Skip to main content
Download PDF

Hematological and plasma profiles and ticks and tick-borne pathogens in wild Formosan black bears (Ursus thibetanus formosanus)

Parasites & Vectors volume 17, Article number: 241 (2024) Cite this article

Abstract

Background

The endangered Formosan black bear (Ursus thibetanus formosanus) is the largest native carnivorous mammal in Taiwan. Diseases, poor management, illegal hunting, and habitat destruction are serious threats to the survival of bear populations. However, studies on the impact of diseases on bear populations are limited. Therefore, this study aimed to establish a database of the hematological and plasma profiles of free-ranging Formosan black bears and investigate the occurrence of ectoparasites, blood parasites, and vector-borne pathogens.

Methods

Formosan black bears were captured in Yushan National Park (YNP) and Daxueshan Forest Recreation Area (DSY) in Taiwan. Blood samples were collected from each bear for hematological analysis and plasma biochemistry using a hematology analyzer. Parasites and pathogens were detected using a thin blood smear with Wright–Giemsa staining and polymerase chain reaction (PCR) assay. Additionally, macroscopic ectoparasites were collected from bears to detect blood parasites and other pathogens. Moreover, the relationships between the bear variables (sex, age, and occurrence of parasites or pathogens), ectoparasites, and infectious agents were also analyzed.

Results

In all, 21 wild bears (14 in YNP and 7 in DSY) were captured and released during the satellite tracking studies. Hematological analysis and plasma biochemistry indicated significant differences in white blood cells (WBC), segments, creatine kinase (CK), and lactate dehydrogenase (LDH) levels between foot snare and culvert-captured bears. Additionally, there were significant differences in total plasma protein (TPP), creatinine, Ca2+, Mg2+, and K+ levels between male and female bears. Moreover, pathogen-infected bears had significantly higher erythrocyte sedimentation rate (ESR; 30 min and 1 h) and globulin levels than uninfected bears. In total, 240 ticks were collected from 13 bears, among which eight adult tick species were identified, including Haemaphysalis flava, Haemaphysalis hystricis, Amblyomma testudinarium, Ixodes ovatus, Dermacentor taiwanensis, Haemaphysalis longicornis, Ixodes acutitarsus, Amblyomma javanense, and nymphs belonging to Haemaphysalis spp. PCR revealed that 13 (61.90%) and 8 (38.10%) bears harbored Hepatozoon ursi and Babesia DNA, respectively. Among the ticks examined, 157 (65.41%) and 128 (53.33%) samples were positive for H. ursi and Babesia, respectively.

Conclusions

To the best of our knowledge, this is the first study to establish a database of the hematological and plasma profiles of wild Formosan black bears and investigate ectoparasite infestation and Hepatozoon and Babesia spp. infection. In conclusion, these findings may serve as a reference for monitoring the health and population of locally endangered bears.

Graphical Abstract

Background

Large carnivores perform vital ecological functions increasing their ecological integrity and biodiversity. The Formosan black bear (Ursus thibetanus formosanus) is a subspecies of Asiatic black bear and is indigenous to Taiwan. Presently, the Formosan black bear is classified as “Vulnerable” by the International Union for Conservation of Nature (IUCN) Red List of Threatened Species and listed in Additional file 1 of the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES). Additionally, the Formosan black bear is the largest native carnivore in Taiwan, and is listed as an endangered species under Taiwan’s Wildlife Conservation Act. Notably, Formosan black bears function as umbrella and landscape species for conservation because of their wide home range [1].

Importantly, the conservation of bear populations needs to be considered in relation to several aspects, such as population structure, environment, genetics, disease, and management conditions. Habitat destruction and illegal hunting are critical threats to the survival of Formosan black bears [2]. Recent ecological studies on carnivores have shown that epidemic diseases seriously threaten several endangered wild animals, especially in populations with reduced numbers, malnutrition, and stress, or in inbreeding groups. However, little is known about the effects of diseases on the population of Formosan black bear. To prevent further decline in the already small bear population, research should focus on potentially threatening diseases and environmental conditions [3].

Blood and plasma biochemical reference values can assist clinical veterinarians in interpreting individual nutritional and physiological conditions and serve as the basis for disease diagnosis. For example, a comprehensive understanding of the physiology, hematology, and serum biochemistry of American black bears (Ursus americanus) and brown bears (Ursus arctos) is crucial for evaluating population health managing both captive and wild bear populations [4,5,6,7,8]. Additionally, serological studies have detected several pathogens in bears in America and Europe [9,10,11,12]. However, information on the hematology and serum biochemistry of Asiatic black bears is limited, except for a few studies on captive bears in Thailand, Taiwan, and South Korea [13,14,15].

A comprehensive understanding of pathogen exposures is important to assess the overall health of bear populations and reveal possible infectious agents that may affect the health of humans and other animals. Blood macro- and micro-parasites, such as heartworms, Hepatozoon ursi, and Babesia spp., have been detected in the blood samples of different bear species in several countries [16,17,18,19,20]. Zoonotic pathogens, including Bartonella spp., Rickettsia spp., and Borrelia burgdorferi s.l., have also been detected in bear populations [21, 22]. Considering that wild bears can act as reservoirs of various pathogens, some of which pose risks to human health via zoonotic transmission, identifying these pathogens may help prevent potential disease threats to human populations. Among ectoparasites, lice (Trichodectes pinguis) and ticks (Haemaphysalis megaspinosa) were found on a gunshot-wounded Asiatic black bear [23]. Additionally, Demodex ursi and various species of hard ticks (Amblyomma americanum, Amblyomma maculatum, Dermacentor variabilis, Ixodes scapularis, Ixodes affinis) were found on American black bears [24,25,26].

Although some physiological data are available [5, 6, 8, 27, 28], knowledge of potential infectious and vector-borne pathogens in Formosan black bears is still lacking. Therefore, this study aimed to establish a database of the hematological and plasma profiles of free-ranging Formosan black bears and investigate the occurrence of ectoparasites, blood parasites, and vector-borne pathogens. Overall, it is anticipated that this study will provide useful information for the conservation and management of endangered Formosan black bear populations.

Methods

Capture-release procedures for Formosan black bears

Formosan black bears were captured from November 2014 to July 2021 at Yushan National Park (YNP) and Daxueshan Forest Recreation Area (DSY) in Taiwan for Global Positioning System (GPS) telemetry. YNP is located in the Central Mountain Range (23° 24′ 26.0604″ N, 121° 1′ 17.3604″ E), which covers an area of 1031.214 km2 (Fig. 1). DSY is located in the southeastern part of the Xueshan Mountain Range, near Taichung City (24° 15′ 11.16″ N, 121° 0′ 31.68″ E), covering an area of 39.63 km2 (Fig. 1). Notably, these areas have a relatively high bear density. All procedures involving bear capture, release, anesthetization, and sampling have been approved by the Forestry and Nature Conservation Agency of the Ministry of Agriculture under the Agreement of the Use of Conserved Wild Animals (No. 1031700938 and 1041701149) and the National Pingtung University of Science and Technology Laboratory Animal Care and Use Committee (IACUC No. NPUST-102-051 and NPUST-104-047).

Fig. 1
figure 1

Two study sites of Formosan black bears (Ursus thibetanus formosanus) captured and released during 2014–2021—Yushan National Park (yellow line) and Daxueshan National Forest Recreation Area (blue line). The sites are distributed in the Central Mountain Range and Xueshan Mountain Range, respectively, of Taiwan. Red grids (1 × 1 km2) represent the predicted distribution of Formosan black bears [29]

Full size image

Black bears were captured using an Aldrich spring-activated foot snare [30] and culvert traps (L × W × H: 200 × 78 × 78 cm) [31] (Fig. 2a, b), with the former only applied in YNP where some sites had no road access and required a 3-day hike. Notably, both traps were used from November 2014 to May 2016, and only culverts were used afterwards. Captured bears were immobilized using mixed doses of different anesthetics based on the capture procedure and the individual bear status. For snare-captured and anxious bears, 0.03 mg/kg of dexmedetomidine (Dexdomitor®, Pfizer Inc., New York, NY) and 3.0 mg/kg of tiletamine-zolazepam (Zoletil®, Virbac Inc., Carros, France) were used. For small bears captured in Culvert traps, 0.025 mg/kg of dexmedetomidine and 2.5 mg/kg of tiletamine-zolazepam were used [32, 33]. Mixed anesthetics were delivered intramuscularly through blow darts.

