Understanding mortality causes is important for the conservation of endangered species, especially in small and isolated populations inhabiting anthropized landscapes where both natural and ...human-caused mortality may hinder the conservation of these species. We investigated the mortality causes of 53 free-ranging brown bears (Ursus arctos) found dead between 1998 and 2023 in the Cantabrian Mountains (northwestern Spain), a highly human-modified region where bears are currently recovering after being critically threatened in the last century. We detected natural traumatic injuries in 52.63% and infectious diseases in 39.47% of the 38 bears for which the mortality causes were registered, with 21.05% of these cases presenting signs of both infectious diseases and traumas. More specifically, almost 30% of the bears died during or after intraspecific fights, including sexually selected infanticide (10.53%). In addition, primary infectious diseases such as infectious canine hepatitis, distemper, clostridiosis and colibacillosis caused the death of 15.79% of the bears. The number of direct human-caused deaths (i.e., shooting, poisoning, snare) decreased over the study period. This study also reveals three new mortality causes triggered by pathogens, two of which-Clostridium novyi and verotoxigenic Escherichia coli-not previously described in ursids, and the other one, canine distemper virus, never reported in brown bears as cause of death. New management strategies for the conservation of Cantabrian bears, which are urgently needed due to the rapid expansion of the population, should consider the mortality causes described in this study and must promote further research to elucidate how the high prevalence of infectious diseases may threaten the current recovery of the population.
The Cantabrian capercaillie (
) is one of the most severely threatened subspecies of capercaillie. Its current population range is restricted to a small area of the Cantabrian Mountains (northwestern ...Spain), with only around 200 individuals remaining. As part of the national strategy for the conservation of the subspecies, the Cantabrian capercaillie Captive Breeding Center of Sobrescobio opened in 2009. Here, we use the information provided by the necropsies performed in this facility on 29 individuals (11 males, 13 females and 5 undetermined; 16 chicks and 13 adults) in order to describe the main mortality causes of captive-bred Cantabrian capercaillies. After necropsy, tissue samples were taken for evaluation using standard methods in histology and microbiology. The majority of the captive animals (18/29, 62.07%) died due to infectious diseases, mainly due to
,
, or
infection. The remaining 11 animals died due to stress-related processes (i.e., rupture of the heart apex and cardiomyopathy or neurogenic shock) (8/29, 27.59%), duodenal obstruction and coelomitis (1/29, 3.45%), perforation of the proventriculus and heart with a briar branch (1/29, 3.45%) or euthanasia due to a valgus leg deformity that prevented proper animal welfare (1/29, 3.45%). Young animals (i.e., younger than 2 months) died mainly due to infectious diseases (14/16, 87.5%), while stress-related causes were responsible for most adult deaths (7/13, 53.85%). We additionally report that two free-ranging adult males died due to exertional myopathy. This study provides relevant information for reducing mortality in captive capercaillies and improving both living conditions in captivity and the adaptation of these animals to the wild.
Full text
Available for:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
This work summarizes the mortality cases of twenty-five free-ranging Eurasian wild brown bears (Ursus arctos arctos) from the Cantabrian mountain range submitted for necropsy in Asturias and Castilla ...y León (northwestern Spain) from 1998 to 2018. Mortality cases were classified both caused by (i) “non-human intervention” or “human intervention” causes and based on (ii) “non-infectious” or “infectious” etiology. In four cases (16%) it was not possible to determine the cause of death due to the inadequate preservation of collected specimens or insufficient tissue availability. Based on “non-human intervention” or “human intervention” causes, fourteen of the 21 (66.7%) brown bears died as a consequence of “non-human intervention” due to traumatic lesions (fights, unknown traumas or infanticide), infectious canine hepatitis, neoplasia or mushroom poisoning. In contrast, seven (33.3%) brown bears died by “human intervention” due to illegal hunting (shooting or snare), handling (during transit in an attempt to reintroduce a bear back into the wild) or strychnine poisoning. Based on “non-infectious” or “infectious” etiology, twelve of the 21 (57.1%) brown bears died due to “non-infectious” causes, namely traumatic lesions such as shooting, snare, fighting or infanticide, handling, strychnine poisoning, mushroom poisoning or neoplasia. The remaining nine (42.9%) animals died due to “infectious” diseases which included gangrenous myositis, infectious canine hepatitis or septicemia. In six of those cases traumatic lesions caused by non-human or human activities were complicated with bacterial infection (clostridiosis and septicemia) which finally caused the death of those animals. Additionally, exertional myopathy was observed in the handled animal and in one bear found in a snare. In a free-ranging population of Eurasian brown bear from the Cantabrian mountain range, main causes of death are attributed to non-human related traumatic lesions and infectious diseases (primary developed such as infectious canine hepatitis or secondary developed such as clostridiosis or septicemia) which is in contrast to previously reported data for other bear populations. These data are valuable and may help in the conservation and management of this recovering population.
