Ostrich Research Articles

Historical ostriches in the Libyan Desert, with ecological and taxonomic considerations

Many historical records extend the known range of the African ostrich Struthio camelus to include almost the entire state territory of Libya. This significant expansion augments the spatial potentialities to reintroduce captive-bred progeny of the endangered red-necked ostriches (S. c. camelus) from zoos and wildlife centres. The latest Libyan ostriches lingered in Cyrenaica and Fezzan into the late 19th century, and presumably near Kufra into the 1930s. Their extermination coincided with the occupation by colonial European administrations. These east Saharan biotopes are extraordinarily resource-poor and climatically challenging due to wide thermal amplitudes and extreme drought. Old photographs from Kufra and Wadi Howar leave undecided if the Libyan ostriches adhered to the subspecies S. c. camelus, which appears possible, or if additional, partly substantiated but yet unconfirmed claims should be heeded which demand up to three subspecies in North Africa. A review of taxonomic interpretations reveals a weak foundation by reliable data of a pan-Saharan subspecies S. c. camelus, and additional research is suggested to provide a sound taxonomic concept, not least for the management of various regional breeding lineages in zoos, which safeguard the survival of this endangered bird. As an auxiliary finding, African wild dogs (Lycaon pictus) are attested as inhabitants of the southern Libyan Desert until the 1930s, where they had preyed upon the now equally extinct ostriches.

Implication of dietary barberry (Berberis Vulgaris) leaves inclusion on growth performance, nutrient digestibility, and carcass traits in ostriches

This study determined production performance, nutrient intake, digestibility, and carcass traits from ostrich chicks fed with barberry (Berberis Vulgaris) leaves (BVL) as a replacement for alfalfa hay (AH). For 150 days, 30 male ostrich (Struthio camelus) (9.10 ± 0.89 kg live weight, mean ± SD) were randomly grouped into five dietary BVL inclusion levels to replace AH: a control diet based on 100% AH (CTRL), and four groups with BVL as a substitute for AH at varying levels including 25% (BVL25), 50% (BVL50), 75% (BVL75), and 100% (BVL100). The average daily feed intakes (ADFI) were recorded and birds were weighed monthly. The nutrient intake and digestibility were measured for the following final 5 days of the trial. The ADFI was higher (p = 0.025) for BVL100 and BVL75 than for CTRL. Ostriches fed on BVL50 had the highest average daily gain (ADG, p = 0.025) and the lowest feed conversation ratio (FCR, p = 0.0001). Return per kg BW gain was also enhanced (p = 0.018) with BVL50 feeding. Dietary BVL levels did not affect the digestibility of OM (p = 0.257), CP (p = 0.260), EE (p = 0.610), CF (p = 0.427), and Ash (p = 0.461). Also, there were no changes in AME (p = 0.180) or AMEn (p = 0.670). The hot carcass weight (HCW, p = 0.331) and dressing BW (p = 0.237) were not affected. Overall, the results suggest that BVL can replace AH in ostrich diets without deleterious impact on performance, however, its partial substitution (for 50% AH of diet) has been associated with improved ADG, FCR, and reduced feeding costs.

Text Mining and Topic Analysis for Ostriches' Welfare Based on Systematic Literature Review from 1983 to 2023.

Ostriches can be utilized as multipurpose animals suitable for producing meat, eggs, feathers, and leather. This growing interest in ostrich farming leads to an increased demand for comprehensive information on their management. But, little attention is paid to the consequences for their welfare. The study aimed to perform a research literature analysis on ostriches' welfare using the text mining (TM) and topic analysis (TA) methods. It identifies prevailing topics, summarizes their temporal trend within the last forty years, and highlights potential research gaps. According to PRISMA guidelines, a literature exploration was achieved using the Scopus® database, retaining keywords about ostriches' welfare. Papers distributed in the English language from 1983 to 2023 were included. Descriptive statistics, TM, and TA were applied to a total of n. 122 documents included. The findings revealed an increasing trend in research records since 1994. TM recognized the terms with the highest weighted frequency and TA identified the main topics of the research area, in the following order: "health and management", "feeding and nutrition", "welfare reproduction", "egg production", and "welfare during transport". The study confirms the increased focus on ostriches' welfare but shows that further studies are required to ensure the welfare of this species.