Fig. 2
figure 2

The setting of (a) snare and (b) culvert traps and sample collection for (c) subadult and (d) adult Formosan black bears

Full size image

After anesthetization, physical signs of anesthetic depth and physiological parameters, including body temperature and respiratory rate, were monitored and recorded. Pulse rate and blood oxygen saturation were monitored using a pulse oximeter (9847 V; NONIN Medical, Plymouth, MN, USA) with a sensor attached to the tongue. Individual sex, age, body weight, and morphometric characteristics were measured and recorded (Fig. 2c, d) [34]. Bear age was estimated and classified as adult or subadult on the basis of first premolar tooth sections or tooth wear [34, 35]. Bears aged 4 years or older were classified as adults [36]. After collection of blood samples and infesting ectoparasites, radio frequency identification (RFID) microchips were implanted into the hind necks of the bears, and ear tags were applied for individual identification. Additionally, GPS collars were attached to each bear for satellite tracking. At the end of the procedure, 10 mg of atipamezole (Antisedan®, Pfizer Inc., New York, NY) for each mg of dexmedetomidine were administered intramuscularly to reverse the anesthetic effect [37].

Sample collection procedures

Blood samples (10–20 mL) were collected from the cephalic or femoral vein in ethylenediaminetetraacetic acid (EDTA) anticoagulant tubes (BD Biosciences, Franklin Lakes, NJ, USA) and stored at 4 °C in a portable refrigerator. Ectoparasites were collected from the skin using tweezers and stored in microcentrifuge tubes containing 70% ethanol [38]. All samples were transported within 3 days to the Veterinary Medical Teaching Hospital and the Laboratory of Public Health and Epidemiology, National Pingtung University of Science and Technology for morphological identification and laboratory processes.

Thin blood smear, hematology, and plasma biochemistry examination

At least six thin Wright–Giemsa stained blood smears were obtained from each bear [39]. Microscopic examination was performed to explore the morphology of blood cells and identify the presence of blood parasites. Additionally, 14 hematological parameters were analyzed, including packed cell volume (PCV), total red blood cells (RBC), hemoglobin (Hb), mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH), mean corpuscular hemoglobin concentration (MCHC), total white blood cells (WBC), white blood cell types (segments, bands, lymphocytes, monocytes, eosinophils, basophils), and total platelet count (thrombocytes). White blood cell classifications were performed using an IDEXX ProCyte Dx Hematology analyzer instrument (IDEXX Laboratories Inc.,Westbrook, ME), whereas the remaining blood parameters were analyzed using the Mythic 18 Vet hematology analyzer instrument (Orphee SA, Switzerland). Additionally, erythrocyte sedimentation rate (ESR; 30 min and 1 h) and platelet fibrinogen (Fib) levels were analyzed using the Wintrobe method and heat precipitation fibrinogen test, respectively. The Fujifilm Dri-Chem 3500 s instrument (Fujifilm, Kanagawa, Japan) was used to measure the following 28 plasma biochemical parameters: total plasma protein (TPP), albumin, globulin, albumin/globulin ratio (A/G), bilirubin (T. Bil), aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase (ALP), gamma-glutamyl transferase (GGT), creatine kinase (CK), lactate dehydrogenase (LDH), cholesterol, triglyceride, glucose, amylase, lipase, creatinine, blood urea nitrogen (BUN), uric acid, free calcium (Ca2+), inorganic phosphorus (iP), and magnesium (Mg2+). Sodium (Na+), potassium (K+), and chloride (Cl−) electrolytes were analyzed using EasyLyte PLUS (Medica Corporation, Bedford, MA). Total carbon dioxide (TCO2), lactate, and plasma iron levels were determined using the Kodak Ektachem DT60 analytical system with DTE and DTSC II modules.

Morphological identification of ectoparasites

The ectoparasites collected in this study were all ticks. Briefly, ticks were surface-rinsed twice with deionized water and observed under a dissecting microscope for morphological identification using taxonomic keys [40, 41]. After morphological identification, each tick was individually placed in a microcentrifuge tube containing 70% ethanol and stored at 4 °C for DNA extraction.

DNA extraction from blood and tick samples of bears

Blood and tick samples were collected to detect parasitic and tick-borne pathogens. Tick samples were dissected in sterilized 1 × PBS. For nymphs, the whole body was cut and manually homogenized, whereas each adult tick was cut into approximately two halves. Half of each adult tick sample was transferred to a clean microcentrifuge tube for DNA extraction. A total of 100 µL of sterile 1 × PBS was added to each tube and stored at 4 °C until DNA extraction. The other half was stored in 70% ethanol as a backup. DNA was extracted from blood and tick samples using the DNeasy Blood and Tissue kit (Qiagen, Hilden, Germany), following the manufacturer’s instructions. All DNA samples were eluted into a 100 µL final volume and stored at −20 °C until used for blood parasite and pathogen detection.

Polymerase chain reaction (PCR)

In this study, the presence of three selected blood parasites (Dirofilaria ursi, Hepatozoon spp., and Babesia spp.) [17, 42, 43] and three zoonotic pathogens (Bartonella spp., Rickettsia spp., and Borrelia burgdorferi s.l.) [21, 22] in blood and tick samples was determined using PCR. PCR was performed using 20 µL of reaction mixture containing 5 µL of DNA template, 0.5 µL of 10 µM of each primer, 10 µL of 2 × Taq buffer (Bio-GENESIS Q-AMPTM 2 × Screening Fire Tag Mix kit, Illumina Co., USA), and distilled water. The primers and PCR conditions used for blood parasite and pathogen detection are listed in Table 1. DNA from each blood parasite, pathogen (positive control), and distilled water (negative control) were used for the PCR assay. Finally, PCR products were separated using a 2% agarose gel stained with nucleic acid stain (50 ppm EtB “out” nucleic acid staining solution, Yeastern Biotech., Taiwan), and the results were visualized with UVIdoc HD5 (Uvitec, Cambridge, UK).

Table 1 Primers for detecting blood parasites and pathogens of wild Formosan black bears used in this study
Full size table

Sequencing and statistical analyses

PCR products were purified using a Plus DNA Clean/Extraction Kit (GMbiolab Co., Ltd., Taichung, Taiwan) and sent for nucleotide sequencing (Genomics BioScience and Technology Co., Ltd., Taiwan). The sequence data were compared with known sequences deposited in the GenBank database using the National Center for Biotechnology Information (NCBI) nucleotide Basic Local Alignment Search Tool (BLAST). For genetic analysis, the validated sequences were aligned and analyzed using MegAlign (DNASTAR, Inc., Madison, WI, USA).

All statistical analyses were performed using GraphPad Prism version 8.4.2. The numerical data of each blood parameter were summarized as medians, means, and standard deviations. Comparisons of blood parameters between each bear variable of the bears, such as sex, age, area, trap type, and pathogen occurrence, were performed using unpaired t-tests for parametric data and Mann–Whitney U tests for non-parametric data. Additionally, multiple comparisons of blood parameters among pathogen infection, co-infection, and non-infection statuses of the bears were performed using the Kruskal–Wallis test, and P < 0.05 was considered statistically significant.

The relationships between bear variables (sex, age, and area) and blood parasite and pathogen infection status; tick variables (sex, life stage, and area) and pathogen harboring status; and bear variables (sex, age, and occurrence of blood parasites and pathogens) and the presence of blood-parasite- and pathogen-carrying ticks were analyzed using the chi-square test. A two-tailed Fisher’s exact test was used when the expected number of observations was less than five, and P < 0.05 was considered statistically significant.

Results

Demography of captured Formosan black bears

In total, 21 Formosan black bears were successfully captured and released (14 in YNP and 7 in DSY) between November 2014 and July 2021. Among the bears captured, there were 13 adults (seven males and six females) and one male subadult in YNP and six adults (three males and three females) and one male subadult in DSY. Blood samples were successfully collected from all bears, and ectoparasites were collected from 13 bears (61.90%) (Additional file 1: Table S1). Additionally, five bears were captured by snares in 2014–2015, while the rest were captured by culvert traps in 2015–2021.

