- Last Updated: 30 June 2011
The aims of seal pup rehabilitation are primarily humanitarian. The pups of all seal species are highly precocial, and therefore a newborn pup that is separated from its mother will be aware of hunger, need for its mother, and be conscious of distress. An older pup that may strand due to illness, injury or weakness will likewise suffer distress. All newborn pups that are separated from their mother will die if not rescued and rehabilitated, as will most stranded older pups. Therefore the reason why pups are taken into rehabilitation is usually based on compassion.
For populations of species with favourable conservation status, the benefits of pup rehabilitation may relate only to the welfare and well-being of those individual pups, which get a second chance at life. In most cases their return to their natal population will have minimal impact on that population. In some populations of some species commonly rehabilitated in Europe and north America, such as harbour seals (Phoca vitulina), grey seals (Halichoerus grypus) an Californian sea lions (Zalophus californianus) , there may even be a degree of conflict between seal rehabilitation and protection advocates and the fisheries or fish-farm lobby seeking to reduce the seal population.
By contrast, in small populations of species or subspecies which may be declining or at risk of extinction, rehabilitation has the potential to play a valuable role in helping a population to stabilise or recover. Such species include the critically endangered Saimaa seal (Pusa hispida saimensis), Ladoga and Baltic ringed seals (P. h. ladogensis and P.h. botnica) the critically endangered Mediterranean and Hawaiian monk seals (Monachus monachus and M. Schauinslandi), and possibly also declining or at-risk populations of the more common species. Schemes related to rehabilitation may be developed, such as the ‘head start’, ‘captive care’ and translocation programmes for weaned female pups of the Hawaiian monk seal.
We would add a caveat here in regard to rehabilitation programmes, however. There may sometimes be a risk of over-zealous collection of ‘orphan’ pups from haul-out sites, which may itself result in disturbance and further pup casualties. Other concerns about rehabilitation facilities may include the spread of viral infections, social isolation, mal-handling, development of inappropriate feeding patterns, conditions which inhibit the expression of natural behaviours, excessive periods in captivity, development of stereotypies, and inappropriate preparation of pups for their release. Although rehabilitation will inevitably involve some compromises compared with the pup in its natural state, we would recommend close links between rehabilitation facilities and wildlife biologists with specialist knowledge of the species and population in question.
To ensure both the welfare of pups being rehabilitated and to be of conservation benefit when the pups are returned to the wild, it is our aim to encourage the design of rehabilitation or captive care procedures which mimic the pup’s nutritional, physical and psycho-social development in the natural state as far as possible. For normal rehabilitation of ‘orphan’ pups, this would usually involve releasing as soon after the natural age of weaning as possible. In order to do this, the natural behavioural ontogeny and both physical, social and behavioural developmental timetable of each rehabilitation species needs to be profiled as a baseline for considering rehabilitation conditions. Then the comparable behavioural ontogeny and developmental timetable of pups in existing facilities needs to be compared with this baseline profile for pups in the natural state. Then it may be possible to adjust the design of rehabilitation facilities and procedures to approximate the natural state more closely.
For the wild pup baseline, physical aspects of pup development to consider would include natural suckling period length, average birth and natural weaning weights. Behavioural and social aspects of development would require activity budget measurements of types and amount of social contact with the mother and other seals, time spent in the water/hauled out, age and movement range of first dispersal and foraging, natural diet of weaned pups, etc.
Describing a full pup developmental profile for each species subject to rehabilitation will require specialist study. The Seal Conservation Society is currently initiating a research project (see project section) to trial such a developmental profile in one commonly rehabilitated species in the northern hemisphere, the harbour seal (Phoca vitulina). If the design of this project proves to be useful, we hope to extend the study to other species. In the meantime, however, such developmental information as is currently available will be added to the website’s species pages.