OSTRICHES AND GEOTOURISM: THE EVOLUTIONARY PATHWAY OF A SMALL TOWN TOURISM DESTINATION IN SOUTH AFRICA

Small towns are a critical tier in the settlement hierarchy. For many small towns tourism is a vital sector of local development. This paper contributes an historical perspective on small town destination development. Using archival sources the paper provides a window on the evolutionary development of one small town tourism destination in South Africa. The case study is Oudtshoorn in the Western Cape. During the late 19th century and early 20th century Oudtsthoorn experienced phases of economic boom and bust which linked to international fashion and the trade in ostrich feathers. The imprint of this era is manifest in the town’s landscape of ‘feather palaces’. In terms of early 20th century tourism growth it is demonstrate d geotourism was a critical driver with the asset of Cango Caves. In the period after the Second World War, the local tourism economy diversifies with the revival and reorientation of ostrich farming which incorporates ostriches as tourism attractions. The evolutionary pathway of this small town changes such that its local tourism economy is anchored on the dual foundations of its geotourism and ostrich attractions.

Chicory supplementation improves growth performance in juvenile ostriches potentially by attenuating enteritis.

Enteritis and dysbiosis are the major causes of high morbidity and mortality of juvenile ostriches. Chicory (CC) has been proven to have excellent antioxidant, anti-inflammatory, and antibacterial activities. However, it's unclear whether CC could improve the survival rate of juvenile ostriches by relieving enteritis and correcting dysbiosis. South African ostrich hatchlings (Struthio camelus domesticus) were fed with and without a CC-supplemented diet, and the body weight gain and mortality were compared over 4 months of age. Fresh fecal samples of clinically healthy ostriches were collected, and 16S DNAs were analyzed. Moreover, ostrich chicks with LPS-induced enteritis were fed with different dosages (0, 20, 40, and 80 mg/kg) of chicoric acid (CA), a major bioactive component of CC, for five consecutive days. The expression levels of tight junction (TJ)-related proteins and inflammatory mediators in the ilea were detected with western blot and immunofluorescence. The ostrich chicks fed on the CC-supplemented diet began to increase in weight at the 1st month of age and became remarkably heavier at the fourth month (p < 0.01) compared with those fed on the non-CC-supplemented diet. Additionally, the mortality percentage was lower in the chicks fed on the CC-supplemented diet than those fed on the non-CC-supplemented diet (19% vs. 36%, respectively). The diet with the CC supplementation significantly increased the abundance of Phascolactobacteria (linear discriminant analysis; LDA >4) and Bacteroidota (26.7% vs. 17.7%, respectively) as well as decreased the enrichment of Clostridium (5.0% vs. 9.1%, respectively) in the ostrich ilea compared to the diet without CC. The supplementation of CA at a dose of 80 mg/kg significantly increased the expression level of ZO-1 and claudin-3 (p < 0.0001) and suppressed the levels of IL-1β, IL-6, and TNF-α (p < 0.0001) in ostriches with LPS-induced ileitis. Our results substantiate that CC or CA supplementation in a diet could effectively improve growth performance and reduce mortality in juvenile ostriches via modulating the gut microbiota and attenuating enteritis.

Morphometric study of ostrich kidneys Struthio camelus Linnaeus, 1758

In recent years, avian medicine has advanced in the recognition of kidney diseases, but little is known about the morphology and renal morphometry of the common ostrich Struthio camelus Linnaeus, 1758. This study aimed to describe the morphometry and location of kidneys in the common ostrich. Twenty-six cadavers, aged one to seven days, which died of natural causes on a farm in the municipality of Magé, state of Rio de Janeiro, Brazil, were donated to the Department of Animal and Human Anatomy at the Universidade Federal Rural do Rio de Janeiro (UFRRJ). The specimens were identified, sexed, and fixed in a 10% aqueous solution of formaldehyde. The kidneys and renal divisions were measured using a precision digital caliper. The kidneys of S. camelus are elongated, and lobular, and have three renal divisions (cranial, middle, and caudal). The average length of the right kidney was 6.69 ± 0.83 cm, and the left kidney was 6.87 ± 0.81 cm. The body length correlated positively and significantly with the lengths of the right kidney (r = 0.8273, p = 0.0017) and left kidney (r = 0.8534, p = 0.0008) in females. The renal cranial limit was observed at the eighth lumbar vertebra (L8) in 22 kidneys (42.3%), and the caudal limit, at the eighth sacrocaudal vertebra (Sc8) in 11 kidneys (21.2%), and the second caudal vertebra (C2) in 11 kidneys (21.2%). The morphometric dimensions and skeletopy of the ostrich kidney contribute to the field of comparative avian anatomy and assist in the interpretation of imaging techniques.

