study. Did “Short duration overnight” imply that the cattle were at these spots just for one night hence short duration? If yes, why not refer to these only as “Overnight?”. If cattle were kraaled for few nights at a time then should such number of nights just be stated? This needs to be made clear in the text. • Line 126-27 You refer to previously kraaled sites that are used by grazers that deposit dung and urine as “newly created” nutrient hotspots. Why do you refer to then as newly created? Why not refer to them as “nutrient enriched or recharged previously kraaled sites? I suggest this because authors asserted that kraaling adds nutrients to the soil. So, why does it now become “newly created” when it has been established already by cattle kraaling? • Line 153-154. You state that “However, the positive herbivore-grass feedback has not been widely tested, particularly in nutrient hotspots”. If authors had stated.. “has not been tested” If would indicate no testing has been done elsewhere before. However, by stating that it has not been widely tested, it suggests that it has been tested but in a limited way. If this is the case, in what limited way has this positive loop been tested? What were the outcomes and how do these inform or influence your study? Materials and methods While the materials and methods are well described in the manuscript, there are some sections that need more detailed attention. These are listed below: - Line 197 Camera traps setting • Line 199-203: Specify how many camera traps were set at each of the previously kraaled sites aged 1,2,3 and 4 years? How many replicates of the previously kraaled sites by age (1,2,3 and 4 years) were established? How many replicates of the control were established and how many camera traps were placed at control sites? Line 219 Estimates of aboveground grass biomass cropped by grazers • Line 225-226 Specify how much grass was clipped? At what height from the ground was grass cut? Did you cut the grass all the way to the ground or what? Please specify. • Line 229. To what nearest measurement was grass height recorded? • Line 231 Specify the height to which grass were clipped inside movable cages at each of the growth season? Or how close to the ground were grass clipped during each growing season? 243 Statistical analysis • Line 244: The number of wildlife sightings varied between the 3 sampling seasons i.e January, n=324), June, n=874 and October, n=1635. It is noted that there was huge variation in number sightings such that the October values were 5 times and 2 times larger than the January and June sightings respectively while the June sightings were about 3 times larger than the January values. To what extent did such variation affect the outcomes of the data analysis comparisons? How did this variance affect / influence the outcomes of the data analysis? Did you take into account of this variation and if so how? Please include such in the text. Results • Line 254-255. You state that Zebra, warthog, impala, elephant, giraffe and grater kudu were the most frequently sighted in the camera traps. The camera must have captured pictures of mammals other than the 6 study animals. Please list the other mammals apart from the 6. The ranch must surely have other mammals that came to the previously kraaled sites. • Line 256-258 Authors write….time after kraal use ‘had no significant’ effect…… .In a similar manner and for consistency authors should write …..while wildlife sightings varied significantly with wildlife species…’ [authors should similarly use the word ‘significant’ or ‘not significant’ throughout the results section and discussion where the statistical outcomes reveal so. This will ensure consistency] • Line 261. Authors should use early season, early dry season and late dry season instead of months January, June and October. • Lines 266-280 Authors refer to statistical outcomes for results plotted in Figure 3 (number of sightings) and Figure 4 (Population). o Authors must clarify or describe how the sighting was converted to population based on camera trap photos. This has not been described in the methods section. o In line 277, authors must indicate that impala and giraffe were the most and least abundant wildlife species at Debsham ranch as estimated from camera trap pictures in 2016. This is important because Camera trap method has limitations as a method or estimating abundance. o Authors therefore must state the extent to which population estimates presented in Figure 4 (line 617-618) and accurate based on how many of these mammals are present on the entire Debshan ranch? o Authors need to indicate limitations of such a method to estimate populations of mammals. • In the results and discussion authors refer to sighting index including Figure 4 (line 621). Yet this is not explicitly indicated so or referred to as such in the Materials and methods especially under statistical analysis. • In Figure 2 (line 620), Figure 3 (line 606), Figure 5 (line 621) and Figure 6 (line 631) and Figure 7 (line 637) please indicate / include the word ‘Mean’ on the Y-axis labels. Discussion • Line 302-303 Authors should state the mechanism which Bailey et al [48] suggested to assert that herbivores were able to identify patches with forage of varying nutritive value. How do herbivores identify nutritive value? How can we be sure? This important because it would contribute to understanding choices which mammals in the present study may have used to select and visit nutrient rich hotspots of previously used kraal sites • Line 308—310. Consider using the phrase ‘nutrient enriched hotspots” than ‘newly created nutrient hotspots’ when referring to these previously kraaled sites. • Line 312-319. You make reference to use of woody plants by giraffes in your study. Why did you not quantify, characterize and compare woody plants at the previously kraaled sites to enable reference to woody plants being preferred and eaten by