Hematological and plasma profiles of captured Formosan black bears

The hematological and plasma biochemical profiles of wild Formosan black bears are summarized in Tables 2 and 3. TPP, creatinine, Ca2+, Mg2+, and K+ levels were higher in male bears than in females, and Fib value was higher in subadults than in adults. Additionally, ESR (1 h), ALP, triglycerides, and uric acid levels were higher in bears captured in YNP than in those captured in DSY, whereas the K+ value was higher in bears captured in DSY. Moreover, WBC, segment, CK, and LDH values were higher in snare-captured bears than in culvert-captured bears, whereas PCV, thrombocytes, TPP, glucose and K+ values were higher in culvert-captured bears. Regarding pathogen-infection-related differences, both ESR (30 min and 1 h) and globulin values were higher in infected bears than in non-infected bears, whereas albumin and A/G values were higher in non-infected bears. Furthermore, we compared blood parameters among bears infected with Babesia spp. (n = 2) and/or H. ursi (n = 7), co-infected with Babesia spp. and H. ursi (n = 6) and uninfected with the parasites (n = 6). Notably, there were significant differences in ESR (1 h; P = 0.0163), albumin (P = 0.0100), globulin (P = 0.0454), A/G (P = 0.0058), ALP (P = 0.0313), and Ca2+ (P = 0.0121) values among groups (Tables 4, 5). Multiple comparisons showed that albumin and A/G values were higher in non-infected bears than in bears co-infected with Babesia spp. and H. ursi (P = 0.0077 and P = 0.0233, respectively). Additionally, Babesia-infected bears had significantly higher (P = 0.0453) globulin levels and lower (P = 0.0278) A/G value than uninfected bears. Moreover, ALP and Ca2+ levels were higher in H. ursi-infected bears than in uninfected (P = 0.0327) and co-infected (P = 0.0314) bears (Table 5).

Table 2 Hematological profiles and the variation by bear sex, age, captured area, trap type, and occurrence of pathogens in wild Formosan black bears
Full size table
Table 3 Plasma biochemical profiles and the variation by bear sex, age, captured area, trap type, and occurrence of pathogens in wild Formosan black bears
Full size table
Table 4 Comparison of hematological profiles and pathogen occurrence variation in wild Formosan black bears
Full size table
Table 5 Comparison of plasma biochemical profiles and pathogen occurrence variation in wild Formosan black bears
Full size table

Diversity of ticks collected from Formosan black bears

In total, 240 ectoparasites (all ticks) were collected from 13 bears. Notably, eight species of adult ticks were identified, including 118 (49.16%) Haemaphysalis flava, 40 (16.67%) Haemaphysalis hystricis, 25 (10.41%) Amblyomma testudinarium, 21 (8.75%) Ixodes ovatus, 9 (3.75%) Dermacentor taiwanensis, 6 (2.5%) Haemaphysalis longicornis, 2 (0.83%) Ixodes acutitarsus, 1 (0.41%) Amblyomma javanense, and 17 (7.08%) nymphs belonging to Haemaphysalis spp. (Table 6). Additionally, one tick was not identified owing to damage to its mouth and body during collection (Table 6).

Table 6 Numbers of ticks in different species collected from Formosan black bears and the proportion of ticks that tested PCR-positive for blood parasites
Full size table

Blood parasite and pathogen detection in bears and ticks

Hepatozoon spp. gamonts were observed microscopically in thin blood smears (Fig. 3). Based on the morphology, the beak-like protrusion at one end of the slightly curved gamont is one of the most characteristic morphological features of H. ursi. PCR showed that 13 (61.90%) bears harbored Hepatozoon DNA. Additionally, DNA fragments from 10 random Hepatozoon-positive samples showed 99.1–99.7% similarity with the H. ursi isolate (EU041718) listed in the GenBank database. Although no Babesia spp. were observed in thin blood smears, Babesia DNA fragments were detected in eight (38.10%) blood samples and showed 90.6–94.4% similarity with Babesia gibsoni (KF171473), Babesia microti (JX962779), Babesia odocoilei (KC460321), and Babesia spp. (KC465978). Additionally, H. ursi and Babesia spp. co-infection was observed in six (28.57%) bears (all captured in YNP). However, PCR showed that all blood samples tested negative for D. ursi, Bartonella spp., Rickettsia spp., and B. burgdorferi s.l. DNA.

Fig. 3
figure 3

The beak-like protrusion at one end of the slightly curved gamont of H. ursi (arrowed) found in thin blood smears of Formosan black bears

Full size image

Among the 240 collected ticks, PCR showed that 157 (65.41%) were positive for Hepatozoon DNA (Table 6). DNA sequencing indicated that 50 randomly selected Hepatozoon-PCR-positive samples showed 99.0% similarity with the H. ursi isolate (EU041718) listed in the GenBank database. Importantly, 128 (53.33%) ticks were Babesia-positive, 40 of which were randomly selected for sequencing (Table 4). Additionally, the sequences showed 93.4–95.5% similarity with B. gibsoni (KF171473), B. microti (JX962779), and B. odocoilei (KC460321) isolates listed in the GenBank database. The results of PCR for Hepatozoon spp. and Babesia spp. in each tick species is shown in Table 4. Moreover, all tick samples tested negative for D. ursi, Bartonella spp., Rickettsia spp., and B. burgdorferi s.l. DNA using PCR.

H. ursi and Babesia spp. infection in Formosan black bears and their ticks

Notably, the prevalence rates of H. ursi and Babesia spp. infection in Formosan black bears were 61.90% (13/21) and 38.10% (8/21), respectively. Additionally, the prevalence of H. ursi infection in bears captured in YNP (92.85%) was significantly higher (P = 0.0001) than that in bears captured in DSY (0%); however, there was no significant difference in sex or age (Table 5). Moreover, there were no significant differences in the prevalence of Babesia spp. infection among bears of different sexes, ages, and areas (Table 7).

Table 7 Numbers of H. ursi- and Babesia spp.-PCR-positive samples in different variables of wild Formosan black bears and ticks
Full size table

Furthermore, the prevalence rates of H. ursi and Babesia spp. infections in ticks collected from the bears were 65.41% (157/240) and 53.33% (128/240), respectively. Adult female ticks (73.84%) had a significantly higher (P = 0.0002) prevalence of H. ursi infection than adult male ticks (50.0%; Table 7). However, there were no significant differences in H. ursi infection rates among ticks from different locations or life stages. Additionally, ticks on bears captured in DSY (84.0%) had a significantly higher (P = 0.0014) Babesia spp. infection rate than those captured in YNP (50.70%; Table 7). However, there was no significant difference in Babesia infection rates among ticks of different sexes or life stages.

The relationships between Formosan black bears’ status and their ticks carrying H. ursi and Babesia spp.

For each individual bear, the blood parasite infection status, numbers and species of ticks, and proportion of ticks harboring blood parasites are shown in Table 8. Ticks were collected from 13 of 21 (56.52%) bears. Notably, each bear was infested with up to four tick species per time (Table 6). H. flava was the predominant tick species (49.16%) infesting wild Formosan black bears in Taiwan, whereas the prevalence of the other tick species was below 20% (Table 4). Regardless of whether individual bears were infected with H. ursi and/or Babesia spp., the infesting ticks harbored blood parasites (Table 8).

Table 8 Numbers of ticks infesting bears, diversity of ticks, and H. ursi and Babesia spp. detected in wild Formosan black bears and ticks
Full size table

Ticks collected from Babesia-positive bears were more likely (P < 0.00001) to harbor Babesia spp. than those collected from Babesia-negative bears [65.30% (96/147) versus 34.40% (32/93)]. However, there were no significant differences in H. ursi detection rates between ticks collected from H. ursi-positive and H. ursi-negative bears.