Petroglyphs as a paleobiogeographic guide for Arabian ostrich ecology and reintroduction

The Arabian ostrich (Struthio camelus syriacus) was an integral element in the wildlife of the Middle East until its extinction in the mid-20th century. Here we discuss the historic and archaeological record that provides baseline information on the past distribution of ostriches in the Negev Desert (Israel). Specifically, we focus on survey data of ancient petroglyph depictions of ostriches and examine their spatial distribution. Through the application of models of optimal habitat reconstruction using data on the houbara bustard as a proxy species for the ostrich, correlated with the spatial distribution of the ostrich petroglyphs and ecological data on the region, we identified the optimal areas that the Syrian ostrich could have inhabited in the past. Finally, we applied our model to examine reintroduction programs of a closely related ostrich subspecies, S. c. camelus, that have been carried out in the Negev to date.

Anatomy of Liver and Radiographic Study on Hepatic Duct in a South African Ostrich Struthio camelus australis

The South African Ostrich Struthio camelus australis, an acarinate flightless ratite bird, native to the African continent has been introduced in many countries including India in the recent past for meat as well as egg purpose. Although this largest extant bird is gaining popularity globally, the functional anatomy of this majestic giant has received relatively less attention. The liver, the largest gland in the body of an Ostrich (weighing approximately 1.5-2 Kg) is also the heaviest among all the birds. The Ostrich lacks gall bladder and thus, the bile needs to be produced continuously as in the case of certain mammals like horses and elephants. The present study aimed to investigate the gross morphological and radiographic characteristics of the liver of the Ostrich. The liver was divisible into two primary lobes: an undivided right lobe and a divided left lobe. The later consisted of dorso-cranial, intermediate, and ventro-caudal lobes. Notably, the ventro-caudal lobe was observed as the largest, while the intermediate lobe was the smallest. The right lobe, larger than the left, was connected to later by a thick isthmus at its cranial extremity. Using barium sulphate injection and positive contrast radiography, the intrahepatic course of the hepatic duct was visualized, revealing two distinct divisions and tributaries thereof for draining bile from the right and left lobes, respectively. A radiographic study of the intrahepatic course of the hepatic duct revealed a single right intralobar duct and two left intralobar ducts. The distinct isthmus was drained by the branch of the left intralobar duct.

Nuclear parcellation and numbers of orexinergic neurons in five species of larger brained birds.

The orexinergic/hypocretinergic system, while having several roles, appears to be a key link in the balance between arousal and food intake. In birds, to date, this system has only been examined anatomically in four species, all with brains smaller than 3.5g and of limited phylogenetic range. Here, using orexin-A immunohistochemistry, we describe the distribution, morphology, and nuclear parcellation of orexinergic neurons within the hypothalami of a Congo gray and a Timneh gray parrot, a pied crow, an emu, and a common ostrich. These birds represent a broad phylogeny, with brains ranging in size from 7.85 to 26.5g. Within the hypothalami of the species studied, the orexinergic neurons were organized in two clusters, and a densely packed paraventricular hypothalamic nucleus cluster located within the medial hypothalamus (Hyp), but not contacting the ventricle, and a more loosely packed lateral hypothalamic cluster in the lateral Hyp. Stereological analysis revealed a strong correlation, using phylogenetic generalized least squares regression analyses, between brain mass and the total number of orexinergic neurons, as well as soma parameters such as volume and area. Orexinergic axonal terminals evinced two types of boutons, larger and the smaller en passant boutons. Unlike the orexinergic system in mammals, which has several variances in cluster organization, that of the birds studied, in the present and previous studies, currently shows organizational invariance, despite the differences in brain and body mass, phylogenetic relationships, and life-histories of the species studied.

