2.3 Human Impact on Animals

2.3.2 Conservation Behaviour

Heart rate measurements in penguins have been employed by a number of studies (also see chapter, Table 3-3 and Table 3-4). As early as 1989, CULIK & al. reported that Adélie penguins exhibited tachycardia (elevated heart rate) in response to human disturbance, especially to being handled (capture and restraint).

Tachycardia is considered a reaction physiologically preparing the animal for the possibility of flight or fight, and the magnitude of the response is often taken to represent an animal’s assessment of the degree of threat to which they are exposed (PRICE & al. 1993). If tachycardia is to be considered a meaningful physiological response to disturbance stimuli, however, care must be taken to distinguish between increases in heart rate due to motor activity and those due to perception of, and reaction to, disturbance, i.e., the ‘emotional response’ (BROOM & JOHNSON 2000). Using a heart rate measuring device which only records heart rate when the penguin is sitting quietly, viz., an artificial egg, serves to separate the former from the latter so that elevations can be attributed to ‘emotional response’ alone. It is acknowledged that it is not permissible to simply extrapolate the (cardiac) reaction of incubating birds to other stages of the breeding cycle (WILSON, R.P. & al.

1991), let alone to the non-breeding period.

To account for individual variation in resting heart rate as well as for susceptibility to climatic conditions, it is recommended that for the assessment of heart rate reactions, each individual serve as their own control (BALDOCK & SIBLY 1990). This is effected by comparing a given individual’s heart rate responses during disturbance to records obtained immediately prior to disturbance (undisturbed/ pre-treatment ‘baseline’) of the same individual.

In THISTHESIS, heart rate was examined (for details see chapter 4) as regards

• extent of tachycardiac (increase) responses during disturbance (human, conspecific),

• overall pattern changes during disturbance (human, conspecific),

• delay until resting levels were reached again,

• extent of fluctuations outside disturbance (‘baseline sessions’),

• parallelity or complementarity with respect to behavioural indicators.

At this time, behaviour scientists were perceived (e.g., CARO 2007; LINKLATER 2004) as either interested in all four of TINBERGEN’s (1963) questions74, but predominantly conducting their experiments inside laboratories and other artificial surroundings (animal behaviour science; focus:

proximate as well as ultimate), or as doing field-work and using interesting predictive75 models, but exclusively looking for adaptive or survival value (behavioural ecology; focus: predominantly ultimate). In the 1990s, scientists from conservation as well as behaviour began to search for ways of integrating behavioural studies into conservation biology, enumerating areas and research questions that would benefit from the cooperation (e.g., SUTHERLAND 1998, DAWKINS 2005/ 2006).

They also pointed out, however, the specific weaknesses (as outlined above) behaviour science would have to overcome in order to make a significant contribution to the aims of conservation (see reviews in ANGELONI & al. 2007/ 2008; CARO 1999; LINKLATER 2004).

In short, the aim of conservation behaviour is to take ‘the best of animal behaviour science and behavioural ecology combined’. Conservation behaviour scientists (e.g., BLUMSTEIN & FERNÁNDEZ -JURICIC 2004) as well as conservation scientists interested in this field (e.g., BUCHHOLZ 2007; CARO

1999, 2007; LINKLATER 2004) stress the importance of looking at proximate (immediate causation and ontogeny) as well as ultimate (survival value and evolution) questions in order to best decide about conservational measures.

True to one of its ‘parents’, viz., behavioural ecology, conservation behaviour continues to make extensive use of models, optimality models among them. Optimality theory has been thoroughly criticised (e.g., GOULD & LEWONTIN 1979; PIERCE & OLLASON 1987), amended and re(de)fined (e.g., MCNAMARA & HOUSTON 1980, 1985; OATEN 1977), and it certainly pays to keep firmly in mind the inherent limitations of models – as some of their ‘original inventors’ seem to indeed have done:

MAYNARD SMITH (1977, p. 632), for instance, suggested that the main role of models (in evolutionary biology) “is to help us to see whether, in particular cases, the proposed causes (i.e. selection pressures) are sufficient to account for the observed results”. And in another paper (MAYNARD SMITH

1978, p. 35, italics in quote), he further justified the use of optimality principles by pointing out that

“[…] in testing a model we are not testing the general proposition that nature optimizes but the specific hypotheses about constraints, optimization criteria and heredity”. Looking at overall usage76, however, scientists seem to have frequently left these cautions behind. Almost thirty years later, SUTHERLAND (2006, p. 599) stated that (in conservation) the

“conventional approach of making assumptions and deriving models to make predictions about the consequences of environmental change is often unsatisfactory for complex problems with considerable uncertainty”.

Given the broadened focus (i.e., the ‘complete Tinbergen’) of conservation behaviour, and judging from reviews (tab. 2-6), scientists in this ‘relatively fresh’ field appear to critically reassess the validity of the models’ assumptions (e.g., BEDNEKOFF & LIMA 1998; LIMA & BEDNEKOFF 1999) as well as their applicability to and suitability for the problem at hand (BLUMSTEIN & al. 2005; TARLOW &

BLUMSTEIN 2006/ 2007).

