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IDENTIFICATION

Adults have nearly bare red crowns and lores (area between eye and bill) that are sparsely covered by black hairlike feathers. The rest of the head and the upper part of the neck are black, except for a small white or light gray spot extending backward from the rear and lower edges of each eye. The body is ashy gray, becoming almost whitish on the underparts. The tail is black, and the upper tail coverts are grayish. The primaries and secondaries are black. Eyes are yellow, legs and toes are black. Males and females are virtually indistinguishable, although males tend to be slightly larger in size.

Juveniles have yellow brown feathers on the crown, and a gray abdomen. Primaries and secondaries are black, the feathers of the back are grayish yellow, and black and white feathers alternate on the neck. By one year of age the bird resembles the adult.

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ICF in Action

Beginning in 1990, ICF and the Tibet Plateau Institute of Biology began a cooperative five-year study of Black-necked Cranes in Tibet. Approximately 3,900 cranes were located in south central Tibet. After the comprehensive study, annual winter counts were continued. In 1991 a breeding survey was conducted primarily in northern Tibet. By 1993 a management plan for wintering Black-necked Cranes was completed and translated into Chinese.

ICF, in cooperation with the Guizhou Environmental Protection Bureau and the New York based Trickle Up Program, started a model program at the Cao Hai Nature Reserve in south-central China which 1) promotes community development with small business grants as incentives to start alternative businesses that will be less detrimental to the reserve's wetlands, 2) promotes reforestation of denuded slopes surrounding the reserve to reduce erosion and silt build up in the wetland, and 3) will develop management plans for the reserve.

Since 1996 ICF has worked with the Royal Society for the Protection of Nature Bhutan (RSPN) to study and protect Black-necked Cranes and their habitats. RSPN & ICF sponsor an annual crane festival in the Phobjikha Valley where local people sing, do crane dances and compete in archery contests. ICF brings eco-tours to the valley for the festival, which benefits the local economy and protects cranes.

In 1998, ICF, Bhutanese, and Japanese colleagues placed a satellite radio transmitter on a Black-necked Crane in Bhutan. During the spring migration the bird was followed to a staging area near Shigetze in southern Tibet and then on to a breeding area in north-central Tibet near Shensa. In the summer of 2000 a joint team from China, ICF, and Bhutan went to that area, captured 18 pre-fledged chicks, and placed color bands on their legs. Some of these cranes were observed in flocks of cranes wintering near Shigatse, but as yet none have been spotted in Bhutan.

In 2001, ICF put income from the new Black-necked Crane Conservation Fund directly to work for these cranes in China and Bhutan. Colleagues in Tibet repeated field surveys and by 2002 most of the major wintering areas were protected within a new Black-necked Crane Nature Reserve.

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ICF in Action Beginning in 1990, ICF and the Tibet Plateau Institute of Biology began a cooperative five-year study of Black-necked Cranes in Tibet. Approximately 3,900 cranes were located in south central Tibet. After the comprehensive study, annual winter counts were continued. In 1991 a breeding survey was conducted primarily in northern Tibet.

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Black-necked cranes are begining their annual swoop into Bhutan

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Black-necked cranes are begining their annual swoop into Bhutan

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This year, the first cranes swooped into Phobjikha on 22 October and eleven birds have now been recorded in the valley, with numbers set to grow to more than 360 individuals as winter creeps across the Tibetan Plateau. Although protected from humans, the cranes face ongoing threats from habitat loss in their summer breeding grounds in Tibet, and from man-made dangers such as overhead power cables and fishing lines. Leopards have also been known to pounce on cranes who roam too close to the edge of the marshlands.

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Skip to Content

Every year, in October and November, the people who inhabit the high valleys of Bhutan scan the skies for the arrival of a special visitor from the Tibetan plateau.

The black-necked crane is revered in Bhutan as a symbol of longevity and the annual migration is a cause for great celebration, as residents mark the passing of another year against the arrival of these famously long-living birds. Blacked-necked cranes are highly territorial and some 10% of the world's population gather every autumn in the Phobjikha Valley, where cranes have been spotted since medieval times. The birds are protected by Bhutanese law, with the threat of life imprisonment for anyone who harms a sacred crane, and legend dictates that the first cranes will circle the ancient monastery at Gangte three times before landing on the broad marshes that line the Phobjikha Valley.

This year, the first cranes swooped into Phobjikha on 22 October and eleven birds have now been recorded in the valley, with numbers set to grow to more than 360 individuals as winter creeps across the Tibetan Plateau. Although protected from humans, the cranes face ongoing threats from habitat loss in their summer breeding grounds in Tibet, and from man-made dangers such as overhead power cables and fishing lines. Leopards have also been known to pounce on cranes who roam too close to the edge of the marshlands.

Bird-watchers brave icy temperatures for close-up views from the walking trails that skirt the edge of the crane's winter territory, starting from the mani walls - made from stones carved with Buddhist mantras - that surround the Gangte monastery. Sightings are almost guaranteed between November and February, and Bhutan's Royal Society for the Protection of Nature celebrates the annual migration with the Black-Necked Crane Festival on 12 November , when villagers and monks in crane costumes perform swirling dances in the courtyard of Gangte monastery.

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Black-necked cranes begin their annual swoop into Bhutan

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Skip to Content Every year, in October and November, the people who inhabit the high valleys of Bhutan scan the skies for the arrival of a special visitor from the Tibetan plateau.

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Two men bring frozen black-necked crane back to life

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Two men bring frozen black-necked crane back to life

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Recently, two men saw a black-necked crane struggling in an ice hole of a river in Shangri-La, southwest China’s Yunnan Province, and then they jumped into the river and took the frozen black-necked crane out of ice water. One man took off his coat and held the black-necked crane in his arms to warm up it. With their help, the black-necked crane was brought back to life. (Photo source: Office Weibo of CCTVNEWS)

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Two men bring frozen black-necked crane back to life(1)

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Recently, two men saw a black-necked crane struggling in an ice hole of a river in Shangri-La, and then they jumped into the river and took the frozen black-necked crane out of ice water. With their help, the black-necked crane was brought back to life.

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Incubation strategies of the Black-necked Crane

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Incubation strategies of the Black-necked Crane

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Conclusions of this Research:

Black-necked Cranes are sensitive to temperature variations within the day and can adjust their behavior so as to maximize benefits from the warmest session of the day and the most intense solar radiation, with decreased cooling of eggs. Our findings demonstrate that Black-necked Crane parents incubated in different but complementary ways, and efficiently enhanced egg care in a dynamic environment. Their incubation behaviors were modified in response to the thermal requirements of eggs and the weather conditions experienced.

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Received: 23 November 2016

Accepted: 26 June 2017

Published: 20 July 2017

Abstract

Background

The behavior of cranes reflects many of their survival strategies, but little has been known of the incubation strategies of cranes, in which both parents share incubation duties, in response to cold temperatures in alpine environments. The lack of information may restrict the effective conservation of the threatened Black-necked Crane ( Grus nigricollis), a biparental bird nesting in high elevation wetlands.

Methods

We directly observed and used infrared video cameras from 2014 to 2015 to study the incubation behavior and quantitatively measured the frequency and details of egg turning behavior in the Black-necked Crane at the Yanchiwan National Nature Reserve in western Gansu Province, China.