giraffes? • Line 329-335. o While authors explained preference of impala and elephants for previously used kraal sites that were one year and four years old (only impala) , they did not explain lack of preference of use of sites that were 2 and 3 years old. Please suggest an explanation and discuss. o In line 331 authors state that impala and elephants can switch between grasses and browse depending on their nutritive quality. This in my view is a suggested possibility because the nutritive quality of the forage was not investigated or assessed; it was merely inferred. If this is so, it is inaccurate for authors to then conclude in line 332 that …. Therefore, impala and elephants were able to make choices from previously kraaled sites of varying ages depending on the quality of either grasses or browse. Authors must address this. • Line 343-347. Authors should address the issue of estimation of population of study mammals based in camera trap data raised earlier. In these 5 lines, authors have merely stated the results but have not dis used or interpreted the results neither have they made any reference to literature. What do these results mean and what contribution do these add to the use of previously kraaled sites by mammals in this study? • Line 352 and 353 In order to assert / suggest the possibility that high aboveground grass biomass may have high risks of predation from ambush-hunting predators such as lions [52] authors must indicate whether lions are present in the Debshan ranch. • Line 357-358. Authors must explain why warthogs kept aboveground biomass and grass height low in previously kraaled sites that were 3-4 years old compared to those that were 1 to 2 years old and also in general. Although authors refer to Huruba et al. [3] who reported that warthogs intensely grazed in previously kraaled sites, they did not state why? Elaborate? • Line 361 reference Burkepile et al. [53] is given the same reference number of [53] in line 363 for Groom and Harris [53] instead of [54] as indicated in the reference section. Please correct. 4. Conclusions are presented in an appropriate fashion and are supported by the data. Conclusions made are generally supported by the data except Line 385 – 386. It is not accurate to conclude that the study has showed that short duration overnight cattle kraaling in natural rangelands creates nutrient hotspots. The use of ‘nutrient’ is inferred and not an outcome of this study because nutrients at the previously kraaled sites were not measured nor quantified and compared but inferred. 5. The article is presented in an intelligible fashion and is written in standard English This statement is true for this manuscript. 6. The research meets all applicable standards for the ethics of experimentation and research integrity. Ethics of Experimentation Authors did not indicate whether they had obtained appropriate research permits and ethical clearance for this study. If they did then they must cite reference numbers for the respective permits and clearance. Publication Ethics Authors have specified their respective contributions to the study (line 397-407) 7. The article adheres to appropriate reporting guidelines and community standards for data availability. Reporting Guidelines Results were rigorously reported, as appropriate based on the type of the data collected. Data Availability Authors have presented data as expected in a scientific journal. The results of the study did not involve gene sequences etc that are deposited following set standards and practice ********** 6. PLOS authors have the option to publish the peer review history of their article (what does this mean?). If published, this will include your full peer review and any attached files. If you choose “no”, your identity will remain anonymous but your review may still be made public. Do you want your identity to be public for this peer review? For information about this choice, including consent withdrawal, please see our Privacy Policy. Reviewer #1: No Reviewer #2: No [NOTE: If reviewer comments were submitted as an attachment file, they will be attached to this email and accessible via the submission site. Please log into your account, locate the manuscript record, and check for the action link "View Attachments". If this link does not appear, there are no attachment files.] While revising your submission, please upload your figure files to the Preflight Analysis and Conversion Engine (PACE) digital diagnostic tool, https://pacev2.apexcovantage.com/. PACE helps ensure that figures meet PLOS requirements. To use PACE, you must first register as a user. Registration is free. Then, login and navigate to the UPLOAD tab, where you will find detailed instructions on how to use the tool. If you encounter any issues or have any questions when using PACE, please email PLOS at figures@plos.org. Please note that Supporting Information files do not need this step. 3 Dec 2021 We corrected and addressed comments in the manuscript. Fig1 is a map created by author using freeware software from shapefiles generated from free basemaps provided by surveyor general in the country. we have updated the funding statement in cover letter as well. Submitted filename: response to reviewers.doc Click here for additional data file. 31 Jan 2022
PONE-D-21-06800R1
Short duration overnight cattle kraaling in natural rangelands: does time after kraal use affect their utilization by wildlife and above ground grass parameters?
PLOS ONE Dear Dr. Huruba, Thank you for submitting your manuscript to PLOS ONE. After careful consideration, we feel that it has merit but does not fully meet PLOS ONE’s publication criteria as it currently stands. Therefore, we invite you to submit a revised version of the manuscript that addresses the points raised during the review process.
The reviewer has made note of additional clarification needed about the data analysis and results presented.  Please address these comments.
 