Discussion

To the best of our knowledge, this is the first study to establish a hematological and plasma biochemical database of free-ranging black bears in Taiwan and investigate ectoparasite infestation, blood parasites, and tick-borne pathogen. In this study, there were no significant differences in hematological values among the different sexes or ages. Notably, the median values of PCV, RBC, Hb, MCV, and other erythrocyte-related parameters in the present study and in wild American black bears were lower than those of captive Formosan black bears [13] and other Asian black bears [14], which may be due to a richer diet in captive environments [49, 50]. However, erythrocyte-related values in wild Formosan black bears were lower than those in wild American black bears [25, 50]. Overall, these differences in hematological values could be species-specific or caused by differences in food resources.

Additionally, plasma biochemical parameters were significantly affected by sex. For example, TPP, creatinine, Ca2+, Mg2+, and K+ levels were significantly higher in male bears than in female bears; however, the reason for this remains unknown. TPP is an indicator of dietary protein levels and is correlated with the primary food sources of bears [51]. Additionally, the lower levels of Ca2+ in female bears than in male bears may be attributed to long-term pregnancy and lactation [50, 52]. In the present study, pathogen-infected bears had higher levels of inflammatory indicators, including ESR (30 min and 1 h) and globulin than uninfected bears. Moreover, there were significant differences in ESR (1 h), albumin, globulin, A/G, ALP, and Ca2+ levels between uninfected and pathogen-infected bears. Furthermore, Wright–Giemsa staining indicated the presence of Hepatozoon spp. gamonts in the blood of bears with high ESR and globulin values. Notably, changes in albumin, globulin, and ALP levels have also observed in other Babesia-infected hosts, such as camels (Camelus dromedarius) [53], dogs (Canis familiaris) [54], and cattle [55] as well as Hepatozoon-infected dogs [56,57,58]. Collectively, these hematological and plasma data may serve as a reference for future investigation on host and tick-borne pathogen relationships in wild bears.

Importantly, the differences in capture procedures also seemed to affect the blood profile of the bears. Consistent with previous findings in wild European brown bears and American black bears [28, 59], WBC, segments, CK, and LDH values were elevated in snare-captured bears, which may be attributed to potential stress and muscle injuries. However, diagnosing muscle injuries in bears requires physical examinations and imaging, which can be challenging in the field. Information based on satellite tracking and blood testing results seemingly can only reveal temporary muscle injuries in snare-captured bears. Therefore, we suggest that, when circumstances warrant, traps should be considered as a priority. Otherwise, snare traps should only be applied in remote areas with poor accessibility or emergency conditions, and when traps can be monitored in real time or checked daily.

Currently, 5 species of soft ticks and 44 species of hard ticks have been recorded in Taiwan [60,61,62]. Among the eight species of hard ticks found in wild Formosan black bears in this study, only A. javanense has not been previously recorded in Taiwan. H. flava appears to be the predominant tick infesting wild Formosan black bears, and has also been found in several mammals in Taiwan, including wild boars (Sus scrofa), deer (Rusa unicolor), and dogs [63]. Additionally, H. flava, A. testudinarium, H. longicornis, and D. taiwanensis have been recorded in wild Japanese black bears (U. t. japanicus) [17, 23]. A. javanense ticks are commonly found in reptiles and mammals, especially in pangolins [64]. Phylogenetic analysis and data of tick species in other animals in the same area would be helpful in investigating the distribution and sources of A. javanense in the country.

To the best of our knowledge, this is the first study to report H. ursi and Babesia spp. in wild Formosan black bears and their ticks. Notably, H. ursi infection had a lower prevalence in Formosan black bears (61.90%) than in Japanese black bears (76.3% and 100%) [17, 43], Indian sloth bears (Melursus ursinus; 70%) [18], and Turkish brown bears (Ursus arctos; 100%) [65]. Additionally, H. ursi detected in this study had a 99.1–99.7% nucleotide similarity with isolates from Japanese black bears (EU041718). Currently, H. ursi is the only Hepatozoon spp. detected in the family Ursidae [66]. Although wild Asiatic black bears have high H. ursi prevalence, there are no current reports on Hepatozoon spp. in other bear species such as American black bears, European brown bears, and polar bears [42, 67, 68], which may be because the suspected vector, H. flava, is mainly distributed in Asian countries [17, 69,70,71,72].

Hepatozoon spp. can be transmitted to hosts via ingestion of sporulated oocysts in ticks or other arthropod vectors [73,74,75]. In addition to the ingestion of vectors, predators, such as wild canids that hunt grey squirrels harboring the cystozoite stage of Hepatozoon spp., have also been suggested as a possible transmission route [76,77,78]. Hepatozoon infection in wild carnivores, such as the red fox (Vulpes vulpes) [79], European wild cat (Felis silvestris silvestris) [80], and pine martens (Martes martes) [81], usually cause little harm to the host. However, Hepatozoon-infected wildlife, which play an important role in the circulation of this pathogen, may represent a complementary natural reservoir for domestic animals [82]. For example, immature and mature meronts of Hepatozoon were histopathologically identified in the lungs of Hepatozoon-infected Japanese black bears [66]. Additionally, the lungs of these bears may harbor the schizogonic developmental stages of H. ursi [17].

Infections with Babesia spp. have been previously reported in Japanese and American black bears [43, 83,84,85]. In the present study, Babesia spp. infecting Formosan black bears were closely related to other Babesia species, such as B. gibsoni from dogs, B. microti from foxes (Vulpes spp.), and B. odocoilei from elks (Cervus elaphus canadensis). Similarly, Babesia DNA from American black bears was closely related to sequences from raccoons or domestic dogs [83]. Collectively, these results indicate that black bears can be infected by several Babesia spp. Furthermore, the unidentified Babesia spp. found in this study showed a 90.6–95.5% sequence similarity with known Babesia spp., highlighting the importance of conducting additional amplification and sequencing of the full-length 18S rRNA gene or other specific genes of Babesia to achieve a more detailed genetic characterization.

Babesia spp. are commonly transmitted to hosts by competent feeding ticks, followed by transfusion of infected blood products and vertical transmission [86, 87]. Babesia infections are typically asymptomatic in wild animals [88, 89]. For example, the clinical impact of babesiosis in bears is limited, and only a single episode of anemia has been reported in a Babesia-infected Japanese brown bear (U. t. japonicus) heavily infested with ticks [90]. However, the role of black bears as potential wildlife reservoirs of Babesia and other vector-borne pathogens warrants further investigation.

Although sex, age, or origin did not significantly affect the prevalence of blood parasites related to sex, age, or location, the prevalence of H. ursi infection was significantly higher in bears captured in YNP (13/14; 92.85%) than in those captured in DSY (0/7; 0%). H. ursi seemed to dynamically circulate among ticks, bears, and the environment in the YNP, but not in the DSY. Among the tick species that harbored Hepatozoon spp., H. flava is likely the most epidemiologically relevant. In Japan, mature Hepatozoon oocysts have been found in H. flava and H. japonica collected from dead Japanese black bears [17]. Overall, these findings indicate that H. flava plays an important role in Hepatozoon transmission to wild black bears. However, the vector competence of H. flava for Hepatozoon transmission requires further study. In the present study, female ticks had a higher prevalence of H. ursi infection than male ticks. Unlike male ticks, female ticks have a larger physiological demand for blood because they require it for engorgement prior to egg laying. This engorgement process provides them with additional opportunities to acquire pathogens from the host.

In Taiwan, Dermacentor taiwanensis and H. flava show a high prevalence of Babesia infections. Dermacentor taiwanensis infests several wild animals, including boar (Sus scrofa taivanus), bamboo partridge (Bambusicola thoracica), murine rodents (Bandicota, Rattus, Mus), tree squirrel (Callosciurus), hares (Lepus), and mustelid and viverrid carnivores (Mustela, Melogale, Paguma) [91]. In the present study, BLAST analysis revealed that Babesia DNA samples from ticks matched several species of Babesia. Although the species of Babesia was not identified due to the wide host range of ticks, we showed that ticks that infest Formosan black bears may be infected by several species of Babesia. Additionally, ticks on bears captured in DSY were more likely to harbor Babesia spp. than those captured in YNP. To further clarify whether the location affects the prevalence of Babesia infection in vectors, Babesia should be detected in ticks from the same environment.