Anatomical and morphometric studies on the axial skeleton of ostrich (Struthio camelus)

The present study showed a descriptive anatomical study of the parts of the axial skeleton in the ostrich (Struthio camelus) in addition to a morphometric study of each bone. We studied 7 male ostriches aged from 1 to 3 years with an average weight of 120.00 kg. The cranium exhibited two vast orbits supported by a sclerotic ring. Hyoid apparatus was fine delicate horseshoe-shaped and comprised Basihyale, Urohyale, and Cornu branchiale. Cornu branchiale were paired and long rod-shaped, consisting of a proximal bony part Ceratobranchiale and slightly curved distal cartilaginous process, the Epibranchiale located on either side of the hyoid apparatus. The whole vertebral column comprised 54 vertebrae, including 18 cervical vertebrae, 7 separated thoracic vertebrae, a synsacrum, and 9 separated caudal vertebrae. Atlas had a butterfly-shape with a narrow width and large vertebral foramen. Axis had a protruded dens with a rounded tip that arose from the cranial surface of the body for articulation with the Incisura fossae of atlas. Several Pneumatic foramina were found in the cervical vertebrae. The transverse foramen was found in all the cervical vertebrae except atlas. The ribs were nine pairs in number, the sternal ribs extended from the third to the seventh rib while the rest were asternal floating ribs. The sternum was a broad quadrilateral extensive bone, lacking the keel bone. It had dorsally several Pneumatic foramina.

Apparent absence of hypothalamic cholinergic neurons in the common ostrich and emu: Implications for global brain states during sleep.

We examined the presence/absence and parcellation of cholinergic neurons in the hypothalami of five birds: a Congo grey parrot (Psittacus erithacus), a Timneh grey parrot (P. timneh), a pied crow (Corvus albus), a common ostrich (Struthio camelus), and an emu (Dromaius novaehollandiae). Using immunohistochemistry to an antibody raised against the enzyme choline acetyltransferase, hypothalamic cholinergic neurons were observed in six distinct clusters in the medial, lateral, and ventral hypothalamus in the parrots and crow, similar to prior observations made in the pigeon. The expression of cholinergic nuclei was most prominent in the Congo grey parrot, both in the medial and lateral hypothalamus. In contrast, no evidence of cholinergic neurons in the hypothalami of either the ostrich or emu was found. It is known that the expression of sleep states in the ostrich is unusual and resembles that observed in the monotremes that also lack hypothalamic cholinergic neurons. It has been proposed that the cholinergic system acts globally to produce and maintain brain states, such as those of arousal and rapid-eye-movement sleep. The hiatus in the cholinergic system of the ostrich, due to the lack of hypothalamic cholinergic neurons, may explain, in part, the unusual expression of sleep states in this species. These comparative anatomical and sleep studies provide supportive evidence for global cholinergic actions and may provide an important framework for our understanding of one broad function of the cholinergic system and possible dysfunctions associated with global cholinergic neural activity.

Anatomical and Functional Study of the Ostrich (Struthio camelus) Lung through Macroscopic Analysis in Combination with Optical and Electron Microscopy Techniques.

The Ostrich occupies a unique position as the largest bird on the planet. Like other ratites, it has been reputed to have a phylogenetically primitive lung. We used macroscopy, light microscopy, transmission and scanning electron microscopy as well as silicon rubber casting to elucidate the functional design of its lung and compare it with what is already documented for the avian species. The neopulmonic region was very small and poorly developed. The categories of the secondary bronchi (SB) present and their respective numbers included laterodorsal (8-10), lateroventral (4-5), medioventral (4-6) and posterior (16-24). The lateral aspects of the laterodorsals were covered with a transparent collapsible membrane internally lined with a squamous to cuboidal epithelium. The bulk of these SB were in close proximity to intercostal spaces and the intercostal muscles and were thought to be important in the propulsion of gases. The lung parenchyma was rigid, with the atria well supported by septa containing smooth muscles, connective tissue interparabronchial septa were absent, and blood capillaries were supported by epithelial bridges. There were two categories of epithelia bridges: the homogenous squamous type comprising two leaflets of type I cells and the heterogeneous type consisting of a type I pneumocyte and type II cell. Additional type two cells were found at the atrial openings as well as the walls of the infundibulae and the air capillaries. The atria were shallow and opened either directly into several air capillaries or into a few infundibulae. The presence of numerous type II cells and the absence of interparabronchial connective tissue septa may imply that the ostrich lung could be capable of some degree of compliance.