Results

At lower ambient temperatures in the morning, crane parents spent more time on the nest with less recess frequency and prolonged on-bout duration, while at higher temperatures around noon, the parents had more frequent recesses from incubation and shorter periods between nest exchanges. They adjusted the amount of time incubating by varying the recess frequency and the length of on-bout duration. Mean nest attendance and egg turning frequency of females were significantly higher than those of the males. The nest attendance and on-bout duration of females showed a significantly negative relationship with those of males. The two parents responded differently to the change of temperature. Females spent more time on the nest at lower morning temperatures, while males increased their time on the nest at higher temperatures after noon. Higher incubation recess frequency and egg turning frequency were observed at noon, probably because parents spent more time foraging, taking advantage of the lower egg cooling rate.

Conclusion

Both Black-necked Crane parents in the alpine environment adjusted their behavior in response to the thermal requirements of eggs and the weather conditions experienced. Our findings demonstrate that parents of this species incubated in different but complementary ways and efficiently enhanced egg care in a dynamic environment, so as to maximize benefits from the warm portion of the day and the intense solar radiation while minimizing the cost of rewarming eggs and the risks of cooling eggs.

Keywords

Time of day Ambient temperature Egg-turning frequency On-bout duration Nest attendance Recess frequency Biparental bird

Background

The majority of extant avian species must defend and incubate eggs until hatching (Weathers and Zaun 2010). Incubation may provide various evolutionary benefits for birds, including a decreased incubation period, accelerated rate of embryonic development, and greater management of incubation conditions (Deeming 2002). Incubation is energetically costly for birds because incubating parents must balance the thermal needs of the eggs with self-maintenance (Smith et al. 2012). Ambient temperature affects energetic costs during incubation and embryonic development during recesses from incubation (Conway and Martin 2000). However, incubation behavior is often neglected as a method for investigating relationships between animals and their environment for conservation and many of their survival strategies and adaptations (Spiegel et al. 2012). Most studies of incubation rhythms in birds have been conducted in moderate environments (Camfield and Martin 2009) and studies under alpine environments have focused mainly on uniparental incubators. However, the situation in species with biparental incubation is more complex due to the potentially different responses of each parent to changes in the cost of incubation (Smith et al. 2012). Spencer et al. ( 2010) emphasized that birds may exhibit sexual differences regarding incubation effort in relation to variation in their own developmental processes and current environmental conditions. Very few studies, however, have investigated the ambient temperature influence on the relative incubation contribution by each sex (Conway and Martin 2000; Bulla et al. 2014), especially in alpine environments.

Egg turning is unique to birds and crucial for embryonic development in most avian species (Shaffer et al. 2014). Optimum egg turning frequency during incubation has been of interest since the observations of feral fowl incubation behavior by Elibol and Brake ( 2006). Regulation of egg temperature through egg turning by incubating parents is crucial to both the survival and proper development of avian embryos. However, egg turning behavior has not been studied as widely as parental attendance pattern, egg physiology, or hatching success (Shaffer et al. 2014). In addition, egg turning frequency in wild birds is rarely studied due to difficulty of observations in darkness (Weathers and Zaun 2010).

We investigated these issues in a population of the Black-necked Crane ( Grus nigricollis), a species breeding exclusively on the high-altitude wetlands of the Qinghai-Tibetan Plateau (Li and Bishop 1999). The species is a monogamous and long-lived migrant waterbird, with pair bonds lasting for years. Both males and females participate in nest building, incubation, and rearing nestlings and fledglings. Early observations suggested that males and females contribute almost equally to incubation with regard to time spent on the nest (Zhang et al. 2017a). Several studies have been attempted to determine the incubation rhythms of the Black-necked Crane with direct observations and data analysis (Kuang et al. 2007; Yang et al. 2007). However, few data are available on the incubation strategies of biparentally incubating cranes in response to cold temperatures in alpine environments. Such strategies could relate to nest attendance, recess frequency, on-bout duration and egg turning frequency. Those behaviors could alter egg temperatures and the time that developing embryos are exposed to cold temperatures. In the present study, we investigated the effects of time of day and variation in ambient temperature on male and female incubation behaviors in a cold environment at the Yanchiwan National Nature Reserve, western Gansu Province, China.

Methods

Study species and study site

The Black-necked Crane is a large ground-nesting bird that breeds only on high-altitude wetlands from Ladakh north to Gansu (Bishop et al. 2012). Their average clutch size is two eggs, with one egg laid per day, and the incubation period ranges from 30 to 34 days (Zhang et al. 2017a). For details about the study area see Zhang et al. ( 2017b).

General field methods

We located 20 nests (10 nests in 2014, 10 nests in 2015) at the Yanchiwan National Nature Reserve. Presence or absence at the nest was detected by observation and recorded using remote infrared thermistor sensor systems (FC-5210 mm, MMS Trail Camera, Shenzhen Baird Share Co., Ltd). Each sensor system consisted of a small (9.4 cm × 14.6 cm) weatherproof miniature video camera with twelve R6 AA size batteries and a 32 G memory card allowing a continuous recording of 4-5 days. These cameras were programmed on a motion sensor with 1280 × 720 video size, high sensitivity, 10 s triggering interval, 60 s video length and 24 h operation mode. Cameras were placed 2-3 m away from nests, and were elevated 1.5-2 m above the ground with a metal stake. The data were also confirmed by direct observation. The ambient temperature was measured by a thermo-probe, which was placed in areas with similar protection from the wind and aspect as the nest and around 25 cm away from the nest scrape at ground level. The probe was connected to a data logger (Tinytag, Gemini Data Loggers Ltd.). Temperatures were logged at 1 min intervals with an accuracy of 0.1 °C. Each video-monitored nest was visited every four days to change batteries and memory cards and download temperature data when both parents left their nest for foraging or other activities. Cameras were collected after each recording session and videotapes were later reviewed for scoring. From these videos, we were able to determine the time of initiation and calculate each recess and on-bout duration. Sex identification referred to the method described by Kuang et al. ( 2007) and Zhang et al. ( 2017a). For each of seven periods during the day (6:30-8:29, 8:30-10:29, 10:30-12:29, 12:30-14:29, 14:30-16:29, 16:30-18:29 and 18:30-20:29 h, Beijing time), we calculated: (1) nest attendance, estimated as the percentage of total time when the eggs were incubated by each parent (individual nest attendance) and pair (total nest attendance), (2) recess frequency, estimated as the average number of breaks taken by each parent (individual recess frequency) and pair (total recess frequency), (3) on-bout duration, estimated as the mean length (in minutes) of uninterrupted incubation by either parent (individual on-bout duration) and pair (total on-bout duration), and (4) egg turning frequency, estimated as number of egg turning times by each parent (individual egg turning frequency) and pair (total egg turning frequency). The behavior was considered as two behaviors if one behavior occurred during two time periods. The average ground temperature outside the nests was taken as the ambient temperature for each period.

Statistical analysis

To determine whether four incubation behaviors and ambient temperatures varied with time, we examined relationships of nest attendance, recess frequency, on-bout duration and egg turning frequency with time of day using curvilinear regression. Ambient temperature, nest attendance, recess frequency, on-bout duration and egg turning frequency failed to meet assumptions for a parametric test. We also included year (2014 and 2015) as a fixed effect. Thus, yearly difference of ambient temperature was tested by Mann-Whitney U test, and sexual differences of nest attendance, recess frequency, on-bout duration and egg turning frequency were tested by non-parametric paired tests. Means are reported with standard error, and all significance values are at 0.05 level based on two-tailed tests. All the statistical analyses were performed by the software SPSS (version 22.0, IBM 2013).

