Age-specific variation of resistance to oxidative stress in the greater flamingo ( Phoenicopterus ruber roseus )

Birds exhibit exceptional longevity and are thus regarded as a convenient model to study the intrinsic mechanisms of aging. The oxidative stress theory of aging suggests that individuals age because molecules, cells, tissues, organs, and, ultimately, animals accumulate oxidative damage over time. Accumulation of damage progressively reduces the level of antioxidant defences that are expected to decline with age. To test this theory, we measured the resistance of red blood cells to free radical attack in a captive population of greater flamingo (Phoenicopterus ruber roseus) of known age ranging from 0.3 to 45years. We observed a convex relationship with young adults (12-20years old) having greater resistance to oxidative stress than immature flamingos (5months old) and old flamingos (30-45years old). Our results suggest that the antioxidant detoxifying system must go through a maturation process before being completely functional. It then declines in older adults, supporting the oxidative theory of aging. Oxidative stress could hence play a significant role in shaping the pattern of senescence in a very long-lived bird specie

Reproductive non-seasonality in rhinoceroses: A review of the in-situ literature and birth records of ex-situ institutions

Mammals whose breeding activity is triggered by seasonal photoperiodic cues typically maintain seasonal reproduction in zoos, with births accumulating to various degrees in spring. For zoo-kept rhinoceroses, accumulation of births in autumn has been suggested, which would make this group unusual. We compare birthing (and hence conception) patterns of free-ranging rhinoceros populations from the scientific literature with those of the global zoo populations based on birth data available from Species360, to facilitate deductions on the cues that trigger rhinoceros reproduction. The patterns do not indicate a photoperiodic element in rhinoceros reproduction but suggest suppression of conception in free-ranging populations at times of resource scarcity. This is not evident in zoos. However, a slight accumulation of autumn births, due to a slight reduction in births in spring, is visible in the zoo populations. Given rhinoceros gestation periods, this is linked to reduced conceptions in November–December. The most parsimonious interpretation is management-related, as has been suggested (Roth 2006, Int. Zoo Yb. 40(1): 130–143): not all facilities are prepared to allow mating at times when outdoor husbandry is reduced due to weather restrictions. Given the long interbirth intervals of rhinoceroses, missed conception opportunities of 1–2 months are unlikely to affect population demographics. Nevertheless, detailed recording of approaches to facilitate mating during winter months by those zoos that achieve this may increase the general skill of rhinoceros management

Body condition scoring system for greater one-horned rhino (Rhinoceros unicornis): Development and application

Preventing obesity in zoo animals is increasingly recognized as an important husbandry objective. To achieve this goal, body condition scoring (BCS) systems are available for an ever-increasing number of species. Here, we present a BCS for the greater one-horned rhinoceros (Rhinoceros unicornis) based on an evaluation (on a scale from 1 to 5) of seven different body regions, and report resulting scores for 62 animals from 27 facilities, based on digital photographs. In animals above 4 years of age, this BCS correlated with the body mass:shoulder height ratio. Although differences between the sexes for individual regions were noted (with consistently higher scores in males for the neck and shoulder and in parous females for the abdomen), the average BCS of all regions did not differ significantly between males (4.3 +- 0.4) and females (4.1 +- 0.5). Linking the BCS to results of a questionnaire survey and studbook information, there were no differences in BCS between animals with and without foot problems or between parous and non-parous females. In a very limited sample of 11 females, those eight that had been diagnosed with leiomyoma in a previous study had a higher BCS (range 3.9–4.9) than the three that had been diagnosed as leiomyoma-free (range 3.5–3.7). The BCS was correlated to the amount of food offered as estimated from the questionnaire. Adjusting the amounts and the nutritional quality of the diet components is an evident measure to maintain animals at a target BCS (suggested as 3–3.5)

Milk composition of indian rhinoceros (Rhinoceros unicornis) and changes over lactation