Full text
Available for:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
Dolphins are marine mammals that often live in coastal habitats. Common causes of severe skeletal disorders among wild dolphins are congenital vertebral anomalities, collisions with sea vessels, ...trauma, hunting-related injury, infectious diseases, environmental pollution, and tumors.
A free-ranging male, 3-year-old common dolphin (Delphinus delphis) was found dead in the coast of Asturias in northern Spain. Postmortem examination revealed lordosis in the caudal vertebral column, while X-ray imaging and computer tomography showed well-organized palisade-like periosteal proliferation, appearing as florid-like accretions, along the spinous apophysis of 26 lumbar-caudal vertebrae. The transverse apophysis was affected on only a few caudal vertebrae. The cortical layer remained intact. Histology of vertebra tissue showed periosteal proliferation of cancellous bone. The animal was diagnosed with hypertrophic osteopathy. The lungs showed diffuse parasitic granulomatous bronchointerstitial pneumonia caused by Halocercus delphini, consolidation of the pulmonary tissue, congestion, and alveolar edema. The animal was also afflicted by parasitic granulomatous gastritis caused by Anisakis simplex sensu lato and tattoo skin disease.
The dolphin suffered from hypertrophic osteopathy associated with pulmonary Halocercus delphini infestation. This syndrome, known as hypertrophic pulmonary osteopathy, has been described in diverse terrestrial mammals, including domestic animals, wildlife and humans, but not in dolphins. This case reports the first description of hypertrophic osteopathy associated to a pulmonary disorder in dolphin, and it provides insights into factors that can induce column malformation in dolphins, suggesting the importance of taking thoracic lesions into account during differential diagnosis.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Background
The Cantabrian capercaillie (Tetrao urogallus cantabricus) is critically endangered. This subspecies has the lowest genetic variability and it is in regression. It belongs to Phasianidae ...family; therefore, the domestic chicken (Gallus gallus domesticus) could be a good model for developing reproductive technologies for use in capercaillie populations with low availability of animals.
Objectives
In this study, we analyzed the response of capercaillie sperm to the freezing–thawing process for contributing to the development of a semen cryobank of Cantabrian capercaillie.
Methods
We used domestic chicken as the animal model in order to obtain the freezing protocol before applying on capercaillie. In the first experiment, two different extenders (EK and LR84) and different concentrations 4% and 6% dimethyl‐acetamide (DMA) v:v of cryoprotectants were evaluated using in‐straw freezing method in domestic chickens. A pilot study in capercaillie males, using the same conditions evaluated in chicken, was performed.
Results
In chicken, we found that the LR84‐4% DMA media provided the best results for freezing semen. In capercaillie study, LR84 extender seemed to be the most appropriate diluent and 4% was the better dose of DMA cryoprotectant agent. Further, based on previous studies carried out in rooster samples, we also tested the glycerol (8% v/v) as a cryoprotectant for capercaillie semen cryopreservation.
Conclusions
Our results suggest that sperm from both domestic and wild species had a similar response to freezing–thawing processes. Mediterranean chickens may be used as a suitable model for developing sperm freezing protocols that can be extrapolated to threatened capercaillie populations. In addition, LR84 media with glycerol was the most efficient extender to freeze capercaillie sperm native.
In this work, we obtained and described, for the first time, the ejaculate of Cantabrian capercaillie (Tetrao urogallus cantabricus). Also, we used a local Spanish breed (Gallus gallus) as the animal model in order to obtain the freezing protocol before applying on capercaillie. Then, we analyzed the response of capercaillie sperm to these freezing‐thawing process and our results suggest that sperm from both domestic and wild species have a similar response to freezing‐thawing processes.