To explore the influences of potential factors on incubation behaviors (nest attendance, recess frequency, on-bout duration, and egg turning frequency), we used generalized linear mixed models (GLMMs) in SPSS. To control for repeated measures of incubation behaviors at a given nest, we included nest identity as a random effect. Year (2014 and 2015), date, days of incubation and time of day were also added as fixed effects since they might potentially influence the incubation behavior (Camfield and Martin 2009). Partner's behavior was also a fixed factor, and partner's behavior × time period interaction was included to determine if the relationship between the incubating crane's behaviors on the nest and partner's behaviors varied over time. Square temperature was added into the model as a fixed effect because there was a significant quadratic relationship between mean ambient temperature and time of day ( R ² = 0.31, F 2,664 = 149.57, p < 0.001). No linear correlations were found between ambient temperature and incubation behaviors (Additional File 1: Fig. S1). Thus, no interaction of ambient temperature × temperature zone was added into the models. Akaike's information criteria (AIC-based model selection) were used for model selection.

Results

A total of 153 incubation days (1334 h with 667 time periods) for Black-necked Cranes were monitored in 11 nests (5 nests in 2014 and 6 nests in 2015) between 20 April 2014 and 15 June 2015. The mean number of days for each nest was 13.91 ± 2.15 (range 5-25 days) and mean number of periods was 121.27 ± 23.39 (range 12-134 periods). Throughout the breeding season, the mean daytime ambient temperature was 10.13 ± 0.27 °C with the highest temperature 30.24 °C and the lowest −1.63 °C, occasionally varying by more than 30 °C in one day. There were no marked differences in mean ambient temperature between years (2014: 10.15 ± 0.34 °C; 2015: 10.10 ± 0.44 °C; Mann-Whitney UZ = −0.60, p = 0.547). The highest mean daytime temperature occurred between 14:30 and 16:29 h (15.01 ± 0.61 °C, Fig. 1) and the lowest occurred between 06:30 and 08:29 h (2.49 ± 0.52 °C, Fig. 1). Moreover, the mean ambient temperature was significantly different among different time periods (Kruskal-Wallis χ = 242.03, p < 0.001).

Nest attendance

For every 2-h interval, the mean total nest attendance was 90.72 ± 0.57% and was significantly quadratic to time of day ( R ² = 0.03, F 2,664 = 9.46, p < 0.001; Fig. 1). The highest nest attendance was 95.46 ± 1.15% between 06:30 and 08:29 h while the lowest was 86.71 ± 1.64% between 10:30 and 12:29 h. The mean female nest attendance was significantly higher than that of males (females: 47.88 ± 1.32%; males: 42.85 ± 1.32%; Wilcoxon Z = −2.01, p = 0.044). Among the seven time periods, the highest female nest attendance (58.88 ± 4.28%) occurred between 06:30 and 08:29 h, and the lowest (40.64 ± 3.19%) between 12:30 and 14:29 h (Fig. 1). Conversely, the highest male nest attendance (47.69 ± 3.32%) was between 12:30 and 14:29 h, and the lowest (36.60 ± 4.15%) was between 06:30 and 08:29 h (Fig. 1). Meanwhile, we found a quadratic relationship between female nest attendance and time of day ( R ² = 0.02, F 2,664 = 6.46, p = 0.002).

Both female and male optimal nest attendance models included date and square temperature (Additional File 2: Tables S1 and S2). Both female and male nest attendances were significantly positively related to year, date and time of day and negatively to days of incubation, but not related to temperature or square temperature (Tables 1, 2). A significant negative relationship was found between female and male nest attendance ( β = −0.63 ± 0.05, p < 0.001, Table 1; β = −0.56 ± 0.04, p < 0.001, Table 2).

Recess frequency

The total female and male recess frequency had a significant quadratic relation to time of day ( R ² = 0.02, F 2,664 = 6.59, p = 0.001). Among the seven time periods, the lowest total recess frequency 2.57 ± 0.14 times was between 06:30 and 08:29 h while the highest was 3.26 ± 0.12 times between 10:30 and 12:29 h. Both parents took recesses more frequently near noon. There were no significant differences between mean female and male recess frequency (1.50 ± 0.04 vs. 1.39 ± 0.04 times, Wilcoxon Z = −1.69, p = 0.092). The highest female recess frequency was 1.72 ± 0.10 times between 10:30 and 12:29 h while the lowest was 1.38 ± 0.10 times between 18:30 and 20:29 h (Fig. 2). The mean male recess frequency had a significant quadratic relationship to time of day ( R ² = 0.01, F 2,664 = 3.85, p = 0.022). The highest male recess frequency was 1.53 ± 0.10 times between 10:30 and 12:29 while the lowest was 1.16 ± 0.10 times between 06:30 and 08:29 h (Fig. 2).

Both optimal female and male recess frequency models included date and square temperature (Additional File 2: Tables S1 and S2). Female recess frequency was significantly positively related to year, date, time of day, and negatively related to day of incubation, temperature, square temperature, male recess frequency and male by time (Table 1). Male recess frequency was significantly positively related to year, date, and time of day, and negatively related to day of incubation, temperature, square temperature and female by time (Table 2).

On-bout duration

The longest on-bout duration was 57.90 ± 4.17 min/bout between 06:30 and 08:29 h while the shortest was 37.96 ± 2.09 min/bout between 10:30 and 12:29 h (Fig. 3). Mean total on-bout duration had a significantly quadratic relation with time of day ( R ² = 0.02, F 2,664 = 6.82, p = 0.001). There were no significant differences in mean daily on-bout duration between females and males (females: 40.93 ± 1.44 min/bout; males: 37.66 ± 1.38 min/bout, n = 930 bouts from 11 nests, Wilcoxon Z = −1.17, p = 0.243). The longest female on-bout duration was 51.99 ± 4.99 min/bout between 06:30 and 08:29 h while the shortest was 31.39 ± 2.97 min/bout between 12:30 and 14:29 h (Fig. 3). Female on-bout duration had a significantly quadratic relation with time of day ( R ² = 0.02, F 2,664 = 7.03, p = 0.001). The longest male on-bout duration was 42.41 ± 3.52 min/bout between 12:30 and 14:29 h while the shortest was 33.96 ± 3.07 min/bout between 10:30 and 12:29 h (Fig. 4).

Both optimal female and male on-bout duration models included date and square temperature (Additional File 2: Tables S1 and S2). Both female and male on-bout duration were significantly positively related to year, date and time of day (Tables 1, 2). Female on-bout duration was significantly negatively related to day of incubation and male on-bout duration but not to temperature, square temperature or male by time, while male on-bout duration was significantly negatively related to day of incubation, female on-bout duration and female by time but not to temperature or square temperature (Tables 1, 2). Female on-bout duration and male on-bout duration showed a significant negative relationship ( β = −0.55 ± 0.07, p < 0.001, Table 1; β = −0.45 ± 0.06, p < 0.001, Table 2).

Egg turning frequency

A crane turns its eggs by standing up, moving backward to the nest's rim, reaching down and hooking the farthest egg with its bill and feet, then drawing the egg backward, thereby rolling it (Additional File 3: Video 1). Total egg turning frequency was 3.75 ± 0.08 turns every 2-h interval and had a significantly quadratic relation with time of day ( R 2 = 0.04, F 2,664 = 12.20, p < 0.001; Fig. 4). The lowest egg turning frequency (3.07 ± 0.19 turns) was between 18:30 and 20:29 h and the highest (4.50 ± 0.22 turns) was between 12:30 and 14:29 h. Mean female egg turning frequency was significantly greater than mean male egg turning frequency (females: 2.01 ± 0.07 turns; males: 1.74 ± 0.07 turns, Wilcoxon Z = −2.44, p = 0.015). Both mean female and male egg turning frequencies had a significantly quadratic relation with time of day (female: R 2 = 0.01, F 2,664 = 3.94, p = 0.020; male: R 2 = 0.02, F 2,664 = 5.30, p = 0.005; Fig. 4). Both the highest female and highest male egg turning frequencies occurred between 12:30 and 14:29 h (females: 2.29 ± 0.19 turns; males: 2.20 ± 0.18 turns), and the lowest female and male egg turning frequencies were between 18:30 and 20:29 h (females: 1.70 ± 0.17 turns; males: 1.37 ± 0.20 turns).

