乌鸫的繁殖行为与坐巢行为初步观察

于2009年3～7月、2010年3～6月,采用焦点动物观察法和全事件行为记录法对乌鸫(Turdusmerula)的孵卵及育雏行为进行了研究。结果表明,乌鸫是雌鸟孵卵,在孵卵期出现卵损失现象,具补卵行为;孵卵前期与后期的坐巢行为存在差异,且其坐巢时间、频次和坐巢率有随孵卵数递增的趋势。双亲育雏但以雌鸟为主,喂食模式3种:雌鸟喂食、雄鸟喂食、雄鸟将食物递给雌鸟由雌鸟喂食。随着雏鸟日龄的增长,喂食次数增多,暖雏行为减少,至育雏后期未观察到暖雏行为。为权衡孵卵期和育雏前期的能量分配,乌鸫在孵卵期及育雏前期分别采取时间长而频次少和时间短而频次多的坐巢策略。     

山噪鹛的生态观察

山噪鹛是甘肃山地留鸟,4—8月繁殖,巢筑于灌木或小乔木横枝上,每窝产蓝绿色卵3—4枚。仅雌鸟孵卵,孵卵期15天。雌、雄共同育雏,育雏期15—16天。对雏鸟的生长过程亦作了简要记述。     

四川瓦屋山金色林鸲的繁殖生态及孵卵节律

20 0 3年 4～ 7月 ,在四川省瓦屋山自然保护区对金色林鸲 (Tarsigerchrysaeus)的繁殖生态和孵卵节律进行了较为深入的研究。金色林鸲营巢期从 4月下旬～ 6月中旬 ,孵卵期一般为 1 6～ 1 7d,育雏期为1 6d。窝卵数一般为 3～ 4枚 ,平均为 (3 . 75± 0. 45 )枚 (n =1 2 ) ,孵化率为 60 0 % ,育雏成功率为 85 2 %。仅雌鸟孵卵 ,根据对 3巢的监测 ,发现雌鸟早晨 6:0 0时左右首次离巢 ,晚上 2 0 :0 0时左右回到巢中 ,每天出巢次数 1 8～ 1 9次。孵卵雌鸟每次出巢时间一般少于 2 0min ,异常离巢时最长达到 65 6min。雌鸟出巢时间的长度和环境温度呈明显的正相关 (Spearman,r=0 . 1 1 8,P =0 . 0 0 7,n =5 3 1 )。金色林鸲雄鸟存在羽毛延迟成熟现象 ,亚成体雄鸟可以繁殖。     

湖北兴山县龙门河地区灰林（即鸟）繁殖习性

2004年5月~2005年7月,在湖北省兴山县龙门河村,对灰林(Saxicola ferrea)的繁殖习性进行了初步研究。研究结果显示,灰林在湖北兴山龙门河地区的繁殖时间为4月中旬至7月下旬。主要在农田边、公路旁、河岸边、山间小路旁等山坡草丛中营巢,巢址选择在牲畜较少光顾的、较陡的土坡上,上方往往有茅草等遮挡,较为隐蔽。筑巢工作全部由雌鸟承担,一般需要5~7 d即可完成。雌鸟每天产一枚卵,产卵时间一般在清晨。窝卵数5枚(n=15),第4枚卵产出后即开始孵化,孵卵工作全部由雌鸟承担。雌鸟的孵卵行为有明显的节律性。孵化期13~14 d。雏鸟晚成性,雌雄共同育雏,育雏期12~13 d。雏鸟离巢前体重有所下降。     

黑头噪鸦的鸣声分析及其繁殖行为联系

黑头噪鸦(Perisoreusinternigrans)是我国青藏高原高山针叶林的特有鸟类,由于分布海拔高、数量稀少,因此对于黑头噪鸦的研究非常少。本文对2 0 0 0年3月～2 0 0 3年6月在甘肃和四川录制的黑头噪鸦的8种叫声进行了描述及声谱分析。结合野外观察,分析了黑头噪鸦的叫声及其行为联系。黑头噪鸦的乞食叫声可能在整个繁殖生活史中具有重要意义。研究中未发现黑头噪鸦对录音回放产生回应。     