The first record of ostrich feather louse (Struthiolipeurus struthionis) collected from farmed ostriches (Struthio camelus) in the United Arab Emirates.

Ostrich (Struthio camelus) farming in the United Arab Emirates (UAE) is a relatively new field of farming. Farmed ostriches are susceptible to ectoparasite infestation, which affects their production. This study was conducted to estimate the prevalence of ectoparasites on ostriches raised on a farm in Abu Dhabi Emirate. The feathers of 42 ostriches (26 females and 16 males) were collected and morphologically examined for ectoparasites. In total, 283 lice (89 males and 194 females) were collected from birds. However, there were no ticks or other ectoparasites. Lice were preserved in 1.5 mL tubes containing 70% ethanol and were later identified using taxonomic keys. The prevalence, mean intensity of infection, and mean abundance were estimated. One louse species, Struthiolipeurus struthionis was identified. To the best of our knowledge, this is the first report of S. struthionis in ostriches raised in the UAE with an overall prevalence of 88%. The prevalence of lice was significantly higher in July (100%) than that in May (66.7%). Likewise, the mean intensity and abundance of lice were significantly higher in June (10.6 and 9.94, respectively) than in May (3.25 and 2.2, respectively). The high prevalence of lice poses a serious risk to ostrich farming by negatively affecting the health and productivity of ostriches.

Morphogenesis of the ostrich (Struthio camelus) trachea and lung in different embryonic and fetal stages.

The ostrich (Struthio camelus) is an important wild species highlighted in national and international livestock industry. This research was conducted to analyze the development of the ostrich respiratory system during fetal and embryonic stages. A total of 50 fertile ostrich eggs were collected from commercial farms and then incubated at 36.00 - 37.00 ˚C and 25.00 ± 2.00% humidity for 40 days. Sections were taken on days 13, 22, 26, 30, 36, and 42 of incubation from the lung and the cranial, middle, and caudal parts of the neck after decapitation of ostrich embryos and blood drainage. After fixation, processing, blocking, and sectioning, all samples were stained by Hematoxylin and Eosin, Alcian Blue (AB), Van Gieson, and Periodic acid-Schiff (PAS) techniques. It was concluded that the trachea in the 13-day-old embryo and goblet cells (PAS-positive and AB-positive) had incomplete rings of hyaline cartilage and differentiation of mesenchymal to the loose connective tissue. The bronchial stage of the lung was observed in the 22-day-old embryo, pseudoglandular stage in the 26-day-old embryo, and parabrachial and air capillary stage in the 30-day-old embryo. The information obtained from this study will be useful for diagnosing pathologies affecting this vital system and results in improving industrial breeding management.

The effect of different cooking methods on sensory attributes, physicochemical properties, and microbial safety of ostrich meat (Struthio camelus).

The present work aimed to determine the impact of various cooking methods on sensory attributes, microbial safety, and physicochemical characteristics of ostrich meat to specify the best cooking method that guarantees the microbial safety of the meat as well as maintains nutritional values and is highly attractive to consumers. One hundred fresh leg muscles of ostriches were divided into five groups. Different cooking techniques were used for each group, as follows: roasting, boiling, grilling, frying, and microwaving. Each method was examined by evaluating the impact of various cooking methods on sensory attributes, proximate chemical analysis, protein and fat oxidation parameters, microbial load, changes in color, and the shear force of ostrich meat. The oven-roasting and grilling methods are highly recommended and more appealing to consumers since they produce tenderer and juicier meat, cause less cooking loss (CL), and maintain the nutritive value of ostrich meat; however, they have the highest protein and fat oxidation rates. On the other hand, boiling and frying methods revealed good fat oxidation parameters, the highest CL, and preserved nutritional value, but unfortunately, they were not highly preferred by consumers. From a hygienic point of view, grilling and microwave cooking are the methods that ensure the microbiological safety of cooked ostrich meat, as they significantly reduce Enterobacteriaceae and psychrotrophic bacterial counts, among other cooking methods. The oven roasting and grilling methods were the most preferable thermal cooking techniques, as they achieved the highest acceptability to consumers and maintained the nutritive values of ostrich meat.