Both optimal female and male egg turning frequency models included date and square temperature (Additional File 2: Tables S1 and S2). Both female and male egg turning frequencies were significantly related to year, date, and were negatively related to day of incubation and temperature. Female and male egg turning frequencies showed no significant negative relationship ( β = −0.10 ± 0.08, p = 0.234, Table 1; β = −0.11 ± 0.10, p = 0.254, Table 2).

Discussion

In the alpine environment, an optimal incubation schedule trades off the incubators' energetic cost against the demand for eggs to be maintained suitably warm. This complicated trade-off can be driven by various influences such as incubation energetic needs and the egg chilling tolerance. Our study demonstrated a multimodal pattern in the parental incubation behaviors of the Black-necked Crane in response to cold temperatures in an alpine environment throughout the entire incubation period. The highest nest attendance, the longest on-bout duration and the lowest total recess frequency all occurred in the early morning (06:30-08:29 h) when the mean ambient temperature is the lowest. This is consistent with parent inactivity of the Black-necked Crane in the morning during incubation in northern Tibet (Kuang et al. 2007). The highest total recess frequency, lowest nest attendance and the shortest on-bout duration occurred between 10:30 and 12:29 h. Meanwhile, the highest egg turning frequency of both parents occurred between 12:30 and 14:29 h when the mean ambient temperature was high. We suggest that biparental behaviors of the Black-necked Crane may reflect the predictable patterns in temperature and solar radiation throughout the alpine day. Both parents took the longest and highest recess frequencies in the warmer hours of the day, and nests were incubated more constantly during the cooling temperatures. Similar parental care was reported in the female King Eider ( Somateria spectabilis) which preferred to take advantage of the warmest part of the day to reduce cooling of eggs, despite that their predators were also more active during the same period (Bentzen et al. 2010). We also noticed that Black-necked Cranes were more active between 10:30 and 12:29 h, much earlier than the most active periods of this species in northern Tibet (Kuang et al. 2007). This difference might be explained as incubation behavior being functionally driven by local foraging conditions (Bentzen et al. 2010).

Total hourly egg turning frequency was 1.87 turns, which fell in hourly egg turning rates of three species, e.g. Cassin's Auklet ( Ptychoramphus aleuticus), Western Gull ( Larus occidentalis), and Laysan Albatross ( Phoebastria immutabilis) (Shaffer et al. 2014). The highest egg turning frequencies of both females and males occurred between 12:30 and 14:29 h, and the lowest frequencies of both parents were between 18:30 and 20:29 h, suggesting that ambient temperature plays a significant role in egg turning behavior for Black-necked Cranes. Both crane parents took advantage of the warmest session of the day when solar radiation was the most intense. This timing indicated they were sensitive to temperature variation within days and modified their behavior so as to maximize benefits from the most intense solar radiation by taking incubation recesses during the warmest part of the day for saving energy. Such behavior appears to be adaptive since at higher ambient temperatures, rate of egg cooling was slower, permitting parents to stay off the nest for a longer time (Deeming 2002).

Female and male nest attendance, on-bout duration, and egg turning frequency showed a significantly negative relationship (Tables 1, 2). We also found that on-bout durations were generally shorter and nest attendance was lower for males than for females during the day. This result was consistent with reports that females conducted a greater portion of incubation than males (Kuang et al. 2007). The highest female nest attendance was from 06:30 to 08:29 h, when females may be short of energy after an overnight incubation. This finding is similar to the incubation behavior during early morning for females of a uniparental species Horned Lark ( Eremophila alpestris) breeding in alpine tundr (Camfield and Martin 2009), but was in contrast to the uniparental incubation pattern for the female King Eider, which took more recesses at low temperatures because recesses were driven by metabolic expenses and local foraging conditions (Bentzen et al. 2010). Our study demonstrated that female Black-necked Cranes shifted priority between self-maintenance and incubation demands depending on various temperature conditions and their parental cooperation. Similarly, Magrath et al. ( 2005) reported that females were more sensitive to the thermal status and demands of the clutch than males.

Female cranes tended to reduce attendance during the warmest period of day, consistent with the biparental incubation pattern of Arctic-breeding female Semipalmated Sandpipers ( Calidris pusilla), which were more often off nest during the warmer period of the day when foraging might be easier (Bulla et al. 2014). However, the increase in nest attendance by males may represent compensation for the reduced attentiveness by the female, consistent with results of Magrath et al. ( 2005). The optimal contribution by one parent should depend on the level of investment by their partner, with a reduction in effort by one parent predicted to result in partial compensation by the other. Sexual differences in the level of resting and movement observed in our study can be explained by the dominant role of females in incubation. Bulla et al. ( 2014) also suggested that the female-biased extent of incubation might be compensated for a more favorable timing of incubation. Biparental care and complementary sexual roles counter the high risk of predation, with males assuming more vigilance and nest defense behaviors, and females spending more time on eggs (Kuang et al. 2007). The strong attachment of the parents to their nest helps to ensure the egg is well protected. A shortcoming of our study was that the behavior of birds was not monitored when birds were absent from the nest or during night. More complex interactions may also be involved in biparental incubation behaviors.

Conclusions

Black-necked Cranes are sensitive to temperature variations within the day and can adjust their behavior so as to maximize benefits from the warmest session of the day and the most intense solar radiation, with decreased cooling of eggs. Our findings demonstrate that Black-necked Crane parents incubated in different but complementary ways, and efficiently enhanced egg care in a dynamic environment. Their incubation behaviors were modified in response to the thermal requirements of eggs and the weather conditions experienced.

Declarations

Authors' contributions

XY and LZ conceived, designed and directed the experiments. BA and LZ coordinated this study, and wrote and revised the manuscript. MS performed the statistical analyses, YS, YS and XD helped with nest site location and infrared cameras set, and revised the manuscript. All authors read and approved the final manuscript.

Acknowledgements

We are indebted to all people who helped with the fieldwork at the Yanchiwan National Nature Reserve and to Lanzhou University for permission to carry out field work. Thanks are also given to Dr. Bo Du for statistical assistance, to Dr. Jim Harris for his invaluable suggestions and revision on the original draft of this manuscript and two anonymous referees for their constructive comments. This research was financially supported by a grant from the State Key Laboratory of Genetic Resources and Evolution, Kunming Institute of Zoology, Chinese Academy of Sciences (GREKF13-12). This work was further supported by Yanchiwan National Nature Reserve.

Competing interests

The authors declare that they have no competing interests.

Ethics statements

All data collected as part of this study were approved by the Lanzhou University Institutional Animal Care and Use Committee (Approval Numbers: SCXK-GAN-2013-0003). Field work was approved by authority of the Forestry Department of Gansu Province (Approval Numbers: 201009).

Open AccessThis article is distributed under the terms of the Creative Commons Attribution 4.0 International License ( http://creativecommons.org/licenses/by/4.0/ ), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. 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.