74 Augmenting HUXLEY’s “three major problems of Biology” by adding ontogeny, TINBERGEN (1963) proposed that the following four questions should be studied by ethologists: 1. causation (physiology; causative mechanism); 2. survival value (adaptive value, function); 3. ontogeny (development); and 4. evolution (phylogeny). He (1963, p. 411) “believe[d]

with HUXLEY that it is useful both to distinguish between them and to insist that a comprehensive, coherent science of Ethology has to give equal attention to each of them and to their integration”.

75 but see PIERCE & OLLASON (1987) for a critical assessment

76 also see GOULD & LEWONTIN (1979) concerning the readiness to entertain non-adaptive explanations, epiphenomenalism of current utility, etc.

On the basis of this development, the antipredator model outlined below is considered a viable framework for the assessment of human disturbance.

Table 2-6: Reviews Concerning Methods and Models Used in Conservation (Behaviour in Reverse Chronological Order). a.o.: among others

Author(s) Year Method/ Model Topic of Review





breeding success, mate choice, fluctuating asymmetry, flight initiation distance, immunocompetence, glucocorticoids, cardiac response

evaluating methods to quantify anthropogenic stressors on wild animals, assessing for each method its ease of use, precision in quantifying impact, accuracy in predicting presence, absence, or population viability, and repeatability across populations and species


extrapolation, experiments, phenomenological models, game-theory population models, expert opinion, outcome-driven modelling, scenarios

methods predicting ecological consequences of environmental change


LIMA 1998 antipredator vigilance randomness, chaos and confusion in the study of antipredator vigilance LIMA & DILL 1990 predation – risk assessment

behavioural decisions made under the risk of predation (review of PULLIAM


ELGAR 1989 predator vigilance & group size critical review of empirical evidence (a.o. PULLIAM 1973)


DILL 1986 economics of flight distance economics of fleeing from predators HART &

LENDREM 1984 vigilance and scanning patterns improving upon PULLIAM's (1973) model of feeding and vigilance in birds Conservation Behaviour – Effects of Human Disturbance on Birds

“The problem of human disturbance to nesting seabirds seems to be increasing, and it involves diverse groups of people: recreationists, tour groups, local residents and scientists alike.” (ANDERSON & KEITH 1980, p. 66)

„The dominant management issue must be the management of acceptable […] uses, rather than the identification of appropriate […] users.“ (MCKERCHER 1996, p. 574)

The area of conservation behaviour research particularly relevant to THISTHESIS is that of the impact of non-lethal human disturbance to animals. Concerns about the effects of human disturbance upon birds have been increasingly raised since the 1970s (e.g., ANDERSON & KEITH 1980, review and details for Brown pelicans, Pelecanus occidentalis californicus; ELLISON & CLEARY 1978 for Double-crested cormorants, Phalacrocorax auritus; FROST & al. 1976 for Jackass penguins, Spheniscus demersus; GILLET & al. 1975 for Glaucous-winged gulls, Larus glaucescens; HAND

1980 for Yellow-footed western gulls, Larus occidentalis livens; OELKE 1978 for Adélie penguins, Pygoscelis adeliae; OLLASON & DUNNET 1980 for Fulmars, Fulmarus glacialis; ROBERT & RALPH 1975 for Western gulls, Larus occidentalis; also see review by CARNEY & SYDEMAN 1999).

Initially, the impacts mentioned were either directly related to scientific research77 (e.g., REID

1968) or resulted from ‘socioeconomic conflicts’ between humans and animals, such as fisheries or ‘guano-harvesting’. The increase in recreational demands, however, soon became an additional factor of concern. ‘Early birds’ in this field reported disturbance on specific colonies or species (e.g., for Adélies: OELKE 1978; REID 1962, 1968; STONEHOUSE 1965, quoted in THOMSON 1977, p. 1178;

STONEHOUSE 1967; THOMSON 1977), but already in 1982, BAUER & THIELCKE (quoted in NEEBE & HÜPPOP

1994, p. 8) considered [human] disturbances to be the main factor responsible for the endangered status of 41 of the 78 bird species red-listed in the Federal Republic of Germany at that time. A number of publications on a variety of species have followed (e.g., BURGER & GOCHFELD 1991;

BURGER & al. 1995; ERIZE 1987; HÜPPOP & HAGEN 1990; KELLER 1989; NEEBE & HÜPPOP 1994; NIMON &

STONEHOUSE 1995; WOEHLER & al. 1994), and to date concern has not abated (e.g., for non-penguins:


& al. 2002; reviews: CARNEY & SYDEMAN 1999; NISBET 2000; SCAR 2008; journal supplements: IBIS Supplement 1, March 2007: Recreational disturbance on birds).

With respect to penguins, a total of 50 studies which scientifically investigated or directly reported on disturbance were reviewed for THISSTUDY. A further 15 studies that mentioned disturbance but did not particularly focus on it were likewise used to gather information. An overview of disturbance-related penguin studies is shown below (table 2-7; the unabridged and quite unwieldy table is found in appendix 2-2), and details on their respective findings will be summarised for behavioural and physiological responses reported. Behavioural Responses of Penguins to Human Disturbance

N.b.: An ethogram of Adélie penguin behaviour during the breeding period is provided in

In document Impact of Human and Other Disturbance on Behaviour and Heart Rate of Incubating Adélie Penguins (Pygoscelis adeliae) (Page 50-53)