Effects of environmental enrichment on ostrich behaviours

This study was aimed to investigate the behavioural differences of ostrich (Struthio camelus) breeders reared under environmental enrichment with natural vegetation in farm conditions. The effect of enriched environment with vegetation on eating, drinking, foraging, pecking, defecation, walking, running, alert, standing, sitting, sleeping, dust bathing, preening, head shake, thermoregulation, kantel, mating, laying, threat and fight behaviours of ostriches were found similar (P &amp;gt; 0.05). The ratio of boom, courtship and displace behaviours were found higher in enriched than in gravel floor (P=0.050; P=0.028 and P=0.001). The foraging, dust bathing, boom, laying and displace behaviours of ostriches were affected by gender (P=0.029, P=0.040, P=0.050, P=0.025 and P=0.001). The eating, foraging, standing, sitting, dust bathing and laying behaviours of ostriches were affected by time of day (P=0.010, P=0.023, P=0.049, P=0.026, P=0.018 and P=0.009). There was a significant interaction of enriched environment and gender effect on eating, standing, boom and displace behaviours of ostriches (P=0.047, P=0.031, P=0.050 and P=0.001). The pecking and standing behaviours of ostriches were affected by enriched environment and time of day interaction (P=0.027 and P=0.023). As a conclusion, enriched environment with natural vegetation in paddock only affected ostriches’ courtship behaviours, also affected male and female eating and standing behaviours differently.

Ostrich (Struthio camelus) syrinx morphology and vocal repertoire across postnatal ontogeny and sex: Implications for understanding vocal evolution in birds.

Vocal production in birds has been the target of considerable research that mostly has focused on phylogenetically well-nested songbirds. Anatomical descriptions and recordings of many non-songbirds have often only focused on a single ontogenetic stage or sex. While basic morphology of the vocal organ (syrinx) of ostrich (Palaeognathae, Struthio camelus) has been known since the 1800s, descriptions of its vocal repertoire and syrinx anatomy since then have been incomplete or inconsistent. New toolkits now enable detailed qualitative description of internal anatomy and meristic data and allow it to be compared to vocal production. Here we describe the anatomy of the syrinx in Struthio camelus for three post-hatching ontogenetic stages and both an adult male and female utilizing dissection and contrast enhanced X-ray computed tomography (diceCT). We find changes in ring geometry and spacing through ontogeny as well as lateral labia thickness. We document a small unpaired, midline, cartilaginous structure, a "pessuliform process" at the tracheobronchial juncture present throughout ontogeny and in both males and females. Investigation of the vocal repertoire of ostriches across ontogeny using a new dataset of 77 recordings led to identification of four vocalizations not previously reported in the literature, including the simultaneous production of a hiss and tonal. We find syrinx morphology largely consistent across ontogeny and in male and female adults. Both are capable of producing long duration tonal calls, but these may be more frequent in male birds. Closed-mouth boom calls remain unique to males. A detailed understanding of diversity in parts of early diverging clades is pivotal in attempting to estimate features of the ancestral syrinx in birds and how avian vocalization evolved.

Histochemical analysis, smooth muscle immunolocalization and volumetric density of the elastic system fibres of the ostrich (Struthio camelus) phallus.