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For instructions see: https://journals.plos.org/plosone/s/submission-guidelines#loc-laboratory-protocols. Additionally, PLOS ONE offers an option for publishing peer-reviewed Lab Protocol articles, which describe protocols hosted on protocols.io. Read more information on sharing protocols at https://plos.org/protocols?utm_medium=editorial-email&utm_source=authorletters&utm_campaign=protocols. We look forward to receiving your revised manuscript. Kind regards, Wendy C. Turner Academic Editor PLOS ONE Journal Requirements: Please review your reference list to ensure that it is complete and correct. If you have cited papers that have been retracted, please include the rationale for doing so in the manuscript text, or remove these references and replace them with relevant current references. Any changes to the reference list should be mentioned in the rebuttal letter that accompanies your revised manuscript. 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Experiments must have been conducted rigorously, with appropriate controls, replication, and sample sizes. The conclusions must be drawn appropriately based on the data presented. Reviewer #1: Partly ********** 3. Has the statistical analysis been performed appropriately and rigorously? Reviewer #1: No ********** 4. Have the authors made all data underlying the findings in their manuscript fully available? The PLOS Data policy requires authors to make all data underlying the findings described in their manuscript fully available without restriction, with rare exception (please refer to the Data Availability Statement in the manuscript PDF file). The data should be provided as part of the manuscript or its supporting information, or deposited to a public repository. For example, in addition to summary statistics, the data points behind means, medians and variance measures should be available. If there are restrictions on publicly sharing data—e.g. participant privacy or use of data from a third party—those must be specified. Reviewer #1: Yes ********** 5. Is the manuscript presented in an intelligible fashion and written in standard English? PLOS ONE does not copyedit accepted manuscripts, so the language in submitted articles must be clear, correct, and unambiguous. Any typographical or grammatical errors should be corrected at revision, so please note any specific errors here. Reviewer #1: Yes ********** 6. Review Comments to the Author Please use the space provided to explain your answers to the questions above. You may also include additional comments for the author, including concerns about dual publication, research ethics, or publication ethics. (Please upload your review as an attachment if it exceeds 20,000 characters) Reviewer #1: The authors have done fairly good job in incorporating suggestions from earlier reviews, there still remains substantial challenges in how the data was analyzed and how the results are presented. First, I still don’t think the concern about how camera trap data was analyzed was adequately addressed. In their response latter, the authors state that “similar images were treated as one to avoid double counting” but there is no mention of this in the manuscript. Again, what does “similar” mean? If a camera trap captures two photographs within a period of 60 seconds, in one photograph there are three impalas and in the subsequent photograph there are five impalas; are there ‘similar images’? Essentially, multiple detections during a single short occasion are not likely to be independent and thus may contribute little information or may bias estimates. Most studies set a minimum time threshold for independent detections; e.g. all successive photographs of one individual (or species) taken within 10 mins are treated as a simple detection (photographic event). There is plenty of literature around this topic and I encourage authors to look at look at this Inferences are made about differences across herbivore guilds, in utilization of kralls. However, there are no results to support this, and the authors do not specify which of the six herbivores belongs to which guild. Ln 243-244: “general linear model (GLM) univariate” -> “univariate general linear model (GLM)”: again, why use univariate models? A more appropriate approach would have been to fist a model that includes all the variables and interactions Ln 244 “effects” -> “differences”? Ln 247: I did not see any post hoc analysis presented anywhere in the results 247-249: why just zebra and warthog? 