Rationale
Metabolism and diet quality play an important role in determining the delay mechanism between the uptake of elements and the deposition of relevant isotope signals in tissues in animals. While many isotope mixing models assume instantaneous reflections of food in animal tissues, this rarely happens. Here, we use data from wildebeest to measure the delay time from consumption to consumption. 34 and its findings in the tail hairs.
Method:
We analyzed 34 S data from GPS-tagged blue antelope in the Serengeti ecosystem using time-lag regression 34 to estimate the time lag time between animal uptake and deposition with isometric data 34 which is the tail hair of the tail.
We have known for a long time that the stable isotope sulfur has not had many applications, especially in ecological research. But over the past two decades, its use has been increasing due to advances in mass spectrometry technology. Specifically, the applicability of the system is in terms of reconstructing the animal's locomotion trajectory and diet.
For example, 34 s has been used in dietary studies of marine and swamp food webs, and 34 s in hair has been applied to study the locomotion of land animals as well as marine habitats.
Sulfur stable isotope ratios are generally considered to have a small fractionation coefficient (ie. Diet-mammalian tissue differences 34 (s) during incorporation into plant and animal tissues, and 34 s values vary with local geology. For example, the reported 34 isotopes between diet and animal tissues are between -3 and +4 dimensions. Between soil and plants, although there are some peripheral values up to +7x, they have been reported. The subfraction coefficient of 34 s it is good for tracking the movement and diet of the animal in the tissue, because its value of 34 s is stably reflected in the tissue in the local environment.
We collected tail hair samples from 11 GPS-tagged antelopes (6 inhabitants and 5 migratory individuals);s1, ancillary material). At the time of the first capture, the wildebeest was equipped with a GPS collar with its tail on the right side shaved to ** level. Date, age, sex, and reproductive status (i.e.: each animal was documented as pregnant or lactating prior to release.) After about a year, the hooded animals were recaptured, and the regrown tail hair was collected along with the ancillary data described above. Before being analyzed in the lab, the tail hairs of each animal are arranged into paper bags. The start and end dates of the samples allowed us to estimate the growth rate of tail hair, and GPS data provided the daily position of the animals throughout the breeding period.
A tail hair of about 25 is bundled together so that the proximal end is aligned. After each bundle was washed with 2:1 chloroform-methanol, it was rinsed with double distilled water to remove solvent residues. Samples are dried for 48 h at room temperature. After drying, measure the total length of the tail hairs. This is used to calculate the growth rate of the tail hairs. The tail hair sample was divided into 8mm segments, which corresponds to approximately 2 weeks of growth. From the most recent part of the hair (proximal) to the oldest part (distal). These parts are then ground with a metal abrasive tube on a dry mm400 (Germany) ball mill. The metal abrasive tube is immersed in liquid nitrogen for 60 seconds to make the hair brittle and easy to powder. These samples were ground for 90 seconds at 600 revolutions per minute. Powdery samples are weighed with a microbalancer. The sample weighs at 10 to 1between 3 mg.
Samples were analysed using a thermal cube elemental analyzer coupled to a visual mass spectrometer (Stockport). The samples were subjected to three non-consecutive tests over a period of 6 months. On these three tracks, we ran a number of unknown laboratories and international standards and obtained the following results.
Laboratory Standard ANR (Fishmeal Muscle) 34 S **ERAGE Value 18335‰ (accepted value 18.81‰),standard deviation 0.748 ( n = 47); international standards nist s1, δ34 s **erage value 0.20‰ (accepted value 0.30‰),standard deviation 0.40 ( n = 20); nist s2, δ34 s **erage value 22.28‰ (accepted value 22.62‰),standard deviation 0.65 ( n = 19); and nist s3, δ34 s **erage value 32.54‰ (accepted value 32.49‰),standard deviation 0.76 ( n = 17)。
Laboratory standards were repeated every 10 samples to correct for linearity and instrument drift during the 72-hour analysis. The isotope ratio is represented by the delta symbol of parts per million: x = [(r sample r standard) 1], where x = 34 and r = 34 s 32 isotopes in a given sample compared to feldspar.
The main results of this study show that the delay between ingestion and deposition of 34 s isotope in the tail hairs is significant, estimated here to be about 78 days. This suggests that sulfur in the animal's body undergoes two or more metabolic processes before being deposited in the tail hairs. These findings are important because understanding how metabolic delays and processing speeds affect 34s in biological substances such as hair, s has important inferences about the animal's movement or dietary changes. Secondary results suggest that the growth rate of wildebeest tail hairs is constant, constant season and gestation status, there is no evidence of differential wear or disintegration at the distal end, and tail hair length is mapped directly to time.