Additional files

Authors' Affiliations

(1)

School of Life Sciences, Lanzhou University

(2)

Gansu Key Laboratory of Biomonitoring and Bioremediation for Environmental Pollution

(3)

School of Basic Medical Sciences, Lanzhou University

(4)

State Key Laboratory of Genetic Resources and Evolution, Kunming Institute of Zoology, Chinese Academy of Sciences

(5)

National Nature Reserve of Yanchiwan

References

1. Bulla M, Valcu M, Rutten AL, Kempenaers B. Biparental incubation patterns in a High-Arctic breeding shorebird: How do pairs divide their duties? Behav Ecol. 2014;25:152-64.

2. Conway CJ, Martin TE. Evolution of passerine incubation behavior: influence of food, temperature, and nest predation. Evolution. 2000;54:670-85.

3. Deeming DC. Patterns and significance of egg turning. In: Deeming DC, editor. Avian incubation behavior, environment, and evolution. Oxford: Oxford University Press; 2002. p. 161-78.

4. Elibol O, Brake J. Effect of egg turning angle and frequency during incubation on hatchability and incidence of unhatched broiler embryos with head in the small end of the egg. Poult Sci. 2006;85:1433-7.

5. Kuang FL, Liu N, Zhuoma C, Li JC, Yang L, Li FX. Diurnal time-activity budgets of Grus nigricollis for the pre-laying phase in northern Tibet. J Zhejiang For Coll. 2007;24:686-91 (in Chinese).

6. Li F, Bishop MA. Ecology and conservation of black-necked cranes (Grus nigricollis). In: Adams NJ, Slotow RH, editors. Proceedings of the XXII international ornithological congress, Durban, South Africa. Johannesburg: Birdlife South Africa; 1999. p. 2533-43.

7. Shaffer SA, Clatterbuck CA, Kelsey EC, Naiman AD, Young LC, Vanderwerf EA, Warzybok P, Bradley R, Janhncke J, Bower G. As the egg turns: monitoring egg attendance behavior in wild birds using novel data logging technology. PLoS ONE. 2014;9:e97898.

8. Weathers WW, Zaun BJ. Egg-turning behavior and nest attentiveness of the endangered Hawaiian goose on Kauai. West Birds. 2010;41:2-9.

9. Zhang L, An B, Shu M, Yang X. Nest-site selection, reproductive ecology and shifts within core-use areas of black-necked cranes at the northern limit of the Tibetan Plateau. PeerJ. 2017b;5:e2939.

See updates

© 2017 BioMed Central Ltd unless otherwise stated. Part of Springer Nature.

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Incubation strategies of the Black-necked Crane ( Grus nigricollis ) in relation to ambient temperature and time of day

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The behavior of cranes reflects many of their survival strategies, but little has been known of the incubation strategies of cranes, in which both parents share incubation duties, in response to cold temperatures in alpine environments. The lack of information may restrict the effective conservation of the threatened Black-necked Crane (Grus nigricollis), a biparental bird nesting in high elevation wetlands.

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Check out the full taxonomy and distribution of Black-necked Crane on HBW Alive.

HBW Alive contains information on Descriptive notes, Voice, Habitat, Food and Feeding, Breeding, Movements, Status and Conservation plus a list of bibliographical references for this species account.

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Black-necked cranes leave their wintering grounds in late March and spend 5-7 days migrating to their northern nesting grounds. They return south again in late October and are able to fly over the Himalaya at incredibly high altitudes. Nesting occurs in May, and nests are generally made on small islands with unobstructed views in inaccessible areas of wetlands and mudflats. Each nesting pair lays two eggs with generally only one chick, if any, surviving to maturity. Although black-necked crane breeding sites are found throughout the central and northern Tibetan Plateau, the crane’s three most important nesting sites are considered to be the Zoige Marshes in northwest Sichuan, Shainza County in the central Tibet Autonomous Region, and the Longbaotan Wetlands in Southern Qinghai.

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China claims to be home to 75 per cent of the remaining 4,200 or so left in the world. Most are found on the Tibetan plateau. The birds have made a strong comeback since the early 1980s when only about 200 remained. Their comeback has been credited to captive breeding programs and the creation of nature reserves in the areas they inhabit.

Captured cranes have been raised in nature centers. A female crane usually lay a single egg unless it is damaged or broken and then she lays another one. Biologists have stolen the eggs after they have been laid, which in turn has made females lay more eggs, as many as 15. The eggs are hatched in incubators after about 30 days. The hatchlings are raised in the center and then released in the wild.

Cao Hai is reserve in western Guizhou near Yunnan. It is the site of mountains and a grassy lake used by water birds, including the black-neck cranes. Environmentalist want the lake to remain protected. Poor farmers want the lake to be drained and the fertile soil to be used for raising crops.

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CRANES

Cranes are admired for their grace and beauty. Symbols of love, happiness, martial fidelity and longevity in east Asia, they are a common motif on kimonos, scrolls, screens, porcelain, lacquerware, bronze mirrors and a popular brand of playing cards. Paper cranes are folded as a sign of peace. Cranes also appear in Russian folk song, ancient Egyptian tombs, Greek myths, Australian aboriginal dances, and prehistoric European cave art.

There are 15 species of crane. They generally make their homes in grasslands and wetlands. Nine species of crane are endangered. Some are near extinction. Their numbers have been reduced by hunting and habitat loss. Captive breeding programs have been set up in several countries to increase their numbers. At some of these places, cranes are raised by humans in crane costumes and taught to fly over grass runways with the help of ultralight planes flown by men in crane costumes.

Most birds in Russia migrate because few other crows and ravens can survive the long cold winters. Rare birds include auks and ivory gulls.

Crane Characteristics and Behavior

Cranes are large birds with long legs and long necks. Male and females look similar. The male is usually a little larger. They tend to feed during the day and spend the night in large communal roosts.

Cranes are opportunistic feeders that eat a wide variety of foods. They forage leftover seeds, nuts and berries and will gobble down any small animal they can catch, including insects, snails, fish, frogs, snakes and even mammals.

Cranes are famous for their songs and dances that accompany their mating rituals. Crane pairs usually stay together until of one of them dies. They establish breeding and feeding territories, which the defend aggressively against intruders. The male is most active in defending the territory.

Crane pairs establish large breeding territories in wetlands and grasslands and zealously defend them. Intruders are warned off with a loud trumpeting . A pair builds a platform nest in shallow water. Typically two eggs are laid, with both sexes share incubation duties. After they hatch chicks remain with their parents until the next breeding season. In many cases only one chick survives. The low reproductive makes rebuilding decimated crane population a difficult task.

Migrating Cranes

The distance covered by migrating cranes is between a 1,000 miles and 3,000 miles. The fly over deserts, tundra and mountain ranges and rely on wetlands along the way to rest and replenish themselves. Cranes can sustain speeds of 30 mph by flying with flapping wings. They prefer to save energy by rising in thermals and being carried by winds. Some cranes know its time to breed based on seasonal markers such as day length and rainfall amounts.

Demoiselle cranes can reach altitudes of 24,000 feet when they cross the Hindu Kush during their fall and spring migrations between nesting grounds in Central Asia and warmer, wintering areas in India. Eurasian cranes migrate between Russia and northern Europe and Spain. They prefer to make their nests in bogs but because bogs are disappearing they make their nests in pocket wetlands in cultivated areas. Whopping cranes and Siberian cranes brought up in captive breeding programs are being taught to migrate by humans with ultra lights and hand gliders. See Siberian cranes

Japanese Cranes (Red-crowned Cranes)

Japanese cranes are the largest birds in Japan. Declared "special natural monuments," they inhabit parts of China, Siberia, Korea and eastern Hokkaido. They are known in Japanese as tancho ("red mountain") and in English as the Japanese crane and the red-crowned crane. [Sources: Jennifer Ackerman, National Geographic, January 2003, Tsuneo Hayashida, National Geographic, October 1983]

A large number of red-crowned cranes live in the Kushiro Mire, a 45,000-acre area of boreal marsh near the city of Kushiro in eastern Hokkaido. It is the crane's main breeding area in Japan and where most of the cranes in Japan congregate in the winter. The marsh has been preserved in its natural state in part because its cool, foggy climate is not conducive to growing rice.

