PUP SURVIVAL IN THE MEDITERRANEAN MONK SEAL (MONACHUS MONACHUS) COLONY AT CABO BLANCO PENINSULA (WESTERN SAHARA‐MAURITANIA)

Abstract

We surveyed pup survival in Mediterranean monk seals (Monachus monachus), at Cabo Blanco Peninsula (Western Sahara‐Mauritania) colony from May 1993 to December 1997. This species breeds and hauls out on beaches inside two main caves. During the study period we detected a total of 93 pups that died or disappeared. The survival rate of 84 pups through the age of first moult (approximately two months) was 0.47. This value is similar to those reported for other pinnipeds breeding in caves but lower than for those breeding on open beaches. Mortality varied seasonally and appeared to increase as a result of storms, large ocean swells, and high tides. Mother‐pup pair separation (and resulting pup starvation) and physical injury caused by impact against the rock walls of the cave and cliffs were established as the causes of most deaths. Beach surface area inside the caves also appeared to be a mediating factor in the effects of sea conditions. High pup mortality may be a limiting growth factor in this population, although cave dwelling protects the population from predators and human disturbance.

Behaviour and energetics of ice-breeding, North Atlantic phocid seals during the lactation period

“…data). Hawaiian (Monachus schauinslandi) and Mediterranean (Monachus monachus) monk seal pups enter the water during the nursing period, but it appears that their aquatic activities are quite limited (Kenyon & Rice 1959, Gazo & Cappozzo 1996. Pups of these species may enter the water primarily for thermoregulatory purposes.…”

First Observations of Parturition and Postpartum Behavior in the Mediterranean Monk Seal (<I>Monachus monachus</I>) in the Eastern Mediterranean

“…this study, the temporary abandonment of the pup observed during this study in conjunction with bad weather conditions could have led to motherpup separation and the eventual death of the pup. Natural mortality related to bad weather conditions has been the sole cause of death recorded for this age class among Mediterranean monk seals in Greece (Androukaki et al, 1999) and has also been associated with the low pup survival rates at the colony at Cabo Blanco (Gazo et al, 2000b). Identifying the most important pupping sites of the species in the country and effectively protecting them is considered therefore one of the outstanding conservation priorities for M. monachus in Greece (Notarbartolo di Sciara et al, 2009).…”

“…World population estimates for the species currently number less than 600 individuals, distributed over isolated subpopulations in the Archipelago of Madeira and the Cabo Blanco region in Mauritania / Morocco in the Atlantic Sea and the eastern Mediterranean Sea (Johnson et al, 2006). General information on the reproductive biology of the species is available only from the colony at Cabo Blanco (Layna et al, 1999;Gazo et al, 2000aGazo et al, , 2000bCedenilla et al, 2009); this information, however, might not necessarily be directly applicable to the other two areas of the species' distribution due to significant differences in habitat occupied (Karamanlidis et al, 2004), female reproductive strategies, and population structure (Dendrinos et al, 2007b). Monk seals in Greece generally inhabit small coastal caves, often close to human populated areas that offer only limited land area, exposing newborns to the danger of being washed-out to the open sea by storms early in life.…”

Population resilience of the Mediterranean monk seal Monachus monachus at Cabo Blanco peninsula

“…Probably the most important measure has been the improvement of an effective no-take fisheries zone by the Moroccan authorities, regular surveillance of the coast and marine patrolling, and the seal awareness of fishermen and inhabitants of the area around the main colonies. Improving recruitment and breeding success by increasing the number of safe breeding sites is typically one of the primary measures to enhance the growth of small populations (Gerrodette & Gilmartin 1990, Gazo et al 2000, Prugnolle et al 2003, Dendrinos et al 2007), but, in our case, more data are necessary to investigate recruitment processes. Further approaches, such as radio or satellite tagging of juveniles or integrated population modelling, might be useful to estimate the missing parameters, i.e.…”

“…It is possible that these immature individuals recruited into the breeding pool several years after the mass mortality. Given that females at Cabo Blanco can reach sexual maturity at an age of 2.5 yr (Gazo et al 2000), it is reasonable that the population growth rate (especially the sub-adult−adult stage) was lower soon after the mass mortality event and has later increased following the recruitment of these animals. At present, we do not have sufficient data to fully investigate recruitment processes, but, from our results, it seems that recruitment at Cabo Blanco is low.…”