四川南充地区白鸰的繁殖习性

2004年2～5月在四川省南充市嘉陵江中上游的河漫滩内对白鹡鸰(Motacilla alba)的繁殖习性进行了研究.结果表明白鹡鸰2月开始繁殖;雌雄参与筑巢,营巢期7～10 d;主要雌鸟孵卵,孵卵期13～14 d,上午800～900时孵卵出现一次高峰;窝卵数(5.00±0.52)(n=16)枚,孵化率42.5%;雌雄参与育雏,育雏期15～16 d,下午1800～1900时育雏出现一次高峰,日育雏次数(112.9±48.6)(n=17),育雏时间间隔(5.60±5.34)min(n=1 584);雏鸟形态生长曲线呈"S"型.     

四川南充地区白鶺鴒的繁殖习性

2004年2~5月在四川省南充市嘉陵江中上游的河漫滩内对白鶺鴒(Motacilla alba)的繁殖习性进行了研究。结果表明:白鶺鴒2月开始繁殖;雌雄参与筑巢,营巢期7~10 d;主要雌鸟孵卵,孵卵期13~14 d,上午8:00~9:00时孵卵出现一次高峰;窝卵数(5.00±0.52)(n=16)枚,孵化率42.5%;雌雄参与育雏,育雏期15~16 d,下午18:00~19:00时育雏出现一次高峰,日育雏次数(112.9±48.6)(n=17),育雏时间间隔(5.60±5.34)min(n=1 584);雏鸟形态生长曲线呈“S”型。     

高山雪鸡繁殖期觅食和警戒行为的性别差异

2004年和2005年的4～7月,采用聚焦取样的方法,观察研究了甘肃省东大山自然保护区和盐池湾自然保护区高山雪鸡(Tetraogallus himalayensis)繁殖期的两性觅食频率和警戒行为。研究表明,无论是繁殖前期还是孵卵期,雌鸟的觅食频率均高于雄鸟,警戒性则低于雄鸟,而且均有显著差异(P<0.05),同性雪鸡在不同时期的差异不显著(P>0.05);高山雪鸡的雄鸟不参与孵卵和育雏,但在雌鸟产卵和孵卵期担任警戒。另外,本文对野生高山雪鸡的警戒行为进行了分类。     

云南思茅红头咬鹃繁殖记录

记录了云南思茅太阳河自然保护区2个红头咬鹃巢的繁殖。红头咬鹃的巢位于枯树干侧面的洞中,窝卵数2～3枚。红外相机监测记录显示,雌、雄亲鸟均参与孵卵,雄鸟白天孵卵,时间较短,雌鸟从傍晚至次日上午孵卵,时间较长。雏鸟孵出后,主要由雌鸟在巢中暖雏,雄鸟送回食物。2个巢均未繁殖成功。     

西藏林芝灰腹噪鹛(Garrulax henrici)繁殖生态及行为节律

灰腹噪鹛(Garrulax henrici)是中国的特有鸟种,也是噪鹛属中繁殖行为研究较少的物种之一。2016年4—7月,在西藏林芝西藏农牧学院内进行了灰腹噪鹛的繁殖生态研究,采用瞬时扫描法观察其求偶期日行为节律,用红外相机监测孵卵期3巢和育雏期2巢灰腹噪鹛的行为。结果表明:灰腹噪鹛4月中旬开始产卵,窝卵数2~3枚,卵长径29.6±0.4mm,短径20.3±0.17 mm,卵重6.66±0.12 g;灰腹噪鹛75.0%的巢树为针叶树,12.5%为阔叶树,8.3%为灌木,4.2%为禾本科;灰腹噪鹛营巢成功率为86.7%,孵化成功率为60%,繁殖成功率为43.3%,影响其繁殖成功率的因素是人为干扰和天敌捕食;求偶期灰腹噪鹛觅食行为占总时间的32.03%,移动占29.27%,上午觅食、移动及鸣唱行为达到高峰,下午休憩行为偏多;孵卵期的主要行为是卧巢孵卵,占总时间的85.31%,翻卵占5.02%;育雏期亲鸟理巢行为占39.74%,卧巢占35.92%,喂食频率平均为2.95次·h-1,灰腹噪鹛单亲喂食频次多于双亲共同喂食。     

