A DNA test to sex most birds.

ION, GENERAL CONCEPTIONS, SELF-CONSCIOUSNESS, MENTAL INDIVIDUALITY. It would be very difficult for any one with even much more knowledge than I possess, to determine how far animals exhibit any traces of these high mental powers. This difficulty arises from the impossibility of judging what passes through the mind of an animal; and again, the fact that writers differ to a great extent in the meaning which they attribute to the above terms, causes a further difficulty. If one may judge from various articles which have been published lately, the greatest stress seems to be laid on the supposed entire absence in animals of the power of abstraction, or of forming general concepts. But when a dog sees another dog at a distance, it is often clear that he perceives that it is a dog in the abstract; for when he gets nearer his whole manner suddenly changes, if the other dog be a friend. A recent writer remarks, that in all such cases it is a pure assumption to assert that the mental act is not essentially of the same nature in the animal as in man. If either refers what he perceives with his senses to a mental concept, then so do both. (44. Mr. Hookham, in a letter to Prof. Max Muller, in the 'Birmingham News,' May, 1873.) When I say to my terrier, in an eager voice (and I have made the trial many times), "Hi, hi, where is it?" she at once takes it as a sign that something is to be hunted, and generally first looks quickly all around, and then rushes into the nearest thicket, to scent for any game, but finding nothing, she looks up into any neighbouring tree for a squirrel. Now do not these actions clearly shew that she had in her mind a general idea or concept that some animal is to be discovered and hunted? It may be freely admitted that no animal is self-conscious, if by this term it is implied, that he reflects on such points, as whence he comes or whither he will go, or what is life and death, and so forth. But how can we feel sure that an old dog with an excellent memory and some power of imagination, as shewn by his dreams, never reflects on his past pleasures or pains in the chase? And this would be a form of self-consciousness. On the other hand, as Buchner (45. 'Conferences sur la Theorie Darwinienne,' French translat. 1869, p. 132.) has remarked, how little can the hardworked wife of a degraded Australian savage, who uses very few abstract words, and cannot count above four, exert her self-consciousness, or reflect on the nature of her own existence. It is generally admitted, that the higher animals possess memory, attention, association, and even some imagination and reason. If these powers, which differ much in different animals, are capable of improvement, there seems no great improbability in more complex faculties, such as the higher forms of abstraction, and selfconsciousness, etc., having been evolved through the development and combination of the simpler ones. It has been urged against the views here maintained that it is impossible to say at what point in the ascending scale animals become capable of abstraction, etc.; but who can say at what age this occurs in our young children? We see at least that such powers

https://www.jstage.jst.go.jp/article/ase1887/22/257/22_257_458/_pdf

The descent of man and selection in relation to sex

Handbook of the Birds of Europe, the Middle East and North Africa: the Birds of the Western Palaearctic. Volume 2. Hawks to Bustards

Senescence in natural populations of animals: Widespread evidence and its implications for bio-gerontology

Sex-specific fitness effects of nutrient intake on reproduction and lifespan

Senescence may result from an optimal balance between current reproductive investment and bodily repair processes required for future reproduction, a theoretical prediction difficult to prove especially in large, long-lived animals. Here we propose that teeth that have fixed dimensions early in life, but that wear during chewing, can be taken as a measure of total lifetime 'repair', and their wear rate as a measure of current expenditure in performance. Our approach also considers the sexual selection process to investigate the advance of senescence in males compared with females, when selection favouring competition over mates reduces the reproductive lifespan of males. We studied carcasses of 2,141 male and 739 female red deer (Cervus elaphus) of different ages, finding that male molariform teeth emerged at a far smaller size than expected from body size dimorphism. This led to higher workload, steeper wear rate and earlier depletion of male teeth than in females, in concordance with sex-specific patterns of lifetime performance and reproduction. These findings provide the empirical support for the disposable-soma hypothesis of senescence, which predicts that investment in bodily repair will decrease when the return from this investment may not be realized as a result of other causes that limit survival or reproduction.

Disposable-soma senescence mediated by sexual selection in an ungulate

Space use by red deer in a Mediterranean ecosystem as determined by radio-tracking

Mating strategies in mammalian herbivores are adapted to the dispersion of females, and female dispersion is mainly determined by resource dispersion, although it is frequently unclear whether females may also be influenced by the location of males. In the red deer (Cervus elaphus) the distribution of females before the rut predicts the places were males should establish territories and even their relative success. However, the number of females using the mating areas in Donana increases during the rut. We observed 20 areas of meadows, used by grazing females before the rut. At the onset of the rut, the number of females increased in some of these areas and decreased in others, and the opposite pattern was found after the rutting period. Changes in the vegetation at mating and nonmating areas could not account for the changes in female distribution; even some of the highest quality meadows were vacated by females during rut. In selecting the mating areas, females avoided isolated small meadows within the scrub area and preferred larger meadows where a number of neighboring rutting males could be found. Females also avoided those areas heavily used by fallow deer (Dama dama), a competing sympatric species. We found that females suffered less sexual harassment when in larger harems and when their harem was surrounded by other harems. Our results, together with those in the literature about this population, indicate that red deer females collect during the early rut in mating areas containing several rutting males, although once there they may select particular sites based on availability of food rather than based on the presence of a particular male. By joining harems in large meadows they are less harassed, and at the same time they probably increase their chances of mating with highly competitive males. The results from Donana support the idea that harassment avoidance may lead to female movements to areas with male territories without lek breeding or female comparison of male phenotypes and may bring an insight into those factors leading to clumps of male territories and leks. Key words: Cervus elaphus, harassment, leks, red deer, mating systems, space use, resource defense, territories. (Behav Ecol 10:525- 532 (1999))

Red deer females collect on male clumps at mating areas

Parents increase their parental effort when aided by helpers in a cooperatively breeding bird

Helping to rear the offspring of others may be a way for younger birds to gain access to future reproduction especially when turnover of breeding opportunities is low. However, this explanation is not applicable to cases where adults also help, or when roles shift between helpers and breeders. Over a period of 6-yr, we studied a marked population of azure-winged Magpie (Cyanopica cyanus) breeding in a non-territorial, colonial system. Magpies bred in a highly flexible cooperative system, in which individuals helped at different stages of the breeding cycle, including nest building, feeding the incubating female and feeding the young and removing the faecal sacs. On average, 50% of hatched nests were assisted by helpers-at-the-nest, and nest success appeared to be positively related to the presence of helpers. Helpers were predominantly males. Although juveniles were more likely to help, both juvenile and adult birds helped. Individual birds behaved as helpers either as a first-option or after having attempted their own breeding (second-option helpers). An individual helper may assist more than one nest during the same breeding season and in different breeding seasons. Reversals between breeder and helper roles were common in both directions, within a breeding season and between years. Helping behaviour is an option for almost any member of the colony. Therefore, hypotheses related to the enhancement of future breeding opportunities for juveniles can be discarded as general explanation of helping in this species. Although the decision to help appeared to be influenced by proximal environmental conditions hindering successful breeding, the associated benefits of helping as opposed to simply recovering for future reproduction, especially for former breeders, deserve further study.

Juliana Valencia

Papers

Disposable-soma senescence mediated by sexual selection in an ungulate

Space use by red deer in a Mediterranean ecosystem as determined by radio-tracking

Red deer females collect on male clumps at mating areas

Parents increase their parental effort when aided by helpers in a cooperatively breeding bird

Flexible Helping Behaviour in the Azure‐Winged Magpie