A New Northernmost Currently Confirmed Record of the Chinese Water Deer Hydropotes Inermis in Northeast Asia from an Urban Campus in Jiamusi, China

Abstract

We report an adult male Chinese water deer Hydropotes inermis repeatedly observed at Jiamusi University, Heilongjiang Province, northeastern China (130°22′02″ E, 46°46′56″ N). Clear photographs documented diagnostic external characters, and fecal samples collected from the same campus area were independently assigned to H. inermis by mitochondrial 16S rRNA sequencing. The locality lies approximately 208 km north of the Wuchang record in terms of latitudinal displacement and represents the northernmost currently confirmed occurrence of the species in its native Northeast Asian range. Repeated use of a university campus with regular pedestrian and vehicle activity suggests apparent tolerance of routine human presence within a human-modified setting, although the observations do not demonstrate urban adaptation, local population establishment, or the provenance of the individual.

1. Introduction

The Chinese water deer Hydropotes inermis Swinhoe, 1870 is an antlerless cervid native to East Asia. Current studies of habitat use indicate that the species has broad and diverse ecological adaptability, occupying lowland patches across a variety of habitats, including wetlands, river valleys, grasslands, forest edges and agricultural land [1,2,3]. Although its native distribution contracted during the twentieth century, recent records indicate a northward shift in its known occurrence in northeastern China and the Russian Far East [4,5,6]. Following its rediscovery in Jilin Province in 2017 [7], confirmed records were subsequently reported from the Russian Far East [8,9], Dongjingcheng Forestry Bureau [10], and Wuchang City, Heilongjiang Province [6] (Figure 1). Here, we report a photographically and genetically confirmed occurrence at Jiamusi University and evaluate its geographic position relative to these previous northern records.

Beginning on 10 May 2026, an adult male H. inermis was repeatedly observed within the campus of Jiamusi University, Jiamusi City, Heilongjiang Province, China. The focal site was a fenced undeveloped area near Xuefu Street, with trees and shrubs adjacent to campus buildings (Figure 2a). During several encounters, the individual remained observable despite normal pedestrian and vehicle activity outside the fence. When an observer approached to approximately 20 m, the animal watched the observer, then lay down in the shrub cover (Figure 2b) and subsequently fled behind a nearby building (Figure 2c). No obvious external injuries or gross abnormalities were visible in the photographs or during direct observation, and the animal could move away rapidly when approached. However, no clinical examination was conducted, and its health status therefore could not be assessed directly. We found no evidence that its use of the fenced, shrub-covered area was associated with injury or poor physical condition.

2. Materials and Methods

During the encounters, observers obtained clear smartphone photographs (Figure 2b). The individual was identified morphologically as a male H. inermis based on the absence of antlers, rounded ears, the lack of the conspicuous white rump patch characteristic of the Siberian roe deer Capreolus pygargus, and prominent upper canine tusks [4,12]. Observation events are summarized in Table S1. All photographed encounters involved an adult male of similar appearance within the same restricted campus area and were considered likely to represent the same individual, although this could not be confirmed conclusively. To further confirm the species identity genetically, we returned to the site to obtain independent molecular evidence. On 9 June 2026, nine fresh fecal samples were collected from the repeatedly used campus area. Samples were photographed in situ before collection (Figure 3), transferred with sterile disposable tools into individually labelled tubes, and stored and transported at −20 °C until DNA extraction. No animal was captured, handled or experimentally disturbed.

3. Results

The photographic identification and molecular results were concordant, and all three sequenced fecal samples were assigned to H. inermis (Supplementary Methods S1; Tables S2 and S3; Figure S1). Although the fecal samples were collected from the same campus area in which the photographed male had been repeatedly observed, the samples were collected after the photographic observation period and no individual-specific genotyping was performed. Therefore, the molecular data independently confirm the presence of H. inermis at the site but cannot demonstrate that the feces originated from the photographed male. Two subspecies, H. i. inermis and H. i. argyropus, have traditionally been recognized based on geographic distribution and pelage characteristics. The short 16S rRNA fragment used in the present study was designed for species-level identification, and its ability to discriminate between these subspecies has not been established. We therefore conservatively identify the Jiamusi record as H. inermis and do not assign it to either subspecies based on locality or the present molecular data [13,14]. The three mitochondrial 16S rRNA sequences generated in this study have been deposited in GenBank under accession numbers [QB050989; QB050990; QB050991].

To distinguish overall geographic separation from the magnitude of northward range displacement, we calculated both the geodesic distance between localities and the northward latitudinal displacement. Geodesic distances were calculated from WGS84 coordinates, whereas northward latitudinal displacement was calculated as the meridional surface distance corresponding to the difference in latitude between Jiamusi and each previous record. To the best of our knowledge, no published and independently verifiable modern occurrence was identified farther north in our search (Supplementary Methods S2). We therefore regard the Jiamusi occurrence as the northernmost currently confirmed record of H. inermis in its native Northeast Asian range (Figure 1, Table S4). The present evidence documents the occurrence of at least one individual at Jiamusi University but does not demonstrate the presence of a resident or breeding population.

4. Discussion

At Jiamusi University, the animal remained within an area exposed to routine pedestrian and vehicle activity and tolerated an approach to approximately 20 m before retreating. We interpret these observations only as apparent tolerance of routine human presence by this individual; they do not demonstrate urban adaptation at either the individual or species level. The provenance of the individual remains unknown. Although its occurrence is geographically consistent with the recent northward shift in documented records, a single-site observation cannot distinguish natural dispersal from escape, deliberate release, or other anthropogenic origins.

When a large mammal is detected well beyond its previously known distribution, both natural dispersal and anthropogenic origins must be considered. The present evidence confirms the species identity and repeated presence of Chinese water deer at Jiamusi University, but it does not identify the source of the individual. Natural dispersal is consistent with the regional expansion documented by camera traps, molecular data and landscape modelling [15], yet an escaped or deliberately released captive individual cannot be excluded solely from a single-site record. This uncertainty is best resolved through continued field monitoring rather than inference from appearance alone. Continued camera-trap and non-invasive genetic monitoring will be required to determine whether the Jiamusi occurrence was transient or reflects local persistence. The Jiamusi record represents the northernmost currently confirmed occurrence of H. inermis in Northeast Asia. The repeated observations are consistent with apparent tolerance of routine human presence by this individual, but whether such behaviour contributes to dispersal through human-modified landscapes remains untested.