Full text
Available for:
FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
Canine adenovirus type 1 (CAdV‐1) is responsible for infectious canine hepatitis. The disease has been described in captive American black bear (Ursus americanus) and European brown bear (Ursus ...arctos arctos), with just one recently reported case in a cub of a free‐ranging brown bear (Ursus arctos horribilis) from Alaska. The aim of this work is to summarize findings related to presence and associated mortality of CAdV‐1 in 21 free‐ranging Cantabrian brown bears (Ursus arctos arctos) submitted to necropsy in Asturias and Castilla y León (northwestern Spain) from 1998 to 2018. On the basis of the anatomopathological findings and laboratory results three free‐ranging brown bears died due to infectious canine hepatitis, which is to our knowledge the first description of death due to this disease in free‐ranging bears in Europe. Gross lesions consisted of petechial haemorrhages and congestion in different internal organs, haemorrhagic fluid in internal cavities, friable and yellowish liver and thickening of gall bladder. Microscopic lesions were observed mainly in liver, kidney and brain and consisted of multifocal necrosis of cells with presence of basophilic intranuclear inclusions. Immunohistochemical (IHC) and real‐time polymerase chain reaction (qPCR) techniques were used to assess the presence of CAdV‐1 in paraffin‐embedded liver samples. Viral antigens were detected by IHC labelling within hepatocytes and Küppfer cells in the three animals. The presence of viral DNA was confirmed by qPCR in one of them. In order to evaluate the circulation of CAdV‐1 in brown bears, a retrospective study was performed using both IHC and qPCR techniques in 11 and 12 additional brown bears, respectively. An extra brown bear was found positive by IHC. This study shows that CAdV‐1 surveillance of brown bears and sympatric carnivores should be considered as major concern for the monitoring the population evolution throughout time in this endangered species.
Full text
Available for:
BFBNIB, DOBA, FZAB, GIS, IJS, IZUM, KILJ, NLZOH, NUK, OILJ, PILJ, PNG, SAZU, SBCE, SBMB, UILJ, UKNU, UL, UM, UPUK
Animal capture is essential in conservation and management programs, both for captive and wild species. This paper describes the effect of midazolam sedation in domestic and wild phasianids with ...respect to dorso-abdominal massage for obtaining semen samples, and on the quality of the sperm thus collected. Three experiments were performed. Experiment 1 - Determination, with respect to semen quality, of the optimum midazolam treatment for sedation in the domestic chicken. This involved sedating birds with either: 1) 2 mL of saline (control C), 2) 2 mg/kg of midazolam (low dose LD), 3) 6 mg/kg of midazolam (high dose HD), or 4) 6 mg/kg of midazolam and waiting 10 min before starting to massage (HD-10) (all performed in duplicate). The response time to the sedative (T1) was recorded, as were the times from the start of massage to ejaculation (T2) and its end (T3). The proportion of animals that showed stress during massage was noted via their waking, wing flapping, and the heterophil-lymphocyte ratio. The volume of all sperm samples obtained was determined, along with sperm concentration, motility, viability, and DNA integrity. Experiment 2 - The same determinations were made in captive red-legged partridges. Experiment 3 - The effect of the discovered optimum conditions (HD-10) for the above species was examined in the capercaillie (a wild species). Sperm quality was not affected by sedation with midazolam in any of the examined species, although the capercaillies and partridges were more nervous during semen collection than were the chickens.
Full text
Available for:
GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
A free-living female Cantabrian brown bear (Ursus arctos arctos) cub severely affected by mange in Asturias (northern Spain) represented the first report of demodicosis for this species. After ...antimicrobial, antiparasitic, anti-inflammatory, and analgesic therapy it recovered and was released back into the wild to the eastern Cantabrian brown bear subpopulation.
Reports on neoplasms in bears are scarce, especially concerning ovarian tumors. A large primary ovarian neoplasm with multiple metastasis was found during the necropsy of a 14-year-old free-ranging ...Eurasian brown bear (Ursus arctos) from Northwestern Spain. Histopathology and immunohistochemistry allowed for the diagnosis of a sex cord stromal tumor. This is a complex group of neoplasms which differ in the predominant cell morphology and immunohistochemical features. The microscopic examination revealed two types of cells, one with eosinophilic cytoplasm, intermingled with larger vacuolated cells rich in lipids. The evaluation of the immunoreactivity to different markers, frequently used in the characterization of gonadal tumors (INHA, inhibin-alpha; PLAP, placental alkaline phosphatase; Ki-67; α-SMA, actin alpha-smooth muscle) and inflammation patterns (IBA1, ionized calcium-binding adapter molecule for macrophages; CD3 for T lymphocytes; CD20 for B lymphocytes), displayed significant INHA positive immunostaining of neoplastic cells, as well as inflammatory cell infiltration, mainly composed of macrophages and B lymphocytes. These findings were consistent with a malignant ovarian steroid cell tumor, not otherwise specified. The present study characterizes an unusual type of neoplasm, and also represents the first report of an ovarian sex cord stromal tumor in Ursidae.
Full text
Available for:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
PDF