Selfish long-term benefits of hoarding in the Siberian jay

We followed the consumption of cached food in Siberian jay flocksduring winter. Siberian jay flocks contain kin associationscomposed of parents in company with mature offspring. Further,flocks often contain immigrants not closely related to the groupmembers. We studied the extent to which Siberian jay offspringkept caches to themselves or whether they showed a kin biasand shared cached food mutualistically with relatives (parents/siblings)thus making an inclusive fitness gain. We recorded the retrievalof cached food using radio-ptilochronology, a technique thatdetects the consumption of a radioactively labeled food itemin the growth bar laid down in a growing feather the day ofconsumption. Food caching entailed a selfish benefit to thehoarder. The hoarding bird showed a substantial "recovery advantage"and retrieved its own cached food seven times as often as anyof its flock mates. There was no evidence for mutualistic sharingof caches among relatives. This selfish benefit persisted throughoutthe 7-week period for which we could follow the consumptionof labeled food.     

Family status and contributions to breeding by Florida scrub jays

Nestling care by Florida scrub jay Aphelocoma c. coerulescens breeders and helpers is quantified. Breeding males and older male helpers deliver more food than first-year helpers and older female helpers. Breeding males adjust the quantity of food they deliver inversely to that delivered by their helpers. Older female helpers, who make many nest visits without delivering food, attempt to usurp the nest-sitting role of the breeding female. The advantages of group breeding to the breeders seem clear. Pairs with helpers live longer and produce more fledglings. The advantages of being a helper, though obscure, probably include non-altruistic factors such as increased survival and, for males, increased chances of obtaining space for breeding. Food contributions of helpers seem to parallel these opportunities.     

The Effects of Social Context on the Food-Caching Behavior of Florida Scrub-Jays (Aphelocoma coerulescens)

Florida scrub‐jays are cooperative breeders that live in family groups consisting of a breeding pair, often with several non‐breeding helpers. Florida scrub‐jays cache food by scatter‐hoarding items for later consumption. Within family groups, members have the opportunity to observe and pilfer the caches of other members. We observed jays harvesting experimentally provisioned peanuts alone and in the presence of other family members, to determine whether jays modify their food‐handling behavior relative to social context. Non‐breeding helpers were less likely to cache in the presence of the dominant male breeder than when alone and all jays tended to cache out of sight when observed by another jay. These changes in caching behavior are consistent with cache protection strategies employed by other species. However, the adaptive value of such cache protection within a sedentary cooperatively breeding family group on a year‐round territory is unclear.     

Offspring retention in the Siberian jay {Perisoreus infaustus): the prolonged brood care hypothesis

We examined aggressive behavior in Siberian jay groups containingboth retained offspring and immigrant juveniles during winterfeeding and during breeding. Selective tolerance of retainedoffspring by parental birds in winter suggests that cooperationevolved through kin selection. Parents exhibited a self-restraintin aggression towards retained offspring at food in winter.Comparatively, nonkin immigrants were aggressively preventedfrom sharing food by the local pair. Parental tolerance in wintercould bring inclusive fitness gains through the direct kin componentif retained offspring experience relaxed competition and enhancedsurvival. Parental tolerance would then favor the evolutionof delayed dispersal. There is no evidence that delayed dispersalamong Siberian jays should have evolved because of indirectfitness benefits to retained offspring from helping to raiseyounger siblings. Offspring retained by parents did not participatein incubation, feeding or nest defense.     