Japanese Crane Characteristics and Behavior

Japanese cranes eat frogs, fish and insects. The can issue a territorial call that can be heard for two miles. They can fly at speeds of 40mph and sometimes the play act by themselves with corn husks.

The Japanese cranes live in northern Hokkaido all through the year and breed in the summer. In sub-zero temperatures the birds stay warm by standing on one leg and protecting its body underneath one wing.

In the winter the cranes in Kushiro sleep standing up one-legged in streams---whose waters are much warmer than the air---for warmth and protection from predators. Members of a group tend to wake up and sleep at different intervals so there is always a "guard bird" on the alert for predators.

Although they can aggressive and fiercely territorial in the summer, tacho sometimes congregate in huge flock in the winter. Describing a gathering in Hokkaido Jennifer Ackerman wrote in National Geographic, "Some stalk the field or stand in pairs, lifting their bills to trumpet a shrill, rolling cry, a "unison" call that carries across fields. One flares its wings and arches its back in a dramatic threat display to relieve the tension of crowding. A swoop of six arriving on motionless wings from their roost site in a nearby river, drop lightly to the ground amidst the others and lower their heads to pluck the scattered corn."

Japanese Crane Mating and Nesting Behavior

Mating is brief. The male leans on the female's back and steadies himself by flapping his wings while the female keep from falling down by placing her beak in the snow. After mating is completed the male and female bow to each other. Mating takes place two or three times a day and continues well into the nesting season.

Nests are built on the ground and tended by both parents during the four- to- five-week incubation period. Females usually lay two eggs but only one chick generally survives. Parents take turns carrying for the young which are vulnerable to attacks from foxes, cows, large raptors and dogs. The chick learns to fly after about three months but remains with its parents for almost a year, after which time it has to fend for itself.

Mates reinforce their bond with "unison" calls. Their loud calls, which an be heard up to three kilometers away, are made by thrusting aire through the bird's long, cooled trachea as if it were some kind of brass instrument, The Japanese expression tsuri no hitoke ("call of the crane") means a voice of authority

Endangered Japanese Crane

Japanese cranes have been hurt by hunting, habitat loss, and deterioration of its breeding environment. Particularly devastating has been the loss of wetlands in Hokkaido, which declined from 200,000 hectares in the 1920s to 60,000 today. Many meandering rivers where the birds lived were straightened and their banks were covered with concrete.

Up until the mid 1800s red-crowned cranes were found in abundance throughout Honshu and Hokkaido, with some of the birds migrating between the two inlands, wintering in Honshu and breeding in Hokkaido. Hunting and loss of habitat forces the birds out Honshu.

The 10 survivors found in the 1920s were found the Kushiro Mire, roosting and feeding in small rivers within the marsh. In 1924 part of the marsh was designated a protected area. That helped them survive but just barely. In 1952 the population had only risen to 33 birds.

In 1952, Hokkaido was struck by a wave of blizzard and severe cold. Local farmers began feeding them corn and buckwheat to help them survive. Every winter after that the farmers fed the cranes and their numbers began to grow.

Over the years the cranes have been carefully studied; captured and released; and tracked and observed. Efforts to raise them in captivity for release failed. In 1982, 1,000 cranes, with 300 of them in Japan, were counted.

Japanese Cranes Today

In the winter the cranes congregate in places where farmers provide then with grain. There are four established feeding centers and several dozen satellite feeding stations---both public and private-in throughout eastern Hokkaido. At the Tsurui-Ito Sanctuary just outside Kushiro National Park, as many as 300 birds gather in the winter for free corn hand outs. The cranes have become very used to humans and are even regarded as pests by some. Farmers complain about them raiding fields and stealing grain intended for livestock. Some have complained about the birds pecking at their windows expecting a handout.

Today, while crane numbers continue to rise at a rate of between 5 to 7 percent a year, their habitat is rapidly shrinking. About 90 pairs nest in Kushiro Mire, which is probably the maximum the marsh can handle. The cranes are famously territorial and crowded them into a particular area reduces the likelihood that their chicks will survive, as adults search larger area for food and defend their territories, leaving nests vulnerable to predators such as foxes, eagles and crows.

In recent years there have been problems associated with tancho cranes encroaching on areas inhabited by humans. Some have disrupted traffic and been hit by cars; others eat crops for food. Some locals have complained about their presence.

The birthrate of the Japanese cranes in Japan is starting to decline. Part of the problem may be lack of fertility due to inbreeding. Having the cranes concentrated in small area also makes them vulnerable to a contagious disease. Birds have been killed by flying into electric wires, being hit by cars and trains and swallowing pesticides after falling into slurry tanks.

Development around the wetlands in Hokkaido where the cranes live has caused the water levels to drop and parts of the marsh to dry up.The marshlands in Kushiro are deteriorating as groundwater levels have dropped and development has increased. In the past 60 years the marshland has decreased in size by 30 percent.

A few cranes that winter in Hokkaido have begun breeding in the Russian-controlled Kurile islands north of Hokkaido. Japanese and Russian researchers and officials have looked into the idea of introducing cranes to open marshes of Sakhalin Island, further north still but tense relations between Russia and Japan over the Kurile Island has prevented much action from taking place.

White-Naped Crane

The white-naped crane is named after the white stripe that runs along the bird's neck. Standing up to 1.5 meters and weighing between 4.75 and 6.50 kilograms, these large birds inhabit wetlands and adjacent grasslands in China, eastern Siberia (near Vladivostok), southern Japan and the demilitarized zone between North and South Korea.

Predominately grey, with a red spot around their eyes, white-naped cranes are monogamous. They incubate two eggs which hatch in about 30 days. Only about 4,900-5,300 of the birds remain. Their existence has been threatened by loss of habitat and disruption of migration patterns.

White-naped cranes and hooded cranes breed in the marshlands in China, Mongolia and Russia and winter in western Kyushu. Flocks of more than 1,000 birds often show up around Izumi in Kumamoto prefecture.

Hooded cranes once wintered all over Japan, but today they are only found in one or two places.

Black-Necked Cranes

The black-necked crane is named after the black coloring on the bird's neck and head. Standing 90 to 130 centimeters tall, with a wingspan of 180 to 200 centimeters and weighing between 6 to 9 kilograms, these large birds have a bright red crown and feed primarily on barley. Tibetans regarded them as holy birds.

The black-necked crane inhabits high altitude wetlands on the Quighia-Tibetan Plateau during the April-to-October breeding season and winters in low elevation agricultural valleys in China, Bhutan, India and Myanmar, particularly on the Yunnan-Guizhou Plateau. For many of these birds their entire migration route is within China.

Black- Necked Crane Breeding dance

Black-Necked Crane Breeding

Black-necked cranes are monogamous. Females lay one or two eggs in a nest set on a small grassy island, surrounded by water for protection. Both parents incubate the eggs, which hatch after about 30 days, and share in the child rearing duties. A family stays together during the migration until the next breeding season when juveniles join non-breeding flocks and form pair-bonds of their own.

Describing the black-necked crane mating dance, Zhang Zhiyen wrote in the Japan Times, "One bird spread its wings, jumped and down, picked up a stick in its bill and threw it into the air. Then it flapped its wings and ran in a large circle, leaping and dancing as if full of joy. At the same time its partner bowed and stretched out its neck, beat its wings and rose and fell, cutting an elegant figure."

