Association patterns reveal dispersal-aggregation dynamics among cattle in a South Texas Rangeland, USA

Abstract

Introduction: The spatial association dynamics of free-ranging cattle herds are not fully understood; however, they can have a direct influence on the spatial patterns of resource utilization. The aim of our study was to examine new analytical methods of identifying the spatio-temporal patterns of behavioral dynamics that determine cattle herd dispersal in the semi-arid rangelands of South Texas. We fitted 10 free-ranging cows with global positioning system collars and obtained positions every 5 min for each animal for 21-day trials, twice during the summer and winter period. We used an association pattern recognition software (ASSOC1) and the herd center of gravity to identify the spatial and temporal thresholds that defined dispersion-aggregation patterns and individual position to determine their relation to social dominance. Results: The association pattern defining herd membership was that animals spent 70% of their time within 200 m of each other. Dominance ranking did not appear to influence association membership or position within the herd. The cattle showed a more dispersed distribution during summer, but in winter, herd members behaved in a more aggregated pattern. This distribution is contrary to patterns described in more northerly and mountainous regions. Conclusions: The spatial thresholds of the cattle herd and the overall distance of all members to the center of the herd were smaller during winter and larger during summer, indicating that this study herd congregated during the winter and dispersed during the summer. Although this study uses a herd of 10 individuals in a 100 ha pasture to evaluate spatio-temporal dynamics, our results provide evidence of the ability of current tracking and spatial association tools to detect and quantify seasonal changes in cattle herd dispersion-aggregation patterns. The use of these data collection and analysis methods could prove useful in larger cattle herds, increase our understanding of herd spatiotemporal behavior, and subsequently help in the development of improved management practices.

Environmental and landscape influences on the spatial and temporal distribution of a cattle herd in a South Texas rangeland

“…The cattle herd was more dispersed during the warm season, when vegetation was most abundant At the seasonal scale, herd spread was greater during the warm growing season than the cold season, when forage was less abundant. Hence, in this study, as in other studies, the spread pattern appears to be partly explained by seasonal changes in available forage biomass, causing the dispersive movement during grazing, in which animals explore larger grazing areas, and subgroups tend to divide (Sato 1982;Owens et al 1991;Cheleuitte-Nieves et al 2018). This finding, however, contradicts those from studies on grazing cattle in northern, mountainous regions and other arid regions where cattle tend to forage and travel in larger and more compact groups during the summer, when forage is abundant, and disperse to search for sparser resources in winter (Dudzinski et al 1982;Lazo 1994;Howery et al 1996;Harris et al 2002Harris et al , 2007.…”

“…When no collar integration was obtained, a series of three consecutive records was interpolated to complete the data set (Ganskopp and Johnson 2007). If more than three successive fixes were not obtained, that portion of the dataset was omitted from analysis (Cheleuitte-Nieves et al 2018).…”

“…Developing better predictive models of ungulate movement patterns is important in assessing the relationships among species distribution, ecosystem change, and pastoralist livestock operations (Butt 2010). Ungulate behavior is influenced by landscape structures and resources, as well as the interaction of ecological processes occurring at different spatial and temporal scales (Hinch et al 1982;Senft et al 1987;Bailey et al 1996;Johnson et al 2002;Seagle and McNaughton 1992;Weladji et al 2002;Bailey 2004Bailey , 2005Peters et al 2004Peters et al , 2006Stephenson et al 2016;Stephenson and Bailey 2017;Cheleuitte-Nieves et al 2018). Therefore, flexible and opportunistic nutritional and physiological strategies can be developed on the basis of this spatio-temporal variability, thus producing distinct spatial distribution patterns in wildlife and livestock, and in natural and managed settings (Scoones 1995;Seagle and McNaughton 1992;Parker et al 2009).…”

“…Biological systems are complex, and processes occurring at different scales jointly influence the system and consequently affect animal behavior in unique ways (Johnson et al 2002;Peters et al 2004Peters et al , 2006. Hence, examination of the multi-scale interaction of system processes might provide novel insights into the factors and processes affecting animal movement dynamics and aid in the development of better predictive models of animal distribution and their effects on the environment (Bailey 1995;Ritchie et al 2009;Cheleuitte-Nieves et al 2018). Furthermore, many of these studies have been conducted in northwestern mountainous rangelands of North America and montane cold regions of Europe.…”

Factors Affecting Site Use Preference of Grazing Cattle Studied from 2000 to 2020 through GPS Tracking: A Review

“…When forage is abundant, herds travel in larger groups, whilst when it is scarce, herds fragment into subgroups, behaving more independently [ 102 ]. The association pattern shaping herd membership reveals that animals devote 70% of their time within 200 m of each other and dominance ranking does not seem to affect association membership or ranking within the herd [ 103 ]. Hence, foraging and short-distance travelling patterns by female beef cattle are not guided by any specific individual, but tend to be affected by a graded type of leadership; that is, the more dominant a cow is, the stronger the effect it may have on the movements of the herd [ 104 ].…”