Keywords

Purpose

Nation-wide wildlife monitoring projects are vital for biodiversity conservation, especially as early warnings of environmental crises and for evaluating the efficiency of implemented conservation strategies. However, such projects have been very rare in the Asia-Pacific region, including Taiwan . Wild bird populations are among the few taxa for which large-scale surveys have been conducted in Taiwan. Dating back to 1974, the New Year Bird Count was the earliest attempt to collect nation-wide bird census data at a specific time of the year (Yen 1982), by encouraging birders to go out birding and upload their records in December and January. Such activities still continue to be implemented in several regions (e.g., Kenting National Park Headquarters 2012). Bird counts focusing on specific species such as migratory raptors (Yang et al. 2011), or in local regions such as Important Bird Areas, have been the main source of long-term biodiversity monitoring during the late twentieth century. These counts have been mostly organized by nongovernment organizations (NGOs). Public participation has hence played an important role in these early attempts of data gathering and biodiversity monitoring.

However, transforming observation and count activities into a well-functioning monitoring project presents difficulties. NGOs in Taiwan were enthusiastic to make contributions when it came to saving the environment, but they were unable to establish persuasive monitoring designs and proper analyses. Academic institutions have the ability to conduct sound monitoring surveys and can also produce numerous biodiversity reports, but such surveys were generally short lived since resources were bound to specific projects only specifically instituted by different agencies. Government institutions, on the other hand, hold the greatest potential to undertake long work tasks, but with limited resources the goal of running large-scale surveys was elusive at best. In short, it was soon recognized that to give birth to a monitoring project on a large spatial and temporal scale, a cross-organizational citizen science collaborating project would be vital.

Development History of the Taiwan Breeding Bird Survey

Despite the abundant examples of migratory species and nonbreeding season surveys, thoughts of conducting projects targeting breeding bird monitoring did not literally emerge until the onset of the twenty-first century. Largely inspired by the headline indicators for sustainable development in the UK, and the North American Breeding Bird Survey, the first suggestions of designing a comprehensive large-scale breeding bird survey in Taiwan were made in 2001. Suggestions were for a project aimed at establishing nation-wide indicators of ecological sustainable developments using breeding bird populations (Chiou et al. 2001). In the following year, to exchange information and gain further consensus on this new idea, a conference titled “Planning and Promoting the Breeding Bird Survey” was held by the Endemic Species Research Institute in Nantou County in Central Taiwan (Endemic Species Research Institute 2002). After the conference, related articles were published in both government reports (Hsu et al. 2003) and journals targeting Taiwanese birders (Hsu 2003a, b) to help raise public awareness. By then, most of the proposed sampling schemes, survey methods, and basic structure for the breeding bird survey were arranged. Furthermore, the idea that the survey should be designed as a citizen science project had also been adopted (Hsu et al. 2003).

In 2007, a project aimed at evaluating the status of biodiversity in Taiwan funded by the Forestry Bureau gave researchers at National Taiwan University a promising chance to bring the idea of a breeding bird survey into reality (Lee et al. 2007). After a final review of previous efforts and preliminary tests of survey methods in 2008, the Taiwan Breeding Bird Survey (BBS Taiwan) was launched in the breeding season of 2009, by National Taiwan University in collaboration with the Chinese Wild Bird Federation (CWBF). The Endemic Species Research Institute (ESRI) joined BBS Taiwan’s working group in 2010 in joint partnership. BBS Taiwan entered its fourth year in 2012, and with its steady growth in site coverage and participants, it is now confidently planning ahead as far as its tenth anniversary year.

Approach

Cross-Organizational Collaboration

BBS Taiwan was designed as a citizen science project and implemented by joint partnerships with NGOs, government agencies, and academic institutions. Cross-organizational collaboration helped to overcome the three main challenges we face in Taiwan when establishing a large-scale monitoring project: (1) shortage of resources, (2) difficulties in persistence, and (3) lack of scientific involvement. Joint partnership within the BBS Taiwan working group includes the Chinese Wild Bird Federation, the Endemic Species Research Institute of the Council of Agriculture, and the Institute of Ecology and Evolutionary Biology of National Taiwan University (Table 3.1).

Table 3.1 Roles of each organization in the Breeding Bird Survey (BBS) Taiwan joint partnership
Full size table

Survey Training Workshops

One of the major challenges in implementing citizen science projects is to ensure the quality of data. Because these data would be used to build national indicators aimed for providing important information for biodiversity conservation, it would be of the most important basal issues to be carefully addressed. Recognizing that data would be collected by amateurs who generally had not been through formal training, the BBS Taiwan workgroup arranged workshops in each county of Taiwan to recruit surveyors and to train them in correct survey methods. The training courses included four essential sections:

  1. 1.

    Introduction to biodiversity monitoring and the goals of BBS Taiwan.

  2. 2.

    Step-by-step survey methods, with a strong emphasis on the concept of standard protocols and the importance of compliance.

  3. 3.

    Birding by ear: because point counts rely strongly on the ability to identify bird species by auditory cues , this section is set to learn and recognize the song and calls of breeding bird species, an exercise commonly neglected by birders in Taiwan.

