桉树成林无性系转化试验研究

通过近两年的桉树成林无性系转化试验,结果表明,桉树成林无性系之间扦插成活率差异显著:夏季扦插成活率高于秋季,且生根时间短,便于管理;不同浓度的ABT生根粉对桉树扦插成活率有极显著影响,以ABT(1号)生根粉100PPM浸泡3小时为最佳;不同年龄的枝条对桉树扦插成活率有显著影响,其中以当年生半木质化枝条扦插成活率为最高.     

Who cares? Individual contributions to pup care by breeders vs non-breeders in the cooperatively breeding banded mongoose (<Emphasis Type="Italic">Mungos mungo</Emphasis>)

Knowledge of the investment rules adopted by breeders and non-breeders, and the factors that affect them, is essential to understanding cooperative breeding as part of a life-history tactic. Although the factors that affect relative contributions to care of young have been studied in some cooperative bird species, there is little data on mammals, making coherent generalisations within mammals and across taxa difficult. In this study, we investigate individual contributions to pup escorting, a strong predictor of offspring provisioning, in the banded mongoose (Mungos mungo), a cooperatively breeding mammal in which reproductive skew is low. Contributions by those under a year old (which virtually never breed) increased with age and body weight but were generally low. Among older age classes (yearlings and adults), individuals that had not bred in the current litter generally contributed less to escorting than those that had bred (with the exception of yearling males). In addition, females that did not breed reduced their investment if they were heavy presumably because such females are more likely to breed in the following event and benefit from saving resources for this. The generally greater contributions by breeders in banded mongooses contrast with the recent findings in meerkats (Suricata suricatta), another obligatorily cooperative mongoose with similar group size but wherein reproductive skew is high. Our results suggest that relative contributions by breeders vs non-breeders are not dependent on group size but on the ratio of breeders to carers and the probability that non-breeders will breed in the near future.     

Territory and group sizes in Eurasian beavers (Castor fiber): echoes of settlement and reproduction?

According to current theories of territoriality, an animal is expected to defend the smallest area that can provide resources for maximisation of reproduction, known as the economically defendable area. In group territorial species however, the strategies behind resource defence are likely to be more complex with corporate territoriality, cooperative breeding, delayed dispersal and intra-group competition all potentially playing a role. Here we examined group territoriality in a social herbivorous rodent, the Eurasian beaver Castor fiber. Beavers in our study do not inhabit economically defendable territories. Instead the sequence of arrival of pairs into unoccupied areas seems to play a more important role in determining the size of the territory, whereas group size is determined by past reproductive success. We argue that the settlement pattern and reproductive history have a lasting impact in the territorial system of beavers due to a combination of the low adult mortality, high dispersal costs, and avoidance of resource depletion.R.D. Campbell and F. Rosell contributed equally to this work     

Effect of parentage and relatedness on the individual contribution to cooperative chick care in carrion crows Corvus corone corone

Carrion crows Corvus corone corone in northern Spain form complex cooperative groups that contain non-dispersing offspring and immigrants. Reproduction is often shared among group members, with polyandry prevalent over joint egg laying. However, due to incest avoidance or sexual immaturity, reproduction is potentially available only to a fraction of group members (potential breeders), while others do not breed (non-breeders). We combined molecular data with video-recorded observations at nests in order to investigate whether potential breeders and non-breeders adjust their individual effort in nestling feeding respectively to their level of parentage and the relatedness with the chicks. Overall, parents of at least one chick in the brood showed the highest feeding rates. Among potential breeders, genetic mothers and fathers fed chicks at significantly higher rates than individuals with no parentage, but they did not adjust their effort according to the proportion of offspring generated. Current direct fitness benefits are therefore important in determining a high provisioning effort, but crows may lack a mechanism to finely assess their share of parentage. Among non-breeders, males contributed more than females to chick feeding, but we found no significant correlation between feeding rate and relatedness to the nestling. We discuss how the latter result can be reconciled with the fact that kin selection has been shown to be important in shaping the crow cooperative society.Communicated by C. Brown     

Modeling the Effects of Limiting the Number of Visitors on Failure Rates of Seabird Nests

Abstract:  Most attempts to manage disturbance by visitors to nature reserves concentrate on limiting visitor access in some way, which is often unpopular with both visitors and managers. In a few nature reserves the daily numbers of visitors are limited, an action that need not necessarily reduce the total number of visitors. As a test of the assumptions that underlie this management practice, we examined the relationship between daily visitor numbers and daily failure rates of nests in two species of seabirds. Daily failure rates for Black-legged Kittiwakes ( Rissa tridactyla ) were weakly correlated with daily visitor numbers but indicated that capping daily visitor numbers slightly reduced overall breeding success. This was not the case for Common Murres ( Uria aalge ), where failure rate declined seasonally but was not significantly correlated with visitor numbers. For some species, it appears that capping daily visitor numbers may have small conservation costs.     