Notably, regardless of whether the individual bears were infected with H. ursi and/or Babesia spp., collected ticks harbored blood parasites. Additionally, ticks collected from Babesia-positive bears were more likely to harbor Babesia spp. than ticks collected from Babesia-negative individuals. Importantly, the collected ticks harbored blood parasites even in bears that were not infected for several reasons, such as meal contamination (current or previous blood meals) and environmental contamination (on tick or host surfaces) [92]. Bears and ticks inhabit environments with a high prevalence of blood parasites, allowing ticks to carry these blood parasites [92]. Considering that previous research on Babesia spp. has rarely mentioned the relationship between host infection status and infesting vectors, this finding provides information on the association between Babesia spp.-infected ticks and Formosan black bears. Although only H. ursi and Babesia spp. were detected in wild Formosan black bears and in infesting ticks in this study, the other investigated blood parasites and pathogens such as D. ursi, Bartonella spp., Rickettsia spp., B. burgdorferi s.l., Ehrlichia chaffeensis, Anaplasma phagocytophilum, and Toxoplasma gondii have been reported in Japanese and American black bears [16, 20, 26, 93, 94]. Overall, the different results can be attributed to various factors, including geographical location, host specificity, tick species diversity, or sampling methodology. Comprehensive epidemiological surveys of parasites and other pathogens, particularly of endangered species, are recommended.

Amblyomma testudinarium, I. acutitarsus, and Rhipicephalus sanguineus s.l. ticks are frequently found in humans in Taiwan, followed by H. hystricis and Rhipicephalus haemaphysaloides [95,96,97]. These ticks harbor and act as potential vectors for zoonotic and human pathogens. In November 2019, a single human case of “severe fever with thrombocytopenia syndrome” (SFTS) was reported in Taiwan, resulting in death 40 days after the onset of clinical signs [98]. The tick-borne SFTS virus can be transmitted by H. longicornis [99], and has also been detected in A. testudinarium in Korea [100]. In Taiwan, the SFTS virus has been identified in serum samples collected from sheep, cattle, and dogs, and in R. microplus ticks collected from cattle [101]. Additionally, the Oz virus, a novel Thogotovirus that causes febrile illness and death in humans, was first isolated from A. testudinarium in Japan [102]. Overall, these findings emphasize the potential risk of zoonotic pathogen transmission. In the present study, both H. longicornis and A. testudinarium infested Formosan black bears. Additionally, both species may potentially infest humans and increase the risk of zoonotic diseases, such as SFTS and febrile illness caused by the Oz virus in Taiwan.

Conclusions

In this study, we established a database of the hematological and plasma profiles of free-ranging Formosan black bears in Taiwan and investigated the occurrence of ectoparasites, blood parasites, and vector-borne pathogens to elucidate the health status and pathogen dynamics within the bear population in Taiwan. Notably, a regional hematological and plasma biochemical database across various subspecies of Asiatic black bears in 18 countries [103] may serve as an essential resource for wildlife veterinarians and biologists in disease diagnosis and monitoring.

Availability of data and materials

All data generated or analyzed during this study are included in this published article.

References

  1. Roberge JM, Angelstam P. Usefulness of the umbrella species concept as a conservation tool. Conserv Biol. 2004;18:76–85.

    Article  Google Scholar 

  2. Lin R. Population viability analysis of Formosan black bears (Ursus thibetanus formosanus). Pingtung: National Pingtung University of Science and Technology; 2013.

    Google Scholar 

  3. Murray DL, Kapke CA, Evermann JF, Fuller TK. Infectious disease and the conservation of free-ranging large carnivores. Anim Conserv. 1999;2:241–54.

    PubMed  PubMed Central  Google Scholar 

  4. Bush M, Phillips L, Montali R. Clinical management of captive tigers. In: Tigers of the world. Park Ridge: Noyes Publications; 1987. p. 171–99.

    Google Scholar 

  5. Erickson AW, Youatt WG. Seasonal variations in the hematology and physiology of black bears. J Mammal. 1961;42:198–203.

    Article  Google Scholar 

  6. Franzmann AW, Schwartz CC. Evaluating condition of Alaskan black bears with blood profiles. J Wildl Manag. 1988;52:63–70.

    Article  CAS  Google Scholar 

  7. Halloran DW, Pearson AM. Blood chemistry of the brown bear (Ursus arctos) from southwestern Yukon Territory, Canada. Can J Zool. 1972;50:827–33.

    Article  CAS  PubMed  Google Scholar 

  8. Hock RJ. Seasonal variations in physiologic functions of arctic ground squirrels and black bears. Bull Mus Comp Zool. 1960;124:155–71.

    Google Scholar 

  9. Cottrell W, Keel MK, Brooks J, Mead D, Phillips J. First report of clinical disease associated with canine distemper virus infection in a wild black bear (Ursus americana). J Wildl Dis. 2013;49:1024–7.

    Article  CAS  PubMed  Google Scholar 

  10. Di Salvo AR, Chomel BB. Zoonoses and potential zoonoses of bears. Zoonoses Public Health. 2020;67:3–13.

    Article  PubMed  Google Scholar 

  11. Farajollahi A, Panella NA, Carr S, Crans W, Burguess K, Komar N. Serologic evidence of West Nile virus infection in black bears (Ursus americanus) from New Jersey. J Wildl Dis. 2003;39:894–6.

    Article  PubMed  Google Scholar 

  12. Zarnke RL, Evans MB. Serologic survey for infectious canine hepatitis virus in grizzly bears (Ursus arctos) from Alaska, 1973 to 1987. J Wildl Dis. 1989;25:568–73.

    Article  CAS  PubMed  Google Scholar 

  13. Chang GR, Mao FC, Yang CC, Chan FT. Hematological profiles of the Formosan black bear (Ursus thibetanus formosanus). Zool Stud. 2006;45:93–7.

    Google Scholar 

  14. Salakij C, Salakij J, Narkkong NA, Trongwonsa L, Pattanarangsan R. Hematology, cytochemistry and ultrastructure of blood cells in Asiatic black bear (Ursus thibetanus). Agric Nat Resour. 2005;39:247–61.

    Google Scholar 

  15. Yang J, Jeong D, Um S, Lee A, Song D, Kim S, et al. Blood chemistry reference intervals of captive Asiatic black bears (Ursus thibetanus). Vet Med. 2017;62:533–40.

    Article  CAS  Google Scholar 

  16. King JM. Pathology, parasitology, and hematology of the black bear in New York. New York Fish Game J. 1960;7:99–111.

    Google Scholar 

  17. Kubo M, Uni S, Agatsuma T, Nagataki M, Panciera RJ, Tsubota T, et al. Hepatozoon ursi n. sp. (Apicomplexa: Hepatozoidae) in Japanese black bear (Ursus thibetanus japonicus). Parasitol Int. 2008;57:287–94.

    Article  PubMed  Google Scholar 

  18. Pawar RM, Poornachandar A, Arun AS, Manikandan S, Shivaji S. Molecular prevalence and characterization of Hepatozoon ursi infection in Indian sloth bears (Melursus ursinus). Vet Parasitol. 2011;182:329–32.

    Article  CAS  PubMed  Google Scholar 

  19. Rogers LL, Rogers SM. Parasites of bears: a review. Bears Biol Manag. 1976;3:411–30.

    Google Scholar 

  20. Uni S. Filarial parasites from the black bear of Japan. Ann Parasitol Hum Comp. 1983;58:71–84.

    Article  CAS  PubMed  Google Scholar 

  21. Chern K, Bird M, Frey K, Huffman JE. Ticks and tick-borne pathogens of black bears (Ursus americanus) in New Jersey. J Pa Acad Sci. 2016;90:25–30.

    Google Scholar 

  22. Leydet BF Jr, Liang FT. Detection of human bacterial pathogens in ticks collected from Louisiana black bears (Ursus americanus luteolus). Ticks Tick Borne Dis. 2013;4:191–6.

    Article  PubMed  Google Scholar 

  23. Yokohata Y, Fujita O, Kamiya M, Fujita T, Kaneko K, Ohbayashi M. Parasites from the Asiatic black bear (Ursus thibetanus) on Kyushu Island, Japan. J Wildl Dis. 1990;26:137–8.

    Article  CAS  PubMed  Google Scholar 

  24. Foster GW, Cames TA, Forrester DJ. Geographical distribution of Demodex ursi in black bears from Florida. J Wildl Dis. 1998;34:161–4.