  4. 4.

    Practice in the field: an exercise of BBS Taiwan survey methods in the field led by experienced surveyors.

Sampling Scheme

The central idea of BBS Taiwan’s sampling scheme is to encompass a set of survey sites that would be representative of all major habitats in Taiwan. We employed stratified random sampling to select our sampling sites. The first step was to divide the island of Taiwan into 41 ecoregions (Su 1992), with a further division into three different elevation zones (0–1,000, 1,000–2,500, 2,500–4,000 m), hence resulting in 91 strata. The second step was to locate areas that are reachable by roads within each stratum. This criterion was added because many montane areas in Taiwan would be difficult and dangerous to be surveyed by volunteers if there was no access road. The final step was to randomly select sites within each stratum with numbers fitting the proportion of area of each stratum to cover the whole of Taiwan Island. Taiwan’s main island has an area of about 36,000 km2, and we set 5 % coverage as a first-stage goal. Consequently, with a survey site expected to cover around 4 km2, we randomly selected 450 survey sites, which were provided to be adopted by surveyors (Fig. 3.1).

Fig. 3.1
figure 1

Breeding Bird Survey (BBS) Taiwan sampling sites selected by stratified random sampling. Border lines are ecological climate zones that were delineated by Su (1992)

Full size image

Survey Methods

From among the various bird survey methods, we decided to use a point-count method (Bibby et al. 2000). This approach was preferred over a transect method, which is also a common technique in breeding bird monitoring (e.g., UK breeding bird survey), mainly because of the difficulty in executing transect surveys in the rugged topography in the mountainous regions of Taiwan (Chiou et al. 2001). Distance sampling (Buckland et al. 2001) and time removal model (Farnsworth et al. 2002) were both implemented into the survey design to account for imperfect detection . Each BBS Taiwan site consists of 6–10 points, and is surveyed twice a year, which gives each site a minimum sampling effort of 12 times: this is the minimum sampling effort required to attain reliable data with a coefficient of variance less than 20 % in the breeding season within each site on Taiwan (Shiu and Lee 2003). The count duration of each point is 6 min, which suggests the likelihood of detecting at least 80 % of the species at each sites (Ding 1993; Shiu and Lee 2003). Surveys are performed within the breeding season between March and June, with sites at higher elevations surveyed in a later sequence. Surveys are conducted within 4 h of sunrise on each day, which is estimated to be the most efficient time period to detect birds in the breeding season (Ding 1993; Chiou et al. 2001).

Analysis

Bird Population Indicators

Tracking trends of breeding bird populations is one of the main goals of BBS Taiwan. For the establishment of population indicators of Taiwan breeding birds, we used TRIM (TRends and Indices for Monitoring data), a software program using Poisson regression to detect trends of abundance data (van Strien et al. 2004). Regression models with site and year effects included are established for each species in TRIM: count data can be weighted by sampling effort, accounting for covariates (such as habitat types), and missing data are also acceptable. According to these advantages, TRIM is widely used to analyze large-scale wildlife population monitoring data, including the Pan-European Common Bird Monitoring Scheme organized by the European Bird Census Council.

Target species of BBS Taiwan were common diurnal breeding birds. The breeding status of birds was determined by the checklist of the birds of Taiwan (Juan et al. 2012), which is updated annually by the Bird Record Committee of the CWBF. Both residents and summer visitors were included as breeding birds. However, several breeding bird species may not be appropriately covered by our sampling scheme and survey methods. Such species include (1) nocturnal birds such as owls and nightjars, (2) colony breeding birds such as egrets or swifts, and (3) breeding bird species that also have large wintering (or passage) populations present within BBS Taiwan’s survey season (March to June), such as White Wagtail (Motacilla alba) and Little Ringed Plover (Charadrius dubius).

National indicators were established for bird species that have data coverage over 30 survey sites. Because geographic, climate, and land-use patterns are significantly different between the different regions of Taiwan (Shiu 2003), we also developed indicators for the North, West, and Eastern regions of Taiwan, which are expected to reveal population trends that are specific to each region.

Current Achievements

Since the launch of BBS Taiwan in 2009, both the number of surveyors and sites sampled have grown encouragingly. In 2012, survey participants have numbered more than 250 persons, and the number of sites sampled per year is currently over 300 sites, rapidly approaching 450 sites: the original target. Spatial distribution of sampled sites was generally homogeneous across Taiwan, covering all major habitats from sea level to nearly 4,000 m into the mountains (Fig. 3.2). Still, future efforts are anticipated to fill gaps, especially in the Northern Region and at certain elevation zones.