False feedings at the nests of carrion crows<Emphasis Type="Italic"> Corvus corone corone</Emphasis>

False feedings, when individuals visit the nest but refrain from feeding the chicks, occur in some cooperative species and have been interpreted in the white-winged chough (Corcorax melanorhamphos) as active deception by helpers towards the rest of the group. In a cooperatively breeding population of carrion crows (Corvus corone corone) 81.5% of the individuals that provided nestling care showed various kinds of false feedings: arriving at the nest with no food, consuming part or all the food brought to the nest, or taking back from a chicks gape the food that had just been delivered. False feedings occurred on average during 16.3% of nest visits, with some individuals performing them at very high rates (up to 64% of nest visits). False feedings occurred at similar rates in unassisted pairs and groups with helpers, and breeding females showed false feeding at significantly higher rates than other group members. Furthermore, individuals showed false feedings regardless of whether they were alone on the nest or in the presence of other group members, and false feedings did not provoke aggression by the rest of the group. False feedings are not likely to represent deceptive help in the carrion crow. We suggest that crows evaluate the chicks condition during nest visits and that false feedings occur as result of a trade-off between their own hunger and the chicks needs.Communicated by W.A. Searcy     

畜禽养殖污染治理技术综述

随着畜禽养殖业的迅速发展,其产生的污染问题已成为我国环境保护的热点和难点问题。本文综述了传统养殖模式下污染物的治理方法,并重点介绍了一种新型的零排放养殖模式,可有效地防治养殖污染,并降低养殖成本,提高产品品质,该模式可扩大试点,并逐步推广。     

What do pairing patterns in common tern, Sterna hirundo, recruits reveal about the significance of sex and breeding experience?

In general, reproductive output in long-lived bird species increases in older compared to younger individuals. Therefore, experienced mates should be advantageous for first-time breeders. To examine requirements and consequences of experienced pair mates we investigated the first pair bonds of common terns, Sterna hirundo, recruiting to their natal colony. We found that male recruits were usually the same age as their mates, whereas female recruits were usually the younger member of the pair. In order to acquire experienced mates, it was necessary for males to arrive early in the year of recruitment. Mates with 2 or more years of breeding experience were only attainable by male recruits characterised by greater body mass and age. Female recruits arrived more than 1 week later than their experienced mates and significantly later in the season than male recruits paired with experienced females. In general, females first bred at a younger age than males, and neither the female recruits body mass nor their age was related to the level of experience of their first mate. These sex-specific differences in obtaining an experienced mate did not result in different levels of reproductive success between the sexes. Male and female recruits with mates with 2 or more years breeding experience benefited from having experienced mates: they had greater reproductive success. First-time breeders paired with mates with only 1 year of breeding experience did not differ from pairs where both members were breeding for the first time in terms of reproductive success, but clutches were larger. Our results illustrate not only different prerequisites for males and females, but also males need for experienced mates. Delayed male breeding (postponing breeding for another year), supposed to be a negative trait, and high body mass, supposed to be a trait of superior individual quality, can be combined in some individuals, improving reproductive success and showing that breeding common terns use a range of tactics to begin reproduction.Communicated by F. Trillmich     

Mating system of the cooperatively breeding noisy miner Manorina melanocephala,as revealed by DNA profiling

In this study we examined parentage within broods of the cooperatively breeding noisy miner using multi-locus DNA profiling. Previous studies of noisy miners described them as highly promiscuous, leading to the suggestion that promiscuous mating behaviour was a tactic used by females to recruit males as provisioners to their nests (Dow 1978). At our study site in south-east Queensland, Australia, we found that both multiple and extra-group paternity (i.e. a female mating with a male outside the group of male provisioners at her nest) were rare. In nests where multiple paternity was possible (i.e. clutch size > 1) 97% of 31 broods were sired by only a single male. Overall, 96.5% of all nestlings (n = 85) were the result of monogamous matings. Also, at the vast majority of nests, the male that sired the nestlings was also the main provisioner among all male nest attendants. Our results show that the mating system of the noisy miner can no longer be considered cooperative polyandry (Brown 1987) but is clearly genetic monogamy. We discuss the implications of this finding for understanding the complex social system of this species.     

Assessing the global zoo response to the amphibian crisis through 20‐year trends in captive collections

Global amphibian declines are one of the biggest challenges currently facing the conservation community, and captive breeding is one way to address this crisis. Using information from the International Species Information System zoo network, we examined trends in global zoo amphibian holdings across species, zoo region, and species geographical region of origin from 1994 to 2014. These trends were compared before and after the 2004 Global Amphibian Assessment to assess whether any changes occurred and whether zoo amphibian conservation effort had increased. The numbers of globally threatened species (GTS) and their proportional representation in global zoo holdings increased and this rate of increase was significantly greater after 2004. North American, European, and Oceanian GTS were best represented in zoos globally, and proportions of Oceanian GTS held increased the most since 2004. South American and Asian GTS had the lowest proportional representation in zoos. At a regional zoo level, European zoos held the lowest proportions of GTS, and this proportion did not increase after 2004. Since 1994, the number of species held in viable populations has increased, and these species are distributed among more institutions. However, as of 2014, zoos held 6.2% of globally threatened amphibians, a much smaller figure than for other vertebrate groups and one that falls considerably short of the number of species for which ex situ management may be desirable. Although the increased effort zoos have put into amphibian conservation over the past 20 years is encouraging, more focus is needed on ex situ conservation priority species. This includes building expertise and capacity in countries that hold them and tracking existing conservation efforts if the evidence‐based approach to amphibian conservation planning at a global level is to be further developed.