    Article  CAS  PubMed  Google Scholar 

  25. Schroeder MT. Blood chemistry, hematology, and condition evaluation of black bears in northcoastal California. Bears Biol Manag. 1987;7:333–49.

    Google Scholar 

  26. Yabsley MJ, Nims TN, Savage MY, Durden LA. Ticks and tick-borne pathogens and putative symbionts of black bears (Ursus americanus floridanus) from Georgia and Florida. J Parasitol. 2009;95:1125–8.

    Article  PubMed  Google Scholar 

  27. Graesli AR, Evans AL, Fahlman A, Bertelsen MF, Blanc S, Arnemo JM. Seasonal variation in haematological and biochemical variables in free-ranging subadult brown bears (Ursus arctos) in Sweden. BMC Vet Res. 2015;11:301.

    Article  PubMed  PubMed Central  Google Scholar 

  28. Huber D, Kusak J, Zvorc Z, Rafaj RB. Effects of sex, age, capturing method, and season on serum chemistry values of brown bears in Croatia. J Wildl Dis. 1997;33:790–4.

    Article  CAS  PubMed  Google Scholar 

  29. Tsai SC. The relative abundance and the distribution prediction models of Formosan black bears (Ursus thibetanus formosanus). Pingtung: National Pingtung University of Science and Technology; 2011.

    Google Scholar 

  30. Johnson KG, Pelton MR. Prebaiting and snaring techniques for black bears. Wildl Soc Bull. 1980;8:46–54.

    Google Scholar 

  31. Erickson AW. Techniques for live-trapping and handling black bears. In: Transactions of the North American Wildlife Conference. 1957. p. 520–43.

  32. Coltrane JA, Farley S, Saalfeld D, Battle D, Carnahan T, Teisberg J. Evaluation of dexmedetomidine, tiletamine, and zolazepam for the immobilization of black bears. Wildl Soc Bull. 2015;39:378–82.

    Article  Google Scholar 

  33. Teisberg JE, Farley SD, Nelson OL, Hilderbrand GV, Madel MJ, Owen PA, et al. Immobilization of grizzly bears (Ursus arctos) with dexmedetomidine, tiletamine, and zolazepam. J Wildl Dis. 2014;50:74–83.

    Article  CAS  PubMed  Google Scholar 

  34. Willey CH. Aging black bears from first premolar tooth sections. J Wildl Manag. 1974;38:97–100.

    Article  Google Scholar 

  35. Shimoinaba S, Oi T. Relationship between tooth wear and age in the Japanese black bear in Hiroshima Prefecture, Japan. Mammal Study. 2015;40:53–60.

    Article  Google Scholar 

  36. Hwang MH, Garshelis D. Activity patterns of Asiatic black bears (Ursus thibetanus) in the Central Mountains of Taiwan. J Zool. 2007;271:203–9.

    Article  Google Scholar 

  37. Jalanka HH, Roeken BO. The use of medetomidine, medetomidine-ketamine combinations, and atipamezole in nondomestic mammals: a review. J Zoo Wildl Med. 1990;21:259–82.

    Google Scholar 

  38. Tsai YL, Lin CC, Chomel BB, Chuang ST, Tsai KH, Wu WJ, et al. Bartonella infection in shelter cats and dogs and their ectoparasites. Vector Borne Zoonotic Dis. 2011;11:1023–30.

    Article  PubMed  Google Scholar 

  39. Peebles DA, Hochberg A, Clarke TD. Analysis of manual reticulocyte counting. Am J Clin Pathol. 1981;76:713–7.

    Article  CAS  PubMed  Google Scholar 

  40. Teng G, Wang D, Gu Y, Meng Y. Economic insects fauna of China: Fasc 40 Acari: Demanyssoideae. Beijing: Science Press; 1993.

    Google Scholar 

  41. Teng K, Jiang Z. Economic insect fauna of China Fasc 39 Acari: Ixodidae. Fauna Sinica Beijing: Science Press; 1991.

    Google Scholar 

  42. Crum JM, Nettles VF, Davidson WR. Studies on endoparasites of the black bear (Ursus americanus) in the southeastern United States. J Wildl Dis. 1978;14:178–86.

    Article  CAS  PubMed  Google Scholar 

  43. Ikawa K, Aoki M, Ichikawa M, Itagaki T. The first detection of Babesia species DNA from Japanese black bears (Ursus thibetanus japonicus) in Japan. Parasitol Int. 2011;60:220–2.

    Article  CAS  PubMed  Google Scholar 

  44. Michalski ML, Bain O, Fischer K, Fischer PU, Kumar S, Foster JM. Identification and phylogenetic analysis of Dirofilaria ursi (Nematoda: Filarioidea) from Wisconsin black bears (Ursus americanus) and its Wolbachia endosymbiont. J Parasitol. 2010;96:412–9.

    Article  CAS  PubMed  Google Scholar 

  45. Inokuma H, Okuda M, Ohno K, Shimoda K, Onishi T. Analysis of the 18S rRNA gene sequence of a Hepatozoon detected in two Japanese dogs. Vet Parasitol. 2002;106:265–71.

    Article  CAS  PubMed  Google Scholar 

  46. Hilpertshauser H, Deplazes P, Schnyder M, Gern L, Mathis A. Babesia spp. identified by PCR in ticks collected from domestic and wild ruminants in southern Switzerland. Appl Environ Microbiol. 2006;72:6503–7.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  47. Norman A, Regnery R, Jameson P, Greene C, Krause D. Differentiation of Bartonella-like isolates at the species level by PCR-restriction fragment length polymorphism in the citrate synthase gene. J Clin Microbiol. 1995;33:1797–803.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  48. Regnery RL, Spruill CL, Plikaytis BD. Genotypic identification of Rickettsiae and estimation of intraspecies sequence divergence for portions of two rickettsial genes. J Bacteriol. 1991;173:1576–89.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  49. Matula GJ. Behavioral and physiological characteristics of black bears in northeastern Pennsylvania. Pennsylvania State University; 1976.

  50. Matula GJ Jr, Lindzey JS, Rothenbacher H. Sex, age, and seasonal differences in the blood profile of black bears captured in northeastern Pennsylvania. Bears Biol Manag. 1980;4:49–56.

    Google Scholar 

  51. Hellgren EC, Rogers L, Seal U. Serum chemistry and hematology of black bears: physiological indices of habitat quality or seasonal patterns? J Mammal. 1993;74:304–15.

    Article  Google Scholar 

  52. Hock RJ. Analysis of the blood of American black bears. Comp Biochem Physiol. 1966;19:285–9.

    Article  CAS  PubMed  Google Scholar 

  53. Swelum AA, Ismael AB, Khalaf AF, Abouheif MA. Clinical and laboratory findings associated with naturally occurring babesiosis in dromedary camels. J Vet Res. 2014;58:229–33.

    CAS  Google Scholar 

  54. Sudhakara Reddy B, Sivajothi S, Varaprasad Reddy L, Solmon RK. Clinical and laboratory findings of Babesia infection in dogs. J Parasit Dis. 2016;40:268–72.

    Article  CAS  PubMed  Google Scholar 

  55. Khinchi R, Bihandi D, Ahuja A, Singh A. Haemato-biochemical changes in Babesia infected cattle. Vet Pract. 2016;17:59.

    Google Scholar 

  56. Assarasakorn S, Niwetpathomwat A, Techangamsuwan S, Suvarnavibhaja S. A retrospective study of clinical hematology and biochemistry of canine hepatozoonosis on hospital populations in Bangkok, Thailand. Comp Clin Path. 2006;15:107–9.

    Article  Google Scholar 

  57. Bai L, Goel P, Jhambh RP. Haematobiochemical changes in dog affected with Babesia canis. J Entomol Zool Stud. 2019;7:1519–20.

    Google Scholar 

  58. Tolkacz K, Kretschmer M, Nowak S, Myslajek RW, Alsarraf M, Wężyk D, et al. The first report on Hepatozoon canis in dogs and wolves in Poland: clinical and epidemiological features. Parasit Vectors. 2023;16:313.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  59. Powell RA. Evaluating welfare of American black bears (Ursus americanus) captured in foot snares and in winter dens. J Mammal. 2005;86:1171–7.