260-261: I don’t see much value in testing the differences in detections across different wildlife species. However, if the authors choose to retain this, they should at least include multiple comparison tests and state which species were actually different Ln 262-263: rephrase for clarity e.g “For each of the six species, there were no significant differences in sightings across the three seasons [early (January), early dry (June) and late dry (October)]…..” Ln 265-267: this should be presented above ln 260-261 The authors need to resolve inconsistent use of scientific and common names in reference to different animals e.g. Ln 257-258, ln 272-273 (and elsewhere): The common practice is to give the two names the first time a species is mentioned, and subsequently refer to on one Line: 274-279: it is not clear what is being tested here. Rephrase for clarity Ln 280-284: I find these two statements, just like the most of the other statements under results section, quite confusing. Ln 285-285: how is this “evidence that most grazing occurred in the three-year-old nutrient enriched hotspots.”? In 282-283, the authors state that three-year-old kralls has the most biomass (most productive), while in 286-287, they state that one year old Kralls had the tallest grass. How is this possible? I thought biomass was correlated with grass height? Ln 287: new paragraph? 292-293: I still don’t see what value the value of comparing camera trap and aerial census data 294-295: not clear ********** 7. PLOS authors have the option to publish the peer review history of their article (what does this mean?). If published, this will include your full peer review and any attached files. If you choose “no”, your identity will remain anonymous but your review may still be made public. Do you want your identity to be public for this peer review? For information about this choice, including consent withdrawal, please see our Privacy Policy. Reviewer #1: No [NOTE: If reviewer comments were submitted as an attachment file, they will be attached to this email and accessible via the submission site. Please log into your account, locate the manuscript record, and check for the action link "View Attachments". If this link does not appear, there are no attachment files.] While revising your submission, please upload your figure files to the Preflight Analysis and Conversion Engine (PACE) digital diagnostic tool, https://pacev2.apexcovantage.com/. PACE helps ensure that figures meet PLOS requirements. To use PACE, you must first register as a user. Registration is free. Then, login and navigate to the UPLOAD tab, where you will find detailed instructions on how to use the tool. If you encounter any issues or have any questions when using PACE, please email PLOS at figures@plos.org. 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10 Mar 2022 the comments have addressed and covered in the response to reviewers letter Submitted filename: response to reviewer comments.doc Click here for additional data file. 28 Mar 2022 Short duration overnight cattle kraaling in natural rangelands: does time after kraal use affect their utilization by wildlife and above ground grass parameters? PONE-D-21-06800R2 Dear Dr. Huruba, We’re pleased to inform you that your manuscript has been judged scientifically suitable for publication and will be formally accepted for publication once it meets all outstanding technical requirements. Within one week, you’ll receive an e-mail detailing the required amendments. When these have been addressed, you’ll receive a formal acceptance letter and your manuscript will be scheduled for publication. An invoice for payment will follow shortly after the formal acceptance. To ensure an efficient process, please log into Editorial Manager at http://www.editorialmanager.com/pone/, click the 'Update My Information' link at the top of the page, and double check that your user information is up-to-date. If you have any billing related questions, please contact our Author Billing department directly at authorbilling@plos.org. If your institution or institutions have a press office, please notify them about your upcoming paper to help maximize its impact. If they’ll be preparing press materials, please inform our press team as soon as possible -- no later than 48 hours after receiving the formal acceptance. Your manuscript will remain under strict press embargo until 2 pm Eastern Time on the date of publication. For more information, please contact onepress@plos.org. Kind regards, Wendy C. Turner Academic Editor PLOS ONE 5 Apr 2022 PONE-D-21-06800R2 Short duration overnight cattle kraaling in natural rangelands: does time after kraal use affect their utilization by wildlife and above ground grass parameters? Dear Dr. Huruba: I'm pleased to inform you that your manuscript has been deemed suitable for publication in PLOS ONE. Congratulations! Your manuscript is now with our production department. If your institution or institutions have a press office, please let them know about your upcoming paper now to help maximize its impact. If they'll be preparing press materials, please inform our press team within the next 48 hours. Your manuscript will remain under strict press embargo until 2 pm Eastern Time on the date of publication. For more information please contact onepress@plos.org. If we can help with anything else, please email us at plosone@plos.org. Thank you for submitting your work to PLOS ONE and supporting open access. Kind regards, PLOS ONE Editorial Office Staff on behalf of Dr. Wendy C. Turner Academic Editor PLOS ONE
  14 in total

