More pricks

A recent Freedom of information request has revealed the number of eggs and nests dealt with by Sandwell Council’s exterminators in 2015. This now gives a three year record of data which may tentatively lead to some basic conclusions about nesting habits and numbers of birds involved. Of course this would have been more complete if Sandwell council had kept official records when its countryside rangers were supposedly tasked with egg pricking from 1997, when the policy passed by the Leisure Committee in January of that year stated that they would be.

We do not believe this happened from either anecdotal evidence or direct evidence observed ourselves through goslings that had hatched. Many on Dartmouth park were actually ringed with BTO and darvic rings. This is irrefutable evidence that egg pricking was not taking place in these years as it was stated it would be. Consequently any increase in numbers can largely be blamed on Sandwell council’s own lack of following its own policy.

We asked as part of this request;

(i) I am requesting a list of Sandwell sites where egg pricking of Canada goose eggs was carried out in 2015, the number of nests identified and eggs pricked at each site.

The council replied with figures.

The tables below show the number of sites visited in 2015 which this year includes Forge Mill Nature Reserve where Pestex were observed and also Swan Pool. We also believe that Icehouse pool was also targeted, though there are no figures given here. Egg pricking on Nature reserve sites  is in itself worthy of discussion and we will look at some of the ramifications of this below. The figures for 2013 and 2014 are shown in a table below that for comparison.

DISCUSSION.

Firstly it is important to note that not all eggs hatch naturally, and would not be fertile when laid, so it would be disingenuous to state that all these eggs would have become new goslings. Some nests may have been abandoned already before egg sitting had commenced as fighting between pairs can occur. This does not limit other species to breeding successfully, indeed the egg prickers may disturb birds when setting foot on the islands. Goslings are also prone to be predated after hatching. Numerous other wildfowl successfully breed on all of the sites where Canada geese lay eggs.

The figures also prove that not all pairs of geese actually breed, and this is consistent with mute swan studies over many years where ringing has shown clear trends that only a small percentage of pairs ever produce young. It would be advantageous to ring the geese to ascertain clear evidence of laying pairs and where these birds actually attempted to nest. This would enter some science into the equation, rather than the black and white figures offered by the council which prove very little.

The counts of adult birds on the sites obviously outnumber the totals of nesting pairs. If the figures on Dartmouth park and Victoria park Tipton are to be believed for 2015 this amounts to just 30 breeding and nesting birds, 15 male and 15 female. Clearly the rest of the flocks at these sites never attempt to breed, and therefore many of them are likely to be none resident with no interest in breeding at all. This is important because the council appear to not distinguish between non breeding ‘migrant’ birds and resident breeding birds. Natural England guidance clearly makes a distinction, so the council would do better to take these statistics on board when considering blanket eradication. There is also no science in rounding up birds without determining their sex, or if they are actually breeding birds or not. Unfortunately the council appear to believe that all the geese are likely to breed, which is not what their own figures or expert opinion confirm.

“2.1 Canada geese can live up to 20 years of age and a pair of geese normally mates for life and can produce up to 100 goslings over that period.”

From report from Adrian Scarrott which is completely misleading.

The majority of the formal park sites have limited breeding appearing to take place over the three year period. This may effectively ensure no geese replace those which die on these sites, but it could also offer scope for others to fly in after the molt has ended. It could also encourage those unsuccessful birds to go elsewhere, including other parks where the council do not want them to go.

The increases in eggs at Dartmouth Park West Bromwich and Victoria park Tipton appear somewhat dubious to us. Having had occasion to go on both islands at Victoria Park, there was on one island only evidence of one nest. On the other island a pair of swans were nesting where the female unfortunately died. These eggs did not hatch. Neither did one of the pairs at Dartmouth Park, swan pool or icehouse pool which appears extremely suspicious.We hope the contractors are able to tell the difference between swan eggs and goose eggs when they encounter an “abandoned” nest!

At Dartmouth park two pairs of geese actually bred successfully producing 9 goslings which fledged. At Victoria Park, one pair produced 3 goslings, which were all presumed eaten by predators within a few days of hatching. Did the egg prickers deliberately leave these nests, or miss them?

Dartmouth park goslings 2015

This has been consistent with swanwatch observations over a number of years, where survival rates at Dartmouth park are fairly good, whereas predation is heavy at the Tipton site, most prominently through great black backed gulls.

The inclusion of two and we believe three of the other Sandwell Valley pools which are not formal parks but “Nature Reserves” has obviously been  included by the council this year with the rationale of reducing numbers gathering at Dartmouth Park. The Forge Mill numbers look eye watering, yet taking into account the high levels of predation likely at such a site they should not at all be taken as evidence that these eggs would have all survived to become adult geese. The experience is quite different. At Sheepwash nature Reserve this year a total of 40 goslings were noted, yet of these only 3 actually survived to fledge- the rest all being presumed predated. There was clear multiple evidence of crow predation witnessed. A similar scenario at Forge Mill is therefore highly likely. The figure of 6.4 eggs per nest at Forge Mill appears high and is in itself a food source to other birds and animals. One could therefore question the rationale of egg pricking at such sites, given the likelihood that natural predators are likely to eat hatched goslings, and that removing this food source may only reduce the food chain chances of “native” species.

Furthermore as we have pointed out before, if those birds that had their nests addled decided to leave the site and fly to Dartmouth Park for example, the council and their contractors have merely provided the scenario that they do not want to achieve in facilitating this themselves through their direct intervention.

The goose killers