The body condition of feral ponies on Assateague island

Abstract

Summary The summer body condition of 47 adult feral ponies on Assateague Island (off the coast of Maryland, USA) was assessed in June 1988 using a visual body condition scoring system. Winter body condition for 36 of the ponies was assessed in February and March, 1989. The ponies were categorised by gender, reproductive status and location on the island, and body condition scores of the ponies in each category were then compared by statistical analyses. No significant seasonal differences were found in the body conditions of the ponies. However, body condition of stallions was better than that of mares. Also, lactating mares had lower body condition scores than non‐lactating mares. Finally, in the summer, ponies on the southern part of the island were in better condition than those on the northern end where food and other resources were more limited. Thus gender, reproductive status and habitat, according to the criteria of this study, all had an effect on the body condition of Assateague Island feral ponies, whereas seasonal effects were not evident. Future studies could clarify the correlation between the condition of the mares during the breeding season and birth rate and survival of foals the following spring.

Seasonal adjustment of energy budget in a large wild mammal, the Przewalski horse (Equus ferus przewalskii) I. Energy intake

“…Body condition was scored on an ordinal scale from 0 (very thin) to 5 (very fat) according to the shape of the rump (from concave to convex) and the visibility of pelvis and ribs (Rudman and Keiper, 1991). To calibrate body-condition scores, we weighed animals immobilized for veterinary treatments during the period of visual assessment to the closest kg using a portable balance.…”

Understanding population dynamics of feral horses in the Tuan and Toolara State Forest for successful long-term population management

“…Body condition score (BCS) was assessed only of individuals that were observed within 100 meters and with the aid of 10 -22x binoculars (Nikon Corporation, Tokyo, Japan). BCS assesses body fat deposition of the neck, back and rump using a five points scale Rudman and Keiper 1991), but may incorporate a 0.5 point scale to allow more precise estimation . Horses with a BCS ≤ 2.0 were considered to be in a poor condition, between 2 -2.5 in a moderate condition, and those with BCS ≥ 3.0 were considered to be in good condition ( , and Rudman and Keiper (1991).…”

“…Visual assessment of body fat storage has been described as an objective and reliable indicator of body condition of horses, as it indirectly reflects the population nutritional status and health, and may offer an insight into population reproduction performance (Henneke et al 1983;Rudman and Keiper 1991;. Body condition of feral horses usually varies with gender, with stallions showing higher BCSs than mares .…”

“…Body condition of feral horses usually varies with gender, with stallions showing higher BCSs than mares . Horses tend to have lower BCSs in winter months and higher in summer months, corresponding to the greater availability of forage (Rudman and Keiper 1991;Duncan 1992;.…”

“…Certain groups and individuals were identified in 2012 only, 2013 only, or in both (numbers in brackets) years of the study ..………………………………………….. 45 Table 3.2: Effect of year on harem group size estimated using generalised linear mixed models (GLMM) within the study period ……………………………………………….…….. 45 Table 3.3: Effect of year on the composition of harems estimated using generalised linear mixed models (GLMM) year by year within the study period …………………………….... 46 Table 3.4: The number and percentage of harems maintained by single stallions (SS) and multiple stallions (MS), and the total number of harems (n) year by year within the study period …...……………………………………………………………………………………..… 48 Table 3.5: Effect of a year on bachelor group size estimated using generalised linear mixed models (GLMM) over the study period …...……………………………….….………. 48 Table 3.6: Age distribution of the feral horse population in each year of the study period ………………………………………………………………………………………………..…… 51 Table 3.7: Annual and overall number (n) and ratio (%) of loyal and transient adult females in 27 harems year by year within the study period …………….……………………….…… 53 , and Rudman and Keiper (1991) …………………..... 66 Table 4.2: Details on foaling season, number of recorded adult females and foals of both gender, and the estimate of foaling and fecundity rates, in the population of feral horses over the study period …..……………………………………………………………………….. 71 Table 4.3: Models used to estimate age specific survival (S), recapture (p) and transition probabilities ( ). Statistics for best-fit model are presented in descending order of the AIC c .…”