Maximum size of prey that a single male lion or tiger can kill

[Pckts]

(04-18-2020, 12:53 AM)Ashutosh Wrote: @Pckts, the study you quote says that the average weight of adult gaurs killed by tigers was 737.8 kilos. Does this figure include female gaurs? Because, if it does, it very well proves that tigers prey on gaurs as big as 1000 kilos as simple sexual dimorphism between the weights of male and female gaurs would give you that average figure.

Also, the incident of gaur killing the big male tiger is from kabini and was narrated by Karanth himself. What that part doesn’t tell you is that tiger was a gaur specialist. He killed many gaurs (big ones too) before one finally got him and he was a bit on the obese side apparently.

"They determined the percentage of age and sex classes killed by tigers and used published weights of each age class, to calculate the mean weight of each of the tiger's main prey species. These weights have subsequently been used in most tiger diet studies. In South‐East Asia, a new and accurate estimate of average prey weights, especially of large prey, may be especially important for estimating prey biomass in a tiger's diet because the complement of large‐ and medium‐sized prey classes (Andheria, Karanth, & Kumar, 2007) differs from South Asia. "

"This study estimated mean weights of gaur and banteng killed by tigers. These averages will help elucidate the role of these two of the largest prey species in the regional diet of tigers. Using the same approach as Karanth and Sunquist (1995), we estimated the proportion of sex and age class of gaur and banteng at tiger kill sites and obtained published weights of each age and sex class. The proportion of these size classes also provides insight into tiger predation strategies. Carbone, Pettorelli, and Stephens (2011) generalized that the prey to predator biomass ratio has a stronger impact on larger carnivores than it does on smaller carnivores. Hayward et al. (2006), Hayward, O’Brien, and Kerley (2007) refined this generality to predict the optimum prey sizes for several large carnivores; for tigers, the ratio was reported to be 1:1 (Hayward, Jedrzejewski, & Jedrzewska, 2012)."

"Using dental annuli and horn characteristics to classify age and sex of gaur and banteng, combined with published weights for these classes (Ahrestani, 2018; Hoogerwerf, 1970), enabled us to calculate the average weights of gaur and banteng killed by tigers. These weights are key to estimating the biomass of these species in the diet of tigers. Because adult male gaur are 1.3 times larger than adult male banteng, and males of both species are >3.5 times larger than Hayward et al. (2012) optimum 1:1 predator to prey ratio, we hypothesize that these species, and especially the large size classes, are approaching the maximum size limit of tiger prey. Support for this hypothesis would be (a) male tigers kill a smaller percentage of larger adult male gaur than smaller adult banteng, (b) female tigers, which average two thirds the weight of adult male tigers, kill a smaller percentage of adult males of both species compared with male tigers, and © female tigers kill fewer males of both species compared with males. It is important to note that our research does not imply prey preference (Hayward et al., 2012); we simply report size, sex, and age class of gaur and banteng killed by tigers in our study area."

"At kill sites (15 00′–15 40′ N, 99 00′–99 25′ E), we collected the lower mandible of each gaur or banteng for aging. We determined sex of adult animals based on the configuration of horns (Ahrestani, 2018). The ages of calves and juveniles were determined by teeth eruptions sequence (Dyce, Sack, & Wensing, 2009). For adult prey, we extracted the first molar from the mandible, washed the tooth in water, decalcified it in a weak acid solution (HNO3 5%), and finally rinsed it again in water to stop decalcification (Klevezal, 1996; Spinage, 1976). Each molar was then dehydrated in isopropyl alcohol, frozen, and sectioned with a microtome to create 15–20 µm longitudinal cross‐sectional slices that were mounted on a glass slide. Slices were stained with Giemsa blood and labeled; stained sections were subsequently examined at 10x magnification, and cementum annuli were counted (Figure 3). We concluded that the local single rainy season resulted in a single annuli pattern in western Thailand and confirmed this by comparing annuli data to horn patterns (Ahrestani & Prins, 2011). A single cementum annuli in tropical ungulates was first reported by Spinage (1976). We also followed Ahrestani and Prins (2011) in grouping ages into the following classes: calves (0–1 year), juveniles (>1 to 3 years), young adult (>3 to 6 years), and mature adults (>6‐years)."