"The male's cry sounded like "Ga-ga ga," while the female's shrill cry went "gage-gage-gagage." They sang on together, their bills pointing up to the sky, and were still easily audible 1.5 km away...A pair of them walked quite near...They bobbed their heads up and down as they walked, crying loudly. The male stepped behind the female, and his cry became more loud and sonorous. Leaping onto the female's back, he mated with her for 5-6 seconds; then both danced and sang for about two minutes."

Endangered Black-Necked Crane

China claims to be home to 75 per cent of the remaining 4,200 or so left in the world. Most are found on the Tibetan plateau. The birds have made a strong comeback since the early 1980s when only about 200 remained. Their comeback has been credited to captive breeding programs and the creation of nature reserves in the areas they inhabit.

Captured cranes have been raised in nature centers. A female crane usually lay a single egg unless it is damaged or broken and then she lays another one. Biologists have stolen the eggs after they have been laid, which in turn has made females lay more eggs, as many as 15. The eggs are hatched in incubators after about 30 days. The hatchlings are raised in the center and then released in the wild.

Cao Hai is reserve in western Guizhou near Yunnan. It is the site of mountains and a grassy lake used by water birds, including the black-neck cranes. Environmentalist want the lake to remain protected. Poor farmers want the lake to be drained and the fertile soil to be used for raising crops.

Image Sources: 1) 2) British Museum 3) 4)Wolfgang Kaeler, International Wildlife Adventures 5) Hubpages blog 6) Nicolas Delerue 7) Japan-Animals blog

Text Sources: New York Times, Washington Post, Los Angeles Times, Times of London, Lonely Planet Guides, Library of Congress, U.S. government, Compton's Encyclopedia, The Guardian, National Geographic, Smithsonian magazine, The New Yorker, Time, Newsweek, Reuters, AP, AFP, Wall Street Journal, The Atlantic Monthly, The Economist, Foreign Policy, Wikipedia, BBC, CNN, and various books, websites and other publications.

&copy 2008 Jeffrey Hays

Last updated May 2016

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CRANES Cranes are admired for their grace and beauty. Symbols of love, happiness, martial fidelity and longevity in east Asia, they are a common motif on kimonos, scrolls, screens, porcelain, lacquerware, bronze mirrors and a popular brand of playing cards. Paper cranes are folded as a sign of peace.

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Environment of reserve improved for black-necked cranes in China's Tibet

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Environment of reserve improved for black-necked cranes in China's Tibet

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A black-necked crane looks after its chicks after they hatched in the Qiangtang nature reserve, southwest China's Tibet Autonomous Region, June 24, 2017. Flocks of black-necked cranes fly here to breed as the environment of reserve has been improved in recent years. (Xinhua/Purbu Zhaxi)

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Environment of reserve improved for black-necked cranes in China's Tibet - Xinhua | English.news.cn

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A black-necked crane looks after its chicks after they hatched in the Qiangtang nature reserve, southwest China's Tibet Autonomous Region, June 24, 2017. Flocks of black-necked cranes fly here to breed as the environment of reserve has been improved in recent years. (Xinhua/Purbu Zhaxi)

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Justification:
This species is classified as Vulnerable because it has a single small population that is in decline owing to the loss and degradation of wetlands, and changing agricultural practices in both its breeding and wintering grounds. However, the population has apparently increased or stabilised in recent years, and if these increases prove to be genuine and sustained then downlisting to a lower threat category may be appropriate.

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Grus nigricollis (Black-necked Crane, Tibetan Crane)

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Home " Grus nigricollis (Black-necked Crane, Tibetan Crane)

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Black-necked Crane ~ great videos and photos

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Black-necked Crane ~ great videos and photos

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The black-necked crane is the only alpine crane in the world ⁽⁵⁾. As the English name suggests, the upper part of the neck and the head are black, except for a small white patch to the rear of the eye and a red bald patch between the bill and the eye. The rest of the body is grey, but the legs, lower parts of the wings and the tail are black. The inner flight feathers are elongated and curve downwards ⁽⁶⁾. Males and females are similar in appearance and juveniles have a buff-coloured head with a white and black neck ⁽⁶⁾. (from arkive.org)

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Black-necked crane videos, photos and facts - Grus nigricollis | Arkive

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The black-necked crane is the only alpine crane in the world. As the English name suggests, the upper part of the neck and the head are black, except for a small white patch to the rear of the eye...

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This tour is designed for tourists wishing to see the Black Neck Cranes roost in the Phobjikha valley during the winter months of November to mid February. Locals have started a Black Neck Crane Festival, which is on the 11th of November this year, where one can watch the birds roosting, as well as bargain for handicrafts and enjoy local games and mask dances in honour of the birds. You will also be visiting old and revered monasteries, temples and fortresses and hike to Taktsang Goemba.

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This tour is designed for tourists wishing to see the Black Neck Cranes roost in the Phobjikha valley during the winter months of November to mid February. Locals have started a Black Neck Crane Festival, which is on the 11th of November this year, where one can watch the birds roosting, as well as bargain for handicrafts and enjoy local games and mask dances in honour of the birds. You will also be visiting old and revered monasteries, temples and fortresses and hike to Taktsang Goemba.

Day 1: Paro-Thimphu

The flight into Paro will provide you with a spectacular view of the Himalayan mountain ranges. During the descent one can enjoy a panoramic view of the Paro valley. Upon arrival you will be received by our representative at the Paro International Airport exit doors.

After lunch you will visit Ta Dzong "Watchtower" Museum complex which houses an impressive collection of old and new thangkas (painted or embroidered religious pictures), religious relics and festival dance masks among other collections with historical value. The Museum also has a natural history collection on display.

Next you will visit Rinpung Dzong which is a perfect example of Bhutanese architecture with its thick buttressed walls. Dzongs were used as forts during times of war and this fort was used numerous times to thwart invasions from Tibet. At present, it is used to house the monastic body as well as district government offices.

Afterwards we will drive to the capital city Thimphu which is a short 1-1hr 20 minutes drive from Paro. We will check in and you will spend the night at the hotel in Thimphu.

Day 2: Thimphu

After breakfast we will start the day off with a visit to the National Memorial Chorten, built in 1974 as a memorial to the third king of Bhutan. The next item on the itinerary will be a visit to Changangkha Lhakhang which is a popular fortress like temple perched on a hill overlooking the Thimphu valley. We will then move towards Buddha Point where a 50m tall Buddha Dordenma is currently in the final stages of completion.

After lunch we will continue sightseeing with a visit to the Folk Heritage Museum where one can visit a restored medieval farmhouse. Then, a visit to the National Institute of Zorig Chusum (the 13 arts and crafts) where specialization courses in Thangka making, woodcarving, embroidery, and sculpting are provided to students.

If time permits, the day will end with a visit to the Takin Zoo (Takin is the national animal of Bhutan). On the drive back to your hotel, you will see the Tashichhodzong, which houses His Majesty's secretariat, office of some of the ministries and the central monk body. You will spend the night in your hotel in Thimphu.

Day 3: Thimphu

After breakfast we will start the day off with a hike to Tango or Cheri Monasteries, a short 45 min hike up laid paths through the thick forest of pine trees.

The alternative item on the agenda is a visit to Phajoding Monastery from where one can get a wonderful view of Thimphu city on the valley floor. The hike to Phajoding will take approximately 4 hours.

In the afternoon we will continue sightseeing in Thimphu with a visit to the Traditional Paper Making Factory to see the workings at the factory, then we will move on to the National Library, which houses a large collection of Bhutanese scriptures dating back to the 8th century.