    Article  Google Scholar 

  60. Chen Z, Yang X, Bu F, Yang X, Yang X, Liu J. Ticks (acari: ixodoidea: argasidae, ixodidae) of China. Exp Appl Acarol. 2010;51:393–404.

    Article  PubMed  Google Scholar 

  61. Tsai YL, Shyu CL, Yao CT, Lin JA. The ixodid ticks collected from dogs and other animals in Taiwan and Kinmen Island. Int J Acarol. 2012;38:110–5.

    Article  Google Scholar 

  62. Shih CM, Chao LL. A catalog of Ixodidae ticks of Taiwan. Department of Parasitology and Tropical Medicine, National Defense Medical Center, Taiwan; 2011.

  63. Maa T, Kuo J. Catalogue and bibliography of ticks and mites parasitic on vertebrates in Taiwan. Quart J Taiwan Museum. 1966;19:373–413.

    Google Scholar 

  64. Kwak ML, Hsu CD, Douay G, Ahmad AA. The first authenticated record of the pangolin tick Amblyomma javanense (Acari: Ixodidae) in Singapore, with notes on its biology and conservation. Exp Appl Acarol. 2018;76:551–7.

    Article  PubMed  Google Scholar 

  65. Akyüz M, Kirman R, Güven E. Morphological and molecular data of Hepatozoon ursi in two brown bears (Ursus arctos) in Turkey. Folia Parasitol. 2020. https://0-doi-org.brum.beds.ac.uk/10.14411/fp.2020.032.

    Article  Google Scholar 

  66. Uni S, Matsubayashi M, Ikeda E, Suzuki Y. Characteristics of a hepatozoonosis in lungs of Japanese black bears (Ursus thibetanus japonicus). J Vet Med Sci. 2003;65:385–8.

    Article  PubMed  Google Scholar 

  67. Gjerde B, Derocher A, Wiig Ø. Absence of trypanosomes in polar bears (Ursus maritimus) from Svalbard. Vet Rec. 1999;145:526–7.

    Article  CAS  PubMed  Google Scholar 

  68. Mörner T, Eriksson H, Bröjer C, Nilsson K, Uhlhorn H, Ågren E, et al. Diseases and mortality in free-ranging brown bear (Ursus arctos), gray wolf (Canis lupus), and wolverine (Gulo gulo) in Sweden. J Wildl Dis. 2005;41:298–303.

    Article  PubMed  Google Scholar 

  69. Fang LZ, Lei SC, Yan ZJ, Xiao X, Liu JW, Gong XQ, et al. Detection of multiple intracellular bacterial pathogens in Haemaphysalis flava ticks collected from hedgehogs in central China. Pathogens. 2021;10:115.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  70. Iqbal A, Nawaz M. Taxonomic studies of Haemaphysalis flava (Neumann), its seasonal prevalence and role in parasitic diseases of sheep/goat in Balochistan. Pak Entomol. 2007;29:1–4.

    Google Scholar 

  71. Kuo CC, Lin YF, Yao CT, Shih HC, Chung LH, Liao HC, et al. Tick-borne pathogens in ticks collected from birds in Taiwan. Parasit Vectors. 2017;10:587.

    Article  PubMed  PubMed Central  Google Scholar 

  72. Yun SM, Lee YJ, Choi W, Kim HC, Chong ST, Chang KS, et al. Molecular detection of severe fever with thrombocytopenia syndrome and tick-borne encephalitis viruses in ixodid ticks collected from vegetation, Republic of Korea, 2014. Ticks Tick Borne Dis. 2016;7:970–8.

    Article  PubMed  Google Scholar 

  73. Garrett JJ, Kocan AA, Reichard MV, Panciera RJ, Bahr RJ, Ewing SA. Experimental infection of adult and juvenile coyotes with domestic dog and wild coyote isolates of Hepatozoon americanum (Apicomplexa: Adeleorina). J Wildl Dis. 2005;41:588–92.

    Article  PubMed  Google Scholar 

  74. Mathew J, Ewing S, Panciera R, Woods J. Experimental transmission of Hepatozoon americanum Vincent-Johnson et al., 1997 to dogs by the Gulf Coast tick Amblyomma maculatum Koch. Vet Parasitol. 1998;80:1–14.

    Article  CAS  PubMed  Google Scholar 

  75. Smith TG. The genus Hepatozoon (apicomplexa: adeleina). J Parasitol. 1996;82:565–85.

    Article  CAS  PubMed  Google Scholar 

  76. Desser SS. Tissue “cysts” of Hepatozoon griseisciuri in the grey squirrel, Sciurus carolinensis: the significance of these cysts in species of Hepatozoon. J Parasitol. 1990;76:257–9.

    Article  CAS  PubMed  Google Scholar 

  77. Ewing S, Mathew J, Panciera R. Transmission of Hepatozoon americanum (Apicomplexa: Adeleorina) by ixodids (Acari: Ixodidae). J Med Entomol. 2002;39:631–4.

    Article  CAS  PubMed  Google Scholar 

  78. Johnson EM, Allen KE, Breshears MA, Panciera RJ, Little SE, Ewing SA. Experimental transmission of Hepatozoon americanum to rodents. Vet Parasitol. 2008;151:164–9.

    Article  PubMed  Google Scholar 

  79. Mierzejewska EJ, Dwużnik D, Koczwarska J, Stańczak Ł, Opalińska P, Krokowska-Paluszak M, et al. The red fox (Vulpes vulpes), a possible reservoir of Babesia vulpes, B. canis and Hepatozoon canis and its association with the tick Dermacentor reticulatus occurrence. Ticks Tick Borne Dis. 2021;12:101551.

    Article  PubMed  Google Scholar 

  80. Hodžić A, Alić A, Prašović S, Otranto D, Baneth G, Duscher GG. Hepatozoon silvestris sp. Nov.: morphological and molecular characterization of a new species of Hepatozoon (Adeleorina: Hepatozoidae) from the European wild cat (Felis silvestris silvestris). Parasitology. 2017;144:650–61.

    Article  PubMed  Google Scholar 

  81. Simpson V, Panciera R, Hargreaves J, McGarry J, Scholes S, Bown K, et al. Myocarditis and myositis due to infection with Hepatozoon species in pine martens (Martes martes) in Scotland. Vet Rec. 2005;156:442–6.

    Article  CAS  PubMed  Google Scholar 

  82. Uiterwijk M, Vojta L, Šprem N, Beck A, Jurković D, Kik M, et al. Diversity of Hepatozoon species in wild mammals and ticks in Europe. Parasit Vectors. 2023;16:1–12.

    Article  Google Scholar 

  83. Shaw M, Kolba N, Huffman JE. Babesia spp. in Ursus americanus (black bear) in New Jersey. Northeast Nat. 2015;22:451–8.

    Article  Google Scholar 

  84. Skinner D, Mitcham JR, Starkey LA, Noden BH, Fairbanks WS, Little SE. Prevalence of Babesia spp., Ehrlichia spp., and tick infestations in Oklahoma black bears (Ursus americanus). J Wildl Dis. 2017;53:781–7.

    Article  CAS  PubMed  Google Scholar 

  85. Westmoreland LSH, Stoskopf MK, Sheppard E, DePerno CS, Gould NP, Olfenbuttel C, et al. Detection and prevalence of Babesia spp. in American black bears (Ursus americanus) from eastern and western North Carolina, USA. J Wildl Dis. 2019;55:678–81.

    Article  CAS  PubMed  Google Scholar 

  86. De Vos A, Imes G, Cullen J. Cerebral babesiosis in a new-born calf. Onderstepoort J Vet Res. 1976;43:75–8.

    PubMed  Google Scholar 

  87. Fukumoto S, Suzuki H, Igarashi I, Xuan X. Fatal experimental transplacental Babesia gibsoni infections in dogs. Int J Parasitol. 2005;35:1031–5.