1.  The maximum attainable body size of herbivorous mammals: morphophysiological constraints on foregut, and adaptations of hindgut fermenters.

Authors:  M Clauss; R Frey; B Kiefer; M Lechner-Doll; W Loehlein; C Polster; G E Rössner; W J Streich
Journal:  Oecologia       Date:  2003-04-24       Impact factor: 3.225

2.  Grasses and browsers reinforce landscape heterogeneity by excluding trees from ecosystem hotspots.

Authors:  Lauren M Porensky; Kari E Veblen
Journal:  Oecologia       Date:  2011-09-21       Impact factor: 3.225

3.  Landscape-scale analyses suggest both nutrient and antipredator advantages to Serengeti herbivore hotspots.

Authors:  T Michael Anderson; J Grant C Hopcraft; Stephanie Eby; Mark Ritchie; James B Grace; Han Olff
Journal:  Ecology       Date:  2010-05       Impact factor: 5.499

4.  Relative growth rates and the grazing optimization hypothesis.

Authors:  D W Hilbert; D M Swift; J K Detling; M I Dyer
Journal:  Oecologia       Date:  1981-10       Impact factor: 3.225

5.  Influence of sward structure on daily intake and foraging behaviour by horses.

Authors:  G Fleurance; P Duncan; H Fritz; I J Gordon; M-F Grenier-Loustalot
Journal:  Animal       Date:  2010-03       Impact factor: 3.240

6.  Maximization of Aboveground Grassland Production: The Role of Defoliation Frequency, Intensity, and History.

Authors:  C L Turner; T R Seastedt; M I Dyer
Journal:  Ecol Appl       Date:  1993-02       Impact factor: 4.657

7.  Lateral diffusion of nutrients by mammalian herbivores in terrestrial ecosystems.

Authors:  Adam Wolf; Christopher E Doughty; Yadvinder Malhi
Journal:  PLoS One       Date:  2013-08-09       Impact factor: 3.240

8.  Herbaceous forage and selection patterns by ungulates across varying herbivore assemblages in a South African Savanna.

Authors:  Anna Christina Treydte; Sabine Baumgartner; Ignas M A Heitkönig; Catharina C Grant; Wayne M Getz
Journal:  PLoS One       Date:  2013-12-16       Impact factor: 3.240

9.  Camera trap placement and the potential for bias due to trails and other features.

Authors:  Joseph M Kolowski; Tavis D Forrester
Journal:  PLoS One       Date:  2017-10-18       Impact factor: 3.240

10.  The importance of nutrient hotspots for grazing ungulates in a Miombo ecosystem, Tanzania.

Authors:  Gabriel Mayengo; Alex K Piel; Anna C Treydte
Journal:  PLoS One       Date:  2020-03-30       Impact factor: 3.240

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