High frequency of extrapair fertilization in a plural breeding bird, the Mexican jay, revealed by DNA microsatellites

We used tetra-nucleotide microsatellite DNA typing to estimate the frequency of extrapair fertilization (EPF) in a plural breeding species, the Mexican jay, Aphelocoma ultramarina, in Arizona. We found EPF in 32 of 51 complete broods (63%) and 55 of 139 nestlings (40%) for which the putative father had been identified (one of the highest rates of EPF known for birds). At least 96.1% of EPF fathers came from within the group. This is by far the highest known within-group EPF rate among socially monogamous, communally rearing species. Most (70%) males of breeding age (3+ years) had no genetic paternity in a given year. Social fathers (i.e. those with nests and mated females) rarely obtained EPFs; of 25 social fathers, 23 had young in only one nest and only two had young in two nests by virtue of EPF. Of the 27 males known to be EPF fathers without a nest of their own, none had young in more than one nest. Only 7% of EPF fathers had their own broods reaching banding age (day 14), compared with 29.7% of social fathers. The proportion of EPF young was significantly larger in smaller broods. Breeding females in all age classes were equally likely to have EPF young. Copyright 2000 The Association for the Study of Animal Behaviour.     

Eavesdropping squirrels reduce their future value of food under the perceived presence of cache robbers

Caching behavior frequently occurs within a social context that may include heterospecific cache pilferers. All else equal, the value of cacheable food should decline as the probability of cache recovering declines. We manipulated gray squirrels' (Sciurus carolinensis) estimate of the probability of cache recovery using experimental playbacks of the vocalizations of a potential cache robber, the blue jay (Cyanocitta cristata). We used giving-up densities (GUDs) to quantify relative changes in squirrels' valuation of cacheable and noncacheable foods. We collected GUDs during playback experiments to test whether squirrels (1) eavesdrop on vocalizations to detect jay presence, (2) devalue cacheable food in the (perceived) presence of jays (i.e., perceive jays as cache pilferers), and (3) are sensitive to distant effects (i.e., lower devaluation of cacheable food at sites far from the perceived location of jays). Consistent with our predictions, squirrels decreased the value of cacheable hazelnuts by two nuts, on average, during jay playbacks, but only at foraging stations near the jay playback sites. We conclude that through eavesdropping, squirrels assess site-specific risks of cache pilfering and alter their caching behavior to reduce the likelihood of pilferage. Evidence suggests that tree seed consumers in eastern deciduous forests exist within a complex communication network.     

FOOD AS A FACTOR CONTROLLING THE BREEDING OF PUFFINVS LHERMINIERI

A study of Puffinus Iherminieri on Plaza Island, Galápagos, showed that, although eggs were laid in all months, there were marked peaks and troughs of laying. Intervals between successive layings varied with the success or failure of the first egg, an average of nine months for successful pairs, eight months for pairs which lost a young, and 6–5 months for those which failed to hatch an egg. However the breeding success did not influence the time between the end of one breeding attempt and the next laying. This suggests that birds were breeding as quickly as possible. The critical factor preventing more frequent breeding appeared to be the time required to replace the wing and tail feathers.
Details are given of the breeding biology, all aspects of which were strongly influenced by frequent and unpredictable food shortages. The average incubation period was 49 days but this was prolonged by temporary desertion due to food shortages. Chick growth and fledging periods (62 to 100 days) were variable. There was no well–defined desertion period and birds were experimentally induced to feed young for up to 120 days.
Overall nesting success was low (26%) and adult survival between breeding attempts was high (92–95%).
Food, planktonic fish larvae and Crustacea, appeared to be rarely abundant and details are given of the effect of food shortage on the breeding.
The breeding synchrony was brought about by food shortages. The ultimate factor controlling breeding appeared to be the availability of food for egg formation and there was no possibility of birds timing breeding so that young were being fed at a time of food abundance.
A comparison is made of the breeding of eight Puffinus species.     

