The multi‐functional use of large tree cavities by arboreal vertebrates in a temperate broadleaved forest of Eastern Europe

Tree cavities offer protected shelters and resources for arboreal vertebrates worldwide. In general, cavities with larger openings are better accessible for predators and are avoided by smaller species for breeding, but can still be attractive for occasional use. The current study explores the diversity of functional use types and species interactions at the largest available tree cavities (entrance width ≥ 10 cm) in a temperate European forest with a low number of large cavity‐breeding species. Year‐round camera observations at 9 cavities (range 0.7–3.5 years) revealed 34 visiting species of birds and mammals, including non‐cavity‐breeding species. The top predator threatening other large‐cavity users was European pine marten (Martes martes), which regularly visited each cavity year‐round, on average every 0.7 months. Tawny owl (Strix aluco) was the only species successfully breeding in cavities, arguably because of its ability to defend the nests. However, other species visited caviti..., Data collection
Data were collected as images produced by remote cameras (camera traps) installed in front of tree cavity entrances. Cameras were set to still mode, making 3 captures per trigger with the delay time 5 seconds, trigger sensitivity was set to the highest.
The unit of observation was a visit by a vertebrate defined as an image or a series of images of one species obtained within 30 seconds before and after other visits. When animals used cavities for roosting, a ‘visit’ was one roosting event per day, irrespective of its length. If two or more species were observed within one event, they were treated as one visit for each species.
The information recorded for each visit was: animal species, number of specimens, time and date of observation, time spent, activity type. Activity types were classified into five categories: passing with no interest to cavity (excluded from analysis), approaching and looking inside, entering the cavity, roosting and breeding in cavities.
Data pre..., , # Data from: The multi-functional use of large tree cavities by arboreal vertebrates

[https://doi.org/10.5061/dryad.nzs7h4505](https://doi.org/10.5061/dryad.nzs7h4505)

## Description of the data and file structure

***observations.csv***

| Field | Description |
| :---------------- | :-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| DateTimeOriginal | Date and Time in original format as exported from exif images ...,

树洞为全球范围内的树栖脊椎动物（arboreal vertebrates）提供了受保护的栖息场所与生存资源。一般而言，开口更大的树洞更容易被捕食者进入，也会被体型更小的物种避开作为繁殖巢穴，但仍可能吸引它们偶尔使用。本研究聚焦于欧洲温带森林中开口宽度≥10厘米的大型树洞（该区域内大型树洞繁殖物种数量较少），探究其功能使用类型的多样性与物种间的相互作用。
对9个树洞开展了为期0.7至3.5年的全年相机监测，共记录到34种鸟类与哺乳动物到访，其中包含非树洞繁殖物种。威胁其他大型树洞使用者的顶级捕食者为欧洲松貂（Martes martes），该物种全年定期造访各树洞，平均每0.7个月到访一次。灰林鸮（Strix aluco）是唯一成功在树洞中繁殖的物种，这或许得益于其具备的巢穴防御能力。不过其他物种也曾到访树洞……

## 数据采集
本研究的数据来源于安装在树洞入口前方的远程相机（相机陷阱，camera traps）所拍摄的影像。相机设置为静态拍摄模式，每次触发将连拍3张照片，间隔时间为5秒，触发灵敏度调至最高。
观测单元为脊椎动物的一次到访，定义为在其他到访事件前后30秒内拍摄到的单物种单张或系列影像。当动物利用树洞休憩时，单日单次休憩事件即计为一次到访，与其持续时长无关。若单次事件中观测到两个及以上物种，则分别为每个物种计为一次到访。
每次到访记录的信息包括：动物物种、个体数量、观测时间与日期、停留时长、行为类型。行为类型分为五类：对树洞无兴趣的路过（分析中已剔除）、靠近并向内观察、进入树洞、在树洞休憩、在树洞繁殖。

## 数据预处理……

# 数据集来源：树栖脊椎动物对大型树洞的多功能利用
[https://doi.org/10.5061/dryad.nzs7h4505](https://doi.org/10.5061/dryad.nzs7h4505)

## 数据与文件结构说明
### observations.csv
| 字段名 | 说明 |
| :---------------- | :-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| DateTimeOriginal | 从EXIF影像中导出的原始格式日期与时间