    Article  PubMed  Google Scholar 

  88. Penzhorn BL. Babesiosis of wild carnivores and ungulates. Vet Parasitol. 2006;138:11–21.

    Article  PubMed  Google Scholar 

  89. Shock BC, Murphy SM, Patton LL, Shock PM, Olfenbuttel C, Beringer J, et al. Distribution and prevalence of Cytauxzoon felis in bobcats (Lynx rufus), the natural reservoir, and other wild felids in thirteen states. Vet Parasitol. 2011;175:325–30.

    Article  PubMed  Google Scholar 

  90. Jinnai M, Kawabuchi-Kurata T, Tsuji M, Nakajima R, Hirata H, Fujisawa K, et al. Molecular evidence of the multiple genotype infection of a wild Hokkaido brown bear (Ursus arctos yesoensis) by Babesia sp. UR1. Vet Parasitol. 2010;173:128–33.

    Article  CAS  PubMed  Google Scholar 

  91. Hoogstraal H, Wassef HY, Santana FJ, Kuntz RE. Dermacentor (Indocentor) taiwanensis (Acari: Ixodoidea: Ixodidae): hosts and distribution in Taiwan and southern Japan. J Med Entomol. 1986;23:286–8.

    Article  CAS  PubMed  Google Scholar 

  92. Dwużnik D, Mierzejewska EJ, Drabik P, Kloch A, Alsarraf M, Behnke JM, et al. The role of juvenile Dermacentor reticulatus ticks as vectors of microorganisms and the problem of ‘meal contamination.’ Exp Appl Acarol. 2019;78:181–202.

    Article  PubMed  Google Scholar 

  93. Nims TN, Durden LA. Ticks and lice of the black bear, Ursus americanus Pallas, in northern Georgia, USA, including a new state record for the chewing louse, Trichodectes euarctidos (Phthiraptera: Trichodectidae). J Entomol Sci. 2011;46:345–7.

    Google Scholar 

  94. Stephenson N, Higley JM, Sajecki JL, Chomel BB, Brown RN, Foley JE. Demographic characteristics and infectious diseases of a population of American black bears in Humboldt County, California. Vector Borne Zoonotic Dis. 2015;15:116–23.

    Article  PubMed  Google Scholar 

  95. Chao LL, Lu CW, Lin YF, Shih CM. Molecular and morphological identification of a human biting tick, Amblyomma testudinarium (Acari: Ixodidae), in Taiwan. Exp Appl Acarol. 2017;71:401–14.

    Article  CAS  PubMed  Google Scholar 

  96. Chao LL, Shih CM. First report of human biting activity of Ixodes acutitarsus (Acari: Ixodidae) collected in Taiwan. Exp Appl Acarol. 2012;56:159–64.

    Article  PubMed  Google Scholar 

  97. Guglielmone AA, Robbins RG. Hard ticks (Acari: Ixodida: Ixodidae) parasitizing humans. Cham: Springer; 2018. p. 230.

    Book  Google Scholar 

  98. Peng SH, Yang SL, Tang SE, Wang TC, Hsu TC, Su CL, et al. Human case of severe fever with thrombocytopenia syndrome virus infection, Taiwan, 2019. Emerg Infect Dis. 2020;26:1612.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  99. Luo LM, Zhao L, Wen HL, Zhang ZT, Liu JW, Fang LZ, et al. Haemaphysalis longicornis ticks as reservoir and vector of severe fever with thrombocytopenia syndrome virus in China. Emerg Infect Dis. 2015;21:1770.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  100. Suh JH, Kim HC, Yun SM, Lim JW, Kim JH, Chong ST, et al. Detection of SFTS virus in Ixodes nipponensis and Amblyomma testudinarium (Ixodida: Ixodidae) collected from reptiles in the Republic of Korea. J Med Entomol. 2016;53:584–90.

    Article  PubMed  Google Scholar 

  101. Lin TL, Ou SC, Maeda K, Shimoda H, Chan JPW, Tu WC, et al. The first discovery of severe fever with thrombocytopenia syndrome virus in Taiwan. Emerg Microbes Infect. 2020;9:148–51.

    Article  CAS  PubMed  PubMed Central  Google Scholar 

  102. Ejiri H, Lim CK, Isawa H, Fujita R, Murota K, Sato T, et al. Characterization of a novel thogotovirus isolated from Amblyomma testudinarium ticks in Ehime, Japan: a significant phylogenetic relationship to Bourbon virus. Virus Res. 2018;249:57–65.

    Article  CAS  PubMed  Google Scholar 

  103. IUCN. 2022. The IUCN red list of threatened species. Version 2022-2. https://www.iucnredlist.org. Accessed 11 Nov 2023.

Download references

Acknowledgements

We thank the Forestry and Nature Conservation Agency and Yushan National Park headquarters for providing logistical support. We are also grateful to the many research assistants, graduate students, and volunteers who helped with fieldwork. We would like to thank anonymous referees for their valuable comments, which helped us to improve the manuscript.

Funding

This research was mainly funded by the National Science and Technology Council, Taiwan: MOST 103-2621-B-020-001 and MOST 104-2621-B-020-001.

Author information

Author notes

  1. Yi-Lun Tsai and Wittawat Wechtaisong have contributed equally to this work.

Authors and Affiliations

  1. Department of Veterinary Medicine, College of Veterinary Medicine, National Pingtung University of Science and Technology, Pingtung, Taiwan

    Yi-Lun Tsai, Wittawat Wechtaisong & Ting-Rong Lee

  2. Veterinary Medical Teaching Hospital, College of Veterinary Medicine, National Pingtung University of Science and Technology, Pingtung, Taiwan

    Yi-Lun Tsai

  3. Center of Excellence in Animal Vector-Borne Diseases, Veterinary Parasitology Unit, Department of Veterinary Pathology, Faculty of Veterinary Science, Chulalongkorn University, Bangkok, Thailand

    Wittawat Wechtaisong

  4. Institute of Wildlife Conservation, College of Veterinary Medicine, National Pingtung University of Science and Technology, Pingtung, Taiwan

    Ting-Rong Lee & Mei-Hsiu Hwang

  5. Institute of Veterinary Clinical Science, College of Veterinary Medicine, National Taiwan University, Taipei, Taiwan

    Chun-Hao Chang & Pin-Huan Yu

Authors
  1. Yi-Lun Tsai
    View author publications

    You can also search for this author in PubMed Google Scholar

  2. Wittawat Wechtaisong
    View author publications

    You can also search for this author in PubMed Google Scholar

  3. Ting-Rong Lee
    View author publications

    You can also search for this author in PubMed Google Scholar

  4. Chun-Hao Chang
    View author publications

    You can also search for this author in PubMed Google Scholar

  5. Pin-Huan Yu
    View author publications

    You can also search for this author in PubMed Google Scholar

  6. Mei-Hsiu Hwang
    View author publications

    You can also search for this author in PubMed Google Scholar

Contributions

YLT and MHH: conceptualization and study design; TRL, YLT, CHC, PHY, and MHH: sample and data collection; WW and TRL: validation and formal analysis; YLT, CHC, and WW: data curation; YLT, MHH, and WW: manuscript writing and editing; MHH: supervision and correspondence.

Corresponding author

Correspondence to Mei-Hsiu Hwang.

Ethics declarations

Ethical approval and consent to participate

All capture, release, anesthesia, and sampling procedures on bears have been approved by the Forestry and Nature Conservation Agency under the Agreement to the Use of Conserved Wild Animals (No. 1031700938 and 1041701149) and the National Pingtung University of Science and Technology Laboratory Animal Care and Use Committee (IACUC No. NPUST-102-051 and NPUST-104-047).

Consent for publication

Not applicable.

Competing interests

The authors declare that they have no competing interests.

Additional information

Publisher’s Note

Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Supplementary Information

Rights and permissions

Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated in a credit line to the data.

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Tsai, YL., Wechtaisong, W., Lee, TR. et al. Hematological and plasma profiles and ticks and tick-borne pathogens in wild Formosan black bears (Ursus thibetanus formosanus). Parasites Vectors 17, 241 (2024). https://0-doi-org.brum.beds.ac.uk/10.1186/s13071-024-06320-7

Download citation

  • Received:

  • Accepted:

  • Published:

  • DOI: https://0-doi-org.brum.beds.ac.uk/10.1186/s13071-024-06320-7

Keywords

Parasites & Vectors

ISSN: 1756-3305

Contact us