The objective of this study was to determine the major nutrient composition of Indian rhinoceros milk (Rhinoceros unicornis) over the first 13 mo of an 18-mo lactation period and to compare the results to those of previous studies on rhinoceros, African elephant (Loxodonta africana), and horse milk (Equus ferus caballus). The following parameters were measured: dry matter (DM), crude ash (ASH), crude protein (CP), ether extract (EE), nitrogen-free extract (NFE; calculated), lactose, calcium (Ca), phosphorus (P), magnesium (Mg), fatty acids (FAs), and gross energy (GE). DM, ASH, CP, and EE were determined with a proximate analysis, lactose with infrared spectroscopy and an enzymatic method, minerals with an autoanalyzer, FA with gas chromatography, and GE with bomb calorimetry. Milk samples were collected from two Indian rhinoceros cows from Zoo Basel. Rhino A gave birth to her third calf on 10 September 2012; three samples were collected and analyzed (colostrum, milk 1 wk and 2 wk postpartum). Rhino B gave birth to her eighth calf on 05 October 2013; samples were collected and 15 were chosen for the analyses (from colostrum to 13 mo postpartum). The composition of rhino B's colostrum was 13.8% DM (wet-weight basis), 4.8% ASH, 61.8% CP, 0.7% EE, 32.6% NFE, 26.7% lactose, 0.59% Ca, 0.54% P, 0.2% Mg (DM basis), and 20.3 MJ GE/kg DM. Rhino B's sample collected 13 mo postpartum averaged 8.0% DM (wet-weight basis), 3.6% ASH, 16.3% CP, 1.8% EE, 78.3% NFE, 84.7% lactose, 0.54% Ca, 0.48% P, 0.09% Mg (on DM basis), and 17.43 MJ GE/kg DM. The main FAs in rhino B's and rhino A's samples were C10 : 0, C12 : 0, C16 : 0, C18 : 1n9c, and C18 : 2n6c. Milk of the Indian rhinoceros is low in fat and protein but high in lactose, which is comparable to the milk composition of other rhinoceros species and horses, but not African elephants

Non-linear feeding functional responses in the Greater Flamingo (Phoenicopterus roseus) predict immediate negative impact of wetland degradation on this flagship species

International audienceAccurate knowledge of the functional response of predators to prey density is essential for understanding food web dynamics, to parameterize mechanistic models of animal responses to environmental change, and for designing appropriate conservation measures. Greater flamingos (Phoenicopterus roseus), a flagship species of Mediterranean wetlands, primarily feed on Artemias (Artemia spp.) in commercial salt pans, an industry which may collapse for economic reasons. Flamingos also feed on alternative prey such as Chironomid larvae (e.g., Chironomid spp.) and rice seeds (Oryza sativa). However, the profitability of these food items for flamingos remains unknown. We determined the functional responses of flamingos feeding on Artemias, Chironomids, or rice. Experiments were conducted on 11 captive flamingos. For each food item, we offered different ranges of food densities, up to 13 times natural abundance. Video footage allowed estimating intake rates. Contrary to theoretical predictions for filter feeders, intake rates did not increase linearly with increasing food density (type I). Intake rates rather increased asymptotically with increasing food density (type II) or followed a sigmoid shape (type III). Hence, flamingos were not able to ingest food in direct proportion to their abundance, possibly because of unique bill structure resulting in limited filtering capabilities. Overall, flamingos foraged more efficiently on Artemias. When feeding on Chironomids, birds had lower instantaneous rates of food discovery and required more time to extract food from the sediment and ingest it, than when filtering Artemias from the water column. However, feeding on rice was energetically more profitable for flamingos than feeding on Artemias or Chironomids, explaining their attraction for rice fields. Crucially, we found that food densities required for flamingos to reach asymptotic intake rates are rarely met under natural conditions. This allows us to predict an immediate negative effect of any decrease in prey density upon flamingo foraging performance