There are few scientific reports on the histology of the phallus of ratite birds. The aim of this study was to conduct a histochemical analysis to determine the distribution of smooth muscle cells and the volumetric density (Vv) of the fibres of the elastic system in the ostrich phallus. Adult ostriches, 14 months old, were used. The phalluses were fixed in Bouin's solution and then transferred to a buffered formalin solution. They were then processed using standard histological stains for paraffin and slices were obtained. The following techniques were performed: HE, Picrosirius red, Alcian Blue at pH 1.0 and 2.5. The Periodic acid-Schiff reagent and Weigert's Resorcin-Fuchsin with previous oxidation were performed. The M42 test system was used to quantify the elastic system fibres. For immunohistochemical analysis, an anti alpha smooth muscle actin monoclonal antibody was used. The surface of the phallus is covered by a non-keratinized stratified squamous epithelium, which becomes stratified cylindrical in the region of the spermatic sulcus. No glands associated with the connective tissue were observed. The Vv of the elastic system fibres was 4.75%. Smooth muscle cells were visualized only in the walls of blood vessels through immunostaining, with an absence in the lymphatic sinuses. Despite similarities with other birds, such as the presence of a fibrous external axis, a lymphatic core, and a spermatic groove, the ostrich phallus shows marked differences, including the absence of an elastic core, a non-keratinized lining epithelium, and the absence of glands throughout its extension.

EFFECTS OF SEASON, SEX AND TIME OF DAY ON OSTRICH BREEDER (Struthio camelus) BEHAVIOR

Ambient temperature has a crucial effect on livestock production performance, behaviors and welfare. In ostrich, previous research primarily focused on survival and reproductive performance during the climatic shifts. This study was carried out to investigate the effect of seasonal variation on behavioral differences of male and female ostrich (Struthio camelus) breeders, reared in farm environment. The individual behaviors related to digestion, locomotor activities, resting, comfort and thermoregulation, reproduction, and aggressive behaviors were recorded. The higher sitting and sleeping behavior were observed in summer season (P≤0.01 and P≤0.001, respectively). The thermoregulation behaviors were observed only in summer season (P≤0.0001). The higher foraging, alertness and spot pecking behaviors were observed in females (P≤0.01, P≤0.05, and P≤0.05, respectively). The boom behavior was only observed in males (P≤0.05). The higher walking behavior was observed in the afternoon and morning (P≤0.05). The higher sleeping, dust bathing, grooming and thermoregulation behaviors were observed at noon (P≤0.001, P≤0.001, P≤0.0001 and P≤0.0001, respectively). There was a significant interaction between season and sex for displace behavior, a sign of aggressive behavior (P=0.006). There was a significant interaction between season and time of day for drinking and defecation related to digestive behaviors (P≤0.05 and P≤0.05, respectively); sleeping described as a resting behavior (P=0.0001); dust bathing and grooming which is related to comfort behaviors (P≤0.0001 and P≤0.0001); thermoregulation (P≤0.0001); copulation described as a reproductive behavior (P=0.003); displace and escape behaviors mostly a sign of aggressive behavior (P≤0.05 and P≤0.05). Ostriches are diurnal animals with a nomadic lifestyle and have higher activity during the early and late times of the day. Identification of the seasonal, sexual and time of day differences on behavior types of ostriches, provides important information for ostrich management and their welfare. Keywords: Ostrich (Struthio camelus), climate-change, behavior, animal welfare.

Heritable variation in thermal profiles is associated with reproductive success in the world's largest bird.

Organisms inhabiting extreme thermal environments, such as desert birds, have evolved spectacular adaptations to thermoregulate during hot and cold conditions. However, our knowledge of selection for thermoregulation and the potential for evolutionary responses is limited, particularly for large organisms experiencing extreme temperature fluctuations. Here we use thermal imaging to quantify selection and genetic variation in thermoregulation in ostriches (Struthio camelus), the world's largest bird species that is experiencing increasingly volatile temperatures. We found that females who are better at regulating their head temperatures ("thermoregulatory capacity") had higher egg-laying rates under hotter conditions. Thermoregulatory capacity was both heritable and showed signatures of local adaptation: females originating from more unpredictable climates were better at regulating their head temperatures in response to temperature fluctuations. Together these results reveal that past and present evolutionary processes have shaped genetic variation in thermoregulatory capacity, which appears to protect critical organs, such as the brain, from extreme temperatures during reproduction.