Fig. 3.2
figure 2

Sites sampled by volunteers within 2009–2011. Green line delineates the borders of Northern, Eastern, and Western regions that were defined by Shiu (2003)

Full size image

Building population indices for reporting the status of breeding birds is the most important goal of BBS Taiwan, and currently the population status of 63 species has been reported, which represents more than 60 % of diurnal land breeding birds on Taiwan. These species include 11 endemic species such as the Taiwan Barbet (Megalaima nuchalis) and the Formosan Magpie (Urocissa caerulea), and also 12 species listed in the Protected Species List of Taiwan by the Council of Agriculture of the Executive Yuan. IUCN Red List species, including the Styan’s Bulbul (Pycnonotus taivanus), Taiwan Partridge (Arborophila crudigularis), and the Taiwan Hwamei (Garrulax taewanus), were also effectively monitored.

Table 3.2 summarizes significant population changes of monitored species since the initiation of BBS Taiwan. Significant trends are defined by log-linear regression models established by TRIM with slopes significantly different from zero (p < 0.05). Regression models with imputed indices were adopted as suggested by Pannekoek and van Strien (2005), with serial correlation and overdispersion taken into account. Full results and additional outputs of the BBS Taiwan working team can be found in annual reports published by the Endemic Species Research Institute (Lee et al. 2010b; Ko et al. 2012), PDF versions are also available on the BBS Taiwan website: http://bbstaiwan.tw/. A noteworthy finding of the current result is that forest species and nonforest species appear to behave oppositely in their direction of population trends. Of the eight species that declined significantly, 75 % were grassland or farmland species, including Oriental Turtle-Dove (Streptopelia orientalis), Himalayan Cuckoo (Cuculus saturatus), Lesser Coucal (Centropus bengalensis), Striated Swallow (Cecropis striolata), Long-tailed Shrike (Lanius schach), and Vinous-throated Parrotbill (Paradoxornis webbianus). In contrast, only 30 % of the ten increasing species prefer grassland or farmland habitats. As the decline of farmland birds is of major concern in Europe and the UK (Benton et al. 2003), whether the current finding in Taiwan implicates a similar situation of farmland biodiversity loss may require additional evidence. Nevertheless, as the status of agro-ecosystems in East Asia is generally unknown (but see Amano 2009), data obtained by BBS Taiwan provide a promising chance to fulfill this gap.

Table 3.2 Breeding bird species with significant population changes between 2009 and 2011 in Taiwan
Full size table

Future Perspectives

Current achievements of BBS Taiwan bear very important and exciting information for Taiwan and the East Asian region. BBS Taiwan presents the possibility of implementing biodiversity monitoring successfully on a national scale, in a region where similar projects were relatively rare. Data collected by BBS Taiwan also have the potential to be used for large-scale research, including the validation of species distribution modeling, gap analysis for evaluation of conservation areas, reevaluation of conservation status of breeding birds in Taiwan, role of landscape heterogeneity with species richness (Miyashita et al., in press), and many more establishing issues. Still, much work lies ahead; most fundamentally in the effort to encourage surveyors to repeat surveys for as long as possible, and also the recruitment and training of new incoming participants. The former task will rely on improving information sharing between project organizers and survey volunteers; whereas the latter has the important goal to maintain data quality. Collaborations with other government agencies and NGOs that express a strong interest in biodiversity conservation are in the pipeline, with the insight that these efforts would raise public awareness for greater biodiversity conservation.

Based on the successful experience of BBS Taiwan, the idea of building a bird monitoring system to census birds in a more comprehensive way has recently been suggested. The system will be composed of several monitoring systems focusing on common breeding, nocturnal breeding, wetland, endangered, wintering migratory, and alien birds, respectively. The obvious way to overcome the foreseeable difficulties is expanding and strengthening the partnerships among NGOs, government agencies, and academic institutions as well as encouraging more volunteers to become involved in well-designed citizen science projects. Meanwhile, projects aimed at monitoring bird population demographics through constant-effort banding (Lin 2012) and the occurrences of alien invasive birds (Fang et al. 2011) have been conducted since 2009 and 2010, respectively. Other projects, such as monitoring of migratory landbirds and wetland birds, are in the preliminary stage of testing field methods.

In addition to birds, increasing numbers of taxa are surveyed on a nation-wide scale in Taiwan, such as anurans, butterflies, bats, and reptiles (Lee et al. 2010a; Deng et al. 2012). The stages of project development differ among taxa. The anuran monitoring network initiated in 2003 is now the most important source regarding the status of amphibians in Taiwan (Yang and Gong 2012). Projects targeting butterflies and bats are focused on designing standardized survey methods and implementing educational workshops to create public interest in these species (Lee et al. 2010a). The reptile project was originally formed by a group of enthusiastic people who were concerned about the negative influences of roadkill and proactively reported their records through Facebook during 2011. Gradually, systematic survey methods have been developed, and hundreds of volunteers continually reported roadkill records with detailed information (Deng et al. 2012). One thing in common among these monitoring projects is that they share the same belief that, to successfully achieve our goals of effective biodiversity monitoring, the need to incorporate the concept of citizen science into survey designs is crucial.

Overall, biodiversity monitoring workgroups in Taiwan are putting great effort into the establishment of even greater national biodiversity indicators in the near future. These indicators, which are essential for biodiversity conservation and climate change adaptation in Taiwan, are expected to trigger large-scale monitoring on more taxa and in more countries within the Asia-Pacific region.