"To determine mean prey size killed by tigers, we multiplied the frequency of each age class, or for adults the sex and age class, by the estimated weight of that class. Age class weights were derived from Ahrestani (2018) and Hoogerwerf (1970). Estimated mean sizes of prey species killed by tigers are used by Ackerman et al. (1984) and Chakrabarti et al. (2016) to calculate the biomass represented by a single scat of each prey species. We also compared the mean weight of gaur and banteng killed by tigers. To evaluate the hypothesis that gaur and banteng are approaching the limit of prey size killed by tigers, we conducted 3 chi‐squared tests comparing the number of kills by male and female tigers of adult male gaur and banteng."

"From June 2005 to May 2017, we visited kill sites of 24 radio—collared tigers (9 males and 15 females) and recorded a total of 82 gaur and 79 banteng kills based on carcass or skeletal remains. Of all gaur killed, 15.9% were adult males and 29.3% were adult females; adult male banteng comprised 29.1% of kills and 26.6% of kills were adult females. (Table 1). In contrast, calves composed 39% of gaur kills versus 26.6% of banteng kills. As a consequence, despite the fact gaur males were approximately 1.3 times heavier than male banteng, and gaur females were 1.1 times the weight of female banteng, the average weights of both gaur killed (397.9 kg) was less than the average weight of banteng killed (423.9 kg) (Table 1)."

"TABLE 1. Mean weights of gaur (Bos gaurus) and banteng (B. javanicus) killed by tigers based on number of kills in different sex and age classes and published weights of those classes from Ahrestani (2018) and Hoogerwerf (1970)"


For Adult Male Gaur they used a mean weight of 900kg and for Adult Male Banteng they used a mean weight of 700kg.

Based on the average sex and age class weights, and the number of kills in each class, the average weight of adult gaur kills was 737.8 kg and they composed 83.7% of the biomass of gaur killed by tigers. Similarly, the mean adult banteng killed weighted 652.2 kg and adults composed 85.6% of biomass of this species killed by tigers. Adults composed 48.8% of gaur and 79.4% of banteng killed by male tigers; whereas, adult gaur and banteng composed 41.1% and 37.8% of female kills, respectively (Table 2).

" For example, Simcharoen et al. (2018) reported that gaur and banteng, two of the largest prey that tigers consume, compose 46%–59% of the tiger's diet. However, in that study, the authors used Karanth and Sunquist’s (1995) average gaur weight of 287 kg for both gaur and banteng. Our study estimated the average weight of these species in Thailand following a similar approach to Karanth and Sunquist (1995). A reassessment of mean weight of these species killed by tigers was needed because Sunquist and Karanth's estimate was the only previous, rigorous estimate published."

Weights are estimates based on certain factors and here they explain that even if a carcass is left, it's not how much a Tiger can consume that should be reduced from the weight but it's the fact that multiple scavengers will also feast upon the prey item.

"Tigers often leave carcasses in the heat of the day to seek shade, drink water, and rest, particularly when a kill is made more open environments. Scavengers use these opportunities to feed on tiger carcasses. In contrast, if a female with large cubs kills in dense cover near water, she and her offspring are likely to remain nearby and there is little opportunity for other species to scavenge. However, neither Chakrabarti et al.’s or Ackerman et al.’s research, or previous diet studies, have adequately estimated the role of scavenging or its impact on the biomass of large prey in the tiger's diet. Camera trap photographs have documented many other species at kill sites; for example, we recently recorded three Asian water monitors (Varanus salvator) (~1.4 m long) and several wild boars (Sus scrofa) scavenging an adult banteng kill between tiger feeding bouts at HKK (unpublished data)."


Also in regards to the Kabini Male, that's no surprising to me, S. Indian Tigers are certainly Gaur specialists. I'd imagine that all Tigers are bovine specialists when they coexist in any actual numbers.
At this point I'm fighting a losing battle, the fact is that Tigers can kill bull Gaurs and they do so. Apparently I'm splitting hairs when I doubt they can kill big, alpha ones straight up. I have my doubts but who knows, maybe they can.  Reply