Day 4: Thimphu - Punakha

After breakfast, we will start the 3 hour journey towards Punakha. On the way, we will make a brief stop at Dochu-la pass (3,140 m above sea level) where on a clear day one can enjoy an incredible view of the Himalayan mountain ranges. This is the place where an impressive collection of 108 chortens and hill side marked by an array of prayer flags can be seen. As you drive down towards Punakha Valley, you can enjoy the view of the hillsides filled with rhododendrons in full bloom during the months of April and May.

Before entering Punakha, you will pay a visit to Chime Lhakhang which was built by the cousin of Lama Drukpa Kuenley who is more famously known to the western world as the Divine Madman. Drukpa Kuenley is considered as a symbol of fertility and couples having difficulty conceiving often visit the temple to receive blessings. After lunch at the Chimi Lhakhang cafeteria we will head towards Punakha.

Punakha was the old capital of Bhutan till the mid 1950's. It was built by Zhabdrung Ngawang Namgyal in 1637. It is the winter residence of the chief abbot Je Khenpo and hundreds of monks who move from Thimphu to Punakha and reside here during the winter months. It is a perfect example of Bhutanese architecture with pillars carved out of cypress trees adorned in gold, red and black colors, thick buttressed walls, and three large courtyards. You will spend the night in your hotel in Punakha.

Day 5: Punakha-Phobjikha

On day 5, we will drive (3 hours) to Phobjikha which is a glacial valley (2900m) and known mainly for the large flock of Black Necked Cranes that roost here during the winter months (November to mid-February).

The sightseeing will continue with a visit to Gangte Goemba which rests on the hill overlooking the entire Phobjikha valley. Moving on, we will visit the Black Necked Crane Information Centre where you can learn more about the Cranes and the environment of the valley.

If time permits, we will arrange short hikes for you before you return to your hotel. You will spend the night at your hotel in Phobjikha.

Day 6: Phobjikha- Wangdiphodrang.

We will spend half a day hiking along the Gangte Nature Trail, exploring the surrounding villages, potato fields and Lhakhangs.

We will then drive to Wangdiphodrang (3 hours) in the afternoon and with some luck you may hope to see the highly endangered White Bellied Heron along the Punatsangchu river bed. You will spend the night at your hotel in Wangdiphodrang.

Day 7: Wangdiphodrang- Paro

The next day we will drive back to Paro (5 hours), with a stop at Dochu La for lunch. Afterwards we will proceed to Paro where you will be given the opportunity to visit handicraft and souvenir stores lined along the main street of Paro town. You will spend the night at your hotel in Paro.

Day 8: Paro

After breakfast we will start the 2 hour hike to Taktshang Goemba which rests at an altitude of 900 metres above the valley. Taktshang, meaning the 'Tiger's Nest', is one of Bhutan's most venerated pilgrimage sites and is a very popular site for all tourists visiting Bhutan.

According to legend, Guru Rinpoche miraculously flew here on the back of a tigress, meditated in a cave for three months and converted the whole of Paro valley to Buddhism.

On the way down we will halt at Taktshang Cafeteria for lunch. In the afternoon, a trip to visit the ruins of Drugyel Dzong, built in 1646 by Zhabdrung Ngawang Namgyal to commemorate his victory over the Tibetans in 1644. Drukgyel means 'the fortress of the victorious Drukpas'.

On the way back, if time permits, we will take you to see Kyichu Lhakhang, one of the oldest temples in Bhutan, built in the 7th century by the famous Buddhist Tibetan King Songtsen Gampo. You will spend the night in your hotel in Paro.

Day 9: Depart Paro

After breakfast at the hotel our representative will bid farewell to you at the airport.

We wish you a safe journey towards your next destination. Tashi Delek.

The best way to see Bhutan SN Adventures

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This tour is designed for tourists wishing to see the Black Neck Cranes roost in the Phobjikha valley during the winter months of November to mid February. Locals have started a Black Neck Crane Festival, which is on the 11th of November this year, where one can watch the birds roosting, as well as bargain ...

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Western development projects severely threaten Tibet’s black-necked cranes

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Western development projects severely threaten Tibet’s black-necked cranes

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(TibetanReview.net, Aug03, 2017) - Mineral exploitation, infrastructure development and changes in agricultural practices are severely threatening the survival of the black-necked crane, the world's least-studied crane species that is endemic to the Tibetan Plateau, and other endangered wild lives, reported the IANS news service Aug 2, citing a new international study.

Under China's Western Development Scheme, many critical but unassessed human activities are pervasive in crane's breeding habitat, the study was cited as saying. The study, titled as "Machine Learning Model Analysis of Breeding Habitats for the Black-necked Crane in Central Asian Uplands under Anthropogenic Pressures", was published by Springer Nature Jul 2017.

Deficient knowledge on these threats are said to be widely overlooked, greatly constraining current research and regional conservation activities,

The Alpine species breeds in the extensive landscape of high Central Asia, including Ladakh in India, and its global population is estimated to be around 10,000.

The study was cited as saying that owing to the Tibetan Plateau's environmental inaccessibility to comprehensive field research, the black-necked crane had remained the world's least-studied crane species.

The study was reported to have been conducted by a team of researchers led by Xuesong Han of the College of Nature Conservation in Beijing Forestry University. Falk Huettmann of the US Department of Biology and Wildlife in the Institute of Arctic Biology of the University of Alaska, Fairbanks, was also said to be associated with the study.

"The rapid development in the Tibetan Plateau, especially water conservancy projects and mining, is a big threat for the survival of black-necked cranes and other endemic species," Huettmann, a wildlife ecologist specialising in macro-ecology and global conservation, was quoted as saying, speaking on the sidelines of the 28 th International Congress for Conservation Biology (ICCB 2017) in the Colombian city of Cartagena.

He has added that the human interference index giving rise to the threat was quite high in the Tibetan Plateau region.

The report said that the International Union for Conservation of Nature (IUCN) had classified the black-necked crane, the flagship species in Tibetan Alpine wetland ecosystems, as "vulnerable" because of its decreasing global population of 10,070 to 10,970.

Its main potential breeding areas include northern parts of the Hengduan Mountains and the southeastern Tibet Valley, the northern side of the middle Kunlun Mountains, parts of the Pamir Plateau, the northern Pakistan Highlands and the western Hindu Kush.

Highland barley was traditionally planted in the middle and lower reaches of the Brahmaputra river, the report noted. However, the Chinese government changed the land use from crane-edible barley plantations to "crane-unbeneficial" but highly-profitable cash crops such as rapeseed.

The massive Han Chinese migration for constructing tourism and affiliated infrastructure was reported to be especially serious.

The report said the potential breeding area of the cranes had been invaded by large-scale construction of water conservancy projects - with nine large hydro power projects being scheduled or already constructed on the Brahmaputra and Mekong rivers.

The researchers have proposed that threats and their links to China's western development plan must be assessed for the long-term maintenance of the endangered crane species and other wildlife on the fragile Tibetan Plateau.

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Western development projects severely threaten Tibet's black-necked cranes

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(TibetanReview.net, Aug03, 2017) - Mineral exploitation, infrastructure development and changes in agricultural practices are severely threatening the survival of the black-necked crane, the world's least-studied crane species that is endemic to the Tibetan Plateau, and other endangered wild lives, reported the IANS news service Aug 2, citing a new international study.

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BLACK-NECKED CRANES NESTING INTIBET AUTONOMOUS REGION, CHINA

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BLACK-NECKED CRANES NESTING INTIBET AUTONOMOUS REGION, CHINA