Causes and consequences of variation in diet composition of nestling Canada jays

Diet quality during development can impact growth, physiology, behaviour and survival. The Canada jay is a resident boreal passerine that caches a wide variety of perishable food items in late summer and autumn for its over‐winter survival and late‐winter reproduction. A previous experiment found evidence that food supplementation of Canada jay pairs during the nestling period had a positive effect on the condition of their nestlings. However, given that foods cached by adults vary widely in nutritional content, the composition of nestling diets could also have an important influence on offspring development. In a population of Canada jays in Algonquin Provincial Park, Ontario, Canada, we investigated the influence of environmental conditions before and during the breeding season on nestling diet composition and the consequences of nestling diet composition on the body condition of nestlings and on their subsequent survival. Using stable‐carbon (δ¹³C) and ‐nitrogen (δ¹⁵N) isotopes, we estimated the proportion of three food groups (vertebrates + human food, invertebrates and plants) in feathers from almost 200 nestlings. Nestling diet in March and April was influenced by environmental conditions 5–6 months prior to hatching, with warmer and more variable autumn temperatures associated with a greater proportion of vertebrate flesh and human food in the diet. However, the proportion of vertebrates and human food in the diet had no influence on nestling body condition or whether an individual was observed the following fall. Our results, in conjunction with previous work on Canada jays, suggest that the quantity of food available to a nestling during development may be more important than diet composition.     

Remotely sensed forest understory density and nest predator occurrence interact to predict suitable breeding habitat and the occurrence of a resident boreal bird species

Habitat suitability models (HSM) based on remotely sensed data are useful tools in conservation work. However, they typically use species occurrence data rather than robust demographic variables, and their predictive power is rarely evaluated. These shortcomings can result in misleading guidance for conservation. Here, we develop and evaluate a HSM based on correlates of long‐term breeding success of an open nest building boreal forest bird, the Siberian jay. In our study site in northern Sweden, nest failure of this permanent resident species is driven mainly by visually hunting corvids that are associated with human settlements. Parents rely on understory nesting cover as protection against these predators. Accordingly, our HSM includes a light detection and ranging (LiDAR) based metric of understory density around the nest and the distance of the nest to the closest human settlement to predict breeding success. It reveals that a high understory density 15–80 m around nests is associated with increased breeding success in territories close to settlements (<1.5 km). Farther away from human settlements breeding success is highest at nest sites with a more open understory providing a favorable warmer microclimate. We validated this HSM by comparing the predicted breeding success with landscape‐wide census data on Siberian jay occurrence. The correlation between breeding success and occurrence was strong up to 40 km around the study site. However, the HSM appears to overestimate breeding success in regions with a milder climate and therefore higher corvid numbers. Our findings suggest that maintaining patches of small diameter trees may provide a cost‐effective way to restore the breeding habitat for Siberian jays up to 1.5 km from human settlements. This distance is expected to increase in the warmer, southern, and coastal range of the Siberian jay where the presence of other corvids is to a lesser extent restricted to settlements.     

Experimental evidence for a novel mechanism driving variation in habitat quality in a food-caching bird

Variation in habitat quality can have important consequences for fitness and population dynamics. For food-caching species, a critical determinant of habitat quality is normally the density of storable food, but it is also possible that quality is driven by the ability of habitats to preserve food items. The food-caching gray jay (Perisoreus canadensis) occupies year-round territories in the coniferous boreal and subalpine forests of North America, but does not use conifer seed crops as a source of food. Over the last 33 years, we found that the occupancy rate of territories in Algonquin Park (ON, Canada) has declined at a higher rate in territories with a lower proportion of conifers compared to those with a higher proportion. Individuals occupying territories with a low proportion of conifers were also less likely to successfully fledge young. Using chambers to simulate food caches, we conducted an experiment to examine the hypothesis that coniferous trees are better able to preserve the perishable food items stored in summer and fall than deciduous trees due to their antibacterial and antifungal properties. Over a 1–4 month exposure period, we found that mealworms, blueberries, and raisins all lost less weight when stored on spruce and pine trees compared to deciduous and other coniferous trees. Our results indicate a novel mechanism to explain how habitat quality may influence the fitness and population dynamics of food-caching animals, and has important implications for understanding range limits for boreal breeding animals.